酶解预处理对剩余污泥磷回收的影响

Effect of Enzymatic Hydrolysis Pretreatment on Phosphorus Recovery from Excess Sludge

城镇污水处理厂排放的剩余污泥是当前环境治理的一大难题.剩余污泥中含有大量的氮、磷等,具有极大的资源回收价值.首先通过试验探究了对剩余污泥进行酶解预处理的最佳条件,然后对比分析了利用鸟粪石结晶法对未经酶解预处理和经酶解预处理的剩余污泥上清液进行磷回收的效果.结果表明,在剩余污泥中添加2%的混合酶(由质量比为1∶1∶1∶1的纤维素酶、中性蛋白酶、溶菌酶、α-淀粉酶混合配制而成),并在45℃、150 r/min条件下振荡培养13 h时,剩余污泥中正磷酸盐的溶出质量浓度最大.利用鸟粪石结晶法对剩余污泥进行磷回收时,若先对剩余污泥进行酶解预处理,可大大提高磷回收效果.

The excess sludge discharged from urban sewage treatment plants is a major problem in current environmental governance.The excess sludge which contains a large amount of nitrogen,phosphorus,etc.,has great resource recovery value.The optimal conditions for enzymatic hydrolysis pretreatment of excess sludge are explored by experiment.Then the effect of struvite crystallization method on phosphorus recovery of the excess sludge supernatant without enzymatic hydrolysis pretreatment and with enzymatic hydrolysis pretreatment is compared and analyzed.The results show that when the excess sludge is added with 2%mixed enzyme which is composed of cellulase,neutral protease,lysozyme andα-amylase with a mass ratio of 1∶1∶1∶1,and cultivated under the conditions of 45℃and150 r/min for 13 h,the dissolved concentration of orthophosphate in the excess sludge is maximum.When using struvite crystallization method to recover phosphorus from the excess sludge,if the excess sludge is pretreated by enzymatic hydrolysis,the phosphorus recovery effect can be greatly improved.