Response of aerobic sludge to AHL-mediated QS:Granulation,simultaneous nitrogen and phosphorus removal performance

The effects of different species and concentrations’signal molecules on aerobic activated sludge system were investigated through batch experiments.Results showed that the fastest NH^(+)_(4)-N oxidization rate and the most extracellular polymeric substances(EPS)secretion were obtained by adding 5 nmol/L N-hexanoyl-l-homoserine lactone(C_(6)-HSL)into the aerobic activated sludge.Further study investigated the correlation among N-acyl-homoserine lactones-mediated quorum sensing(AHLs-mediated QS),nutrient removal performances and microbial communities with the long-term addition of 5 nmol/L C_(6)-HSL.It was found that C_(6)-HSL-manipulation could enhance the stability and optimize the decontamination performance of aerobic granular sludge(AGS)system.Microbial compositions considerably shifted with long-term C_(6)-HSL-manipulation.Exogenous C_(6)-HSL-manipulation inhibited quorum quenching-related(QQ-related)activities and enhanced QS-related activities during the stable period.The proposed C_(6)-HSL-manipulation might be a potential technology to inhibit the growth of harmful bacteria in AGS,which could provide a theoretical foundation for the realization of more stable biological wastewater treatments.

磷酸铵镁法处理好氧颗粒污泥破胞释磷废水的研究

针对目前国内利用磷酸铵镁(MAP)法回收废水中磷的研究主要集中于高浓度含磷废水这一现状,对好氧颗粒污泥破胞释磷后上清液含磷质量浓度为30～80 mg/L的废水,采用MAP法回收低浓度含磷废水中的氮、磷。研究了初始pH和温度对氮、磷的去除效果及MAP结晶形成的影响。结果表明,不同温度条件下的最适宜pH范围均为9.5～10.0,考虑到回收MAP晶体的纯度,初始pH为9.5可作为MAP结晶回收磷的控制条件。

曝气方式对好氧颗粒污泥处理城市低C/N废水的探究

针对城市低C/N废水脱氮除磷效率低的现状,开发了基于不同曝气方式的好氧颗粒污泥(AGS)脱氮除磷新技术,研究了不同曝气方式对AGS去除污染的性能及污泥特征并探究相关作用机制。结果表明,相较于均匀曝气方式,逐步提高曝气强度利于AGS对污染物的去除,逐步提高曝气强度反应器中稳定出水化学需氧量(COD),溶解性磷酸盐(SOP)的去除效率分别高达91.7%~92.3%和90.5%,出水NH4+-N的质量浓度低至2.6~3.1 mg/L,上述去除效能显著高于均匀曝气及逐步降低曝气强度的反应器。机制分析表明逐渐提高曝气强度利于聚磷微生物对COD的吸收,SOP释放的浓度最高达40.3 mg/L,且出水NO3--N质量浓度低至6.3 mg/L,反硝化能力加强。此外,AGS污泥特征分析表明逐渐提高曝气提高污泥沉降性及污泥中生物量,且蛋白质与多糖的比值升高至1.42,高于其他曝气方式。