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Tang L, Gao W, Lu Y, Tabelin CB, Liu J, Li H, Yang W, Tang C, Feng X, Jiang J, Xue S. The formation of multi-metal(loid)s contaminated groundwater at smelting site: Critical role of natural colloids. JOURNAL OF HAZARDOUS MATERIALS 2024; 471:134408. [PMID: 38678716 DOI: 10.1016/j.jhazmat.2024.134408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/22/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
The occurrence and migration of colloids at smelting sites are crucial for the formation of multi-metal(loid)s pollution in groundwater. In this study, the behavior of natural colloids (1 nm-0.45 µm) at an abandoned smelting site was investigated by analyzing groundwater samples filtered through progressively decreasing pore sizes. Smelting activities in this site had negatively impacted the groundwater quality, leading to elevated concentrations of zinc (Zn), lead (Pb), arsenic (As), and cadmium (Cd). The results showed that heavy metal(loid)-bearing colloids were ubiquitous in the groundwater with the larger colloidal fractions (∼75 -450 nm) containing higher abundances of pollutants. It was also observed that the predominant colloids consisted of Zn-Al layered double hydroxide (LDH), sphalerite, kaolinite, and hematite. By employing multiple analytical techniques, including leaching experiments, soil colloid characterization, and Pb stable isotope measurements, the origin of groundwater colloids was successfully traced to the topsoil colloids. Most notably, our findings highlighted the increased risk of heavy metal(loid)s migration from polluted soils into adjacent sites through the groundwater because of colloid-mediated transport of contaminants. This field-scale investigation provides valuable insights into the geochemical processes governing heavy metal(loid) behavior as well as offering pollution remediation strategies specifically tailored for contaminated groundwater.
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Affiliation(s)
- Lu Tang
- School of Metallurgy and Environment, Central South University, Hunan 410083, China
| | - Wenyan Gao
- School of Metallurgy and Environment, Central South University, Hunan 410083, China
| | - Yongping Lu
- China Railway Seventh Bureau Group Nanjing Engineering Co. Ltd., Nanjing 210012, China
| | - Carlito Baltazar Tabelin
- Department of Materials and Resources Engineering and Technology, College of Engineering, Mindanao State University-Iligan Institute of Technology, Iligan City 9200, Philippines
| | - Jie Liu
- School of Metallurgy and Environment, Central South University, Hunan 410083, China
| | - Haifeng Li
- China Railway Seventh Bureau Group Nanjing Engineering Co. Ltd., Nanjing 210012, China
| | - Weichun Yang
- School of Metallurgy and Environment, Central South University, Hunan 410083, China
| | - Chongjian Tang
- School of Metallurgy and Environment, Central South University, Hunan 410083, China
| | - Xiang Feng
- Henan Academy of Geology, Henan 450001, China
| | - Jun Jiang
- School of Metallurgy and Environment, Central South University, Hunan 410083, China
| | - Shengguo Xue
- School of Metallurgy and Environment, Central South University, Hunan 410083, China.
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2
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Sun Y, Jones K, Sun Z, Shen J, Bu F, Ma F, Gu Q. Effects of freeze-thaw action on in vivo and in vitro bioavailability of arsenic in soils from derelict industrial sites. JOURNAL OF HAZARDOUS MATERIALS 2024; 464:132980. [PMID: 37979426 DOI: 10.1016/j.jhazmat.2023.132980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 10/09/2023] [Accepted: 11/08/2023] [Indexed: 11/20/2023]
Abstract
Arsenic is a metalloid with carcinogenic properties and has been classified as a Category I carcinogen by the International Agency for Research on Cancer (IARC). Freeze-thaw processes affect the migration and transformation of soil heavy metals, as well as adsorption/desorption and redox reactions. However, there is limited research directly addressing the impact of freeze-thaw processes on the bioavailability of soil heavy metals. In this study, we focused on As and selected As-contaminated soil samples from three types of legacy sites in heavy industrial areas. Under controlled freeze-thaw experimental conditions, we utilized both in vivo and in vitro bioavailability measurement methods to investigate whether and how freeze-thaw processes affect the bioavailability of soil As. The results of this study showed that freeze-thaw processes reduced soil pH (P < 0.05), CEC, SOM, and particle size, with decreases of 0.33, 1.2 cmol/kg, 5.2 g/kg, and 54 µm, respectively. It also increased weight specific surface area (BET) (P < 0.05), with an increase of 300 m2/kg. Freeze-thaw processes increased the proportions of exchangeable (P < 0.05), carbonate-bound, and iron-manganese oxide-bound As (P < 0.05), but reduced the proportions of organic-bound and residual As (P < 0.05). Freeze-thaw processes significantly increased the relative bioavailability and bioaccessibility of As, with increases of 32 ± 9.6% and 13 ± 0.23%, respectively. Soil pH, SOM, BET and electronic conductivity (EC) were identified as factors which could contribute to the increased bioavailability of As due to freeze-thaw processes. These results provide new insights and evidence for refining the assessment of human health risks associated with heavy metal contamination in polluted soils.
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Affiliation(s)
- Yiming Sun
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Kevin Jones
- Lancaster Environment Centre (LEC), Lancaster University, Lancaster LA1 4YQ, UK
| | - Zongquan Sun
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jialun Shen
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Fanyang Bu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Fujun Ma
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Qingbao Gu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
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3
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Das TK, Han Z, Banerjee S, Raoelison OD, Adeleye AS, Mohanty SK. PFAS release from the subsurface and capillary fringe during managed aquifer recharge. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 343:123166. [PMID: 38110050 DOI: 10.1016/j.envpol.2023.123166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/24/2023] [Accepted: 12/12/2023] [Indexed: 12/20/2023]
Abstract
Managed aquifer recharge (MAR) is a sustainable way of harvesting groundwater in water-stressed urbanized areas, where reclaimed wastewater or stormwater is applied on a large basin to infiltrate water into the groundwater aquifer naturally. This process could rapidly fluctuate the water table and move the capillary fringe boundary, and the change in flow dynamic and associated geochemical changes could trigger the release of sequestered pollutants, including per- and polyfluoroalkyl substances (PFAS), also known as 'forever chemicals', from the subsurface and capillary fringe. Yet, the potential of PFAS release from the subsurface and capillary zone during recharge events when the water table rapidly fluctuates has not been evaluated. This study uses laboratory column experiments to simulate PFAS release from pre-contaminated subsurface and capillary fringe during groundwater table fluctuation. The results reveal that the groundwater level fluctuations during MAR increased the release of perfluorobutanesulfonic acid (PFBS) and perfluorooctanesulfonic acid (PFOS) from the capillary fringe, but the fraction released depended on PFAS type and their association with soil colloids. A higher proportion of PFOS in column effluent was found to be associated with particles, while a greater portion of released PFBS was in a free or dissolved state. The direction of water table fluctuation did not affect the release of PFAS in this study. A lack of change in the concentration of bromide, a conservative tracer, during flow interruption, indicates that diffusion of PFAS through reconnected pores during water table rise had an insignificant effect on PFAS release. Overall, this study provides insights into how PFAS can be released from the subsurface and capillary fringe during managed aquifer recharge when the groundwater level is expected to fluctuate quickly.
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Affiliation(s)
- Tonoy K Das
- Civil and Environmental Engineering, University of California Los Angeles, Los Angeles, USA.
| | - Ziwei Han
- Civil and Environmental Engineering, University of California Irvine, Irvine, CA, USA
| | - Swapnil Banerjee
- Civil and Environmental Engineering, University of California Los Angeles, Los Angeles, USA
| | - Onja D Raoelison
- Civil and Environmental Engineering, University of California Los Angeles, Los Angeles, USA
| | - Adeyemi S Adeleye
- Civil and Environmental Engineering, University of California Irvine, Irvine, CA, USA
| | - Sanjay K Mohanty
- Civil and Environmental Engineering, University of California Los Angeles, Los Angeles, USA.
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4
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Xu F, Guan J, Zhou Y, Song Z, Shen Y, Liu Y, Jia X, Zhang B, Guo P. Effects of freeze-thaw dynamics and microplastics on the distribution of antibiotic resistance genes in soil aggregates. CHEMOSPHERE 2023; 329:138678. [PMID: 37059196 DOI: 10.1016/j.chemosphere.2023.138678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 04/04/2023] [Accepted: 04/11/2023] [Indexed: 05/03/2023]
Abstract
This is the first study investigating the effects of freeze-thaw (FT) and microplastics (MPs) on the distribution of antibiotic resistance genes (ARGs) in soil aggregates (i.e., soil basic constituent and functional unit) via microcosm experiments. The results showed that FT significantly increased the total relative abundance of target ARGs in different aggregates due to the increase in intI1 and ARG host bacteria. However, polyethylene MPs (PE-MPs) hindered the increase in ARG abundance caused by FT. The host bacteria carrying ARGs and intI1 varied with aggregate size, and the highest number of hosts was observed in micro-aggregates (<0.25 mm). FT and MPs altered host bacteria abundance by affecting aggregate physicochemical properties and bacterial community and enhanced multiple antibiotic resistance via vertical gene transfer. Although the dominant factors affecting ARGs varied with aggregate size, intI1 was a co-dominant factor in various-sized aggregates. Furthermore, other than ARGs, FT, PE-MPs, and their integration promoted the proliferation of human pathogenic bacteria in aggregates. These findings suggested that FT and its integration with MPs significantly affected ARG distribution in soil aggregates. They amplified antibiotic resistance environmental risks, contributing to a profound understanding of soil antibiotic resistance in the boreal region.
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Affiliation(s)
- Fukai Xu
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, PR China
| | - Jiunian Guan
- School of Environment, Northeast Normal University, Changchun, 130117, PR China
| | - Yumei Zhou
- Shanghai Institute of Technology, Shanghai, 201418, PR China
| | - Ziwei Song
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, PR China
| | - Yanping Shen
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, PR China
| | - Yibo Liu
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, PR China
| | - Xiaohui Jia
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, PR China
| | - Baiyu Zhang
- Department of Civil Engineering, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL, A1B 3X5, Canada.
| | - Ping Guo
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, PR China.
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5
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Wang W, Shi L, Wu H, Ding Z, Liang J, Li P, Fan Q. Interactions between micaceous minerals weathering and cesium adsorption. WATER RESEARCH 2023; 238:119918. [PMID: 37121199 DOI: 10.1016/j.watres.2023.119918] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 03/24/2023] [Accepted: 03/25/2023] [Indexed: 05/17/2023]
Abstract
The environmental behavior of radioactive cesium (RCs) in contaminated areas is generally governed by soil and sediment components and natural weathering conditions. In this study, desorption tests and spectroscopic approaches were used to explore the interaction between the weathering of micaceous minerals (i.e., biotite and phlogopite) and the adsorption of Cs+ and the critical role of weathering in the environmental behavior of RCs. Results showed that the reaction sequence between weathering and Cs+ adsorption significantly affected the surface species of Cs+ and the structure of biotite and phlogopite. Regardless of whether it occurred before, after, or during Cs+ adsorption, weathering generated more high-affinity adsorption sites, namely, interlayer sites (ITs) and frayed edge sites (FESs), to different extents, and then facilitated the uptake of Cs+ at FESs and ITs on micaceous minerals in a poorly exchangeable state. Cs+ stabilized the micaceous mineral structure once it was absorbed within collapsed interlayers by hindering cation exchange and preventing further destruction during weathering. As important weathering factors, high temperature and Ca2+ content promoted the binding of Cs+ in the interlayers of biotite and phlogopite by enhancing interlayer cation exchange. These findings are beneficial for a better understanding of the environmental behaviors of RCs in the hydrosphere and pedosphere.
