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 ...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.展开更多
在实际运行中,部分市政污水处理厂生化系统的BOD5污泥负荷(LS)长期达不到设计值,甚至在设计值的半数以内。文章根据相关公式及定义,对实际运行LS≤0.10 kg BOD5/(kg MLSS·d)的生化系统中LS、MLVSS/MLSS(f)和泥龄(θC)之间的关系式...在实际运行中,部分市政污水处理厂生化系统的BOD5污泥负荷(LS)长期达不到设计值,甚至在设计值的半数以内。文章根据相关公式及定义,对实际运行LS≤0.10 kg BOD5/(kg MLSS·d)的生化系统中LS、MLVSS/MLSS(f)和泥龄(θC)之间的关系式进行推导,并结合计算示例,探讨在进水LS长期低于设计值运行的情况下,生化系统中f和θC的计算结果和发展趋势,并以此作为类似生化系统调试和运行中控制θC的参考依据。展开更多
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).
文摘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.
文摘在实际运行中,部分市政污水处理厂生化系统的BOD5污泥负荷(LS)长期达不到设计值,甚至在设计值的半数以内。文章根据相关公式及定义,对实际运行LS≤0.10 kg BOD5/(kg MLSS·d)的生化系统中LS、MLVSS/MLSS(f)和泥龄(θC)之间的关系式进行推导,并结合计算示例,探讨在进水LS长期低于设计值运行的情况下,生化系统中f和θC的计算结果和发展趋势,并以此作为类似生化系统调试和运行中控制θC的参考依据。
