溶解氧对膜生物反应器处理高氨氮废水的影响

采用膜生物反应器(MBR)处理高氨氮有机废水,探讨了溶解氧(DO)对有机物、氨氮、总氮等去除效果的影响。当进水COD1500mg/L,NH4+-N150mg/L,TP为15mg/L,pH7.5～8.0,MLSS控制在6000～7000mg/L,DO在0.5～4mg/L时对COD的去除效果没有明显影响,都可高达95%;在DO为4.0和2.0mg/L时对NH4+-N的去除率都很高,最高可达99.17%,在DO为0.5mg/L时明显降低,最低降至48.30%。在DO2.0mg/L时,取得了较好的同步硝化反硝化效果,COD、NH4+-N、TN去除率分别高达97%、97%、68%。MBR中硝化反应的比氨氮消耗速率与氨氮浓度成零级反应动力学,比氨氮硝化速率为0.0979/d,比常规处理系统中的污泥硝化活性高。

Effect of po on High Concentration of Ammonia Nitrogen Wastewater Treatment in Membrane Bioreactor

Membrane bioreactor (MBR) was used to treat high concentration of ammonia nitrogen wastewater. The effect of dissolved oxygen (DO) concentration on the removal of organic matter, ammonia nitrogen and total nitrogen was studied respectively. Results showed that at the condition of influent COD_(Cr) 1,500mg/L, NH_4~+-N 150mg/L, TP 15mg/L, pH 7.5～8.0 and MLSS 6,000～7,000mg/L, DO had no significant effect on the removal of COD_(Cr), with the removal efficiency all up to 95% in the range of 0.5～4.0mg/L of DO. Removal efficiency of NH_4~+-N were excellent when DO was 4.0 and 2.0mg/L, with the highest removal rate up to 99.17%. The removal rate decreased to 48.30% when DO was 0.5mg/L. At the condition of DO 2.0mg/L, simultaneous nitrification and denitrification (SND) happened, with removal efficiency of COD_(Cr), NH_4~+-N and TN up to 97%, 97% and 68% respectively. In MBR specific consumption rate of NH_4~+-N manifested zero-order reaction kinetic with respect to concentration of N_4~+N, with specific nitrifying rate of NH_4~+-N up to 0.0979/d. Nitrifying bacteria in MBR had stronger nitrifying activity than those in conventional activated sludge system.