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Affiliation(s)
- Wei Wang
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Petroleum Resources, Gansu Province, Lanzhou 730000, China; Key Laboratory of Strategic Mineral Resources of the Upper Yellow River, Ministry of Natural Resources, Lanzhou 730046, China
| | - Leiping Shi
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Petroleum Resources, Gansu Province, Lanzhou 730000, China; Key Laboratory of Strategic Mineral Resources of the Upper Yellow River, Ministry of Natural Resources, Lanzhou 730046, China
| | - Hanyu Wu
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Zhe Ding
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Petroleum Resources, Gansu Province, Lanzhou 730000, China; Key Laboratory of Strategic Mineral Resources of the Upper Yellow River, Ministry of Natural Resources, Lanzhou 730046, China
| | - Jianjun Liang
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Petroleum Resources, Gansu Province, Lanzhou 730000, China; Key Laboratory of Strategic Mineral Resources of the Upper Yellow River, Ministry of Natural Resources, Lanzhou 730046, China
| | - Ping Li
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Petroleum Resources, Gansu Province, Lanzhou 730000, China; Key Laboratory of Strategic Mineral Resources of the Upper Yellow River, Ministry of Natural Resources, Lanzhou 730046, China
| | - Qiaohui Fan
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Petroleum Resources, Gansu Province, Lanzhou 730000, China; Key Laboratory of Strategic Mineral Resources of the Upper Yellow River, Ministry of Natural Resources, Lanzhou 730046, China.
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6
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Li M, He L, Hsieh L, Rong H, Tong M. Transport of plastic particles in natural porous media under freeze-thaw treatment: Effects of porous media property. JOURNAL OF HAZARDOUS MATERIALS 2023; 442:130084. [PMID: 36206711 DOI: 10.1016/j.jhazmat.2022.130084] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/25/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Freeze-thaw (FT) cycles would alter physical and chemical properties of soil and thus influence the transport of plastic particles (one type of emerging contaminant with great concerns). This study was designed to investigate the effects of FT treatment on the mobility of plastic particles (nanoplastics as representative) in columns packed with natural soils (i.e. loamy sand and sandy soil, quartz sand employed as comparison). We found that FT treatment of different types of porous media would induce different transport behaviors of plastic particles. Specifically, FT treatment of quartz sand did not affect plastic particles mobility. While FT treatment of loamy sand and sandy soil increased plastic particles transport. The increased pore sizes and disintegration of small soil particles from soils (the detached soil would serve as mobile vehicle for the transport of plastic particle) led to the facilitated mobility of plastic particles in two types of soils after FT treatment. The presence of preferential flow paths induced by FT treatment also drove to the enhanced mobility of plastic particles in sandy soil with FT treatment. This study clearly showed that the mobility of model plastic particles in two types of natural soils was greatly enhanced by FT treatment.
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Affiliation(s)
- Meng Li
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China; Currently at Department of Forensic Science, Fujian Police College, Fuzhou 350007, PR China
| | - Lei He
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Lichun Hsieh
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Haifeng Rong
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Meiping Tong
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
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7
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Morgalev SY, Lim AG, Morgaleva TG, Morgalev YN, Manasypov RM, Kuzmina D, Shirokova LS, Orgogozo L, Loiko SV, Pokrovsky OS. Fractionation of organic C, nutrients, metals and bacteria in peat porewater and ice after freezing and thawing. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:823-836. [PMID: 35904738 DOI: 10.1007/s11356-022-22219-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
To better understand freezing - thawing cycles operating in peat soils of permafrost landscapes, we experimentally modelled bi-directional freezing and thawing of peat collected from a discontinuous permafrost zone in western Siberia. We measured translocation of microorganisms and changes in porewater chemistry (pH, UV absorbance, dissolved organic carbon (DOC), and major and trace element concentrations) after thawing and two-way freezing of the three sections of 90-cm-long peat core. We demonstrate that bi-directional freezing and thawing of a peat core is capable of strongly modifying the vertical pattern of bacteria, DOC, nutrients, and trace element concentrations. Sizeable enrichment (a factor of 2 to 5) of DOC, macro- (P, K, Ca) and micro-nutrients (Ni, Mn, Co, Rb, B), and some low-mobile trace elements in several horizons of ice and peat porewater after freeze/thaw experiment may stem from physical disintegration of peat particles, leaching of peat constituents, and opening of isolated (non-connected) pores during freezing front migration. However, due to the appearance of multiple maxima of element concentration after a freeze-thaw event, the use of peat ice chemical composition as environmental archive for paleo-reconstructions is unwarranted.
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Affiliation(s)
- Sergey Yu Morgalev
- Centre "Biotest-Nano", Tomsk State University, 36 Lenin Avenue, Tomsk, 634050, Russia
| | - Artem G Lim
- BIO-GEO-CLIM Laboratory, Tomsk State University, 35 Lenina Pr, Tomsk, Russia
| | - Tamara G Morgaleva
- Centre "Biotest-Nano", Tomsk State University, 36 Lenin Avenue, Tomsk, 634050, Russia
| | - Yuri N Morgalev
- Centre "Biotest-Nano", Tomsk State University, 36 Lenin Avenue, Tomsk, 634050, Russia
| | - Rinat M Manasypov
- BIO-GEO-CLIM Laboratory, Tomsk State University, 35 Lenina Pr, Tomsk, Russia
| | - Daria Kuzmina
- BIO-GEO-CLIM Laboratory, Tomsk State University, 35 Lenina Pr, Tomsk, Russia
| | - Liudmila S Shirokova
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Nab Severnoi Dviny, 23, Russia
- Geosciences and Environment Toulouse, UMR 5563 CNRS, University of Toulouse, 14 Avenue Edouard Belin, 31400, Toulouse, France
| | - Laurent Orgogozo
- Geosciences and Environment Toulouse, UMR 5563 CNRS, University of Toulouse, 14 Avenue Edouard Belin, 31400, Toulouse, France
| | - Sergey V Loiko
- BIO-GEO-CLIM Laboratory, Tomsk State University, 35 Lenina Pr, Tomsk, Russia
| | - Oleg S Pokrovsky
- Geosciences and Environment Toulouse, UMR 5563 CNRS, University of Toulouse, 14 Avenue Edouard Belin, 31400, Toulouse, France.
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8
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Hu NW, Yu HW, Wang QR, Zhu GP, Yang XT, Wang TY, Wang Y, Wang QY. Colloid-facilitated mobilization of cadmium: Comparison of spring freeze-thaw event and autumn freeze-thaw event. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 852:158467. [PMID: 36057305 DOI: 10.1016/j.scitotenv.2022.158467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
Freeze-thaw action has the potential to facilitate the mobilization of colloid-associated contaminants in soil. However, the differences in colloid-associated contaminants following autumn freeze-thaw (AFT) events and spring freeze-thaw (SFT) events remain unclear. In this study, the potential influence mechanisms of AFT and SFT on both the generation and migration of colloids and colloid-associated cadmium (Cd) in soil were explored. Higher aggregate stabilities were found in soils after AFT compared with after SFT. After SFT, lower Cd concentrations were found in soil aggregates of 0.25-0.50 mm and <0.106 mm and higher concentrations were found in 0.106-0.25 mm aggregates. Moreover, SFT generated higher amounts of colloidal Cd than AFT, while AFT increased the total Cd concentration in leachates. Additionally, compared with SFT, AFT led to higher Cd concentrations in dissolved and colloid-associated forms in leachates. These findings demonstrate that higher amounts of colloid and fewer loadings of Cd in colloids in Cd contaminated soil can be found after SFT events. Thus, to better understand the environmental risk of contaminants in areas subject to seasonal freeze-thaw cycles, the differences between freeze-thaw processes in spring and autumn should be considered.
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Affiliation(s)
- Nai-Wen Hu
- Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Hong-Wen Yu
- Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
| | - Qi-Rong Wang
- Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Guo-Peng Zhu
- Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xiu-Tao Yang
- Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
| | - Tian-Ye Wang
- Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
| | - Yang Wang
- Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
| | - Quan-Ying Wang
- Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
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9
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Wang X, Diao Y, Dan Y, Liu F, Wang H, Sang W, Zhang Y. Effects of solution chemistry and humic acid on transport and deposition of aged microplastics in unsaturated porous media. CHEMOSPHERE 2022; 309:136658. [PMID: 36183879 DOI: 10.1016/j.chemosphere.2022.136658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Microplastics (MPs) are susceptible to aging in the environment, and aged MPs are highly migratory in soil due to their smaller particle size and more negative surface charge, but the effects of soil environmental factors on the fate and transport of aged MPs are still unclear. In this study, the transport behavior of pristine/aged MPs in unsaturated sandy porous media was examined under different ionic strength (IS), cationic type (Na+, Ca2+) and humic acid (HA) conditions. The results indicated that the surface charge, surface oxygen-containing functional groups and surface morphology of MPs changed significantly after aging, and that the mobility of aged MPs was significantly enhanced than the pristine MPs under all test conditions. The retention amounts of pristine/aged MPs in unsaturated porous media increased with IS, and IS had a less inhibitory effect on the transport of aged MPs than pristine MPs. The mobility of pristine/aged MPs in Ca2+ solutions was significantly weaker than that in Na+ solutions due to enhanced straining and electrostatic adsorption. HA promoted the mobility of pristine/aged MPs in unsaturated porous media under all IS Na+ (1, 10, and 25 mM) solutions and lower IS (1 mM) Ca2+ solutions, and the ability of HA to promote the transport of aged MPs was significantly stronger than that of pristine MPs due to the higher adsorption of HA on the surface of aged MPs. However, at higher IS (10 mM) Ca2+ solution conditions, the bridging effect of Ca2+ led to the formation of HA-MPs complexes, which altered the hydrophobicity of the pristine/aged MPs surface and the pristine/aged MPs were mainly retained on the air-water interface (AWI). CFT theory and two-site kinetic retention models indicated that the retention of pristine/aged MPs in unsaturated media was dominated by monolayer adsorption, straining and clogging effects. The current research findings may provide insights into the fate and transport of aged MPs in soil and their potential risk of groundwater contamination.
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Affiliation(s)
- Xiaoxia Wang
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Yinzhu Diao
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Yitong Dan
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Feihong Liu
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Huan Wang
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Wenjing Sang
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
| | - Yalei Zhang
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
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10
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Radziemska M, Gusiatin MZ, Cydzik-Kwiatkowska A, Majewski G, Blazejczyk A, Brtnicky M. New approach strategy for heavy metals immobilization and microbiome structure long-term industrially contaminated soils. CHEMOSPHERE 2022; 308:136332. [PMID: 36088975 DOI: 10.1016/j.chemosphere.2022.136332] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/25/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
The progress of engineering technologies highly influences the development of methods that lead to the condition improvement of areas contaminated with heavy metals (HMs). The aided phytostabilization fits into this trend, and was used to evaluate HM-immobilization effectiveness in phytostabilized soils under variable temperatures by applying 16 freezing-thawing cycles (FTC). Diatomite amendment and Lolium perenne L., also were applied. Cd/Ni/Cu/Pb/Zn each total content in phytostabilized soils were determined, along with the verification for each metal of its distribution in four extracted fractions (F1 ÷ F4) from soils. Based on changes in HM distribution, each metal's stability was estimated. Moreover, HM accumulation in plant roots and stems and soil microbial composition were investigated. Independently of the experimental variant (no-FTC-exposure or FTC-exposure), the above-ground biomass yields in the diatomite-amended series were higher as compared to the corresponding control series. The evident changes in Pb/Zn-bioavailability were observed. The metal stability increase was mainly attributed to metal concentration decreasing in the F1 fraction and increasing in the F4 fraction, respectively. Diatomite increased Cd/Zn-stability in not-FTC-exposed-phytostabilized soils. FTC-exposure favorably influenced Pb/Zn stability. Diatomite increased soil pH values and Cd/Ni/Cu/Zn-bioaccumulation (except Pb) in roots than in stems (in both experimental variants). FTC-exposure influenced soil microbial composition, increasing bacteria abundance belonging to Actinobacteria, Gammaproteobacteria, and Sphingobacteria. At the genus level, FTC exposure significantly increased the abundances of Limnobacter sp., Tetrasphaera sp., Flavobacterium sp., and Dyella sp. Independently of the experimental variant, Sphingomonas sp. and Mycobacterium sp., which have a tolerance to HM contamination, were core bacterial groups, comprising about 6 ÷ 7% of all soil bacteria.
