电化学处理对污泥重金属的影响研究

Study on Electrochemical Treatment of Heavy Metal Sludge

为了提高污水厂剩余污泥中重金属的处理效果,探索电化学法对污泥中重金属的影响。利用电化学法对不同条件下处理后的污泥固相及滤液中存在的重金属进行了研究,分析了不同电解条件下重金属总量迁移规律,并通过改性BCR连续提取法对重金属的性态迁移进行分析。结果显示,污泥固相重金属在电化学氧化作用下均向液相有一定迁移,但程度较小。电化学氧化作用对剩余污泥中各种重金属的性态转化有一定作用,主要趋势是少量增加了可交换态和残渣态的比例,转化的幅度由于重金属元素中了的不同而略显差异。电化学氧化法可以有效破坏污泥絮体结构,氧化有机物质,对剩余污泥的处理效果较好。

In order to improve the treatment effect of residual heavy metals in sewage sludge, effect of the electrochemical method on heavy metals in sludge was investigated. Heavy metals in sludge filtrate and solid treated under different conditions were studied by electrochemical method. Migration rule of heavy metals under different electrolysis conditions was analyzed, and heavy metal migration behavior analysis was carried out by modified BCR sequential extraction method. The results show that there is the action of a certain migration of heavy metals from sludge solid phase to liquid phase under electrochemical oxidation, but the migration level is low. Electrochemical oxidation action has a certain effect on speciation transformation of heavy metals in sewage sludge, the ratio of exchangeable and residual heavy metals increases slightly; the amplitude of conversion is slightly different because of different heavy metal types. The electrochemical method can effectively destroy the sludge floc structure, and can oxidize organic substances, so it has better treatment effect on excess sludge.