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Zhang W, Yu H, Huang J, Jiao W. Influence of pH on the leaching behavior of a solidified arsenic contaminated soil. ENVIRONMENTAL TECHNOLOGY 2024; 45:4169-4180. [PMID: 37540778 DOI: 10.1080/09593330.2023.2243392] [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: 03/07/2023] [Accepted: 07/18/2023] [Indexed: 08/06/2023]
Abstract
Stabilization/solidification is widely used for treatment of arsenic (As)-contaminated soils. The stability of the soil may deteriorate significantly when exposed to acid or alkaline leachate. In this study, semi-dynamic leaching tests under different pH were carried out to investigate the leaching behavior of As from the solidified soils. Spectroscopic and microscopic analyses were performed to reveal the related mechanisms. The results showed that the leaching of As was closely correlated with the pH of the leachate, because the encapsulation effect of the cementitious matrix and the chemical speciation and valence of As were all significantly influenced by pH. In the strongly acidic leachant (pH 3.0), the leached As concentration increased by an order of magnitude, and the effective diffusion coefficient of As reached 3.71 × 10-13 m2/s. This is because that pores and cracks increased owing to the acidic corrosion of CSH, such that the physical encapsulation effect was reduced and the mobility of As increased. The leachability index showed that the solidified soil was unsuitable for 'controlled utilization' under strongly acidic conditions. The leached As concentration was the lowest in the weakly alkaline leachant (pH 9.0) because under weakly alkaline conditions the hydration process of the cement was facilitated, and more CSH gels were attached to the surface of the soil particles, forming a tighter structure for As encapsulation. However, as pH increased from 9.0-11.0 the leached As concentration increased due to an increased content of As(III)-O in the solidified soil.
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Affiliation(s)
- Wenjie Zhang
- College of Civil and Architectural Engineering, Taizhou University, Taizhou, People's Republic of China
| | - Haisheng Yu
- Shanghai Construction Group Co., Ltd., Shanghai, People's Republic of China
| | - Jinxiang Huang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, People's Republic of China
| | - Weiguo Jiao
- Department of Civil Engineering, Guizhou Institute of Technology, Guiyang, People's Republic of China
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Li M, Zhou J, Cheng Z, Ren Y, Liu Y, Wang L, Cao L, Shen Z. Pollution levels and probability risk assessment of potential toxic elements in soil of Pb-Zn smelting areas. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:165. [PMID: 38592368 DOI: 10.1007/s10653-024-01933-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 02/21/2024] [Indexed: 04/10/2024]
Abstract
Soil pollution around Pb-Zn smelters has attracted widespread attention around the world. In this study, we compiled a database of eight potentially toxic elements (PTEs) Pb, Zn, Cd, As, Cr, Ni, Cu, and Mn in the soil of Pb-Zn smelting areas by screening the published research papers from 2000 to 2023. The pollution assessment and risk screening of eight PTEs were carried out by geo-accumulation index (Igeo), potential ecological risk index (PERI) and health risk assessment model, and Monte Carlo simulation employed to further evaluate the probabilistic health risks. The results suggested that the mean values of the eight PTEs all exceeded the corresponding values in the upper crust, and more than 60% of the study sites had serious Pb and Cd pollution (Igeo > 4), with Brazil, Belgium, China, France and Slovenia having higher levels of pollution than other regions. Besides, PTEs in smelting area caused serious ecological risk (PERI = 10912.12), in which Cd was the main contributor to PREI (86.02%). The average hazard index (HI) of the eight PTEs for adults and children was 7.19 and 9.73, respectively, and the average value of total carcinogenic risk (TCR) was 4.20 × 10-3 and 8.05 × 10-4, respectively. Pb and As are the main contributors to non-carcinogenic risk, while Cu and As are the main contributors to carcinogenic risk. The probability of non-carcinogenic risk in adults and children was 84.05% and 97.57%, while carcinogenic risk was 92.56% and 79.73%, respectively. In summary, there are high ecological and health risks of PTEs in the soil of Pb-Zn smelting areas, and Pb, Cd, As and Cu are the key elements that cause contamination and risk, which need to be paid attention to and controlled. This study is expected to provide guidance for soil remediation in Pb-Zn smelting areas.
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Affiliation(s)
- Mingyue Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Jinyang Zhou
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Zhiwen Cheng
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yuanyang Ren
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yawei Liu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Linling Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Liu Cao
- Jiyuan Industrial and Urban Integration Demonstration Zone Ecological Environment Bureau, Jiyuan, 459000, China
| | - Zhemin Shen
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai, 200233, People's Republic of China.