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Affiliation(s)
- Maja Radziemska
- Institute of Environmental Engineering, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776, Warsaw, Poland.
| | - Mariusz Z Gusiatin
- Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Słoneczna St. 45G, 10-719, Olsztyn, Poland
| | - Agnieszka Cydzik-Kwiatkowska
- Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Słoneczna St. 45G, 10-719, Olsztyn, Poland
| | - Grzegorz Majewski
- Institute of Environmental Engineering, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776, Warsaw, Poland
| | - Aurelia Blazejczyk
- Institute of Civil Engineering, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776, Warsaw, Poland
| | - Martin Brtnicky
- Institute of Chemistry and Technology of Environmental Protection, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00, Brno, Czech Republic; Department of Agrochemistry, Soil Science, Microbiology and Plant Nutrition, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic
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11
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Wang Z, Zhang Y, Flury M, Zou H. Freeze-thaw cycles lead to enhanced colloid-facilitated Pb transport in a Chernozem soil. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 251:104093. [PMID: 36265266 DOI: 10.1016/j.jconhyd.2022.104093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 09/12/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Freeze-thaw cycles in soils lead to break up of soil aggregates and the formation of dispersible soil colloids. Leaching events following freeze-thaw cycles can therefore mobilize and transport colloids through the soil profile. Here, we investigated the effect of freeze-thaw cycles on the subsequent mobilization of colloids in a Pb contaminated soil, and we quantified the amount of colloid-facilitated Pb transport. Soil contaminated with Pb (250 mg/kg or 1000 mg/kg) was packed into 15 cm tall columns, and the soil water content adjusted to field capacity (0.306 kg/kg). Columns were subjected to freeze-thaw cycles of 12 h freezing at -20 °C followed by 12 h of thawing at 25 °C. Then, the soil columns were leached with distilled water, and the effluent was analyzed for colloids, soluble Pb, and colloidal-bound Pb. Freeze-thaw cycles were found to generate dispersible soil colloids and lead to colloid-facilitated Pb transport. Colloid and Pb mobilization increased with increasing number of freeze-thaw cycles. The majority (83-97%) of the Pb that leached out of the columns was colloid-bound. Our findings suggest that freeze-thaw cycles in high latitude areas can mobilize heavy metals, which are otherwise immobile, through colloid-facilitated transport. More frequent freeze-thaw cycles in high-latitude regions, as predicted by climate change models, thus increases the risk of metal leaching from contaminated soils and can lead to subsequent ground water pollution.
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Affiliation(s)
- Zhan Wang
- College of Land and Environment, Shenyang Agricultural University, Shenyang, Liaoning 110866, China
| | - Yulong Zhang
- College of Land and Environment, Shenyang Agricultural University, Shenyang, Liaoning 110866, China
| | - Markus Flury
- Department of Crop & Soil Sciences, Washington State University, Pullman, WA 99164, United States of America; Department of Crop & Soil Sciences, Washington State University, Puyallup, WA 98371, United States of America
| | - Hongtao Zou
- College of Land and Environment, Shenyang Agricultural University, Shenyang, Liaoning 110866, China.
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12
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Wang Q, Li J, Wang F, Sakanakura H, Tabelin CB. Effective immobilization of geogenic As and Pb in excavated marine sedimentary material by magnesia under wet-dry cycle, freeze-thaw cycle, and anaerobic exposure scenarios. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 848:157734. [PMID: 35917967 DOI: 10.1016/j.scitotenv.2022.157734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/24/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Massive amounts of marine sedimentary materials with geogenic heavy metal(loids) are excavated by the subsurface construction projects and then exposed to weathering conditions, which pose potential threats to the environment. In the present study, 2 % magnesia (MgO) was applied to immobilize geogenic arsenic (As) and lead (Pb) in excavated marine sedimentary material. To better evaluate the immobilization efficiency under different environmental scenarios, the untreated and amended solids were subjected to wet-dry cycles, freeze-thaw cycles, and anaerobic incubation until 49 days. The leaching behaviors of As and Pb were investigated and their size fractionations in the leachates were compared. The results indicate that most Pb exists in particulate and agglomerated colloidal fractions (0.1-5 μm) in the leaching suspensions, while most As is found in dissolved forms (<0.1 μm). It is therefore necessary to consider the element type and exposure scenarios during environmental risk evaluation, particularly using the batch test as a routine compliance testing procedure. In the control test without MgO addition, the wet-dry cycle resulted in the "self-induced" immobilization of As and Pb. The pH decreases to the neutral range and the formation of amorphous Fe-(oxyhydr)oxides following pyrite oxidation largely explained the decreased As and Pb leaching. In comparison, the freeze-thaw cycle and anaerobic incubation tended to enhance As and Pb leaching. Overall, MgO addition significantly reduced the leachability of As and Pb and displayed sustained immobilization performance under all studied scenarios. These findings could be largely attributed to solid particle aggregation induced by MgO addition, including the adsorption of As and Pb onto newly formed Fe-(oxyhydr)oxides and/or MgSi precipitates. This study offers a simple and effective strategy for the sustainable management of excavated marine sedimentary materials contaminated by geogenic As and Pb.
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Affiliation(s)
- Qianhui Wang
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, China; Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, Nanjing, Jiangsu 210023, China
| | - Jining Li
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, China; Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, Nanjing, Jiangsu 210023, China.
| | - Fenghe Wang
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, China; Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, Nanjing, Jiangsu 210023, China
| | - Hirofumi Sakanakura
- Center for Material Cycles and Waste Management, National Institute for Environmental Studies, Tsukuba 305-8506, Japan
| | - Carlito Baltazar Tabelin
- School of Minerals and Energy Resources Engineering, University of New South Wales, Sydney, NSW 2052, Australia
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13
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Koutnik VS, Leonard J, Brar J, Cao S, Glasman JB, Cowger W, Ravi S, Mohanty SK. Transport of microplastics in stormwater treatment systems under freeze-thaw cycles: Critical role of plastic density. WATER RESEARCH 2022; 222:118950. [PMID: 35964509 DOI: 10.1016/j.watres.2022.118950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 07/12/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Stormwater treatment systems remove and accumulate microplastics from surface runoff, but some of them can be moved downward to groundwater by natural freeze-thaw cycles. Yet, it is unclear whether or how microplastic properties such as density could affect the extent to which freeze-thaw cycles would move microplastics in the subsurface. To examine the transport and redistribution of microplastics in the subsurface by freeze-thaw cycles, three types of microplastics, with density smaller than (polypropylene or PP), similar to (polystyrene or PS), or greater than (polyethylene terephthalate or PET) water, were first deposited on the top of packed sand-the most common filter media used in infiltration-based stormwater treatment systems. Then the columns were subjected to either 23 h of drying at 22 ⁰C (control) or freeze-thaw treatment (freezing at -20 ⁰C for 6 h and thawing at 22 ⁰C for 17 h) followed by a wetting event. The cycle was repeated 36 times, and the effluents were analyzed for microplastics. Microplastics were observed in effluents from the columns that were contaminated with PET and subjected to freeze-thaw cycles. Comparison of the distribution of microplastics in sand columns at the end of 36 cycles confirmed that freeze-thaw cycles could disproportionally accelerate the downward mobility of denser microplastics. Using a force balance model, we show that smaller microplastics (<50 µm) can be pushed at higher velocity by the ice-water interface, irrespective of the density of microplastics. However, plastic density becomes critical when the size of microplastics is larger than 50 µm. The coupled experimental studies and theoretical framework improved the understanding of why denser microplastics such as PET and PVC may move deeper into the subsurface in the stormwater treatment systems and consequently elevate groundwater pollution risk.
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Affiliation(s)
- Vera S Koutnik
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Jamie Leonard
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Jaslyn Brar
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Shangqing Cao
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Joel B Glasman
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Win Cowger
- Moore Institute for Plastic Pollution Research, Long Beach, CA, USA
| | - Sujith Ravi
- Department of Earth & Environmental Science, Temple University, Philadelphia, PA, USA
| | - Sanjay K Mohanty
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA.
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14
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He L, Li M, Wu D, Guo J, Zhang M, Tong M. Freeze-thaw cycles induce diverse bacteria release behaviors from quartz sand columns with different water saturations. WATER RESEARCH 2022; 221:118683. [PMID: 35716413 DOI: 10.1016/j.watres.2022.118683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/20/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Bacteria present in natural environment especially those in cold regions would experience freeze-thaw (FT) process during day-night and season turns. However, knowledge about the influence of FT on bacteria release behaviors in porous media was limited. In present study, the bacteria release behaviors from quartz sand columns without and with 1 and 3 FT treatment cycles under three water saturations (θ=100%, 90%, and 60%) were investigated. We found that for all three water saturated columns without FT treatment, negligible bacteria released from columns via background salt solution elution, while the subsequent release of bacteria from sand columns via low ionic strength (IS) solution elution decreased with decreasing column water saturations. More importantly, we found unlike the negligible bacteria release in columns without FT treatment, for columns with high saturations (θ=100% and 90%), FT treatment could promote bacteria release with background salt solution elution. Moreover, for high saturated columns, FT treatment would decrease subsequent bacteria release with low IS solution elution. This phenomenon was more obvious with increasing FT treatment cycles. In contrast, FT treatment had negligible influence on bacteria release from columns with lower saturation (θ=60%). The decreased bacterial sizes, the loss of bacterial flagella, as well as the change of local configuration of porous media (via changing water into ice and ice back into water) during the FT processes contributed to increased bacteria release via background salt solution elution from high saturated sand columns. While, the reduced amount of bacteria being retained at secondary energy minima drove to the subsequently decreased bacteria release via low IS solution elution. The results of this study clearly showed that for porous media with high saturations, FT cycles would increase the risk of bacteria detaching from porous media with flushing by the background solution.
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Affiliation(s)
- Lei He
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Meng Li
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Dan Wu
- Beijing Institute of Metrology, Beijing 100029, China
| | - Jia Guo
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Beijing Key Laboratory of Water Resources and Environmental, Engineering, China University of Geosciences (Beijing), Beijing 100083, China
| | - Mengya Zhang
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Meiping Tong
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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15
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Koutnik VS, Leonard J, Glasman JB, Brar J, Koydemir HC, Novoselov A, Bertel R, Tseng D, Ozcan A, Ravi S, Mohanty SK. Microplastics retained in stormwater control measures: Where do they come from and where do they go? WATER RESEARCH 2022; 210:118008. [PMID: 34979466 DOI: 10.1016/j.watres.2021.118008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 12/17/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Stormwater control measures (SCM) can remove and accumulate microplastics and may serve as a long-term source of microplastics for groundwater pollution because of their potential for downward mobility in subsurface. Furthermore, the number of microplastics accumulated in SCM may have been underestimated as the calculation typically only accounts for microplastics accumulated via episodic stormwater loading and ignores microplastic accumuation via continuous atmospheric deposition. To evaluate the source pathways of accumulated microplastics and their potential for downward mobility to groundwater, we analyzed spatial distributions of microplastics above ground on the canopy around SCM and below ground in the subsurface in and outside the boundaries of fourteen SCM in Los Angeles. Using an exponential model, we link subsurface retardation of microplastics to the median particle size of soil (D50) and land use. Despite receiving significantly more stormwater, microplastic concentrations in SCM at surface depth or subsurface depth were not significantly different from the concentration at the same depth outside the SCM. Similar concentration in and outside of SCM indicates that stormwater is not the sole source of microplastics accumulated in SCM. The high concentration of microplastics on leaves of vegetation in SCM confirms that the contribution of atmospheric deposition is significant. Within and outside the SCM boundary, microplastics are removed within the top 5 cm of the subsurface, and their concentration decreases exponentially with depth, indicating limited potential for groundwater pollution from the microplastics accumulated in SCM. Outside the SCM boundary, the subsurface retardation coefficient decreases with increases in D50, indicating straining of microplastics as the dominant removal mechanism. Inside the boundary of SCM, however, the retardation coefficient was independent of D50, implying that microplastics could have either moved deeper into the filter layer in SCM or that compost, mulch, or organic amendments used in the filter media were pre-contaminated with microplastics. Overall, these results provide insights on microplastics source, accumulation, and downward mobility in SCM.
