基于蛋白质回收的剩余污泥酶解技术研究

Study on Enzyme Hydrolysis of Waste Activated Sludge Based on Protein Recovery

研究酶解技术联合热碱方法水解剩余污泥,进而高效溶出蛋白质。结果表明,与酶解技术结合,热碱水解对剩余污泥蛋白质的溶出有明显的促进作用。与单独酶解相比,溶菌酶和木瓜蛋白酶的剩余污泥蛋白质溶出率分别提高了46.84%和45.56%。碱性蛋白酶和木瓜蛋白酶复配联合热碱水解法水解剩余污泥,效果优于其他复合酶。当污泥浓度为30 g/L时,复合酶(碱性蛋白酶∶木瓜蛋白酶=1∶12,质量比)投加质量分数为1%,在pH为7.0和温度为55℃条件下酶解2.0 h,再在pH为12.5和温度为90℃条件下热碱水解1.5 h后,剩余污泥蛋白质溶出效果最佳,上清液中蛋白质质量浓度和蛋白质溶出率分别达6 050 mg/L和84.33%。

Protein recovery from waste activated sludge(WAS) is a kind of new way of sludge reutilization. The purpose of this manuscript is to investigate a combined method of enzymatic hydrolysis with thermal alkali hydrolysis for efficiently dissolving proteins from WAS. The results showed that thermal alkali hydrolysis strongly promoted the dissolution of WAS proteins after combined with enzymatic hydrolysis. Compared with single enzyme hydrolysis,the protein dissolution rates hydrolyzed by lysozyme and papain were increased by 46.84% and 45.56%,respectively. Combined with thermal alkali hydrolysis,the multi-enzymes with alkaline protease and papain got the highest dissolution rate of WAS proteins. With 30 g/L of WAS and 1% of multi-enzymes(alkaline protease∶papain=1∶12),the dissolution of WAS proteins was optimal after WAS was enzyme-hydrolyzed for 2.0 h under pH=7.0 and 55 ℃,and then experienced thermal alkali hydrolysis under pH=12.5 and 90 ℃ for 1.5 h. Accordingly,the soluble protein concentration and dissolution rate were 6 050 mg/L and 84.33%.