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Sima J, Wang J, Song J, Du X, Lou F, Pan Y, Huang Q, Lin C, Wang Q, Zhao G. Dielectric barrier discharge plasma for the remediation of microplastic-contaminated soil from landfill. CHEMOSPHERE 2023; 317:137815. [PMID: 36640970 DOI: 10.1016/j.chemosphere.2023.137815] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/19/2022] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
The huge amount of plastic waste accumulated in landfills has caused serious microplastic (MP) pollution to the soil environment, which has become an urgent issue in recent years. It is challenging to deal with the non-biodegradable MP pollutants in actual soil from landfills. In this study, a coaxial dielectric barrier discharge (DBD) system was proposed to remediate actual MP-contaminated landfill soil due to its strong oxidation capacity. The influence of carrier gas type, applied voltage, and air flow rate was investigated, and the possible degradation pathways of MP pollutants were suggested. Results showed the landfill soil samples contained four common MP pollutants, including polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC) with sizes ranging from 50 to 1500 μm. The MP pollutants in the soil were rapidly removed under the action of reactive oxygen species (ROS) generated by DBD plasma. Under the air flow rate of 1500 mL min-1, the maximum remediation efficiency represented by mass loss reached 96.5% after 30 min treatment. Compared with nitrogen, when air was used as the carrier gas, the remediation efficiency increased from 41.4% to 81.6%. The increased applied voltage from 17.5 to 24.1 kV could also promote the removal of MP contaminants. Sufficient air supply was conducive to thorough removal. However, when the air flow rate reached 1500 mL min-1 and continued to rise, the final remediation efficiency would be reduced due to the shortened residence time of ROS. The DBD plasma treatment proposed in this study showed high energy efficiency (19.03 mg kJ-1) and remediation performance (96.5%). The results are instructive for solving MP pollution in the soil environment.
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Affiliation(s)
- Jingyuan Sima
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jun Wang
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China; Jiaxing Research Institute, Zhejiang University, Jiaxing, 314000, China.
| | - Jiaxing Song
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xudong Du
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Fangfang Lou
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yuhan Pan
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Qunxing Huang
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Chengqian Lin
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China; Jiaxing Research Institute, Zhejiang University, Jiaxing, 314000, China
| | - Qin Wang
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Guangjie Zhao
- China United Engineering Corporation Limited, Hangzhou, 310051, China
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Guo X, Hu H, Meng H, Liu L, Xu X, Zhao T. Vertical distribution and affecting factors of Escherichia coli over a 0-400 cm soil profile irrigated with sewage effluents in northern China. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 205:111357. [PMID: 32979799 DOI: 10.1016/j.ecoenv.2020.111357] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/28/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
Quantification and evaluation of the spatial distribution and the primary factors that affect Escherichia coli (E. coli) distribution in soils is important to assess soil pollution and potential contamination of groundwater. However, little information is available on distribution of E. coli in deep soil layers. To analyze the spatial distribution and factors affecting E. coli over a 0-400 cm soil profile, soil samples were collected from two land use type in the sewage irrigation fields. The primary factors dominating the spatial distribution of E. coli were quantified by the model of principal component analysis with multiple linear regression (PCA-MLR). The results indicated that the number of E. coli under cropland decreased greatly with soil depth. The average number of E. coli over the 0-400 cm profile under forestland was 49 × 104 colony-forming unit/g (cfu/g), which was significantly higher than that under cropland (20 × 104 cfu/g). For forestland and cropland, the average number of E. coli at depths of 300-400 cm decreased by 85% and 88%, respectively, compared to that at depths of 0-100 cm. The presence of E. coli at the depths of 300-400 cm was at high level (forestland: 3 × 104 cfu/g; cropland: 2 × 104 cfu/g) for the potential risks of shallow groundwater. The PCA-MLR model estimated that the factors of soil organism, soil salt and land type use contributed 28%, 29% and 43%, respectively, to the distribution of E. coli. According to the Monte Carlo simulation, the average number of E. coli over the 0-400 cm profile was 46 ± 17 × 104 cfu/g in the sewage irrigated area, and the interval distribution with a probability of 95% varied between 14 × 104 cfu/g and 78 × 104 cfu/g. The findings of this study are useful for understanding negative effects of sewage irrigation on pathogens in deep soil and are critical to assess the potential risks of groundwater pollution.
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Affiliation(s)
- Xiaoming Guo
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo, 454003, China.
| | - Hui Hu
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo, 454003, China
| | - Hongqi Meng
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo, 454003, China
| | - Lin Liu
- Nanjing Center, China Geological Survey, Nanjing, 210016, China
| | - Xiaotao Xu
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo, 454003, China
| | - Tongqian Zhao
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo, 454003, China.