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Affiliation(s)
- Vera S Koutnik
- Department of Civil and Environmental Engineering, University of California at Los Angeles, Los Angeles, CA, USA
| | - Jamie Leonard
- Department of Civil and Environmental Engineering, University of California at Los Angeles, Los Angeles, CA, USA
| | - Joel B Glasman
- Department of Civil and Environmental Engineering, University of California at Los Angeles, Los Angeles, CA, USA
| | - Jaslyn Brar
- Department of Civil and Environmental Engineering, University of California at Los Angeles, Los Angeles, CA, USA
| | - Hatice Ceylan Koydemir
- Department of Electrical and Computer Engineering, University of California at Los Angeles, Los Angeles, CA, USA
| | - Anna Novoselov
- Department of Civil and Environmental Engineering, University of California at Los Angeles, Los Angeles, CA, USA
| | - Rebecca Bertel
- Department of Earth & Environmental Science, Temple University, Philadelphia, PA, USA
| | - Derek Tseng
- Department of Electrical and Computer Engineering, University of California at Los Angeles, Los Angeles, CA, USA
| | - Aydogan Ozcan
- Department of Electrical and Computer Engineering, University of California at Los Angeles, Los Angeles, CA, USA; Department of Bioengineering, University of California at Los Angeles, Los Angeles, CA, USA; California NanoSystems Institute, University of California at Los Angeles, Los Angeles, CA, USA
| | - Sujith Ravi
- Department of Earth & Environmental Science, Temple University, Philadelphia, PA, USA
| | - Sanjay K Mohanty
- Department of Civil and Environmental Engineering, University of California at Los Angeles, Los Angeles, CA, USA.
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16
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Xu G, Zheng Q, Yang X, Yu R, Yu Y. Freeze-thaw cycles promote vertical migration of metal oxide nanoparticles in soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 795:148894. [PMID: 34252772 DOI: 10.1016/j.scitotenv.2021.148894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/03/2021] [Accepted: 07/03/2021] [Indexed: 06/13/2023]
Abstract
Understanding the migration of engineered nanoparticles (ENPs) in soil is of great significance for evaluating the potential risks of ENPs to ecosystem. So far, their migration under freeze-thaw cycles (FTCs) has not been investigated. This study explored the impacts of FTCs on the migration of three commonly used ENPs, copper oxide (CuO-NPs), cerium oxide (CeO2-NPs), and zinc oxide (ZnO-NPs), in three types of soil. After 32 FTC cycles, the highest migration rate of ENPs was found in black soil due to its higher clay particle content. CeO2-NPs with low surface charge exhibited the highest mobility among three ENPs, which migrated to 9-11 cm layer with the concentration of 42.1 mg/kg in the black soil column. ZnO-NPs were less influenced by FTCs as they were adsorbed onto sand grains due to electrostatic interaction, which migrated to 3-5 cm layer with the concentration of 25.2 mg/kg in the black soil. Higher moisture contents (50% and 100%) resulted in increased migration depth of the ENPs in all soils. Lower freezing temperature (-25 °C) caused fragmentation of large soil particles and produced more clay colloids. FTCs promoted the movement of moisture, which penetrated the soil and thus facilitated the movement of ENPs by increasing the contents and movement of clay colloids. This work reveals the migration behavior of ENPs in soils in freeze-thaw period and provides insights into the fate and environmental risk of nanomaterial at middle and high latitudes.
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Affiliation(s)
- Guanghui Xu
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiang Zheng
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; Department of Earth Sciences, Jilin University, Changchun 130106, China
| | - Xiutao Yang
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rui Yu
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Yong Yu
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
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17
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Borthakur A, Cranmer BK, Dooley GP, Blotevogel J, Mahendra S, Mohanty SK. Release of soil colloids during flow interruption increases the pore-water PFAS concentration in saturated soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 286:117297. [PMID: 33971474 DOI: 10.1016/j.envpol.2021.117297] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Groundwater flow through aquifer soils or packed bed systems can fluctuate for various reasons, which could affect the concentration of natural colloids and per- and polyfluoroalkyl substances (PFAS) in the pore water. In such cases, PFAS concentration could either decrease due to matrix diffusion of PFAS or increase by the detachment of colloids carrying PFAS. Yet, the effect of flow fluctuation on PFAS transport or release in porous media has not been examined. To examine the relative importance of either process, we interrupted the flow during an injection of groundwater spiked with perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA), and bromide as conservative tracer through clay-rich soil, so that diffusive transport would be prominent during flow interruption. After flow interruption, the PFAS concentration did not decrease indicating an insignificant contribution of matrix diffusion. The concentration increased, potentially due to enhanced release of colloid-associated PFAS. Analysis of samples before and after flow interruption by particle size analysis and SEM confirmed an increase in soil colloid concentration after the flow interruption. XRD analysis of soil and the colloids proved that PFAS were associated with specific sites of the colloids. Due to a higher affinity of PFOA to soil colloids, the total PFOA concentration in the effluent samples increased more than PFBA after the flow interruption process. The results indicate that colloids may have a disproportionally higher role in the transport of PFAS in conditions that release colloids from porous media. Thus, fluctuations in groundwater flow can increase this colloid facilitated mobility of PFAS.
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Affiliation(s)
- Annesh Borthakur
- Department of Civil and Environmental Engineering, University of California, Los Angeles, USA
| | - Brian K Cranmer
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, USA
| | - Gregory P Dooley
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, USA
| | - Jens Blotevogel
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, USA
| | - Shaily Mahendra
- Department of Civil and Environmental Engineering, University of California, Los Angeles, USA
| | - Sanjay K Mohanty
- Department of Civil and Environmental Engineering, University of California, Los Angeles, USA.
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18
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Borthakur A, Wang M, He M, Ascencio K, Blotevogel J, Adamson DT, Mahendra S, Mohanty SK. Perfluoroalkyl acids on suspended particles: Significant transport pathways in surface runoff, surface waters, and subsurface soils. JOURNAL OF HAZARDOUS MATERIALS 2021; 417:126159. [PMID: 34229412 DOI: 10.1016/j.jhazmat.2021.126159] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/28/2021] [Accepted: 05/15/2021] [Indexed: 06/13/2023]
Abstract
Eroded particles from the source zone could transport a high concentration of perfluoroalkyl acids (PFAAs) to sediments and water bodies. Yet, the contribution of suspended particles has not been systematically reviewed. Analyzing reported studies, we quantitatively demonstrate that suspended particles in surface water can contain significantly higher concentrations of PFAAs than the sediment below, indicating the source of suspended particles are not the sediment but particles eroded and carried from the source zone upstream. The affinity of PFAAs to particles depends on the particle composition, including organic carbon fraction and iron or aluminum oxide content. In soils, most PFAAs are retained within the top 5 m below the ground surface. The distribution of PFAAs in the subsurface varies based on site properties and local weather conditions. The depth corresponding to the maximum concentration of PFAA in soil decreases with an increase in soil organic carbon or rainfall amount received in the catchment areas. We attribute a greater accumulation of PFAAs near the upper layer of the subsurface to an increase in the accumulation of particles eroded from source zones upstream receiving heavy rainfall. Precursor transformation in the aerobic zone is significantly higher than in the anaerobic zone, thereby making the aerobic subsurface zone serve as a long-term source of groundwater pollution. Collectively, these results suggest that suspended particles, often an overlooked vector for PFAAs, can be a dominant pathway for the transport of PFAAs in environments.
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Affiliation(s)
- Annesh Borthakur
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA.
| | - Meng Wang
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Meng He
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Katia Ascencio
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Jens Blotevogel
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO, USA
| | | | - Shaily Mahendra
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Sanjay K Mohanty
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA.
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19
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Chen C, Huang H, Mo X, Xue H, Liu M, Chen H. Insights into the kinetic processes of solute migration by unidirectional freezing in porous media with micromodel visualization at the pore-scale. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 784:147178. [PMID: 33905921 DOI: 10.1016/j.scitotenv.2021.147178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/27/2021] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
Field investigations have proved that frozen soil does not act as a completely impermeable barrier for contaminants in cold regions. However, the subsurface behaviors of solutes in freezing and frozen porous media are still unclear. To unveil their nature, the pore-scale behavior of potassium permanganate in saturated porous media subjected to the unidirectional freezing was investigated using micromodel visualizations. An optical microscope was applied to obtain the pore-scale kinetics of solute redistribution in a two-dimensional micromodel using a calibration curve between the color intensity and concentration. We found that (1) the solute migration was not only limited to the ice-water interface but also occurred in the freezing area; (2) the redistribution of solutes had a significant hysteresis effect relative to the freezing front movement during the freezing of the porous media. By combining these results with the theory of sea ice, we suggested that the formation and re-motion of solute-rich inclusions in the mushy layer appear to be vital processes responsible for these phenomena. It was believed that the major mechanism for the re-motion of liquid inclusions was brine diffusion and expulsion in this experiment. The results of this study provide a better understanding of the physics of contaminant migration and their complex kinetics at the pore scale, which has important implications for the assessment and remediation of contaminated soils in seasonal frozen soils and permafrost.
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Affiliation(s)
- Changfu Chen
- Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China
| | - Huan Huang
- China Institute of Geo-Environment Monitoring, Beijing 100081, China
| | - Xiaojie Mo
- Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China
| | - Haihan Xue
- Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China
| | - Mingzhu Liu
- Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China.
| | - Honghan Chen
- Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), Beijing 100083, China
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20
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Alam S, Borthakur A, Ravi S, Gebremichael M, Mohanty SK. Managed aquifer recharge implementation criteria to achieve water sustainability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 768:144992. [PMID: 33736333 DOI: 10.1016/j.scitotenv.2021.144992] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
Depletion of groundwater is accelerated due to an increase in water demand for applications in urbanized areas, agriculture sectors, and energy extraction, and dwindling surface water during changing climate. Managed aquifer recharge (MAR) is one of the several methods that can help achieve long-term water sustainability by increasing the natural recharge of groundwater reservoirs with water from non-traditional supplies such as excess surface water, stormwater, and treated wastewater. Despite the multiple benefits of MAR, the wide-scale implementation of MAR is lacking, partly because of challenges to select the location for MAR implementation and identify the MAR type based on site conditions and needs. In this review, we provide an overview of MAR types with a basic framework to select and implement specific MAR at a site based on water availability and quality, land use, source type, soil, and aquifer properties. Our analysis of 1127 MAR projects shows that MAR has been predominantly implemented in sites with sandy clay loam soil (soil group C) and with access to river water for recharge. Spatial analysis reveals that many regions with depleting water storage have opportunities to implement MAR projects. Analyzing data from 34 studies where stormwater was used for recharge, we show that MAR can remove dissolved organic carbon, most metals, E. coli but not efficient at removing most trace organics, and enterococci. Removal efficiency depends on the type of MAR. In the end, we highlight potential challenges for implementing MAR at a site and additional benefits such as minimizing land subsidence, flood risk, augmenting low dry-season flow, and minimizing salt-water intrusion. These results could help identify locations in the water-stressed regions to implement specific MAR for water sustainability.
