聚环氧琥珀酸对污泥中锌的萃取

Extraction of Zn from Sewage Sludge with PESA

研究了环境友好高分子聚环氧琥珀酸（PESA）对污水厂污泥中重金属锌的萃取作用。结果表明．PESA对污泥中的重金属锌具有良好的萃取效果。利用改进的BCR法对萃取前后污泥中的锌进行了形态分析。结果表明，被PESA萃取的锌主要来自水溶态、酸溶态和可还原态等3种结合态。随着萃取体系pH值的升高，锌的萃取效率逐渐下降；在实验范围内，PESA与污泥中重金属总量的摩尔比为1：1～10：1时。随着PESA浓度的增加，锌的萃取效率逐渐提高，且对萃取体系pH值的依赖性减小。在pH=4时，在PESA与污泥中重金属总量的摩尔比为3：1～10：1范围内．锌的萃取效率均大于70％。

Poly-epoxy-succinic acid （PESA） , as an environmental from the sewage sludge of Shanghai Taopu Wastewater Treatment benign chelant, was used to remove zinc Plant. Extraction of sewage sludge with aqueous solution of PESA was carried out under various conditions. The influences of pH and concentration of PESA on the extraction efficiency for zinc were investigated. The results show that PESA has a higher extraction efficiency of zinc from sludge than those of other heavy metals, and the extracted zinc mainly comes from the water soluble, acid soluble and reducible fractions. It was found that pH and concentration of PESA have a significant effect on the extraction efficiency of zinc. The extraction efficiency for zinc with pH increasing. When the concentration of PESA increases, the extraction efficiency o the effect of pH decreases. The extraction efficiency of zinc reaches above 70% when pH ratio of PESA to total amount of heavy metals ranges from 3 to 10. decreases gradually f zinc increases and is 4 and the molar