基于剩余污泥的超声法提取微生物絮凝剂

Extraction of microbial flocculant from waste sludge by ultrasonic method

通过超声系列实验,对超声法从剩余污泥中提取微生物絮凝剂(MBF)进行了系统研究。从剩余污泥中提取的MBF在碱性条件下表现出较好的絮凝活性。提高污泥浓度有利于提取出较高絮凝活性的MBF。由于超声波的破解作用,超声频率或功率过高均不利于MBF的提取。在20 kHz的超声频率下,连续超声比脉冲为1、4或8 s超声时的提取效果均要好。经过工艺优化,采用20 kHz、120 W的超声波对剩余污泥(19.4 g/L)连续超声30 s,所提取的MBF对高岭土悬浊液的絮凝率接近70%。结果表明,超声法可用于从剩余污泥中直接提取MBF,在降低MBF生产成本的同时实现污泥的资源化利用。

The extraction of microbial flocculant（MBF） from waste sludge by ultrasonic method was systematically investigated in the present study.The MBF extracted from the sludge showed higher flocculation efficiency under alkaline conditions than that under neutral or acid conditions.Increasing the sludge concentration enhanced the flocculation efficiency of the extracted MBF.High ultrasonic frequency or high ultrasonic power caused adverse effects on the MBF extraction because of the crack role of ultrasound.Extraction efficiency with continuous ultrasonic was higher than that with 1 s,4 s or 8 s under ultrasonic frequency of 20 kHz.Under the ultrasonic treatment conditions of frequency of 20 kHz,power of 120 W,and continuous ultrasonic time of 30 s,the flocculation efficiency of the MBF extracted from waste sludge（19.4 g/L） for kaolin suspension was close to 70%.Therefore,ultrasonic method is feasible to extract MBF from waste sludge,which facilitates the resource utilization of waste sludge other than decreasing the cost of MBF production.