短程硝化反硝化工艺处理低C/N餐厨废水

针对餐厨废水的水质特点,提出低C/N下的短程硝化反硝化餐厨废水处理组合工艺。通过控制微氧区、好氧区DO分别为0.5 mg/L和2.5 mg/L;硝化液,微氧区混合液和污泥回流比分别为200%、100%和100%,可以实现NO2--N累积率达到90%以上,COD、氨氮平均去除率为73.42%和98.57%。较低的C/N使得反硝化效果不佳,对反应器进水补充适量的甲醇作为碳源,在COD/TN约为4的情况下,以NO2--N为主的反硝化可以使反应器对TN的去除率达到94%,出水各项指标符合相关排放标准,实现了餐厨废水高效和经济的生物脱氮。

Short-cut nitrification and denitrification process for treating low C/N food wastewater

According to the characteristics of its water quality, a short-cut nitrification and denitrification treatment of low C/N ratio food wastewater was presented. Through 0.5 mg/L and 2.5 mg/L of DO in micro-oxygen zone and aerobic zone, and 200%, 100% and 100% reflux ratio of nitrifying liquid, micro-oxygen mixture and the sludge, the accumulation rate of NO2--N could be achieved more than 90%, and average removal rates of COD and NH4+-N could be 73.42% and 98.57%, respectively. Since denitrification effect would be inhibited under the low ration of C/N, methanol was added to the reactor as a source of carbon to increase the ratio of C/N. When the COD/TN was around 4, the TN removal rate of reactor could reach 94% under the NO2--N based denitrification, and the effluent could meet emission standards. Therefore, this study could provide an efficient and economical biological denitrification of food wastewater.