熟污泥改性黄土对铜的吸附解吸特征

为探明熟污泥改性黄土对重金属的容纳能力,以熟污泥改性黄土为供试土样,采用序批实验法研究了供试土样对铜(Cu)的吸附解吸特征,并分析了供试土样对铜的固定能力及影响因素.供试土样对铜的吸附量在铜添加浓度小于100mg/L时急剧增加,在铜添加浓度大于100mg/L时增加缓慢,而解吸量的变化趋势则恰恰相反.Langmuir型吸附等温式是描述供试土样对铜的吸附过程的最佳模型,而吸附量与解吸量的关系可以很好的用指数函数来描述.供试土样对铜的固定吸附量随熟污泥含量的增加而增加,有机质含量是决定性因素.

Sorption and desorption of copper in loess improved by composted sludge

To seek the heavy metal fixed sorption ability of selected soils, the loess improved by composted sludge was collected as study soil. Laboratory batch experiments were conducted to study the sorption and desorption of copper (Cu) on tested soils, and the fixed copper and influence factors were also studied. The copper sorbed by tested soils increased dramatically when initial copper concentration was less than 100mg/L, but it increased slowly when initial copper concentration was more than 100mg/L. The changing trend of desorption was contrary to the changing trend of sorption. Langmuir model well described equilibrium isotherms of copper sorption, and the exponential model well described the relation of sorption and desorption. As the composted sludge concentration increased, the fixed copper on soil samples increased, and the determining factor was the organic matter concentration.