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Cheng F, Guo S, Zeng H, Wu B. Effect of electrokinetic process on in situ stabilization and detoxification of arsenic-contaminated soil with high content of calcium. ENVIRONMENTAL RESEARCH 2024; 241:117504. [PMID: 38173247 DOI: 10.1016/j.envres.2023.117504] [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: 07/05/2023] [Revised: 10/23/2023] [Accepted: 10/23/2023] [Indexed: 01/05/2024]
Abstract
Owing to the high risk of human exposure to arsenic-contaminated soil, reducing its toxicity is essential. This study used the electrokinetic (EK) process with iron-rich electrodes to synchronously achieve the accumulate, stabilize and detoxify soil arsenic. Changes in arsenic valence, leaching toxicity, and microbial communities related to toxicity were comprehensively considered. The results demonstrated that arsenic was mainly transported toward the anode and accumulated by electromigration owing to the negatively charged arsenic anions under EK conditions. The cathode approaching effectively promote arsenic movement to the anode; the largest As(T) transportation rate of 30.61% was achieved near the cathode (S4). The transportation ratio of As(III) was 1.84 times more than that of As(V). The As(III) content and leaching toxicity of soil arsenic in all treatments decreased after applying the EK process. In particular, the anode approaching effectively elevated the average ratios of soil As(III) oxidation and stabilization to 37.88% and 61.73%, respectively. Correspondingly, the total phospholipid fatty acid content increased substantially after EK treatment and showed a pollution stress elimination effect. The electrokinetic effect can essentially cause highly active and easily migrated arsenic to accumulate near the anode and middle sections. The electric field mediated iron mineralization and stabilized arsenic by oxidizing As(III) and reacting with newly formed iron-rich phases (S). Meanwhile, the electric field regulated the form of soil calcium from CaCO3 to CaSO4 and caused calcium-bound arsenic to change to a more stable form. According to these results, in situ stabilization and detoxification of arsenic-contaminated soil can be realized by the EK process, avoiding stabilizer addition and excavation.
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Affiliation(s)
- Fenglian Cheng
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process, Shenyang, 110016, China
| | - Shuhai Guo
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process, Shenyang, 110016, China.
| | - Hui Zeng
- Shenyang University of Chemical Technology, Shenyang, 110014, China
| | - Bo Wu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process, Shenyang, 110016, China
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Vinayagam S, Sathishkumar K, Ayyamperumal R, Natarajan PM, Ahmad I, Saeed M, Alabdallah NM, Sundaram T. Distribution and transport of contaminants in soil through mining processes and its environmental impact and health hazard assessment: A review of the prospective solutions. ENVIRONMENTAL RESEARCH 2024; 240:117473. [PMID: 37871785 DOI: 10.1016/j.envres.2023.117473] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/21/2023] [Accepted: 10/21/2023] [Indexed: 10/25/2023]
Abstract
Environmental regulations were concerned with support in reaction to the enormous ecological harm caused by mining in the past. Because mining, dumping, and tailings can generate waste and radioactive consequences, society must develop methods for successfully treating mining waste from mine dumps, tailings, and abandoned mines. Strict policies associated with environmental regulations to avoid the possible dangers caused by garbage and radioactivity. Several characteristics, including background contamination from natural sources related to mineral deposits, contamination from industrial activities in three-dimensional subsurface space, a problem with long-term remediation following mine closure, a problem with secondary contaminated areas near mine sites, land use conflicts, and abandoned mines, distinguish it. Reusing and recycling mine waste occasionally results in cost-effective advantages in the mining sector by offsetting natural resource requirements and reducing the volume of garbage materials. These benefits stem from recycling and reusing mining waste, which can lower the amount of garbage that must be managed. This review focuses on realistic strategies for anticipating mining exploration control and attempts to examine those methods in-depth. Management strategies for limiting the environmental impact of mining dumps, stockpiles, and tailings were discussed. The environmental assessment was also mentioned to carry out specific control and take preventive actions.
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Affiliation(s)
- Saranya Vinayagam
- Department of Biosciences, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, 602105, India
| | - Kuppusamy Sathishkumar
- Rhizosphere Biology Laboratory, Department of Microbiology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Ramamoorthy Ayyamperumal
- Key Laboratory of Western China's Environmental System, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Prabhu Manickam Natarajan
- Department of Clinical Sciences, Center of Medical and Bio-allied Health Sciences and Research, College of Dentistry, Ajman University, Ajman, United Arab Emirates
| | - Irfan Ahmad
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia
| | - Mohd Saeed
- Department of Biology, College of Sciences, University of Hail, Saudi Arabia
| | - Nadiyah M Alabdallah
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, 31441, Dammam, Saudi Arabia; Basic & Applied Scientific Research Centre, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam, 31441, Saudi Arabia
| | - Thanigaivel Sundaram
- Department of Biotechnology, Faculty of Science & Humanities, SRM Institute of Science and Technology, Chengalpattu District, Kattankulathur, Tamil Nadu, 603203, India.
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