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Affiliation(s)
- Sarfaraz Alam
- Civil and Environmental Engineering, University of California Los Angeles, CA, USA.
| | - Annesh Borthakur
- Civil and Environmental Engineering, University of California Los Angeles, CA, USA.
| | - Sujith Ravi
- Earth and Environmental Science, Temple University, PA, USA
| | | | - Sanjay K Mohanty
- Civil and Environmental Engineering, University of California Los Angeles, CA, USA.
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21
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Abstract
As an important type of soil erosion, freeze-thaw erosion occurs primarily at high latitude and altitude. The overview on the effect of freeze-thaw on soil erosion was provided. Soil erosion was affected by freeze-thaw processes, as thawing and water erosion reinforce each other. Remote sensing provided an unprecedented approach for characterizing the timing, magnitude, and patterns of large-scale freeze-thaw and soil erosion changes. Furthermore, the essence of soil freeze-thaw was the freeze and thaw of soil moisture in the pores of soil. Freeze-thaw action mainly increased soil erodibility and made it more vulnerable to erosion by destroying soil structure, changing soil water content, bulk density, shear strength and aggregate stability, etc. However, the type and magnitude of changes of soil properties have been related to soil texture, water content, experimental conditions and the degree of exposure to freeze-thaw. The use of indoor and field experiments to further reveal the effect of freeze-thaw on soil erosion would facilitate improved forecasting, as well as prevention of soil erosion during thawing in regions with freeze-thaw cycles.
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22
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Koutnik VS, Leonard J, Alkidim S, DePrima FJ, Ravi S, Hoek EMV, Mohanty SK. Distribution of microplastics in soil and freshwater environments: Global analysis and framework for transport modeling. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 274:116552. [PMID: 33545526 DOI: 10.1016/j.envpol.2021.116552] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/15/2021] [Accepted: 01/17/2021] [Indexed: 05/22/2023]
Abstract
Microplastics are continuously released into the terrestrial environment from sources where they are used and produced. These microplastics accumulate in soils, sediments, and freshwater bodies, and some are conveyed via wind and water to the oceans. The concentration gradient between terrestrial inland and coastal regions, the factors that influence the concentration, and the fundamental transport processes that could dynamically affect the distribution of microplastics are unclear. We analyzed microplastic concentration reported in 196 studies from 49 countries or territories from all continents and found that microplastic concentrations in soils or sediments and surface water could vary by up to eight orders of magnitude. Mean microplastic concentrations in inland locations such as glacier (191 n L-1) and urban stormwater (55 n L-1) were up to two orders of magnitude greater than the concentrations in rivers (0.63 n L-1) that convey microplastics from inland locations to water bodies in terrestrial boundary such as estuaries (0.15 n L-1). However, only 20% of studies reported microplastics below 20 μm, indicating the concentration in these systems can change with the improvement of microplastic detection technology. Analysis of data from laboratory studies reveals that biodegradation can also reduce the concentration and size of deposited microplastics in the terrestrial environment. Fiber percentage was higher in the sediments in the coastal areas than the sediments in inland water bodies, indicating fibers are preferentially transported to the terrestrial boundary. Finally, we provide theoretical frameworks to predict microplastics transport and identify potential hotspots where microplastics may accumulate.
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Affiliation(s)
- Vera S Koutnik
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA.
| | - Jamie Leonard
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Sarah Alkidim
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Francesca J DePrima
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA
| | - Sujith Ravi
- Department of Earth & Environmental Science, Temple University, Philadelphia, PA, USA
| | - Eric M V Hoek
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA; UCLA Institute of the Environment & Sustainability, Los Angeles, California, USA; UCLA California NanoSystems Institute, Los Angeles, California, USA
| | - Sanjay K Mohanty
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, USA; UCLA Institute of the Environment & Sustainability, Los Angeles, California, USA.
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23
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Tirpak RA, Afrooz AN, Winston RJ, Valenca R, Schiff K, Mohanty SK. Conventional and amended bioretention soil media for targeted pollutant treatment: A critical review to guide the state of the practice. WATER RESEARCH 2021; 189:116648. [PMID: 33227609 DOI: 10.1016/j.watres.2020.116648] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/15/2020] [Accepted: 11/15/2020] [Indexed: 06/11/2023]
Abstract
Bioretention systems are widely used green infrastructure elements that utilize engineered bioretention soil media (BSM) for stormwater capture and treatment. Conventional bioretention soil media, which typically consists of sand, sandy loam, loamy sand or topsoil amended with compost, has limited capacity to remove and may leach some stormwater pollutants. Alternative engineered amendments, both organic and inorganic, have been tested to supplement BSM. Yet, municipalities and regulatory agencies have been slow to adopt these alternative amendments into their design specifications, partly because of a lack of clear guidance on how to select the right amendment to treat a target stormwater contaminant under highly variable climatic conditions. This article aims to provide that guidance by: (1) summarizing the current design BSM specifications adopted by jurisdictions worldwide, (2) comparing the performance of conventional and amended BSM, (3) highlighting advantages and limitations of BSM amendments, and (4) identifying challenges for implementing amendments in field conditions. The analysis not only informs the research community of the barriers faced by stormwater managers in implementing BSM amendments but also provides guidelines for their adoption by interested agencies to comply with existing regulations and meet design needs. This feedback loop could catalyze further innovation in the development of sustainable stormwater treatment technologies.
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Affiliation(s)
- R Andrew Tirpak
- Department of Food, Agricultural, and Biological Engineering, The Ohio State University. 590 Woody Hayes Drive, Columbus, OH, 43210, USA
| | - Arm Nabiul Afrooz
- California State Water Resources Control Board, 1001 I Street, Sacramento, CA, 95833, USA
| | - Ryan J Winston
- Department of Food, Agricultural, and Biological Engineering, The Ohio State University. 590 Woody Hayes Drive, Columbus, OH, 43210, USA; Deptartment of Civil, Environmental, and Geodetic Engineering, The Ohio State University, 2070 Neil Ave., Columbus, OH, 43210, USA.
| | - Renan Valenca
- Department of Civil and Environmental Engineering, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA, 90095, USA
| | - Ken Schiff
- Southern California Coastal Water Research Project, Costa Mesa, CA, 92626
| | - Sanjay K Mohanty
- Department of Civil and Environmental Engineering, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, CA, 90095, USA
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24
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Effect of Freeze-Thaw Cycles on Soil Detachment Capacities of Three Loamy Soils on the Loess Plateau of China. WATER 2021. [DOI: 10.3390/w13030342] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Soil detachment is the initial phase of soil erosion and is of great significance to study in seasonal freeze-thaw regions. In order to elucidate the effects mechanism of freeze-thaw cycles on soil detachment capacity of different soils, a sandy loam, a silt loam, and a clay loam were subjected to 0, 1, 5, 10, 15, and 20 freeze-thaw cycles before they were scoured. The results revealed that with increased freeze-thaw cycles, soil bulk density and water-stable aggregates content decreased after the first few times and then kept nearly stable after about 10 cycles, especially for sandy loam. The shear strength of all soils gradually decreased as freeze-thaw cycles increased, except the values of clay loam increased subsequent to the 5th and 15th cycles. After the 20th cycle, the degree of decline of silt loam was the greatest (77.72%), followed by sandy loam (63.18%) and clay loam (39.77%). The soil organic matter of clay loam was much greater than silt loam and sandy loam and all significantly increased after freeze-thaw. Soil detachment capacity of silt loam and sandy loam was positively correlated with freeze-thaw cycle, which was contrary to findings for clay loam. The values of clay loam increased at first and then decreased during the cycles, reaching minimum values at about the 15–20th cycle. After the 20th cycle, the values of sandy loam and silt loam significantly increased 1.62 and 4.74 times over unfrozen, respectively, which was greater than clay loam (0.53 times). A nonlinear regression analysis indicated that the soil detachment capacity of silt loam could be estimated well by soil properties (R2 = 0.87, p < 0.05). This study can provide references for the study of the soil erosion mechanism in seasonal freeze-thaw regions.
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25
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An S, Zhang F, Chen X, Gao M, Zhang X, Hu B, Li Y. Effects of freeze-thaw cycles on distribution and speciation of heavy metals in pig manure. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:8082-8090. [PMID: 31897986 DOI: 10.1007/s11356-019-07518-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
To understand the potential environmental influence of animal manure under freeze-thaw cycles, pig manure was used to conduct a simulation experiment to explore the effects of freeze-thaw cycles on heavy metal distribution and form transformation. Thirty cycles of freezing and thawing were performed alternately by freezing at - 18 ± 2 °C for 24 h and thawing at 20 ± 2 °C for 24 h. By a serial wet sieving procedure, manure samples were separated into different sizes of 1000, 250, 75, 38, and < 38 μm. Solid samples were collected from the dry matter at each stage of sieve; then the washing waters were collected as liquid samples accordingly. The concentrations of heavy metals in solid/liquid samples and their five forms were analyzed. It showed that the concentrations of heavy metals in the solid and liquid samples gradually increased because of organic matter degradation during freezing and thawing cycles. The distribution of heavy metals on particles of different sizes was also affected by the degradation and breakup of pig manure; the metals showed a tendency to aggregate in small particles (< 38 μm). Among them, the percentage of Cu and Zn on < 38 μm particles increased by 162.3% and 554.1%, respectively. After several freeze-thaw cycles, the concentrations of EXCH-X (metals of exchangeable form) increased significantly, those of CARB-X (carbonate-bound form) and Fe/Mn-X (Fe/Mn oxide-bound form) decreased accordingly. These form transformations may be largely influenced by the enhancement of dissolved organic matter (DOM) and the reduction of pH value. Therefore, frequent freeze-thaw cycles may promote the mobility and bioavailability of heavy metals in pig manure. The results are significant for understanding the pollution risk of pig manure in the freeze-thaw regions.
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Affiliation(s)
- Siyu An
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Fengsong Zhang
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xingcai Chen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Min Gao
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Xuelian Zhang
- Beijing Soil and Fertilizer Extension Service Station, Beijing, 100029, China
| | - Baiyang Hu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Yanxia Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
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26
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Xu Q, Ye B, Mou X, Ye J, Liu W, Luo Y, Shi J. Lead was mobilized in acid silty clay loam paddy soil with potassium dihydrogen phosphate (KDP) amendment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113179. [PMID: 31542670 DOI: 10.1016/j.envpol.2019.113179] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
The immobilization effectiveness between Pb and phosphorus in soil varies with soil types. To clarify the effect of phosphate on the availability of Pb in agricultural soil, a culture experiment with three types of paddy soil was performed with potassium dihydrogen phosphate (KDP) added. EDTA, DGT and in-situ solution extraction methods were used to represent different available Pb content. Results showed that the concentration of EDTA-Pb in HN soil was slightly elevated after exogenous KDP added. The supplement of 300 mg/kg KDP significantly increased the content of soluble Pb in both acid silty clay loam soil and neutral silty loam soil (increased by 104.65% and 65.12%, respectively). However, there was no significant influence of KDP on the concentration of DGT extracted Pb. XANES results showed that Pb(OH)2, PbHPO4, humic acid-Pb and GSH-Pb were the major speciation of Pb in soil colloids. The proportion of Pb(OH)2 and humic acid-bounded Pb in soil colloids were elevated after exogenous KDP added. Our results indicated that there was a mobilization effect of KDP on Pb by increasing the amount of colloidal Pb in soil solution, especially in acid silty clay loam paddy soil. Such colloid-facilitated transport might promote the uptake of Pb in rice and pose a potential threat to human health.
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Affiliation(s)
- Qiao Xu
- Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Binhui Ye
- Chengbang Eco-Environment Co., Ltd., Hangzhou, 310002, China
| | - Xiaoyu Mou
- Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Jien Ye
- Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Wenyu Liu
- Department of Civil and Environmental Engineering, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Yating Luo
- Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Jiyan Shi
- Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China.
