两点进水在倒置AAO流程除磷中的作用

Influence of two-point-fed on P removing from inverse AAO process

利用计算机仿真研究两点进水对倒置AAO流程除磷的作用,发现将污水按选择池进水流量与厌氧池进水流量的分配比(简称进水流量分配比)为1.0/0、0.9/0.1、0.8/0.2、0.7/0.3、0.6/0.4、0.5/0.5分流到选择池和厌氧池,会影响中等COD负荷(200~220 mg/L)下该流程的除磷效果。原因在于,污水分流到厌氧池虽然能提高厌氧池内乙酸浓度,但同时会因稀释作用而降低厌氧池及好氧池中聚磷菌的浓度,影响聚磷菌厌氧释磷及好氧吸磷的作用。两点进水对低COD负荷(140~180 mg/L)及高COD负荷(260~340 mg/L)下该流程的除磷效果无明显影响,前者因各反应池(除二沉池外)内聚磷菌浓度本身很低,后者则因各反应池内聚磷菌浓度本身很高,改变进水流量分配比不会改变这2种情况下各反应池内聚磷菌释磷或吸磷的强度。

An inverse AAO process in a newly built wastewater treatment plant was computer simulated to study the function of two-point-fed mode for P removing.The wastewater was fed into AAO process from two points of selecting tank(Q1) and anaerobic tank(Q2) with different flow ratio(Q1/Q2).Applied the inverse AAO process for treating middle COD load(200-220 mg/L) wastewater,reducing the flow ratio will lower its P removing function.The reason was that although the carbon source to the anaerobic tank was increased by inputting more raw wastewater to the anaerobic tank,the concentration of polymeric phosphorus organisms(PAO) in the anaerobic and the aerobic tanks was reduced,and as a result,the function of anaerobic P released and aerobic P absorbance was weakened.Applied the inverse AAO process for treating low COD load(140-180 mg/L) wastewater and high COD load(260-340 mg/L) wastewater,flow ratio of two-point-fed mode had no significant influence on P removing because changing the flow ratio could not cause any essential effect on the PAO concentration in the two cases.