附加回流的生物接触氧化工艺净化滇池大清河水质的示范工程研究

Demonstration work of inter-cycle biological contact oxidation process for purification of Daqing River in Dianchi Lake watershed

针对滇池流域污染最为严重的大清河,采用附加回流生物接触氧化工艺(IBCOP)开展河道水体的旁路处理示范工程研究。IBCOP示范工程的设计规模为1 000 m3/d,HRT为4.75 h,在2007年11月至2008年4月冬旱季期间,根据气候和进水水质条件调节回流比,示范工程运行了3种工况。研究结果表明:示范工程对COD和NH4+-N具有较高的去除效果,平均去除率为46.8%和48.8%,高回流比有利于去除NH4+-N;受到低温、低碳源、高进水DO和生物膜生长不佳等因素影响,示范工程对TN去除效果较低,平均去除率为10.2%,调节回流比不能显著改善碳源不足的情况;水绵的吸收和底泥的沉积是示范工程除磷的主要机理,TP平均去除率为17.9%,低TP浓度进水、生物膜的脱落以及高回流比不利于除磷。

Daqing River is the most seriously polluted river in the Dianchi Lake watershed. A bypass demonstration work of the inter-cycle biological contact oxidation process （IBCOP） , with the treatment scale of 1000 m3/d and the HRT of 4.75 h, was built around the river bank to purify the river water. During the winter dry season from Nov. 2007 to Apr. 2008, three sets of conditions of the demonstration work were operated by regulating cycling ratio based on the influent qualities and climatic conditions. The results showed that the IBCOP demonstration work kept better removal efficiencies for COD and NH4＋ -N, and the average removal rates were 46.8% and 48.8% respectively. The higher cycling ratio （150%） was favorable for removal of NH4＋-N. The average removal rate of TN was lower as 10.2% , owing to the negative impacts of low temperature, carbon source shortage, higher DO level of the influent, and loose and porous biofilm, regulating cycling ratio could not improve the condition of carbon source shortage remarkably. The absorption by Spirogyra sp. and deposition of sludge were the main causes of TP removal and the average removal rate of TP was 17.9% , low TP concentration of influent, detachment of biofilm and higher cycling ratio were detrimental for TP removal.