电絮凝法处理重金属底泥清淤尾水

Electrocoagulation treatment of heavy metal sediment dredging tail water

采用电絮凝法处理湘江霞湾港重金属底泥清淤尾水,研究了电极转换方式、起始p H值和电流密度对尾水中各污染物去除效果的影响。实验结果表明,采用先由铁作为阳极反应20 min,然后转换铝作为阳极反应10 min的组合方式,当起始p H值为6,电流密度为100 A·m-2时,Cd、Zn、Cu、Pb、Hg、As、NH+4-N和TP的去除效率分别可以达到99.2%、98.6%、99.3%、98.4%、99.5%、99.7%、84.8%和95.9%。电絮凝法去除尾水中重金属的主要机制是分布于悬浮物中的重金属主要通过疏松态铝的絮凝以及氢气的气浮作用去除,而分布于过滤液中的重金属主要以其氢氧化物沉淀去除。

The electrocoagulation method was applied in the treatment of heavy-metal sediment dredging of tail- water in the Xiawangang of the Xiang Jiang River. In this experiment, the effects of electrode alternating, initial pH value, and current density on the removal of various pollutants were investigated. The results showed that in specific conditions, high removal efficiencies were achieved for Cd 99.2% , Zn 98.6% , Cu 99.3% , Pb 98.4% , Hg 99.5% , As 99.7% , NH4 -N 84.8% , and TP 95.9%. The relevant conditions were employing the Fe anode for 20 min, subsequently the A1 anode for 10 min, the initial pH 6, and the current density 100 A · -2 m It was found that the heavy metals in the suspended particles were removed by the flocculation of loose alu- minum and the floatation of hydrogen, whereas the heavy metals in filtrates were removed by hydroxide precipita- tion.