JOURNAL OF HAZARDOUS MATERIALS
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2022
·
IF 14.224
Yunhao Xie,Lun Lu,Baoliang Chen
The demands for genuine remediation of heavy metal contaminated soil have triggered extensive studies in the soil washing method. However, numerous soil washing methods show poor sustainability for target soil, due to the tremendous cost, hidden secondary pollution and severe soil deterioration. Here, an asymmetrical alternating current electrochemically-mediated remediation platform (ACRP) is developed by fabricating an amidoxime-functionalized electrode (Ami-electrode). The real soil contaminated with 1200 mg/kg Cr(VI) is remediated efficiently to less than safety level (30 mg/kg), meanwhile no exorbitant soil nutrient loss is observed and no secondary pollution occurs. Furthermore, the consumption of washing effluents for the ACRP method is 24 times lower than the traditional washing method. Ami-electrode with asymmetrical alternating current promote the electrocatalytic efficiency by inhibiting the Coulomb repulsion between Cr(VI) species and cathode. With the aid of Ami-electrode and positive bias, Cr(VI) species in effluents are adsorbed on chelating site. By subsequent negative bias, Cr element is reduced and recycled in the less hazardous form of amorphous Cr(III) hydroxide, and effluents are regenerate concurrently in a cyclic system. Durability experiment and cost calculation verify the exceptional sustainability and feasibility for remediation practices. This work provides a sustainable remediation method for Cr(VI)-contaminated soil, and then paves the way to develop electrochemically soil remediation platform for practical applications.
研究领域:
环境科学
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电化学
·
土壤修复技术
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DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2025
·
IF 5.4
Yongshan Ma,Qingxiang Guan,Huayun Zang,Fengxia Zhang,Tianyi Jiang,Xuemei Li,Yanyan Zhu
Solar-driven photocatalysis is a promising green technology for wastewater treatment. Molybdenum disulfide (MoS 2 ) is a highly efficient visible-light photocatalyst. However, due to the rapid recombination of photoinduced electron-hole (e - -h + ) pairs, its photocatalytic activity is severely limited, thereby hindering its practical application. To solve this problem, a novel MoS 2 -3,4,9,10-perylene tetracarboxylic acid (MoS 2 -PTCDG) heterojunction was synthesized via a hydrothermal method. In this composite, PTCDG nanosheets are embedded in the interlayer spaces of three-dimensional flower-like MoS 2 nanospheres, forming an organic–inorganic heterostructure. This design not only improves the separation efficiency of photogenerated e - -h + pairs, but also the hydrophilic terminal carboxyl groups on PTCDG can serve as adsorption sites for Cr(VI) pollutants. The MoS 2 -PTCDG composite demonstrates exceptional photocatalytic activity and stability in degrading Cr(VI) under simulated sunlight, achieving a reaction rate constant 2.5 times higher than that of pure MoS 2 . This study highlights the potential of rationally designed organic–inorganic heterostructures to overcome the limitations of traditional MoS 2 -based photocatalysts, thus offering new insights into the development of high-performance photocatalytic materials for environmental remediation.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Yuxin Liu,Qintie Lin,Jieyi Pan,Yirong Deng,Junli Zheng,Mingchao Lyu,Hao Luo,Yang Luo
The existing remediation technologies for Cr(VI) contamination soil suffer from long processing times. Microwave catalysis is an efficient environmental remediation technology, and the reasonable design of microwave catalysts can enable a microwave catalytic system to rapidly complete the remediation of Cr(VI). In this study, a microwave catalyst, NRFC-3, with high microwave absorption performance and electron density was designed via a nitrogen enrichment strategy. Density functional theory (DFT) calculations verified that the electron density of the material was increased by nitrogen-enriched strategy. Under the experimental conditions, the electrons (e − ) of NRFC-3 originate from “hot spots” and the current density is not lower than 3.78 × 10 9 e·g −1 ·s −1 . In addition, the reduction of Cr(VI) in the MW/NRFC-3 system is feasible through DFT predictions, and this conclusion was experimentally verified. The MW/NRFC-3 system has a remediation efficiency of 100 % for Cr(VI)-contaminated soil within 25 min, significantly reduced the toxicity of Cr(VI) to the environment and humans, and had long-term stability. The potential application of the MW/NRFC-3 system was verified by remediation experiments on Cr(VI)-contaminated soils of different degrees. This study provides a new technology for the rapid and harmless treatment of Cr(VI)-contaminated soil.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL ENGINEERING SCIENCE
·
2022
·Vol. 39
·期 1
·64-72
·
IF 2.172
Shaolin Tan,Yi Xin,Kun Liu,Enzhi Zhang,Shijie Li,Manqing Zhao,Huanfang Gao
