有机负荷率对厌氧颗粒污泥处理畜禽养殖废水效能的影响探究

Study on the Effect of Organic Loading Rate on the Efficiency of Anaerobic Granular Sludge in the Treatment of Livestock and Poultry Wastewater

针对高浓度畜禽养殖废水厌氧处理效率低,构建了外循环厌氧反应器(EGSB),开展了进水有机负荷率(OLR)对EGSB处理畜禽养殖废水过程内污染物去除效能及颗粒污泥形成规律的影响,并解析相关作用机制。结果表明进水OLR提高至9.0 kg/(m^(3)·d),COD、氨氮及总磷去除维持在91.2%~95.3%、89.6%和76.9%,产气及甲烷产率分别提高至4.64~4.94 L/(L·d)和2.96~3.40 L/(L·d)。适宜提高OLR提高了污泥颗粒化,在工况III内,污泥浓度提高至6.1~6.5 g/L,大粒径污泥质量浓度增加。OLR提高增加了颗粒污泥内胞外聚合物(EPS)含量,并影响了EPS内蛋白质/多糖比值。此外,OLR能影响EGSB内微生物群落特征,且当OLR为9.0kg/(m^(3)·d)时,Firmicutes、Bacteroidetes和Proteobacteria是主要的门级别微生物,且相对丰度分别高达25.6%、16.5%和15.2%。研究结果为畜禽养殖废水高效处理提供一定理论依据。

In view of the low anaerobic treatment efficiency of high-concentration livestock and poultry breeding wastewater,an external loop anaerobic reactor(EGSB)was constructed.The effect of influent organic loading rate(OLR)on the pollutant removal efficiency and the formation of granular sludge in the process of EGSB treating livestock and poultry breeding wastewater was carried out.The relevant mechanism was analyzed.The results showed that the influent OLR was increased to 9.0 kg/(m^(3)·d),the removal of COD,ammonia nitrogen and total phosphorus was maintained at 91.2%~95.3%,89.6%and 76.9%respectively,and the gas production and methane yield were increased to 4.64~4.94 L/(L·d)and 2.96~3.40 L/(L·d).The proper increase of OLR improves the sludge granulation.In condition III,the sludge concentration increases to 6.1~6.5 g/L and the mass concentration of large particle size sludge increases.The increase of OLR increased the content of extracellular polymer(EPS)in granular sludge and affected the ratio of protein to polysaccharide in EPS.In addition,OLR can affect the characteristics of microbial communities in EGSB,and when the OLR is 9.0 kg/(m^(3)·d),Firmicutes,Bacteroidetes and Proteobacteria are the main phyla microorganisms,and their relative abundance is 25.6%,16.5%and 15.2%,respectively.The results provide a theoretical basis for the efficient treatment of livestock and poultry wastewater.