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Yu Y, Zhan C, Li Y, Zhou D, Yu J, Yang J. A comparison of metal distribution in surface soil between wetland and farmland in the Sanjiang plain. HYDRORESEARCH 2023. [DOI: 10.1016/j.hydres.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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Yu X, LeMonte JJ, Li J, Stuckey JW, Sparks DL, Cargill JG, Russoniello CJ, Michael HA. Hydrologic Control on Arsenic Cycling at the Groundwater-Surface Water Interface of a Tidal Channel. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:222-230. [PMID: 36534790 DOI: 10.1021/acs.est.2c05930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Historical industrial activities have resulted in soil contamination at sites globally. Many of these sites are located along coastlines, making them vulnerable to hydrologic and biogeochemical alterations due to climate change and sea-level rise. However, the impact of hydrologic dynamics on contaminant mobility in tidal environments has not been well studied. Here, we collected data from pressure transducers in wells, multi-level redox sensors, and porewater samplers at an As-contaminated site adjacent to a freshwater tidal channel. Results indicate that sharp redox gradients exist and that redox conditions vary on tidal to seasonal timescales due to sub-daily water level fluctuations in the channel and seasonal groundwater-surface water interactions. The As and Fe2+ concentrations decreased during seasonal periods of net discharge to the channel. The seasonal changes were greater than tidal variations in both Eh and As concentrations, indicating that impacts of the seasonal mechanism are stronger than those of sub-daily water table fluctuations. A conceptual model describing tidal and seasonal hydro-biogeochemical coupling is presented. These findings have broad implications for understanding the impacts of sea-level rise on the mobility of natural and anthropogenic coastal solutes.
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Affiliation(s)
- Xuan Yu
- Center for Water Resources and Environment, School of Civil Engineering, Sun Yat-sen University, Guangzhou510275, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai519082, China
| | - Joshua J LeMonte
- Department of Geological Sciences, Brigham Young University, Provo, Utah84602, United States
| | - Junxia Li
- School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology & Key Laboratory of Source Apportionment and Control of Aquatic Pollution, Ministry of Ecology and Environment, China University of Geosciences, Wuhan430074, China
| | - Jason W Stuckey
- Department of Natural Sciences and Environmental Science Program, Multnomah University, Portland, Oregon97220, United States
| | - Donald L Sparks
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware19716, United States
| | - John G Cargill
- Department of Natural Resources and Environmental Control, New Castle, Delaware19720, United States
| | | | - Holly A Michael
- Department of Earth Sciences and Department of Civil & Environmental Engineering, University of Delaware, Newark, Delaware19716, United States
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Zhu L, Zhang X, Zhang J, Liu T, Qiu Y. Saltwater intrusion weakens Fe-(oxyhydr)oxide-mediated (im)mobilization of Ni and Zn in redox-fluctuating soil-groundwater system. WATER RESEARCH 2022; 221:118799. [PMID: 35780765 DOI: 10.1016/j.watres.2022.118799] [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: 03/01/2022] [Revised: 06/03/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
Iron in the form of (oxyhydr)oxides plays a profound role in the (im)mobilization of heavy metals in environmental geochemical processes occurring in the soil-groundwater system. Here, the influence of saltwater intrusion on Fe-(oxyhydr)oxide-mediated (im)mobilization of Ni(II) and Zn(II) in redox-fluctuating shallow aquifers was evaluated by chemical extraction, μ-XRF-XANES analysis, and 16S rRNA high-throughput sequencing. In phreatic water, the ferrihydrite-bound Ni/Zn (Fh-Ni/Zn) in soils contributed to a 12%-17% increase in carbonate-bound Ni/Zn (Cb-Ni/Zn) due to its own reductive dissolution, whereas the illite-adsorbed Ni/Zn (illite-Ni/Zn) only contributed 6%, 7%. The relative abundance of non-salt tolerant anaerobic Herbaspirillum and iron-reducing associated Ralstonia in soils accounted for nearly 50%. During the oxidation stage, the dissolved ferrihydrite reprecipitated to bind free Ni/Zn. However, saltwater invasion strongly weakened the dissolution-precipitation of ferrihydrite by inhibiting the growth of non-salt tolerant anaerobes and iron-reducing bacteria, and highlighted the contribution of illite-Ni/Zn. Under brackish water intrusion, illite-Zn contributed to a 12% increase in Cb-Zn, thereby surpassing the contribution of Fh-Zn (8%). Under seawater invasion, the dissolution-precipitation of ferrihydrite hardly occurred and the anaerobic salt-tolerant Bacillus (> 95%) prevailed. Therefore, the increase of Cb-Ni/Zn (7%-15%) in the reduction stages was contributed by illite-Ni/Zn. However, in the oxidation stages, the carbonate replaced the original role of reprecipitated ferrihydrite to bind the free Ni/Zn in solutions. These newly recognized mechanisms may be the key to predicting the mobility of toxic elements and developing appropriate remediation techniques of permeable reactive barriers under salinity stress.
