北方某污水处理厂Bardenpho-MBBR改造运行分析

Operation Analysis of Bardenpho-MBBR Upgrading and Retrofitting in a Northern Wastewater Treatment Plant

在不停产、不减产的情况下,北方某污水处理厂采用Bardenpho-MBBR工艺实施了二次扩建提标改造,强化去除TN,保证了出水水质稳定达到国家一级A标准。2017年1月—8月,污水厂先后经历了冬季低温、夏季高水质负荷冲击、雨季高水力冲击等阶段,但系统出水水质仍可优于国家一级A标准,出水BOD_5、COD、NH_4^+-N、TN平均值分别为2.7、18、0.5、7.4 mg/L,平均去除率分别为99%、97%、97.1%、87%。伴随着进水水质的剧烈变化,进水负荷波动较大且无规律性,最大BOD_5负荷为1.8 kg/(m^3·d),最大TN负荷为0.34 kg/(m^3·d),连续10 d内最大负荷是最小负荷的3~5倍,24 h内负荷升高30%,在以上不利条件下,通过控制DO浓度、排泥等综合调整措施,确保了系统的稳定运行。生化池沿程氮素分析表明,在总氮和氨氮去除率分别为85.9%、99.5%的条件下,调整反硝化碳源在前、后缺氧段的投加比例,前、后缺氧段可分别去除30.5%和25.9%的硝酸盐氮,另外有27.4%的总氮在好氧段被去除,推测发生了同步硝化反硝化作用。MBBR负荷高、抗冲击负荷能力强、处理效果好,适用于污水厂提标、提量升级改造。

A wastewater treatment plant （WWTP） in the north China was upgraded and retrofitted for the second time without stopping production and reduction, where Bardenpho - MBBR process was used to strengthen the removal of TN and the effluent quality stably met the first level A standard in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants （ GB 18918 - 2002）. From January to August in 2017, the WWTP successively experienced low temperatures in winter, high water load impact in summer and high hydraulic impact during rainy season, but the effluent quality was still superior to the first Level A standard. The average concentrations of BODs, COD, NH4 - N and TN in effluent were 2.7 rag/L, 18 mg/L, 0. 5 mg/L and 7.4 mg/L, and the average removal rates were 99% , 97% , 97.1% and 87% , respectively. Along with wild fluctuation of influent quality, the influent load fluctuated in wild range without regulation. The maximum BOD5 and TN loads reached 1.8 kg/（ m3 · d） and 0.34 kg/（ m3 · d） respectively. The maximum load was 3 to 5 times to the minimum load for 10 days, and the load increased by 30% in 24 hours. Under the above adverse conditions, the system was stable by controlling DO concentration, sludge discharge and other comprehensively adjusting measures. According to nitrogen analysis along the biochemical tank, 30.5% and 25.9% nitrate was removed in preanoxic zone and post-anoxic zone respectively by adjusting carbon adding ratio when TN and ammonia nitrogen removal rates were 85.9% and 99.5% respectively. At the same time, over 27.4% TN was removed in the aerobic tank, where simultaneous nitrification and denitrification was speculated to take place. MBBR has the advantages of withstanding high load, strong anti-shock loading capability and good treatment efficiency, which is suitable for WWTP