蛋白酶和EDTA-2Na协同作用对剩余污泥水解的影响

Effect of synergistically adding protease and EDTA-2Na on waste activated sludge hydrolysis

采用投加蛋白酶和螯合剂乙二胺四乙酸二钠(EDTA-2Na)联合预处理剩余污泥,研究了蛋白酶浓度、温度和EDTA-2Na浓度对污泥酶法水解释碳效果的影响。结果表明,蛋白酶浓度、温度和EDTA-2Na浓度对剩余污泥水解的影响具有协同效应。在最佳蛋白酶浓度20 mg/g TS条件下,剩余污泥释放的SCOD为1 318.82 mg/L。同时,在最佳螯合剂ED-TA-2Na浓度0.20 g/g TS下,SCOD为9 014 mg/L。在20 mg/g TS的蛋白酶和0.20 g/g TS的EDTA-2Na的联合作用下,SCOD达到12 628.98 mg/L。在20 mg/g TS的蛋白酶、0.2 g/g TS的EDTA-2Na和55℃条件联合作用下,SCOD达到最大值16 878 mg/L,多糖浓度达到最大值2 695.3 mg/L,NH4+-N的浓度达到最大值156.73 mg/L。此外,在不同蛋白酶和EDTA-2Na浓度条件下,剩余污泥水解释放的SCOD符合一级动力学。

The release efficiency of carbon source from the hydrolysis of waste activated sludge（WAS） was enhanced by adding protease and EDTA-2Na.The influences of protease dosage,temperature,and concentration of EDTA-2Na on the efficiency of carbon release in the protease hydrolysis were investigated.Results showed that protease concentration and temperature,as well as EDTA-2Na had significant impacts on WAS hydrolysis.When the optimal concentration of protease was 20 mg/g TS,released SCOD was 1 318.82 mg/L.When optimal concentration of EDTA-2Na was 0.20 g/g TS,SCOD could reach 9 014 mg/L.Furthermore,by simultaneously adding 20 mg/g TS protease and 0.20 g/g TS EDTA-2Na,SCOD concentration could reach 12 628.98 mg/L.The maximum SCOD,polysaccharides and NH4＋-N concentrations reached 8 991.3 mg/L,2 695.3 mg/L and 156.73 mg/L,respectively,when protease concentration was 20 mg/g TS,EDTA-2Na dosage was 0.20 g/g TS and temperature was 55℃.Moreover,under different dosages of protease and concentrations of EDTA-2Na,SCOD release process was consistent with first-order reaction dynamics.