阳极腐蚀对电脱水污泥中重金属的影响

Impact of Anode Corrosion on Heavy Metals in Electrically Dehydrated Sludge

电渗透脱水技术作为一种新型的固液分离技术,对于城市污水厂污泥的深度脱水是非常有效的,但存在严重的阳极腐蚀问题。用原子吸收分光光度法研究了惰性阳极以及5种金属阳极下的污泥电脱水技术对污泥中重金属(Cr、Ni、Zn、Cu、Pb)含量的影响。结果表明,阳极使用惰性材料时,电渗透脱水技术能有效去除一部分重金属,且电压越大越有利于重金属的去除。在金属阳极下,电渗透脱水技术存在不同程度的阳极腐蚀问题,且阳极腐蚀质量与试验次数呈线性相关;阳极使用金属材料时,污泥中的Cr、Ni、Cu含量大幅度增加,Zn、Pb含量略有降低。

Electro-osmotic dewatering, as a new type of solid-liquid separation technology, is quite effective for deep dehydration of sewage sludge. However, there are serious anode corrosion problems. The influence of electric dehydration using the inert anode and five kinds of metal anodes on heavy metals content in sewage sludge （Cr, Ni, Zn, Cu and Pb） was investigated by atomic absorption spectrophotometry. The results showed that when inert material was used as the anode, part of the heavy metals could be effectively removed by the electro-osmotic dewatering. The larger conductive voltage was more beneficial for heavy metal removal. In the metal anode, the electro-osmotic dehydration technology had anode corrosion problems. The anode corrosion quality was linearly related with the test number. When metal material was used as the anode, the contents of Cr, Ni and Cu in the sludge would be increased substantially, oppositely the contents of Zn and Pb would be decreased slightly.