生物表面活性剂强化污泥水解的研究

Enhanced Hydrolysis of Waste Activated Sludge by Biosurfactant

为了解生物表面活性剂对剩余污泥水解效果的影响,采用向污泥中投加鼠李糖脂的方式,研究了水解时间、生物表面活性剂投加量以及pH值对污泥水解过程的影响.结果表明,鼠李糖脂显著降低了污泥水解液的表面张力,促进了悬浮固体的溶解和胞外酶的溶出,从而强化了污泥水解.污泥水解过程中,SCOD、蛋白质和还原糖的浓度均呈现先增加后降低的趋势,前6 h内符合一级反应动力学.在鼠李糖脂最佳投加剂量0.3 g.g-1下反应6 h,SCOD、蛋白质和还原糖的浓度分别由371.9、93.3和9.0 mg.L-1上升到3 994.5、800.0和401.7 mg.L-1.生物表面活性剂对污泥水解的强化作用受pH值的影响,随着pH值的增大,水解效率不断增大.当pH=11时,水解效率达到最大值,SCOD、蛋白质和还原糖的浓度分别为5 249.9、1 658.3和597.1 mg.L-1.

The effects of biosurfactant on the hydrolysis of waste activated sludge including reaction time,dosage of rhamnolipid and pH were investigated.It was found that the rhamnolipid could greatly reduce the surface tension of sludge hydrolysis liquid,resulting in the solubilization of organic solid and the release of extracellular enzyme.During the hydrolysis process,the concentrations of SCOD,soluble reducing sugar and soluble protein showed an obvious increase in the initial and then decrease later.Sludge hydrolysis process fitted to the first-order reaction dynamics within 6 h.At rhamnolipid dosage of 0.3 g·g^-1,the concentrations of SCOD,reducing sugar and protein after 6 h of hydrolysis increased from 371.9,93.3 and 9.0 mg·L^-1 to 3 994.5,800.0 and 401.7 mg·L^-1,respectively.The efficiency of sludge hydrolysis was improved with the increase of pH value,and the maximal concentrations of SCOD,reducing sugar and protein were,respectively,5 249.9,1 658.3 and 597.1 mg·L^-1 at pH 11.