重庆永川区城区河道疏浚淤泥处置问题的探讨

摘要

为探究重庆永川城区河道疏浚淤泥的处置问题,分析了城区河道的淤泥样品,以水泥为基材对不同初始含水率和水泥掺量的污染较为严重的临江河下游淤泥进行了固化处理,研究了固化淤泥的孔隙水重金属浓度和压缩特性.结果表明:临江河下游淤泥中的重金属含量最高,固化处理后淤泥孔隙水中Cu和Zn的浓度大幅降低,水泥掺量越大,淤泥含水率越小,固化处理后屈服应力越大.临江河下游疏浚淤泥固化处理时水泥掺量宜为100 kg/m3,堆场堆放时宜采用表面固化处理技术.%Urban dredged material of Yongchuan region were analyzed to explore the dispose and application of urban river sludge.Portland cement was used to modify the polluted dredged material in the downstream of Linjiang River with different initial water contents and cement contents.Heavy metal concentrations and compression features are analyzed.The following conclusions can be drawn from the results:the sludge in Linjiang River downstream is more polluted than other rivers.Dredged materials are heavily polluted by Cu.The concentration of Cu and Zn in the pore water is decreased linearly before cement content is 100 kg/m3,and the decrease rate slow down after 100 kg/m3.It is less than the environmental capacity of heavy metals when cement contents are more than 50 kg/m3.The yield stress of solidified dredged material increases with the increasing cement content and decreasing initial water content.The proper cement content of the dredged material in Linjiang River downstream is 100 kg/m3,solidification surface treatment of storage yards is preferred.