基于A^(2)O-MBR工艺的耐盐活性污泥微生物群落研究

Study on microbial community of salt-tolerant activated sludge based on A^(2)O-MBR process

基于厌氧/缺氧/好氧-生物反应器(A^(2)O-MBR)工艺装置,逐步提高进水中的总溶解性固体(TDS)进行耐盐活性污泥的驯化,考察驯化过程中TDS对化学需氧量(COD)、氨氮(NH_(4)^(+)-N)、总氮(TN)处理效果的影响。通过高通量测序技术分析膜池活性污泥耐盐驯化过程中微生物群落结构的变化。结果表明,随着TDS的增加,活性污泥微生物群落的丰富度和多样性降低。在污泥驯化初期,Arenimonas(砂单胞菌属)、Thiobacillus(硫杆菌属)为优势菌属,出水水质波动明显。当TDS为4000 mg/L时,Hydrogenophaga(噬氢菌属)的相对丰度最高,有利于氮污染物的去除,出水中各类污染物的浓度显著降低。在TDS为7000 mg/L的条件下,原优势菌属被Dechloromonas(脱氯菌属)、Thauera(陶氏菌属)和Rheinheimera(莱茵海默氏菌属)等耐盐优势菌属取代,驯化后的活性污泥在高TDS条件下仍有较强的脱氮能力及降解COD的能力,装置出水COD、NH_(4)^(+)-N、TN均可满足《污水综合排放标准》(DB 12/356—2018)的要求。

Based on anaerobic/anoxic/aerobic-bioreactor(A^(2)O-MBR)process,the total dissolved solids(TDS)in influent was gradually increased for salt-tolerant activated sludge acclimation.The effects of TDS on the treatment effects of chemical oxygen demand(COD),ammonia nitrogen(NH_(4)^(+)-N)and total nitrogen(TN)during acclimation were investigated.The changes of microbial community structure during the salt-tolerant acclimation of activated sludge in membrane tank were analyzed by high-throughput sequencing technology.The results showed that abundance and diversity of microbial community in activated sludge decreased with the increase of TDS.In the initial stage of sludge acclimation,Arenimonas(Sandomonas spp.)and Thiobacillus(Thiobacillus spp.)were the dominant genera,and the effluent quality fluctuated significantly.When TDS was 4000 mg/L,the relative abundance of Hydrogenophaga(Hydrogenophaga spp.)was the highest,which was beneficial to the removal of nitrogen pollutants,and the concentration of various pollutants in effluent were significantly reduced.Under the condition of TDS 7000 mg/L,the original dominant genera were replaced by salt-tolerant dominant genera such as Dechloromonas,Thauera and Rheinheimera.The acclimated activated sludge still had strong denitrification and COD degradation ability under high TDS conditions,and COD,NH_(4)^(+)-N and TN in the effluent could meet the requirements of Integrated Wastewater Discharge Standard(DB 12/356-2018).