进水负荷与硝化液回流比对低污泥浓度A^2/O工艺脱氮效果的影响

Effect of influent loading and reflux ratio on de-nitrification under low sludge concentration

采用连续流A2/O工艺对模拟生活废水进行了长期连续实验,考察了低污泥浓度[MLSS=(1500±200)mg/L]下进水负荷与回流比对脱氮效率的影响。结果表明,通过调节进水流量改变进水负荷,当进水负荷从5.03 gCOD/(gMLSS.d)逐渐提高至10.05 gCOD/(gMLSS.d)时,COD去除率≥95%,氨氮去除率由69.59%升高为95%,总氮去除率由53.53%升高到80%;当进水负荷由10.05 gCOD/(gMLSS.d)提高至20.31 gCOD/(gMLSS.d)时,氨氮去除率下降为50%,总氮去除率下降为40%。通过调节进水COD改变进水负荷,当进水负荷从10.05 gCOD/(gMLSS.d)逐渐提高到124.11 gCOD/(gMLSS.d)时,COD和氨氮的去除率均>90%,总氮去除率从70%逐渐增加到85%。在混合液回流比分别为300%、200%和100%的条件下,回流比对COD和氨氮去除效果影响较小,COD去除率≥90%,氨氮去除率≥95%;回流比对总氮去除效果影响较大,随回流比的增大总氮去除率减小。当内回流比为100%时,总氮去除率最高,达到79.76%。

A long-term continuous experiment of simulated wastewater was carried out using A2/O process and effect of influent loading and reflux ratio on the removal efficiency of nitrification was investigated at low MLSS of（1500±200） mg/L.The results show that the influent loading increases gradually from 5.03 gCOD/（gMLSS.d）to 10.05 gCOD/（gMLSS·d）and removal efficiency of COD is higher than 95% when influent loading is changed by adjusting influent flow rate.Removal efficiency of NH4＋-N increases from 69.59% to 95% and removal efficiency of TN increases from 53.53% to 80%,respectively.Furthermore,when influent loading is enhanced to 20.31 gCOD/（gMLSS.d）,removal efficiencies of NH4＋-N and TN decrease to 50% and 40%,respectively. The influent loading increases from 10.05 gCOD/（gMLSS.d） to 124.11 gCOD/（gMLSS·d） when influent loading is changed by adjusting influent COD.Removal efficiencies of COD and NH4＋-N are all higher than 90% and removal efficiency of TN increases gradually from 70% to 80%,respectively.When the reflux ratio of mixture is 300%,200% and 100%,respectively,removal efficiencies of COD and NH4＋-N are less affected by reflux ratio.Removal efficiencies of COD and NH4＋-N are higher than 90% and 95%,respectively.And meantime,removal efficiency of TN drops with the increasing reflux ratio,which is greatly influenced by reflux ratio.When the internal reflux ratio is 100%,removal efficiency of TN reaches the highest and it is higher than 80%.