State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
J Hazard Mater. 2013 Sep 15;260:74-81. doi: 10.1016/j.jhazmat.2013.04.006. Epub 2013 Apr 29.
The primary goal of this research is to investigate the stabilization of heavy metals in lightweight aggregate (LWA) made from sewage sludge and river sediment. The effects of the sintering temperature, the (Fe₂O₃+CaO+MgO)/(SiO₂+Al₂O₃) ratio (K ratio), SiO₂/Al₂O₃ and Fe₂O₃/CaO/MgO (at fixed K ratio), pH, and oxidative conditions on the stabilization of heavy metals were studied. Sintering at temperatures above 1100 °C effectively binds Cd, Cr, Cu and Pb in the LWA, because the stable forms of the heavy metals are strongly bound to the aluminosilicate or silicate frameworks. Minimum leachabilities of Cd, Cr, Cu and Pb were obtained at K ratios between 0.175 and 0.2. When the LWA was subjected to rigorous leaching conditions, the heavy metals remained in the solid even when the LWA bulk structure was broken. LWA made with sewage sludge and river sediment can therefore be used as an environmentally safe material for civil engineering and other construction applications.
本研究的主要目的是研究从污水污泥和河泥制成的轻集料（LWA）中稳定重金属。研究了烧结温度、（Fe₂O₃+CaO+MgO）/（SiO₂+Al₂O₃）比（K 比）、SiO₂/Al₂O₃ 和 Fe₂O₃/CaO/MgO（在固定 K 比下）、pH 值和氧化条件对重金属稳定化的影响。在 1100°C 以上的温度下烧结可以有效地将 LWA 中的 Cd、Cr、Cu 和 Pb 固定，因为重金属的稳定形态与铝硅酸盐或硅酸盐骨架紧密结合。在 K 比为 0.175 到 0.2 之间时，Cd、Cr、Cu 和 Pb 的浸出率最低。当 LWA 受到严格的浸出条件时，即使 LWA 大块结构被破坏，重金属仍留在固体中。因此，用污水污泥和河泥制成的 LWA 可以用作土木工程和其他建筑应用的环境安全材料。
