CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Zhenlei Wang,Tingting Zhang,Yunliang Zhao,Yanhui Miao,Lingjie Zhang,Damiano Sarocchi,Shaoxian Song,Qiwu Zhang
Large scale of Cd-contaminated soil has become a serious threat to environmental safety and human health, whereas field applicability of existing remediation technologies has encountered numerous obstacles, such as poor stability, secondary pollution, long operation time, and high chemical cost. Herein, a novel activated calcite with significantly enhanced immobilization stability of Cd in soil has been synthesized based on mechanochemical technology. Our results demonstrate that the passivation rate of bioavailable Cd in Cd-contaminated soil (initial concentration 3 mg/kg) could be maintained at 65 % after 50 days of passivation cultured with activated calcite. Mechanistic studies have revealed that the outstanding performance is attributed to the enhancement of the CO 3 2– and Ca 2+ release properties of calcite through mechanical activation, leading to a 550 % increase in Ca 2+ release. The CO 3 2– fraction binds in situ to the free Cd in the soil, forming a stable carbonate-bound state. Simultaneously, the OH – released from the continuous hydrolysis of CO 3 2– effectively regulates and stabilizes the soil pH within the neutral range. Further, SEM-EDS and sequential extraction procedures (SEP) analyses implied that the specific adsorption of Cd by in-situ formed iron oxides in soil was visibly related to the release of OH – from activated calcite and immobilized the free state Cd in the more stable iron oxide-bound state. The current work shows the high sustainability and stability of Cd-contaminated soil immobilization by activated calcite materials.
研究领域:
环境科学
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土壤修复
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Yutong Li,Xiaoxiao Ma,Yile Du,Shuangli Chen,Pingping Wu,Sijing Zhang
The immobilization of cadmium in soil to reduce its bioavailability is a common approach in soil remediation . However, fluctuations in soil pH, redox potential , and microbial activity can still lead to cadmium release. To address this challenge, MgFe 2 O 4 /chitosan carbon aerogel beads (MCSCA) were synthesized for in-situ remediation to remove Cd from the soil. A two-week remediation period was conducted to assess the effectiveness of MCSCA in Cd-contaminated soil. Different proportions (1%, 2%, and 3% by soil weight) of MCSCA were incorporated into the soil for remediation, followed by MCSCA separation through water flotation . The results demonstrated that after three remediation cycles, 55.46%, 72.27%, and 75.70% of the total cadmium were removed by 1%, 2%, and 3% MCSCA additions, respectively, corresponding to the removal of 76.51%, 87.39%, and 90.28% of bioavailable cadmium. Regeneration of MCSCA was accomplished using 0.1 M HCl , achieving cadmium desorption rates of 97.14%, 96.43%, and 90.48% for 1%, 2%, and 3% MCSCA additions, respectively. The regenerated MCSCA maintained higher remediation efficiency, removing 62.72%, 75.20%, and 80.96% of bioavailable cadmium even after three cycles, with MCSCA recovery rates of 94.40%, 92.30%, and 91.40%, respectively. In a pot experiment, pakchoi plants grown in soil post three rounds of remediation with different ratios (1%, 2%, and 3%) of MCSCA xhibited reductions in total cadmium content by 44.75%, 59.38%, and 69.88%, respectively, compared to plants grown in Cd-contaminated soil. In summary, this study underscores the effectiveness of MCSCA in remediating Cd-contaminated soils, offering a promising approach for soil remediation.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）