剩余污泥高速转盘破解及破解液厌氧消化特性

采用自主开发并设计制造的高速转盘剩余污泥破解装置进行剩余污泥破解实验,考察不同的运转条件对污泥粒径、破解率的影响,并对破解污泥的厌氧消化特性进行实验研究。实验发现:转盘在高混合液悬浮固体(MLSS)质量浓度(高黏度)的剩余污泥中高速旋转所产生的流体剪切力是导致污泥破解的主要因素,破解污泥的中值粒径可达15μm以下、破解率在50%以上。高速转盘破解污泥的厌氧消化性能明显提高:在污泥停留时间为10 d的厌氧消化实验中,破解污泥CH4产生量与混合液挥发性悬浮固体(MLVSS)去除率与未破解污泥的相比分别提高了近20%和12.1%;在不同投配比条件下(3.33%,5%,10%,20%)的半连续式厌氧消化实验中,各个投配比条件下破解污泥的CH4产量均明显提高,若注重污泥的资源化利用考虑,最佳投配比应介于5%—10%。

Disintegration of excess sludge by high speed rotary disk and anaerobic digestibility of its disintegrated sludge

High Speed Rotary Disk(HSRD),new equipment for excess sludge disintegration,was designed and manufactured.To investigate the disintegration effects of HSRD,the experiments under different operation conditions were carried out.The anaerobic digestibility of the disintegrated sludge was studied as well.According to the results,the fluid shearing force generated by the high speed rotating disk in the sludge with high mixed liguor suspended solids(MLSS) mass concentration(high viscosity) is the main factor that contributed to the sludge disintegration,and the median particle diameter of the disintegrated sludge is smaller than 15 μm while disintegration rate is higher than 50%.Moreover,the anaerobic digestibility is improved evidently.The CH4 generation amount and mixed liquor volatile suspended solids(MLVSS) removal rate are increased by about 20% and 12.1%,respectively,sludge residence time(SRT) is 10 d.In the semi-continuous experiments with different dosing ratio(3.33%,5%,10% and 20%),CH4 generation amount is increased under each dosing ratio conditions.If resource recovery is under consideration,the optimum dosing ratio is about 5%-10%.