COD对生物除磷颗粒污泥稳定性影响研究

Influence of COD on phosphorus removal granular sludge stability

颗粒污泥稳定性是影响其应用的主要因素之一。以SBR中成熟的生物除磷颗粒污泥为研究对象,探讨进水COD浓度对系统稳定性的影响。结果表明,当进水COD浓度由300 mg/L逐渐升高到500 mg/L时,磷去除率由93%降低到88%;当进水COD浓度在400 mg/L以下时,污泥的最大比释磷速率和比吸磷速率分别为45.2 mg/(g MLSS.h)和33.5mg/(g MLSS.h),污泥中P的含量为5.6%～7%,出水SS在50 mg/L以下;当进水COD浓度提高到550 mg/L时,磷去除率仅为63%,此时反应器出水SS在150 mg/L以上,颗粒污泥周围丝状菌过度生长,而且菌丝粗壮,颗粒污泥解体。因此,生物除磷颗粒系统具有一定的耐COD冲击能力,但在高COD负荷下会导致颗粒污泥系统崩溃。

The stability was one of important factors for application of granular sludge.With the influent COD concentration changed the stability of the biological phosphorous removal granular sludge was studied in a sequencing batch reactor（SBR）.When the influent COD concentration gradually increased from 300 mg/L to 500 mg/L,the phosphorus removal efficiency decreased from 93% to 88%.When the influent COD concentration was below 400 mg/L,the max.specific phosphorus release rate and the max.specific phosphorus uptake rate were 45.2 mg/（g MLSS·h） and 33.5 mg/（g MLSS·h）,respectively,and the phosphorus content of MLSS was 5.6%-7%,and the effluent SS was below 50 mg/L.When the influent COD concentration was stepped up to 550mg/L,the phosphorus removal efficiency decreased to 63%,the effluent SS was above 150 mg/L,the filamentous bacteria overgrew,and the granular sludge was disintegrated.The biological phosphorous removal granular sludge could stand some impacts of COD concentration,and the system would break down at high COD concentrations.