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27
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Wang Z, Flury M. Effects of freezing-thawing and wetting-drying on heavy metal leaching from biosolids. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2019; 91:465-474. [PMID: 30791144 DOI: 10.1002/wer.1011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/21/2018] [Accepted: 08/19/2018] [Indexed: 06/09/2023]
Abstract
The goal of this study was to evaluate the effects of freezing-thawing and wetting-drying on heavy metals leaching from biosolids. Biosolid samples were irrigated with water at two flow rates and three flow stop events in 24 hr intervals. During the period of flow stop, biosolids were subjected to different temperatures, water contents, or freezing-thawing. Leachates were analyzed for heavy metals. The concentrations of metals in biosolids ranged from lower than detection limits (for Pb) to 1,039 mg/kg (for Zn). The leaching percentage of metals ranged from 0% (Pb, Ag, Cs) to 25% (Ni). Lower flow rate with longer residence time induced more metal leaching compared with higher flow rate with shorter residence time. At each flow rate, flow stop caused enhanced metal leaching. Higher drying temperature enhanced metal leaching. Water content or freezing-thawing had no significant effects on metal leaching. We expect that intermittent irrigation or rainfall would enhance the risk of metals leaching from biosolids after land application. However, freezing of biosolids during winter will likely not cause an enhanced leaching of metals in spring when biosolids and soils thaw. Application of biosolids in fall should therefore not cause enhanced leaching of metals out of land-applied biosolids. PRACTITIONER POINTS: Lower flow rate with longer residence time induced more metal leaching compared with higher flow rate with shorter residence time. Flow stop or higher drying temperature enhanced metal leaching from biosolids. Water content or freezing-thawing had no significant effects on metal leaching.
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Affiliation(s)
- Zhan Wang
- College of Land and Environment, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Arable Land Conservation (Northeast China), Ministry of Agriculture, Shenyang, China
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Shenyang, China
- Department of Crop & Soil Sciences, Washington State University, Pullman, WA
| | - Markus Flury
- Department of Crop & Soil Sciences, Washington State University, Pullman, WA
- Department of Crop & Soil Sciences, Washington State University, Puyallup, WA
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28
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Zhang W, Cheng JH, Xian QS, Cui JF, Tang XY, Wang GX. Dynamics and sources of colloids in shallow groundwater in lowland wells and fracture flow in sloping farmland. WATER RESEARCH 2019; 156:252-263. [PMID: 30921541 DOI: 10.1016/j.watres.2019.03.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 03/04/2019] [Accepted: 03/12/2019] [Indexed: 06/09/2023]
Abstract
Field-scale studies of natural colloid mobilization and transport in finely fractured aquifer as well as the source identification of groundwater colloids are of great importance to the safety of shallow groundwater. In this study, the daily monitoring of fracture flow from a sloping farmland plot and the biweekly monitoring of three lowland shallow wells within the same catchment were carried out simultaneously in 2013. The effects of physicochemical perturbations on groundwater colloid dynamics were explored in detail using partial redundancy analysis, structural equation modeling, Pearson correlation and multi-linear regression analyses. The characterization and source identification of groundwater colloids were addressed via multiple parameters. The daily colloid concentration in the fracture flow varied between 0.54 and 31.90 mg/L (1.64 mg/L on average). Unique periods of high colloid concentration (5.59 mg/L on average) occurred during the initially generated flow following the dry season. In comparison, a narrower colloid concentration range of 0.24-11.66 mg/L was observed in the lowland shallow wells, with a smaller temporal variation than that of the fracture flow. A low percentage (2.4-7.0%) of colloids and a high percentage (47.7-92.0%) of coarse particles (2-10 μm) were present in the lowland well water. Hydraulic perturbation by rainwater infiltration in the sloping farmland was the dominant mechanism for colloid mobilization in general; this effect retreated to secondary importance behind chemical perturbations (pH, Mg2+ and DOC) at low flow discharges (<1.3 L/min). In contrast, water chemistry (e.g., EC, cations and DOC concentrations) exhibited a major effect on colloid dynamics in the water of the lowland wells, except for the extremely high-salinity water of one well, in which water temperature showed a negative dominant influence on colloid stability. The combined use of multiple parameters (e.g., mineral composition and organic matter, calcium carbonate and δ13C contents) traced groundwater colloids to the shallow soil in the upper farmlands. It is strongly advised that in finely fractured aquifers within agricultural catchments, not only the small colloids but also the coarse particles in the size range of 2-10 μm should be monitored in case of colloid-associated contamination from agricultural wastes e.g., N, P, pesticides and/or heavy metals, especially at the early stages of the rainy seasons.
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Affiliation(s)
- Wei Zhang
- School of Tourism and Land Resource, Chongqing Technology and Business University, Chongqing, 400067, China; Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian-Hua Cheng
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qing-Song Xian
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jun-Fang Cui
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xiang-Yu Tang
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gen-Xu Wang
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China; University of Chinese Academy of Sciences, Beijing, 100049, China
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Wen J, Tang C, Cao Y, Li X, Chen Q. Assessment of trace metals in an aquifer with river-groundwater interaction: The influence of colloidal redistribution and porous matrix change on the migration of metals. CHEMOSPHERE 2019; 223:588-598. [PMID: 30797168 DOI: 10.1016/j.chemosphere.2019.01.184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 01/27/2019] [Accepted: 01/30/2019] [Indexed: 06/09/2023]
Abstract
An aquifer where receives steady lateral recharge from an AMD-polluted river, was chosen to understand the profound influence of the "solid-liquid phase" evolution on the mobility of trace metals. The results showed that the accumulation of trace metals in groundwater was observed near the riparian zone. Zn and Cd almost remained in the "truly dissolved" phase (<3 kDa), whereas Cu and Pb were mainly in the coarse colloid (0.22 μm-30 kDa) and shifted from the coarse colloid to the "truly dissolved" phase along the flow path. The evolution of relatively high dispersive colloids to low dispersive colloids indicated that the Al-rich mineral colloids as the dominance migrated with the groundwater flow path, and flocculated gradually so that the porous matrix was coated by gibbsite. The coating of gibbsite dissociates OH- in acidic environment, resulting in the decreasing negative charge in porous matrix. Thus, the mobility of Cu and Pb was shifted from the colloid-facilitated transport to the co-precipitation with colloids, whereas the mobility of Zn and Cd was changed from the high electrostatic binding to the low electrostatic binding. Numerical simulation also confirmed the varying retardation factor and the total penetration time followed an order of Pb > Cu > Zn > Cd. Therefore, the changes in "two phases" in the aquifer-not only in water phase but also in colloid phase and porous matrix-have a profound influence on metal migration that take place in shallow groundwater where there are close hydraulic connection between river and groundwater.
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Affiliation(s)
- Jing Wen
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510006, People's Republic of China
| | - Changyuan Tang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510006, People's Republic of China; School of Geography and Planning, Sun Yat-Sen University, Guangzhou, 510000, People's Republic of China
| | - Yingjie Cao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510006, People's Republic of China.
| | - Xing Li
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
| | - Qian Chen
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
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30
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Chen X, Gao M, Li Y, Zhang X, Zhang F, Hu B. Effects of freeze-thaw cycles on the physicochemical characteristics of animal manure and its phosphorus forms. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 88:160-169. [PMID: 31079628 DOI: 10.1016/j.wasman.2019.03.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 06/09/2023]
Abstract
The variations of phosphorus (P) in animal manure during freeze-thaw cycles (FTCs) profoundly influence on non-point source P loss in winter. Therefore, understanding how FTCs influence the physicochemical properties of animal manure and its P availability is crucial. In this study, the freeze-thaw treatment was performed by incubating the pig manure at -20 °C for 12 h and at 18 °C for 12 h. The freeze-only treatment was maintained at -20 °C as a control. In addition, the pig manure was kept at two moisture levels during the FTCs and sampled every five cycles. Six forms of P in the manure were extracted and analyzed. After 30 cycles, the dissolved organic carbon had increased from 10.49 to 13.56 g/kg, and the pH had decreased from 6.25 to 5.77. The particles originally >1000 μm were broken into particles <250 μm. The forms of P in manure shifted from Ca-P, occluded P, and residual P towards NH4Cl-P, Al-P and Fe-P, resulting in a 23% increase in bioavailable P. These variations were highly coincident with the increase in moisture content and FTC frequency. The proportion of particles <38 μm increased by more than 2% after the FTCs, and the manure P was mainly concentrated in these particles, which might be readily washed away by the melt water. Overall, the study indicated that FTCs could enhance the bioavailability of P in pig manure and the mobility of particle-associated P. These findings are significant for reducing animal manure pollution in freeze-thaw season.
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Affiliation(s)
- Xingcai Chen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 100875 Beijing, China
| | - Min Gao
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 100875 Beijing, China
| | - Yanxia Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 100875 Beijing, China.
| | - Xuelian Zhang
- Beijing Soil and Fertilizer Extension Service Station, Beijing 100029, China
| | - Fengsong Zhang
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101 Beijing, China
| | - Baiyang Hu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 100875 Beijing, China
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31
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Buma B, Batllori E, Bisbing S, Holz A, Saunders SC, Bidlack AL, Creutzburg MK, DellaSala DA, Gregovich D, Hennon P, Krapek J, Moritz MA, Zaret K. Emergent freeze and fire disturbance dynamics in temperate rainforests. AUSTRAL ECOL 2019. [DOI: 10.1111/aec.12751] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Brian Buma
- Department of Integrative Biology; University of Colorado, Denver; 1151 Arapahoe St. Denver Colorado 80204 USA
| | - Enric Batllori
- Universitat Autònoma de Barcelona; Cerdanyola del Vallòs Spain
| | - Sarah Bisbing
- Department of Natural Resources & Environmental Science; University of Nevada - Reno; Reno Nevada USA
| | - Andres Holz
- Department of Geography; Portland State University; Portland Oregon USA
| | - Sari C. Saunders
- Coast Area Research; BC Ministry of Forests, Lands, Natural Resource Operations, and Rural Development; Nanaimo British Columbia Canada
| | - Allison L. Bidlack
- Alaska Coastal Rainforest Center; University of Alaska Southeast; Juneau Alaska USA
| | - Megan K. Creutzburg
- Institute for Natural Resources; Oregon State University; Portland Oregon USA
| | | | - Dave Gregovich
- Alaska Department of Fish and Game; Wildlife Conservation Division; Douglas Alaska USA
| | - Paul Hennon
- USDA Forest Service; PNW Research Station; Juneau Alaska USA
| | | | - Max A. Moritz
- Agriculture and Natural Resources Division; University of California Cooperative Extension; Santa Barbara California USA
- Bren School of Environmental Science & Management; University of California; Santa Barbara California USA
| | - Kyla Zaret
- Department of Geography; Portland State University; Portland Oregon USA
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32
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Ding B, Rezanezhad F, Gharedaghloo B, Van Cappellen P, Passeport E. Bioretention cells under cold climate conditions: Effects of freezing and thawing on water infiltration, soil structure, and nutrient removal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 649:749-759. [PMID: 30176485 DOI: 10.1016/j.scitotenv.2018.08.366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/22/2018] [Accepted: 08/26/2018] [Indexed: 06/08/2023]
Abstract
Bioretention cells are a popular control strategy for stormwater volume and quality, but their efficiency for water infiltration and nutrient removal under cold climate conditions has been poorly studied. In this work, soil cores were collected from an active bioretention cell containing engineered soil material amended with a phosphate sorbent medium. The cores were used in laboratory column experiments conducted to obtain a detailed characterization of the soil's bioretention performance during six consecutive freeze-thaw cycles (FTCs, from -10 to +10 °C). At the start of each FTC, the experimental column undergoing the FTCs and a control column kept at room temperature were supplied with a solution containing 25 mg/L of bromide, nitrate and phosphate. Water saturated conditions were established to mimic the presence of an internal water storage zone to support anaerobic nitrate removal. At the end of each FTC, the pore solution was allowed to drain from the columns. The results indicate that the FTCs enhanced the infiltration efficiency of the soil: with each successive cycle the drainage rate increased in the experimental column. Freezing and thawing also increased the saturated hydraulic conductivity of the bioretention soil. X-ray tomography imaging identified a key role of macro-pore formation in maintaining high infiltration rates. Both aqueous nitrate and phosphate supplied to the columns were nearly completely removed from solution. Sufficiently long retention times and the presence of the internal water storage zone promoted anaerobic nitrate elimination despite the low temperatures. Dissolved phosphate was efficiently trapped at all depths in the soil columns, with ≤2% of the added stormwater phosphate recovered in the drainage effluent. These findings imply that, when designed properly, bioretention cells can support high infiltration rates and mitigate nutrient pollution in cold climates.
