某电路板遗留场地重金属复合污染土壤淋洗效果研究

Study on Leaching Effect of Heavy Metal Complex Contaminated Soil in A Circuit Board Site

针对线路板生产过程造成的铜镍复合污染土壤,以草酸、柠檬酸、乙酸、EDTA-2Na为淋洗剂,研究药剂类型、水土比、淋洗管摆放方式、淋洗时间对淋洗效果的影响。结果表明:(1)不同淋洗剂对土壤重金属去除效果有所差异,对铜表现为:柠檬酸>乙酸>EDTA-2Na>草酸;对镍表现为:乙酸>柠檬酸>草酸>EDTA-2Na;(2)淋洗管的放置方式对铜淋洗效率有较大影响,表现为横放>竖放,但对镍淋洗效率影响较小;(3)适当增加水土比对重金属淋洗效率有促进作用;(4)淋洗时间对本项目铜镍的淋洗去除效率影响较小。

In view of copper-nickel composite contaminated soil caused by circuit board production, oxalic acid, citric acid, acetic acid and EDTA-2 NA were used as leaching agents to study the effects of reagent type, soil and water ratio, leaching tube placement and leaching time on leaching effect.The results showed that different leaching agents had different removal effects on soil heavy metals, For copper, citric acid>acetic acid>EDTA-2 Na>oxalic acid, For nickel, acetic acid>citric acid>oxalic acid>EDTA-2 Na. The placement of the leaching tube had a great influence on the leaching efficiency of copper, in the order of horizontal>vertical, but had little influence on the leaching efficiency of nickel. Appropriately increasing the soil/water ratio can promote the leaching efficiency of heavy metals. Leaching time had little influence on the leaching removal efficiency of copper and nickel in this project.