NIU Hua-peng1, LI Sheng-rong2, SHEN Jun-feng2
(1.China University of Petroleum, Beijing 102249, China;
2. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China)
Abstract: Land disposal of fly ash (FA) and sewage sludge (SS) is a major problem due largely to their potentially harmful constituents. Previous studies, however , showed that the combined use of FA and SS might help reduce the associated pollution potential. In this paper, pot-planting experiments were performed to evaluate the effects on the plant growth and heavy metal accumulation characteristics in the plants when soils were amended with the mixture of FA and SS. The results showed that the application of FA and SS was significantly capable of accelerating the growth of plants，and the nutrients could be released slowly. Analysis of heavy metals indicated that the contents of Pb, Cr, Hg, Cd, As, Ni, Cu and Zn came up to the second-class environmental quality standards of soil, and the mixture of FA and SS didn’t increase the capacity to transfer the heavy metals from soils to corns and the biological effectiveness. On the other hand, the contents of all the heavy metals in plant tissues were substantiallylower than their toxicity limits, and the values of S/R showed that the transfer ability of heavy metals in the plants was weak and the metals were mainly accumulated in roots. Consequently, the land application of FA-SS mixture might result in the accumulation of some heavy metals in plant tissues, but the probability of affecting human health through the food chains would be reduced considerably by selecting the plant whose fruit is above its root.
Key words: heavy metal; fly ash; sewage sludge; calcic soil; mining environmental remediation
EARTH AND ENVIRONMENT Vol. 39, No.3, Tot No.285, 2011, Page 371-375
