厌氧水解酸化-好氧氧化Ａ1/Ａ2/O工艺剩余污泥减量对系统运行效果的影响

在碱减量印染废水Ａ₁/Ａ₂/O生物处理系统中,利用污泥回流可以实现对剩余污泥的有效减量.剩余污泥回流到Ａ₁段,增加了Ａ₁段中污泥的有机负荷,却提高了系统对COD的去除率.在Ａ₁段COD容积负荷2.54 kg/(m³·d)、水力停留时间为9.45 h和7.56 h条件下,Ａ₁段COD的去除率分别由15.9％提升至23.9％,12.3％提升至22.8％.在进水COD浓度1 000 mg/L、Ａ₁段COD容积负荷2.54 kg/(m³·d)、进水色度450倍、系统温度30℃条件下,Ａ₁段出水色度有污泥回流时较无污泥回流下降30％以上,系统出水的色度比无污泥回流时降低30％左右.回流剩余污泥使Ａ₁段出水pH略低于无污泥回流的情况,但对Ａ₂段和O段pH值影响不大.在有剩余污泥回流的系统中,系统各段出水的SS浓度均比无回流系统大.长期污泥回流会造成系统内难生物降解物质的积累,必须适时地进行排泥、气水冲刷等恢复系统污泥活性的措施.

Running effects affected by sludge reducing by anaerobic hydrolysis-acidification and aerobic oxidation process of A1/A2/O bio-treatment system

In the A1/A2/O bio-treatment system dealing with alkali minimization and dyeing-printing wastewater, residual sludge could be reduced effectively by recycling of sludge. The COD removal rate in A1 segment could be improved by residual sludge recycling to A1 segment. The COD elimination rate in A1 segment was raised from 15.9% to 23.9% and from 12.3% to 22.8% while the COD volume loading of A1 segment was 2.54 kg/(m3 x d) and the HRT of A1 was 9.45 h and 7.56 h respectively. The recycling of sludge is useful to color removal of the system. When the COD of influxion was 1000 mg/L, the COD volume loading of A1 was 2.54 kg/(m3 x d), the chroma of influxion was 450 and the temperature of the system was 30 degrees C, the chroma removal rate with sludge recycling decreased more than 30% and about 30% compared with the system without sludge recycling in A1 segment and in the whole process respectively. The pH in A1 segment with sludge recycling was a little lower than that without sludge recycling, but the performance of A1 and O segments was affected less severely by sludge recycling. The SS in every segment with sludge recycling was higher than that without sludge recycling. Inert substance could be accumulated because of long time sludge recycling and it's necessary to activate the sludge by aerating and washing.