处理BPA模拟废水的SBR工况参数对污泥有机毒性的影响研究

在处理双酚A(BPA)模拟废水的序批式活性污泥系统(SBR)反应器中,保持进水COD含量均为300 mg·L-1左右,通过改变水力停留时间HRT从12~8 h,污泥龄SRT从20~10 d,考察污泥有机毒性和其他水质指标的变化.试验分析了空白组和40 mg·L-1初始浓度BPA对照组在不同工况条件下周期末出水COD值、污泥有机毒性分布规律以及稳定期单周期内COD值和污泥有机毒性的变化趋势.结果表明,缩短水力停留时间和污泥龄有利于活性污泥降解BPA,并消减稳定期污泥的有机毒性;出水COD稳定在50 mg·L-1左右,且水相和泥相均无BPA残留.在应用PCR-DGGE技术分析SBR系统内微生物菌群多样性和不同样品间的相似性过程中,得出污泥总毒性抑制率与微生物多样性呈负相关性关系,进水成分的不同和运行参数改变是导致污泥总毒性差异的主要原因.

Effects of Operating Parameters on Organic Toxicity of Sludge Treating Synthetic Bisphenol A Wastewater

In order to investigate the influence of hydraulic retention time (HRT) and sludge retention time (SRT) on sludge organic toxicity in sequencing batch reactors (SBR_S), the sludge toxicity was compared when HRT and SRT were controlled at various levels. The influents COD were controlled at around 300 mg·L^-1, HRT and SRT were changed from 12 h to 8 h and from 20 d to 10 d, respectively. The effluents COD, BPA contents both in liquid and sludge were measured, and sludge toxicity was also analyzed and compared between the blank group (no BPA content) and BPA control groups (40 mg·L^-1). The results showed that the effluents COD of two SBRs were both below 50 mg·L^-1, and there were no BPA content in liquid and sludge. Furthermore, decrease HRT and SRT is helpful to remove BPA and reduce sludge toxicity. Additional investigation revealed a correlation between the properties of bacterial community and total sludge toxicity by the PCR-DGGE analysis, and different influent compositions and operation parameters were the main reasons for leading the difference of sludge toxicity.