In this article, low-molecular-weight organic acids were applied to remediate the hexavalent chromium [Cr(VI)]-contaminated soil. The influence of different parameters (washing concentration, solid–liquid ratio, time, and pH value) on the repair effect was explored, and the form distribution and desorption kinetic experiments of the soil were performed. The results show that the pH of eluents can significantly affect the form distribution of chromium, with the exchangeable form increasing considerably at a lower pH. The kinetics of Cr(VI) desorption can be described by the pseudo-second-order kinetics equation. The best washing scheme was determined to be the citric acid as the eluent at a concentration of 0.3 mol/L, a solid to liquid ratio of 1:10, pH 4, and a washing time of 6 h. The removal rate can be as high as 73.52%. After washing, the leaching concentration of Cr(VI) in the soil was reduced from 23.76 to 1.05 mg/L, well below the regulatory constraint of 5 mg/L. Additionally, the characterizations of X-ray diffractometer and scanning electron microscope showed little effect of adopting citric acid as a washing agent on soil structure and surface morphology. This study can provide a theoretical basis for the remediation of Cr(VI)-contaminated soil at industrial sites.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Hiba Shaghaleh,Yousef Alhaj Hamoud,Qin Sun,Mohamed S. Sheteiwy,Hamada AbdElgawad
Soil flushing and adsorption-based soil remediation are promising options for removing heavy metals in agricultural soil. However, they encounter limitations in low removal efficiency, secondary pollution potential, or the need for a purification/recovery process. Optimizing flushing solutions or the functional properties of adsorbents could fundamentally eliminate the drawbacks of these methods. Yet, their practical application remains a formidable challenge. Herein, a new combined remediation strategy of multiple-pulse water soil flushing (MF) with novel aminated cellulose nanofibers (A-NFCs)/AEM/AM@MIL-100(Fe) nanocomposite hydrogel adsorbent (ANCMH) was adopted to remove Cr(VI) from agricultural soil. The characteristic analyses approved Cr(VI) adsorption-coupled reduction/swelling-based mechanisms on ANCMH with the maximum theoretical adsorption capacity of 338.24 mg g −1 at pH 6.8 governed by pseudo-second-order and Freundlich models. Instead of conventional MF application using environmentally problematic extractant fluids, a 5-day soil column simulation trial of MF coupled with ANCMH adsorbent layers (MF@ANCMH) was applied in medium-to-highly Cr(VI)-contaminated soil followed by easy ANCMHs separation, preventing secondary pollution. Innovatively, the water flushing-stop flux events favorably decreased the pH of neutral soil by 0.83 folds and allowed Cr(VI) release from the soil matrix to be adsorbed by ANCMHs, achieving a high Cr(VI) removal efficiency of 98.9 %. Compared to the soil treated with ANCMH individually and soil flushed with water or Na 2 EDTA, the MF@ANCMH-treated soil reached the corresponding regulation of permissible levels for Cr(VI) residential scenarios in agricultural soil of 5.6 ppm with 3-cycles of ANCMH reuse. The residual Cr in MF@ANCMH-remediated soil displayed minimal bioavailability at root-zoon soil of ≤4.2 ppm and a 97.66 % reduction in its exchangeable-carbonate fraction compared to untreated soil, corresponding to a risk assessment code score below 1 %. Also, the application of MF@ANCMH resulted in Cr bioaccumulation below 0.1 ppm in cultivated wheat plants, prevented the physiological phytotoxicity symptoms, and elevated their antioxidant enzyme activity, photosynthesis, growth, and yielding indicators compared to that grown in untreated soil. Furthermore, it improved soil organic matter, microbial community, diversity, and microecological functions. This study provides a promising alternative remediation strategy for neutral soil that can maintain soil/crop quality and soil health with high chemical/environmental stability of pollutants after remediation, demonstrating its sustainability and feasibility in agricultural soil.
研究领域:
环境科学
·
土壤学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Xingyu Liu,Lei Yang,Haitong Zhao,Wei Wang
The pollution of hexavalent chromium (Cr(VI)) in soil is a serious environmental issue. Herein, nanoscale zero-valent iron (NZVI) supported on rice husk-derived biochar (RBC) was employed as an efficient remediation material to minimize the harm of Cr(VI) in soil. A one-step carbothermal reduction method was used instead of the conventional wet chemistry method for material preparation in this study. Rice husk, an agricultural waste, was adopted as the carbon source (reductant) and support for nanometal synthesis simultaneously, so that the NZVI could be in-situ generated on the acquired biochar during the pyrolysis process. By pyrolyzing at 800 °C, the obtained biochar-supported nanoscale zerovalent iron (NZVI-RBC) exhibited high thermal stability and oxidation resistance. In the treatment of contaminated soil, the Cr(VI) no longer leached out from the soil after a complete removal of Cr(VI) (62.4 mg/L) from soil leachate in 120 min when the used NZVI-RBC dosage was above 8% of the soil in weight. This long-term remediation effect of NZVI-RBC may be related to the electron shuttle function of biochar. Furthermore, the bioavailability of Cr in the contaminated soil was significantly decreased. The present study provided a simple, feasible, and sustainable alternative to make full use of the agricultural waste resource to synthesize composite remediation agent containing NZVI and remediate Cr(VI) contaminated groundwater and soil.
研究领域:
环境科学
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纳米技术
·
土壤学
·
废物管理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）