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Guo X, Zhao T, Liu L, Xiao C, He Y. Effect of Sewage Irrigation on the CT-Measured Soil Pore Characteristics of a Clay Farmland in Northern China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15051043. [PMID: 29789473 PMCID: PMC5982082 DOI: 10.3390/ijerph15051043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/10/2018] [Accepted: 05/17/2018] [Indexed: 11/16/2022]
Abstract
Sewage irrigation has a strong influence on the physical, chemical, and biological properties of soil. However, the effects of sewage irrigation on the pore characteristics of soil are not well understood. This study compares the effects of sewage irrigation and groundwater irrigation on computed tomography (CT)-measured pore parameters and examines the relationships between CT-measured pore parameters and soil physicochemical and microbial properties. Intact soil cores were collected from S1 irrigated with sewage for 25 years, S2 irrigated with sewage for 52 years, and CK irrigated with groundwater. Various soil pore characteristics were determined, including the total pore number, macropore number (>1 mm diam.), coarse mesopore number (0.264⁻1 mm diam.), total porosity, macroporosity, coarse mesoporosity, and circularity. The results indicated that sewage irrigation significantly affected soil pore number and porosity. Compared with S1 and S2, CK exhibited a higher average total pore number (91), macropore number (40), coarse mesopore number (51), total porosity (2.08%), macroporosity (1.90%), and coarse mesoporosity (0.18%) throughout the 50⁻350 mm layer. At depths of 200⁻350 mm, S2 exhibited the lowest average total pore number (33), macropore number (13), coarse mesopore number (21), total porosity (0.42%), macroporosity (0.35%), and coarse mesoporosity (0.07%) among the three sites. In addition, the average pore numbers and porosity at depths of 200⁻350 mm decreased with increasing sewage irrigation time. There were significant positive correlations between pore features (including pore numbers and porosity) and soil properties (phosphorus content and fungi numbers). Our results suggest that decreased macropore numbers and macroporosity in the sewage-irrigated farmland may strongly intensify the accumulation of metals and nutrients in the upper layer. The findings of this study are useful for understanding the negative effects of sewage irrigation on soil pore structure and are critical for developing sustainable strategies in agriculture.
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Affiliation(s)
- Xiaoming Guo
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo 454003, China.
| | - Tongqian Zhao
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo 454003, China.
| | - Lin Liu
- Nanjing Center, China Geological Survey, Nanjing 210016, China.
| | - Chunyan Xiao
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo 454003, China.
| | - Yuxiao He
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo 454003, China.
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Characteristics of soil C:N ratio and δ 13C in wheat-maize cropping system of the North China Plain and influences of the Yellow River. Sci Rep 2017; 7:16854. [PMID: 29203811 PMCID: PMC5715070 DOI: 10.1038/s41598-017-17060-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/17/2017] [Indexed: 11/08/2022] Open
Abstract
To better understand the characteristics of soil organic matter (SOM) in the North China Plain, we evaluate the large scale variations of soil organic carbon (SOC), total nitrogen (TN), carbon to nitrogen (C:N) ratio and stable carbon isotopic compositions (δ13C) in SOC over 0-100 cm. To assess the influence of the Yellow River, 31 sites are selected from the wheat-maize double cropping system, and grouped into two: 10 sites near and 21 sites far from the river. Our data show that mean soil C:N ratio is low (7.6-9.9) across the region, and not affected by the Yellow River. However, SOC and TN are significantly (P < 0.05) lower in subsoil near the Yellow River (2.0 and 0.2-0.3 g kg-1 for SOC and TN) than far away (3.1 and 0.4 g kg-1); δ13C is significantly more negative below 60 cm near the river (-23.3 to -22.6‰) than far away (-21.8 to -21.4‰). We estimate that the contributions of wheat and maize to SOC are 61.3-68.1% and 31.9-38.8%, respectively. Our analyses indicate that the overall low levels of SOC in the North China Plain may be associated with the low soil C:N ratio and less clay content. The hydrological processes may also partly be responsible, particularly for those near the Yellow River.
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Yang P, Ge J, Yang M. Identification of Heavy Metal Pollution Derived From Traffic in Roadside Soil Using Magnetic Susceptibility. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2017; 98:837-844. [PMID: 28374112 DOI: 10.1007/s00128-017-2075-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 03/28/2017] [Indexed: 06/07/2023]
Abstract
The study integrates surface and vertical distribution of magnetic susceptibility and heavy metal contents (Pb, Cu, Zn and Fe) to characterize the signature of vehicle pollutants in roadside soils at Linfen city, China. Sites with reforestation and without vegetation cover were investigated. The results showed that magnetic susceptibility and heavy metal contents were higher at the roadside without trees than in the reforest belt. The variations of magnetic susceptibility and heavy metal contents decreased both with distance and with depth. The maximum value was observed at 5-10 m away from the roadside edge. The vertical distribution in soil revealed accumulation of pollutants in 0-5 cm topsoils. The average contents were higher than the background values and in the order Fe (107.21 g kg-1), Zn (99.72 mg kg-1), Pb (90.99 mg kg-1), Cu (36.14 mg kg-1). Coarse multi domain grains were identified as the dominating magnetic particles. Multivariate statistical and SEM/EDX analyses suggested that the heavy metals derived from traffic sources. Trees act as efficient receptors and green barrier, which can reduce vehicle derived pollution.
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Affiliation(s)
- Pingguo Yang
- College of Life Sciences, Shanxi Normal University, Linfen, 041000, China.
| | - Jing Ge
- College of Life Sciences, Shanxi Normal University, Linfen, 041000, China
| | - Miao Yang
- College of Arts and Sciences, Shanxi Agricultural University, Taigu, 030800, China
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