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Affiliation(s)
- Brenden Ding
- Department of Civil and Mineral Engineering, University of Toronto, 35 St George St, Toronto, ON M5S 1A4, Canada
| | - Fereidoun Rezanezhad
- Ecohydrology Research Group, Water Institute and Department of Earth & Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Behrad Gharedaghloo
- Department of Geography and Environmental Managements, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Philippe Van Cappellen
- Ecohydrology Research Group, Water Institute and Department of Earth & Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Elodie Passeport
- Department of Civil and Mineral Engineering, University of Toronto, 35 St George St, Toronto, ON M5S 1A4, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College St, Toronto, ON M5S 3E5, Canada.
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33
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Mohanty SK, Valenca R, Berger AW, Yu IKM, Xiong X, Saunders TM, Tsang DCW. Plenty of room for carbon on the ground: Potential applications of biochar for stormwater treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 625:1644-1658. [PMID: 29996460 DOI: 10.1016/j.scitotenv.2018.01.037] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/05/2018] [Accepted: 01/05/2018] [Indexed: 06/08/2023]
Abstract
Low impact development (LID) systems are increasingly used to manage stormwater, but they have limited capacity to treat stormwater-a resource to supplement existing water supply in water-stressed urban areas. To enhance their pollutant removal capacity, infiltration-based LID systems can be augmented with natural or engineered geomedia that meet the following criteria: they should be economical, readily available, and have capacity to remove a wide range of stormwater pollutants in conditions expected during intermittent infiltration of stormwater. Biochar, a carbonaceous porous co-product of waste biomass pyrolysis/gasification, meets all these criteria. Biochar can adsorb pollutants, improve water-retention capacity of soil, retain and slowly release nutrients for plant uptake, and help sustain microbiota in soil and plants atop; all these attributes could help improve removal of contaminants in stormwater treatment systems. This article discusses contaminant removal mechanisms by biochar, summarizes specific biochar properties that enhance targeted contaminants removal from stormwater, and identifies challenges and opportunities to retrofit biochar in LID to optimize stormwater treatment.
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Affiliation(s)
- Sanjay K Mohanty
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095-1593, USA.
| | - Renan Valenca
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095-1593, USA
| | - Alexander W Berger
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095-1593, USA
| | - Iris K M Yu
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Xinni Xiong
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Trenton M Saunders
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095-1593, USA
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
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Rod K, Um W, Chun J, Wu N, Yin X, Wang G, Neeves K. Effect of chemical and physical heterogeneities on colloid-facilitated cesium transport. JOURNAL OF CONTAMINANT HYDROLOGY 2018; 213:22-27. [PMID: 29657081 DOI: 10.1016/j.jconhyd.2018.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 03/09/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
A set of column experiments was conducted to investigate the chemical and physical heterogeneity effect on colloid facilitated transport under slow pore velocity conditions. Pore velocities were kept below 100 cm d-1 for all experiments. Glass beads were packed into columns establishing four different conditions: 1) homogeneous, 2) mixed physical heterogeneity, 3) sequentially layered physical heterogeneity, and 4) chemical heterogeneity. The homogeneous column was packed with glass beads (diameter 500-600 μm), and physical heterogeneities were created by sequential layering or mixing two sizes of glass bead (500-600 μm and 300-400 μm). A chemical heterogeneity was created using 25% of the glass beads coated with hydrophobic molecules (1H-1H-2H-2H-perfluorooctyltrichlorosilane) mixed with 75% pristine glass beads (all 500-600 μm). Input solution with 0.5 mM CsI and 50 mg L-1 colloids (1-μm diameter SiO2) was pulsed into columns under saturated conditions. The physical heterogeneity in the packed glass beads retarded the transport of colloids compared to homogeneous (R = 25.0), but showed only slight differences between sequentially layered (R = 60.7) and mixed heterogeneity(R = 62.4). The column with the chemical, hydrophobic/hydrophilic, heterogeneity removed most of the colloids from the input solution. All column conditions stripped Cs from colloids onto the column matrix of packed glass beads.
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Affiliation(s)
- Kenton Rod
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Wooyong Um
- Pacific Northwest National Laboratory, Richland, WA 99354, USA; Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea.
| | - Jaehun Chun
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Ning Wu
- Colorado School of Mines, Golden, CO 80401, USA
| | - Xialong Yin
- Colorado School of Mines, Golden, CO 80401, USA
| | - Guohui Wang
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
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35
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Xia B, Qiu H, Knorr KH, Blodau C, Qiu R. Occurrence and fate of colloids and colloid-associated metals in a mining-impacted agricultural soil upon prolonged flooding. JOURNAL OF HAZARDOUS MATERIALS 2018; 348:56-66. [PMID: 29367133 DOI: 10.1016/j.jhazmat.2018.01.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/28/2017] [Accepted: 01/11/2018] [Indexed: 06/07/2023]
Abstract
Colloids formed during soil flooding can potentially facilitate the mobilization of metal contaminants. Here, laboratory batch incubations with a contaminated soil were performed to monitor temporal changes in the porewater dynamics of metals, the morphology and composition of colloids, and the speciation of colloids-associated metals during 30 days of flooding. The concentrations of colloidal and dissolved metals increased initially and peaked at a certain time, but then decreased with the on-going sulfate reduction. The combined analysis of spectrometric, spectroscopic, and size-fractionation results revealed that the dynamics of Cu were dominated by microbe-associated colloids and were mediated largely by Cu(0) biomineralization and subsequent sulfidation, while the microbe-associated and freely dispersed colloids were equally relevant for governing the dynamics of Cd and Pb. Mobilization of Zn, on the other hand, was dominated by its dissolved form, probably due to the low thermodynamic stability of Zn-sulfide. Additionally, adsorption via organic functional groups was another mechanism for metal incorporation into colloids. We also provided direct spectroscopic evidence for the formation and persistence of dispersed heterocolloids consisting of CuxS and CdS during flooding. Our findings suggest that colloids-induced metal mobilization should be considered in assessing bioavailability and risks of metals in contaminated soils upon flooding.
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Affiliation(s)
- Bing Xia
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, China; Anhui Academy of Environmental Science Research, Hefei, China
| | - Hao Qiu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, China; Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture/Tianjin Key Laboratory of Agro-Environment and Safe-Product, Tianjin, China.
| | | | - Christian Blodau
- Institute of Landscape Ecology, University of Münster, Münster, Germany
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China.
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36
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Buma B. Transitional climate mortality: slower warming may result in increased climate‐induced mortality in some systems. Ecosphere 2018. [DOI: 10.1002/ecs2.2170] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Brian Buma
- Department of Natural Sciences University of Alaska Southeast Juneau Alaska 99801 USA
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37
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Haque ME, Shen C, Li T, Chu H, Wang H, Li Z, Huang Y. Influence of Biochar on Deposition and Release of Clay Colloids in Saturated Porous Media. JOURNAL OF ENVIRONMENTAL QUALITY 2017; 46:1480-1488. [PMID: 29293838 DOI: 10.2134/jeq2017.06.0223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Although the potential application of biochar in soil remediation has been recognized, the effect of biochar on the transport of clay colloids, and accordingly the fate of colloid-associated contaminants, is unclear to date. This study conducted saturated column experiments to systematically examine transport of clay colloids in biochar-amended sand porous media in different electrolytes at different ionic strengths. The obtained breakthrough curves were simulated by the convection-diffusion equation, which included a first-order deposition and release terms. The deposition mechanisms were interpreted by calculating Derjaguin-Landau-Verwey-Overbeek interaction energies. A linear relationship between the simulated deposition rate or the attachment efficiency and the fraction of biochar was observed ( ≥ 0.91), indicating more favorable deposition in biochar than in sand. The interaction energy calculations show that the greater deposition in biochar occurs because the half-tube-like cavities on the biochar surfaces favor deposition in secondary minima and the nanoscale physical and chemical heterogeneities on the biochar surfaces increase deposition in primary minima. The deposited clay colloids in NaCl can be released by reduction of ionic strength, whereas the presence of a bivalent cation (Ca) results in irreversible deposition due to the formation of cation bridging between the colloids and biochar surfaces. The deposition and release of clay colloids on or from biochar surfaces not only change their mobilizations in the soil but also influence the efficiency of the biochar for removal of pollutants. Therefore, the influence of biochar on clay colloid transport must be considered before application of the biochar in soil remediation.
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38
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Kinsley C, Kennedy K, Crolla A. A combined reed bed/freezing bed technology for septage treatment and reuse in cold climate regions. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 76:286-293. [PMID: 28726695 DOI: 10.2166/wst.2017.189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A combined reed bed-freezing bed (RB-FB) technology was effective at treating septage under Canadian climatic conditions over a 5-year period with average loading rates of 82-104 kg TS/m2/y. Varying hydraulic and solid loading rates as well as the increasing sludge cake with time had little to no effect on treatment efficiency, with almost complete removal of organic matter, solids, heavy metals and nutrients. Filtrate concentrations varied significantly between the freeze-thaw and growing seasons for many parameters, although the differences were not important from a treatment or reuse perspective with filtrate quality similar to a low to medium strength domestic wastewater. The potential to reuse the filtrate as a source of irrigation water will depend upon local regulations. The dewatered sludge cake consistently met biosolids land application standards in terms of pathogen and metals content, with Escherichia coli numbers declining with time as sludge cake depth increased. A combined RB-FB technology can provide a cost-effective solution for septage management in northern rural communities with potential for beneficial reuse of both the filtrate and dewatered sludge cake.
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Affiliation(s)
- C Kinsley
- Department of Civil Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, Ontario, Canada K1N 6N5 E-mail: ; Ontario Rural Wastewater Centre, Université de Guelph - Campus d'Alfred, 31 St. Paul St., Alfred, Ontario, Canada K0B1A0
| | - K Kennedy
- Department of Civil Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, Ontario, Canada K1N 6N5 E-mail:
| | - A Crolla
- Ontario Rural Wastewater Centre, Université de Guelph - Campus d'Alfred, 31 St. Paul St., Alfred, Ontario, Canada K0B1A0
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39
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Xu M, Zheng Y, Chen W, Mao N, Guo P. Leachate Properties and Cadmium Migration Through Freeze-thaw Treated Soil Columns. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2017; 98:113-119. [PMID: 27909755 DOI: 10.1007/s00128-016-1982-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 11/18/2016] [Indexed: 06/06/2023]
Abstract
Soil column leaching experiments were conducted to study the effects of multiple freeze-thaw cycles on the vertical migration of cadmium (Cd). Three Cd-spiked leaching solutions of different properties were derived from snowmelt, sludge, and straw, designated as B, W and J, respectively. The leaching solutions varied in dissolved organic matter (DOM) concentrations in the order of J > W > B. Changes in leachate properties and Cd concentration were observed. The results showed that pH values of all the leachate solutions through freeze-thaw treated soil columns were higher than those of leachates through unfrozen soils. However, electrical conductivity (EC) values decreased compared with leachates in unfrozen treated soil columns. Although the concentrations of DOM in leachate solutions had no evident differences between the freeze-thaw and unfrozen treated soil columns, the concentrations of DOM in the leachate solutions B, W and J were different. Freeze-thaw cycles resulted in increased concentrations of Cd in the leachate solutions in the order J > W > B, and promoted a deeper migration of Cd in the soil columns. Thus, it was shown that freeze-thaw cycles may increase the risk of groundwater pollution by Cd.
