Zhang Hongling, Sun Lina, Sun Tieheng
Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
J Environ Sci (China). 2008;20(6):710-6. doi: 10.1016/s1001-0742(08)62117-8.
Stabilized sewage sludge (SS) by fly ash (FA) and alkaline mine tailing as artificial soil, to be applied on the ecological rehabilitation at mining junkyards, offers a potentially viable utilization of the industrial by-product, as well as solves the shortage of soil resource in the mine area. An incubation experiment with different ratios of SS and FA was conducted to evaluate the solubility of ions and trace elements from stabilized sewage sludge. Results showed that fly ash offset a decrease in pH value of sewage sludge. The pH of (C) treatment (FA:SS = 1:1) was stable and tended to neutrality. The SO4(2-) and Cl- concentrations of the solution in the mixture were significantly decreased in the stabilized sewage sludge by alkaline fly ash and mine tailing, compared to the single SS treatment. Stabilized sewage sludge by FA weakened the nitrification of total nitrogen from SS when the proportion of FA in the mixture was more than 50%. The Cr, Ni, and Cu concentrations in the solution were gradually decreased and achieved a stable level after 22 days, for all treatments over the duration of the incubation. Moreover stabilized sewage sludge by fly ash and/or mine tailing notably decreased the trace metal solubility. The final Cr, Cu, and Ni concentrations in the solution for all mixtures of treatments were lower than 2.5, 15, and 50 microg/L, respectively.
用粉煤灰（FA）和碱性尾矿稳定化的污水污泥（SS）作为人造土壤应用于采矿垃圾场的生态修复，既为工业副产品提供了一种潜在可行的利用方式，又解决了矿区土壤资源短缺的问题。进行了不同比例的污水污泥和粉煤灰的培养实验，以评估稳定化污水污泥中离子和微量元素的溶解性。结果表明，粉煤灰抵消了污水污泥pH值的下降。（C）处理（粉煤灰：污水污泥 = 1:1）的pH值稳定且趋于中性。与单一污水污泥处理相比，碱性粉煤灰和尾矿稳定化的污水污泥中混合溶液的SO4(2-)和Cl-浓度显著降低。当混合物中粉煤灰的比例超过50%时，粉煤灰稳定化的污水污泥会削弱污水污泥中总氮的硝化作用。在培养期间，所有处理的溶液中Cr、Ni和Cu的浓度逐渐降低，并在22天后达到稳定水平。此外，粉煤灰和/或尾矿稳定化的污水污泥显著降低了痕量金属的溶解性。所有处理混合物溶液中最终的Cr、Cu和Ni浓度分别低于2.5、15和50微克/升。