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Affiliation(s)
- Ling Zhu
- Department of Environmental Science, College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
| | - Xiaoxian Zhang
- Department of Environmental Science, College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
| | - Jichen Zhang
- Department of Environmental Science, College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
| | - Tingran Liu
- Department of Environmental Science, College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
| | - Yuping Qiu
- Department of Environmental Science, College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China.
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Tan B, Liu C, Tan X, You X, Dai C, Liu S, Li J, Li N. Heavy metal transport driven by seawater-freshwater interface dynamics: The role of colloid mobilization and aquifer pore structure change. WATER RESEARCH 2022; 217:118370. [PMID: 35405553 DOI: 10.1016/j.watres.2022.118370] [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: 01/25/2022] [Revised: 03/13/2022] [Accepted: 03/25/2022] [Indexed: 06/14/2023]
Abstract
Co-transport of colloidal substances and pollutants is a pivotal link that significantly affects the environment of coastal groundwater. The effect of colloid mobilization and aquifer pore structure change on heavy metal transport driven by seawater-freshwater interface dynamics is not fully understood. In this study, packed column experiments were conducted to model the seawater intrusion (SWI) and freshwater replenishment (FWR) processes using a sampled medium from a coastal sandy aquifer. Hydrodynamic, hydrochemical variables, and heavy metal (Pb, Cu, Cd) transport during the propagation of the seawater-freshwater interface were tested and analyzed. During the SWI stage, cation exchange induced heavy metal liberations, and it developed peak concentrations synchronized with the seawater-freshwater interface at the pore volume of 1.00. The colloid-facilitated transport for heavy metals was the predominant mechanism in the FWR stage, characterized by a peak release lagging the interface propagation by approximately 0.5 pore volumes. Because the colloidal fraction was mobilized during aquifer desalination, it lagged behind the decline of the salinity gradient. Furthermore, Derjaguin-Landau-Verwey-Overbeek (DLVO) calculations explained that the replenishment decreased the depth of the secondary energy minimum of the colloids; meanwhile, the thickness of the electrical double layer increased from 0.63 nm to 10.14 nm, resulting in a repulsive energy barrier up to 3,213 kT. The transport of colloids led to a reduction in porosity from 18.16% to 2.28% of the total immobile domain. At these times, the dimension of the transported colloids evolved, showing a size-selective transport and therefore regulating the total emission fluxes of the heavy metals. These mechanisms were proposed to be incorporated in colloid filtration theory for targeting the coastal scenario.
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Affiliation(s)
- Bo Tan
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, 610065 Chengdu, Sichuan, China
| | - Chao Liu
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, 610065 Chengdu, Sichuan, China
| | - Xiao Tan
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, 610065 Chengdu, Sichuan, China
| | - Xueji You
- Department of Hydraulic Engineering, College of Civil Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Chaomeng Dai
- Department of Hydraulic Engineering, College of Civil Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Shuguang Liu
- Department of Hydraulic Engineering, College of Civil Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Jun Li
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, 610065 Chengdu, Sichuan, China.
| | - Naiwen Li
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, 610065 Chengdu, Sichuan, China
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Sun T, Huang J, Wu Y, Yuan Y, Xie Y, Fan Z, Zheng Z. Risk Assessment and Source Apportionment of Soil Heavy Metals under Different Land Use in a Typical Estuary Alluvial Island. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17134841. [PMID: 32635623 PMCID: PMC7369809 DOI: 10.3390/ijerph17134841] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 11/16/2022]
Abstract
Understanding the environmental risks of soil heavy metals (HMs) and identifying their main sources are the essential prerequisites for the prevention and management of soil pollution. Based on a detailed survey of soil HMs (Cu, Cr, Ni, Zn, Pb, Cd, As and Hg) from different land use types (including agricultural land, construction land, wetland, and forest land) in an estuary alluvial island, the environmental risk and source apportionment of soil HMs were investigated. Altogether, 117 soil samples were taken in the study area to appraise the soil HMs environmental risk by using the geo-accumulation index (Igeo), potential ecological risk index (RI), and human health risk assessment (HRA) and to identify its main sources by using positive matrix factorization (PMF) model. The average concentrations of soil HMs (except As) surpassed their reference background values in China. There were no significant differenced in the mean concentrations of HMs in different land use types, except that the Hg concentration in the construction land was significantly higher than that in others. The results of Igeo showed that Cd pollution was unpolluted to moderately polluted, and that the others were unpolluted. The potential ecological risk level for Cd and Hg was "moderated potential risk", while for Cu, Cr, Ni, Zn, Pb and As was "low potential risk". Higher contamination was distributed at the west-central area. The results of the HRA indicated that the non-carcinogenic risk and the carcinogenic risk that human beings suffered from HMs in different land uses were insignificant. To more accurately identify the sources of soil HMs, the PMF model coupled with the GIS-spatial analysis was applied. The results showed that agricultural activities, natural source, industrial discharge and river transportation, and atmosphere deposition were the main determining factors for the accumulation of soil HMs in the study area, with the contribution rate of 24.25%, 23.79%, 23.84%, and 28.12%, respectively. The study provides an underlying insight needed to control of the soil HM pollutions for an estuary alluvial island.