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Affiliation(s)
- Meng Xu
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China
- Shandong Geological Sciences Institute, Jinan, 250013, China
| | - Yue Zheng
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China
| | - Weiwei Chen
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China
| | - Na Mao
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China
| | - Ping Guo
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China.
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40
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Li J, Kosugi T, Riya S, Hashimoto Y, Hou H, Terada A, Hosomi M. Potential for leaching of arsenic from excavated rock after different drying treatments. CHEMOSPHERE 2016; 154:276-282. [PMID: 27058919 DOI: 10.1016/j.chemosphere.2016.03.129] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/19/2016] [Accepted: 03/28/2016] [Indexed: 06/05/2023]
Abstract
Leaching of arsenic (As) from excavated rock subjected to different drying methods is compared using sequential leaching tests and rapid small-scale column tests combined with a sequential extraction procedure. Although the total As content in the rock was low (8.81 mg kg(-1)), its resulting concentration in the leachate when leached at a liquid-to-solid ratio of 10 L kg(-1) exceeded the environmental standard (10 μg L(-1)). As existed mainly in dissolved forms in the leachates. All of the drying procedures applied in this study increased the leaching of As, with freeze-drying leading to the largest increase. Water extraction of As using the two tests showed different leaching behaviors as a function of the liquid-to-solid ratio, and achieved average extractions of up to 35.7% and 25.8% total As, respectively. Dissolution of As from the mineral surfaces and subsequent re-adsorption controlled the short-term release of As; dissolution of Fe, Al, and dissolved organic carbon played important roles in long-term As leaching. Results of the sequential extraction procedure showed that use of 0.05 M (NH4)2SO4 underestimates the readily soluble As. Long-term water extraction removed almost all of the non-specifically sorbed As and most of the specifically sorbed As. The concept of pollution potential indices, which are easily determined by the sequential leaching test, is proposed in this study and is considered for possible use in assessing efficacy of treatment of excavated rocks.
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Affiliation(s)
- Jining Li
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan
| | - Tomoya Kosugi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan
| | - Shohei Riya
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan
| | - Yohey Hashimoto
- Department of Bioapplications and Systems Engineering (BASE), Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan
| | - Hong Hou
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Dayangfang 8, Beijing 100012, PR China
| | - Akihiko Terada
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan
| | - Masaaki Hosomi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan.
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41
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Mohanty SK, Saiers JE, Ryan JN. Colloid Mobilization in a Fractured Soil: Effect of Pore-Water Exchange between Preferential Flow Paths and Soil Matrix. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2310-2317. [PMID: 26829659 DOI: 10.1021/acs.est.5b04767] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Exchange of water and solutes between contaminated soil matrix and bulk solution in preferential flow paths has been shown to contribute to the long-term release of dissolved contaminants in the subsurface, but whether and how this exchange can affect the release of colloids in a soil are unclear. To examine this, we applied rainfall solutions of different ionic strength on an intact soil core and compared the resulting changes in effluent colloid concentration through multiple sampling ports. The exchange of water between soil matrix and the preferential flow paths leading to each port was characterized on the basis of the bromide (conservative tracer) breakthrough time at the port. At individual ports, two rainfalls of a certain ionic strength mobilized different amounts of colloids when the soil was pre-exposed to a solution of lower or higher ionic strength. This result indicates that colloid mobilization depended on rainfall solution history, which is referred as colloid mobilization hysteresis. The extent of hysteresis was increased with increases in exchange of pore water and solutes between preferential flow paths and matrix. The results indicate that the soil matrix exchanged the old water from the previous infiltration with new infiltrating water during successive infiltration and changed the pore water chemistry in the preferential flow paths, which in turn affected the release of soil colloids. Therefore, rainfall solution history and soil heterogeneity must be considered to assess colloid mobilization in the subsurface. These findings have implications for the release of colloids, colloid-associated contaminants, and pathogens from soils.
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Affiliation(s)
- Sanjay K Mohanty
- Civil, Environmental and Architectural Engineering, University of Colorado , Boulder, Colorado 80309, United States
| | - James E Saiers
- Yale School of Forestry and Environmental Studies, Yale University , New Haven, Connecticut 06511, United States
| | - Joseph N Ryan
- Civil, Environmental and Architectural Engineering, University of Colorado , Boulder, Colorado 80309, United States
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42
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Dittrich TM, Reimus PW. Reactive transport of uranium in fractured crystalline rock: Upscaling in time and distance. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 165:124-132. [PMID: 26431639 DOI: 10.1016/j.jenvman.2015.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 09/09/2015] [Accepted: 09/11/2015] [Indexed: 06/05/2023]
Abstract
Batch adsorption and breakthrough column experiments were conducted to evaluate uranium transport through altered material that fills fractures in a granite rock system at the Grimsel Test Site in Switzerland at pH 6.9 and 7.9. The role of adsorption and desorption kinetics was evaluated with reactive transport modeling by comparing one-, two-, and three-site models. Emphasis was placed on describing long desorption tails that are important for upscaling in time and distance. The effect of increasing pH in injection solutions was also evaluated. For pH 6.9, a three-site model with forward rate constants between 0.07 and 0.8 ml g(-1) h(-1), reverse rate constants between 0.001 and 0.06 h(-1), and site densities of 1.3, 0.104, and 0.026 μmol g(-1) for 'weak/fast', 'strong/slow', and 'very strong/very slow' sites provided the best fits. For pH 7.9, a three-site model with forward rate constants between 0.05 and 0.8 mL g(-1) h(-1), reverse rate constants between 0.001 and 0.6 h(-1), and site densities of 1.3, 0.039, and 0.013 μmol g(-1) for a 'weak/fast', 'strong/slow', and 'very strong/very slow' sites provided the best fits. Column retardation coefficients (Rd) were 80 for pH 6.9 and 10.3 for pH 7.9. Model parameters determined from the batch and column experiments were used in 50 year large-scale simulations for continuous and pulse injections and indicated that a three-site model is necessary at pH 6.9, although a Kd-type equilibrium partition model with one-site was adequate for large scale predictions at pH 7.9. Batch experiments were useful for predicting early breakthrough times in the columns while column experiments helped differentiate the relative importance of sorption sites and desorption rate constants on transport.
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Affiliation(s)
- Timothy M Dittrich
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Paul W Reimus
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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43
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Mohanty SK, Boehm AB. Effect of weathering on mobilization of biochar particles and bacterial removal in a stormwater biofilter. WATER RESEARCH 2015; 85:208-215. [PMID: 26320722 DOI: 10.1016/j.watres.2015.08.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/12/2015] [Accepted: 08/17/2015] [Indexed: 06/04/2023]
Abstract
To improve bacterial removal, a traditional stormwater biofilter can be augmented with biochar, but it is unknown whether bacterial removal remains consistent as the biochar weathers during intermittent exposure to stormwater under dry-wet and freeze-thaw cycles. To examine the effect of weathering on bacterial removal capacity of biochar, we subjected biochar-augmented sand filters (or simplified biofilters) to multiple freeze-thaw or dry-wet cycles for a month and then compared their bacterial removal capacity with the removal capacity of unweathered biofilters. To isolate the effect of physical and chemical weathering processes from that of biological processes, the biofilters were operated without any developed biofilm. Biochar particles were mobilized during intermittent infiltration of stormwater, but the mobilization depended on temperature and antecedent conditions. During stormwater infiltration without intermediate drying, exposure to natural organic matter (NOM) in the stormwater decreased the bacterial removal capacity of biochar, partly due to exhaustion of attachment sites by NOM adsorption. In contrast, exposure to the same amount of NOM during stormwater infiltration with intermediate drying resulted in higher bacterial removal. This result suggests that dry-wet cycles may enhance recovery of the previously exhausted attachment sites, possibly due to diffusion of NOM from biochar surfaces into intraparticle pores during intermediate drying periods. Overall, these results indicate that physical weathering has net positive effect on bacterial removal by biochar-augmented biofilters.
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Affiliation(s)
- Sanjay K Mohanty
- Dept. of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA; Engineering Research Center (ERC) for Re-inventing the Nation's Urban Water Infrastructure (ReNUWIt), USA.
| | - Alexandria B Boehm
- Dept. of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA; Engineering Research Center (ERC) for Re-inventing the Nation's Urban Water Infrastructure (ReNUWIt), USA
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Mohanty SK, Saiers JE, Ryan JN. Colloid Mobilization in a Fractured Soil during Dry-Wet Cycles: Role of Drying Duration and Flow Path Permeability. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:9100-9106. [PMID: 26134351 DOI: 10.1021/acs.est.5b00889] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In subsurface soils, colloids are mobilized by infiltrating rainwater, but the source of colloids and the process by which colloids are generated between rainfalls are not clear. We examined the effect of drying duration and the spatial variation of soil permeability on the mobilization of in situ colloids in intact soil cores (fractured and heavily weathered saprolite) during dry-wet cycles. Measuring water flux at multiple sampling ports at the core base, we found that water drained through flow paths of different permeability. The duration of antecedent drying cycles affected the amount of mobilized colloids, particularly in high-flux ports that received water from soil regions with a large number of macro- and mesopores. In these ports, the amount of mobilized colloids increased with increased drying duration up to 2.5 days. For drying durations greater than 2.5 days, the amount of mobilized colloids decreased. In contrast, increasing drying duration had a limited effect on colloid mobilization in low-flux ports, which presumably received water from soil regions with fewer macro- and mesopores. On the basis of these results, we attribute this dependence of colloid mobilization upon drying duration to colloid generation from dry pore walls and distribution of colloids in flow paths, which appear to be sensitive to the moisture content of soil after drying and flow path permeability. The results are useful for improving the understanding of colloid mobilization during fluctuating weather conditions.
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Affiliation(s)
- Sanjay K Mohanty
- †Civil, Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | | | - Joseph N Ryan
- †Civil, Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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De Kock T, Boone MA, De Schryver T, Van Stappen J, Derluyn H, Masschaele B, De Schutter G, Cnudde V. A pore-scale study of fracture dynamics in rock using X-ray micro-CT under ambient freeze-thaw cycling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2867-2874. [PMID: 25683464 DOI: 10.1021/es505738d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Freeze-thaw cycling stresses many environments which include porous media such as soil, rock and concrete. Climate change can expose new regions and subject others to a changing freeze-thaw frequency. Therefore, understanding and predicting the effect of freeze-thaw cycles is important in environmental science, the built environment and cultural heritage preservation. In this paper, we explore the possibilities of state-of-the-art micro-CT in studying the pore scale dynamics related to freezing and thawing. The experiments show the development of a fracture network in a porous limestone when cooling to -9.7 °C, at which an exothermal temperature peak is a proxy for ice crystallization. The dynamics of the fracture network are visualized with a time frame of 80 s. Theoretical assumptions predict that crystallization in these experiments occurs in pores of 6-20.1 nm under transient conditions. Here, the crystallization-induced stress exceeds rock strength when the local crystal fraction in the pores is 4.3%. The location of fractures is strongly related to preferential water uptake paths and rock texture, which are visually identified. Laboratory, continuous X-ray micro-CT scanning opens new perspectives for the pore-scale study of ice crystallization in porous media as well as for environmental processes related to freeze-thaw fracturing.
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Affiliation(s)
- Tim De Kock
- UGCT-Department of Geology and Soil Science, Faculty of Sciences, Ghent University , Krijgslaan 281/S8, 9000 Ghent, Belgium
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