DO浓度对MBR运行效果的影响研究

为了研究DO浓度对MBR运行效果的影响,选取DO的质量浓度分别为(1.0±0.2)、(3.5±0.2)、(6.0±0.2)mg/L进行纵向对比试验,以CODCr、NH3-N浓度和脱氢酶活性(DHA)为考察指标,分析DO浓度对MBR运行效果的影响规律。试验结果表明,当DO的质量浓度为3.5 mg/L时,MBR的CODCr生物去除率、NH3-N生物去除率及NH3-N系统去除率较DO的质量浓度为1.0、6.0 mg/L时的大,各DO浓度条件下的CODCr系统去除率无明显差别;各DO浓度条件下,膜对CODCr补偿作用明显,对NH3-N补偿作用不明显;当DO的质量浓度为3.5 mg/L时,MBR混合液的DHA较DO的质量浓度为6.0、1.0 mg/L的要大,其值为15.77 mgTF]/(h·L)。DO浓度对MBR运行效果的影响表现为:DO浓度适宜,可促进MBR中CODCr、NH3-N的生物去除,提高MBR的微生物活性。膜对CODCr补偿作用明显,对NH3-N补偿作用不明显。

Study on influence of DO concentration on running effect of MBR

In order to study the influence of DO concentration on running effect of MBR, a comparative ex-periment on MBR with DO mass concentrations of (1.0 ± 0.2)、 (3.5 ± 0.2) and (6.0 ± 0.2) mg/L respectively was carried out. Taking CODCr concentration, NH3-N concentration and dehydrogenase activity(DHA) as the re-search indicators, the influence of DO concentration on running effect of MBR were analyzed. The results of the experiment showed that, when the mass concentration of DO was 3.5 mg/L, the biological removal rates of CODCr, NH3-N and the systematic removal rate of NH3-N were all higher than those of the MBR with DO mass concen-trations of 1.0 and 6.0 mg/L. There was no significant difference among the systematic removal rates of CODCr under different DO concentration conditions; the compensation action of the membrane for CODCr was more obvi-ous than for NH3-N. When the mass concentration of DO was 3.5 mg/L, the DHA of the mixed liquid in MBR was 15.77 mg TF]/(L·h) which was higher than that with DO mass concentrations of 6.0 and 1.0 mg/L. The study clearly indicated that a proper concentration of DO was helpful to the biological removal of CODCr and NH3-N, as well as the improvement of biological activity of MBR.