聚环氧琥珀酸(PESA)在生物处理明胶高钙废水中的应用

APPLICATION OF POLYEPOXYSUCCINIC ACID( PESA) IN BIOLOGICAL TREATING HIGH CALCIUM GELATIN WASTEWATER

对于COD 1 500 mg/L,Ca2+浓度为1 600 mg/L的明胶高钙废水,通过在生物处理中加入绿色阻垢剂聚环氧琥珀酸(PESA),研究其对污泥浓度MLSS、污泥容积指数SVI、出水Ca2+保留率、污泥钙含量及化学需氧量COD去除率的影响,确定其对高钙废水生物处理过程中污泥减量化的效果。结果表明:加入PESA的反应器中,COD去除率达到60%以上;MLSS低于普通生物反应器,可抑制污泥增长量50 mg/(L·d),减量化效果为27%;SVI值经18 d运行后明显上升,说明PESA可表现出较大的反钙离子压缩性,使得污泥体积释放,絮凝、吸附,传质能力增强;Ca2+保留率基本维持在100%,污泥中钙含量明显低于空白生物反应器,当污泥中钙含量低于5%时,钙离子架桥作用减弱,需要增加沉淀时间为2 h来保证出水浊度,絮凝能力下降,应及时排泥,污泥停留时间应该控制在21 d左右。PESA能阻止曝气过程中析出的钙盐附着在活性污泥表面,保持污泥的良好活性,从而达到污泥减量化目的。

The effect of PESA( polyepoxysuccinic acid) on mixed liquor suspended solids( MLSS),sludge volume index( SVI),the calcium retention rate,the calcium content of activated sludge and COD removal rate of the gelatin high calcium wastewater by activated sludge process have been investigated while the COD was 1500 mg / L,calcium concentration was1 600 mg / L in the wastewater,in order to determine the effect of PESA on sludge reduction. The resluts showed that MLSS was lower than ordinary activated sludge reactor,the COD removal of PESA reactor reached above 60%,the inhibited growth rate of sludge was 50 mg /( L·d),and the reduction rate reached 27%; the SVI value increased apparently after 18 d,suggested that the advantage of PESA in the decompressibility of calcium ions resulted in the release,flocculation,adsorption and mass-tranfer of activated sludge increased. The calcium retention rate of PESA activited sludge reactor maintained at 100% basically. The calcium content in PESA activited sludge was significantly lower than the content of the ordinary reactor. The sedimentation time needed increased to 2 h to ensure water turbidity in case that the calcium ion bridging function was weakened while the content was lower than 5%. The sludge retention time should be controlled at 21 d while the fluccuation of sludge was decreased. The bioactivity of sludge was still well kept while PESA inhibited the adsorption of calcium salt in the surface of activited sludge during the aeration process. Then the purpose of sludge reduction was achieve accordingly.