Research on Acidic Stability of Immobilized Heavy Metals in Sediment from Polluted River

• 作者: Deqin ZHAI Dingpeng XIONG Shuo TAN Yuxi YANG
• 来源期刊: 气象与环境研究:英文版
• 学科: 工学
• 关键词: Treated SEDIMENT Heavy metals SOLIDIFICATION/STABILIZATION Buffer capacity SOLIDIFICATION STABILITY
• 年，卷（期）: 2020,（2）
• 页码范围: 76-81
• 页数: 6页
• 分类号: TG1

摘要

The heavy metals can accumulate in sediment after discharged into surface water bodies. Before the sediment can be further landfilled or recycled,a large amount of heavy metal in it needs to be treated,known as solidification/stabilization. The properties of treated sediment may change with environment such as acid rain and landfill time,which may lead to the release of heavy metals from treated sediment into environment,posing great risks to environment and human health. In this study,the quantitative relationship has been tested between the dissolution of heavy metals from treated sediment and the p H of the leaching solution,by changing the p H of the treated sediment-leaching solution continuously. The results showed that when the p H of the treated sediment-leaching solution was higher than 5. 5,the heavy metals released from the treated sediment into solution were relatively low;when the p H of the treated sediment-leaching solution dropped to about 5. 5,a large amount of Cu,Zn,Ni and other heavy metals were released. The solidification of Cu,Zn,Cr and Cd in the treated sediment is relatively stable,while that of Ni and Pb still need to be improved. The buffer capacity of the treated sediment to acid is 0. 999 meq/g,which means it has relatively high capacity to buffer the pH change caused by external acid.