游离和固定化SRB污泥处理含锌废水比较研究

采用聚乙烯醇(PVA)-硫酸铵包埋法对硫酸盐还原菌(SRB)进行固定化处理。以含锌废水为处理对象,利用内聚营养源固定化小球与游离污泥做对比实验,考察硫酸根去除率、锌离子去除率、出水COD值等因素,并借助EDX分析小球内部锌离子含量。实验结果表明,采用内聚营养源固定化小球,硫酸根去除率为55.7%,锌离子去除率达98%,出水COD<100mg/L,进行多次循环实验,出水锌离子浓度仍达到污水综合排放二级标准;采用游离污泥,硫酸根去除率为46.1%,锌离子去除率为98.2%,出水COD1800mg/L以上,用于二次处理废水,锌离子去除率仅为60.4%。固定化小球循环处理废水四次后,每克固定化小球内部锌离子含量为0.04364mg。

Comparative Study on Treating Wastewater Containing Zinc by Free and Immobilized Sludge of SRB

Sulfate-reducing bacteria(SRB)were immobilized with PVA-(NH4)2SO4 method.Wastewater containing zinc was treated with immobilized beads with inner cohesive carbon source in contrast with free sludge to investigate removal efficiency of SO42-and Zn(II)as well as effluent COD,and content of Zn(II)within bead was analyzed by EDX.Results showed that removal efficiency of SO42-and Zn(II)with immobilized beads with inner cohesive carbon source was 55.7% and 98% respectively and effluent COD was less than 100mg/L.In repeated cyclic tests,Zn(II)concentration of treated water still satisfy Class II of discharge standard of wastewater.Removal efficiency of SO42-and Zn(II)with free sludge was 46.1% and 98.2% respectively,and COD was more than 1800mg/L.Removal efficiency of Zn(II)was only 60.4% in the second time test.Inner content of Zn(II)was 0.04364mg/g beads after fourth cycle of wastewater treatment.