云南某废弃菜叶处理厂废水处理工程实例

Wastewater Treatment Project of a Waste Vegetable Disposal Plant in Yunnan

废弃菜叶处理(破碎+厌氧产沼气)过程中产生的废水是一种污染物浓度较高、C/N偏低的废水。云南某废弃菜叶处理厂废水处理工程采用A^(2)O^(2)(二级O池为MBR膜池)工艺,以强化氮的脱除,保证出水TN的达标。对A^(2)O^(2)工艺的启动特性、运行效果及运行费用组成进行了分析。在工艺启动过程中,COD的去除效率可以稳定在70%以上;当硝化反应发生后,对NH_(4)^(+)-N的去除率>99.5%;投加一定量的碳源后,对TN可以达到较高的去除率。稳定运行后,出水的COD、NH_(4)^(+)-N、TN和TP分别稳定在300、10、45、5 mg/L以下,满足《污水排入城镇下水道水质标准》(GB/T 31962—2015)的C级标准。经测算,处理成本为27.564元/m^(3)。

The wastewater from waste vegetable disposal including crushing and digestion is characterized by high pollutant concentration and low C/N ratio.To enhance the removal efficiency of nitrogen and ensure the discharge standard of total nitrogen,the A^(2)O^(2)(secondary O tank is MBR)process is adopted to treat wastewater from a waste vegetable leaf disposal plant in Yunnan Province.The start-up characteristics,operation effect and the treatment cost of the A^(2)O^(2) process were analyzed.In the start-up stage,the COD removal efficiency was above 70%,the ammonia nitrogen removal efficiency was above 99.5%after nitrification,and TN can achieve a high removal rate after adding a certain amount of carbon sources.After stable operation,the effluent COD,ammonia nitrogen,total nitrogen and total phosphorous were below 300,10,45 and 5 mg/L respectively,which met level C criteria in Wastewater Quality Standards for Discharge to Municipal Sewers(GB/T 31962-2015).According to calculation,the wastewater treatment cost was 27.564 yuan/m^(3).