The effect of fine grits and fine debris concentrations on the MLVSS/MLSS ratio of an activated sludge system  

作　　者：Zhao Jiang Zhiheng Xia Shuai Liu QiWei Haitao Fan Lu Qi Guohua Liu Hongchen Wang 

机构地区：[1]Low-carbon Water Environment Technology Research Center,School of Environment&Natural Resources,Renmin University of China,Beijing 100872,China

出　　处：《Journal of Environmental Sciences》2025年第1期607-616,共10页环境科学学报(英文版)

基　　金：supported by the National Special Project for Science and Technology on Water Pollution Control and Management(No.2017ZX07102-003);the Fundamental Research Funds for the Central Universities,and the Research Funds of Renmin University of China(No.2020030257).

摘　　要：This study embarks on an explorative investigation into the effects of typical concentrations and varying particle sizes of fine grits(FG,the involatile portion of suspended solids)and fine debris(FD,the volatile yet unbiodegradable fraction of suspended solids)within the influent on themixed liquor volatile suspended solids(MLVSS)/mixed liquor suspended solids(MLSS)ratio of an activated sludge system.Through meticulous experimentation,it was discerned that the addition of FG or FD,the particle size of FG,and the concentration of FD bore no substantial impact on the pollutant removal efficiency(denoted by the removal rate of COD and ammonia nitrogen)under constant operational conditions.However,a notable decrease in the MLVSS/MLSS ratio was observed with a typical FG concentration of 20 mg/L,with smaller FG particle sizes exacerbating this reduction.Additionally,variations in FD concentrations influenced both MLSS andMLVSS/MLSS ratios;a higher FD concentration led to an increased MLSS and a reduced MLVSS/MLSS ratio,indicating FD accumulation in the system.A predictive model for MLVSS/MLSS was constructed based on quality balance calculations,offering a tool for foreseeing the MLVSS/MLSS ratio under stable long-term influent conditions of FG and FD.This model,validated using data from the BXH wastewater treatment plant(WWTP),showcased remarkable accuracy.

关 键 词：Fine grits and fine debris Activated sludge system MLVSS/MLSS ratio Predictive model 

分 类 号：X703[环境科学与工程—环境工程]