污泥运行指标对A/A/O氧化沟生物脱氮的影响研究

Research on the influence of sludge running indexes on the biological denitrification by A/A/O oxidation ditch process

采用实际城市污水，研究污泥回流比、污泥龄和污泥浓度（MLSS）对中试A/A/O氧化沟脱氮的影响。结果表明：系统脱氮能力随污泥回流比增大而增强，大于90％时，NH4＋-N和TN去除率没有明显提高，还会增加能耗。污泥回流比为60％～90％，泥龄为15～20d时脱氮效果较好，还需根据进水负荷和脱氮效果进行调节。MLSS对工艺同时硝化反硝化（SND）有显著影响，当MLSS从3000mg/L增至6000mg/L时，NH4＋-N去除率从81．7％增至98.8％，TN去除率从47．2％增至66％．SND/TN从19．8％增至37．4％。

Using actual domestic sewage,the effects of different sludge recycle rate, SRT and MLSS on denitrification by pilot scale A/A/O oxidation ditch process have been studied. The results show that with the increase of sludge recycle rate,the denitrification capacity of the system is enhanced. When the sludge recycle rate is greater than 90%,the removing rates of NH4＋-N and TN do not improve significantly, but the energy consumption is increased. When the sludge recycle rate is generally in the range of 60% to 90% ,and sludge age 15-20 d,the denitrification efficacy is good. Adjustment needs to be made, according to in_fluent loading and denitrification efficacy. MLSS has obvious effect on simultaneous nitrification and denitrification （SND） processes. When MLSS increases from 3 000 mg/L to 6 000 mg/L,NH4＋-N removing rate increases from 81.7% to 98.8% ,TN removing rate increases from 47.2% to 66% ,and SND/TN increases from 19.8% to 37.4%.