Pedosphere 19(2): 137--142, 2009
ISSN 1002-0160/CN 32-1315/P
©2009 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Extraction of cadmium from sewage sludge using polyepoxysuccinic acid |
| ZHU Zhi-Liang1, ZHANG Li-Hua1,2, ZHANG Hua1, QIU Yan-Ling1, ZHANG Rong-Hua1 and ZHAO Jian-Fu1 |
1 State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China);
2 Chemistry and Biology Engineering Department, Sanming College, Sanming 365004 (China) |
| ABSTRACT |
| Polyepoxysuccinic acid (PESA), as an environmental benign biodegradable chelant, was used to remove heavy metals from the sewage sludge of Shanghai Taopu Wastewater Treatment Plant. The extraction of cadmium (Cd) from sewage sludge using aqueous solution of PESA was studied. It was found that PESA was capable of extracting Cd from the sludge, and the extraction effciency was dependent on both pH and the concentration of the chelating reagent. The extraction effciency decreased gradually with increasing of pH, whereas the dependency on pH decreased as the concentration of PESA increased. In the case of the high PESA to total metal ratio, e.g., 10:1, the extraction effciency reached above 70% within the pH range from 1 to 7. The highest extraction effciency obtained in the experiment was 78%. By comparing the contents of the heavy metals in sewage sludge before and after the extraction, it was found that the extracted Cd came mainly from the four fractions: acid-soluble, reducible, oxidizable, and water-soluble fractions. |
| Key Words: cadmium, extraction, PESA, sewage sludge |
| Citation: Zhu, Z. L., Zhang, L. H., Zhang, H., Qiu, Y. L., Zhang, R. H. and Zhao, J. F. 2009. Extraction of cadmium from sewage sludge using polyepoxysuccinic acid. Pedosphere. 19(2): 137-142. |
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