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You X, Liu S, Dai C, Zhong G, Duan Y, Tu Y. Acceleration and centralization of a back-diffusion process: Effects of EDTA-2Na on cadmium migration in high- and low-permeability systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 706:135708. [PMID: 31787287 DOI: 10.1016/j.scitotenv.2019.135708] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/01/2019] [Accepted: 11/21/2019] [Indexed: 06/10/2023]
Abstract
Pollutant accumulation in the low-permeability zones (LPZs) in groundwater systems is regarded as a secondary source, and its consequent back-diffusion can extend the timeframe of pump-and-treat remediation. However, the bioavailability and mobility of heavy metals and the medium characteristics can be changed during the process. This study investigated the accumulation and back-diffusion law of toxic metals and the effects of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) on them by implementing a series of tank experiments. In these experiments, a cadmium solution was injected first, and deionized water or EDTA-2Na constantly washed the system consisting of different medium layers. The experimental results showed that the cadmium breakthrough curves had some concentration gradient reverse points where the curves fluctuated with elution by deionized water, which did not exist when EDTA-2Na was the eluent. In these scenarios, the mass of accumulated cadmium in the media before elution was large, with a value of 931 mg (153 mg/kg), when the low-permeability medium was clay. However, when EDTA-2Na was injected together with cadmium, the value dropped to 319 mg (52.3 mg/kg), greatly reducing the cadmium accumulation. Additionally, the use of EDTA-2Na as an eluent resulted in the appearance of a secondary peak in the breakthrough curve, showing that EDTA-2Na accelerated and centralized the back-diffusion. Notably, the reduced cadmium accumulation in LPZs with the elution by EDTA-2Na was partly due to a reduced adsorption capacity of the clay minerals. The above results can advance the technology related to pump-and-treat remediation.
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Affiliation(s)
- Xueji You
- Department of Hydraulic Engineering, College of Civil Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Shuguang Liu
- Department of Hydraulic Engineering, College of Civil Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; The Yangtze River Water Environment Key Laboratory of the Ministry of Education, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Chaomeng Dai
- Department of Hydraulic Engineering, College of Civil Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
| | - Guihui Zhong
- Department of Hydraulic Engineering, College of Civil Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yanping Duan
- School of Environmental and Geographical Sciences, Shanghai Normal University, No. 100 Guilin Road, Shanghai 200234, China.
| | - Yaojen Tu
- School of Environmental and Geographical Sciences, Shanghai Normal University, No. 100 Guilin Road, Shanghai 200234, China
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Zhang X, Yang H, Cui Z. Migration and speciation of heavy metal in salinized mine tailings affected by iron mining. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 76:1867-1874. [PMID: 28991801 DOI: 10.2166/wst.2017.369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The negative effects of heavy metals have aroused much attention due to their high toxicity to human beings. Migration and transformation trend of heavy metals have a close relationship with soil safety. Researching on migration and transformation of heavy metals in tailings can provide a reliable basis for pollution management and ecosystem restoration. Heavy metal speciation plays an important role in risk assessment. We chose Anshan tailings for our study, including field investigations and laboratory research. Four typical heavy metal elements of mine tailings {Fe (373.89 g/kg), Mn (2,303.80 mg/kg), Pb (40.99 mg/kg) and Cr (199.92 mg/kg)} were studied via Tessier test in vertical and horizontal direction. The main speciation of heavy metals in Anshan tailings was the residual. However, heavy metals have a strong ability for migration and transformation in vertical and horizontal directions. Its tendency to change from stable to unstable speciation results in increasing bioavailability and potential bioavailability. Fe, Mn, Pb and Cr showed different ability in the migration and transformation process (Mn > Pb > Fe > Cr) depending on the characteristics of heavy metals and physicochemical properties of the environment.
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Affiliation(s)
- Xu Zhang
- School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China E-mail: ; Xu Zhang and Huanhuan Yang contributed equally to this work
| | - Huanhuan Yang
- School of Life Science, Shandong University, Ji'nan 250100, China; Xu Zhang and Huanhuan Yang contributed equally to this work
| | - Zhaojie Cui
- School of Environmental Science and Engineering, Shandong University, Ji'nan 250100, China E-mail:
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