|
| Control effects of column leaching combined with mercapto-modified palygorskite immobilization on weakly alkaline Cd and Pb-contaminated soils |
| Received:August 27, 2019 |
| View Full Text View/Add Comment Download reader |
| KeyWord:alkaline soil;Cd and Pb contamination;column leaching;chelators;mercapto-modified palygorskite;immobilization |
| Author Name | Affiliation | E-mail | | WANG Ya-le | Agro-environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China | | | XU Ying-ming | Agro-environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China | ymxu1999@126.com | | PENG Yun-ying | Agro-environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China | | | ZHAO Li-jie | Agro-environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China | | | QIN Xu | Agro-environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China | | | HUANG Qing-qing | Agro-environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China | |
|
| Hits: 1549 |
| Download times: 1665 |
| Abstract: |
| In order to study the control technology for Cd and Pb-contaminated soils, column leaching and immobilization experiments with mercapto-modified palygorskite(MPAL) were conducted to investigate the remediation effects of combined technologies on weakly alkaline contaminated soils. The results showed that ethylenediaminetetraacetic acid(EDTA) and ethylenediamine disuccinic acid(EDDS) were better than L-glutamic acid N,N-diacetic acid(GLDA) in extracting Cd and Pb, and the suitable extraction concentration was 3 mmol·L-1. The leaching efficiencies of Cd and Pb in EDTA were 58.60% and 30.60% and those in EDDS were 44.78% and 24.33%, respectively. With the increase in the leachate volume, the pH of the leachate increased slowly and gradually stabilized after 400 mL. Compared with the original soil, DTPA-Cd and DTPA-Pb in the soil after H2O, EDTA, GLDA, and EDDS-assisted leaching declined by 32.09% and 16.08%, 67.16% and 33.64%, 33.58% and 18.93%, and 75.37% and 51.15%, respectively. Then, the soil after column leaching was remediated by MPAL with a dosage of 0.3%. In comparison with H2O+MPAL, DTPA-Cd, and DTPA-Pb in EDTA+MPAL, GLDA+ MPAL and EDDS+MPAL declined by 98.26% and 48.01%, 97.88% and 45.80%, 98.26% and 55.59%, respectively. MPAL could convert exchangeable and carbonate-bound Cd and Pb into Fe/Mn oxide-bound fractions in the soil. The results revealed that EDDS+MPAL could significantly decrease the total amounts and exchangeable concentrations of Cd and Pb in the soil. The combined methods could complete the goal of reducing the total amount of heavy metals and further decreasing the bioavailability of residual heavy metals in Cd and Pb-contaminated alkaline soils. |
|
|
|
