盐度对EGSB反应器的运行及厌氧颗粒污泥的影响

高盐废水通常含有高COD浓度,难以处理,引用具有耐盐性能的生物反应器处理高盐废水成为必要.使用模拟高盐废水在3.267 kg·(m~3·d)~(-1)的COD容积负荷下,将Cl~-浓度逐步从0提升至10 000 mg·L~(-1),研究盐度对膨胀颗粒污泥床(expanded granular sludge bed,EGSB)反应器的影响.结果表明,Cl~-浓度小于7 500 mg·L~(-1)时,对微生物的抑制作用较低;Cl~-浓度为7 500 mg·L~(-1)时,反应器的COD去除率能保持在98.1%左右,容积产气率能够基本保持在1.3 m~3·(m~3·d)~(-1)以上,大粒径的厌氧颗粒污泥仍然占据体系的主体;当Cl~-浓度为10 000 mg·L~(-1)时,反应器中的厌氧颗粒污泥受到严重影响.采用高通量测序技术对0和5 000 mg·L~(-1)两个Cl~-浓度下的厌氧颗粒污泥的微生物菌群结构进行分析,结果表明,盐度影响了微生物的种群分布,在5 000 mg·L~(-1)的Cl~-浓度下,主要的优势菌属由Cl~-浓度为0时的Methanoregula与Longilinea变为Methanobacterium、Methanospirillum、Methanothrix和Paludibacter.

Effects of Salinity on the Operation of EGSB Reactors and the Anaerobic Granular Sludge

The existence of high concentrations of salinity and organics would have a great impact on the microorganisms when using bioreactors to treat wastewater. Thus, it is necessary to find bioreactors resistant to high concentrations of salinity. The effect of salinity on an expanded granular sludge bed reactor (EGSB) was studied by increasing the Cl^- concentration from 0 to 10000 mg·L^-1 using simulated high salinity wastewater with a COD volume loading of 3.267 kg·(m³·d)^-1. The results show no obvious inhibitory effect of Cl^- on the microorganism when the concentration of Cl^- was below 7500 mg·L^-1. Above 1.3 m³·(m³·d)^-1 volumetric gas production rate was maintained and COD removal rate could achieved 98.1% when the Cl^- concentration up to 7500 mg·L^-1 while the large particle size of anaerobic granular sludge occupying the majority of of the system. The anaerobic granular sludge was seriously affected when the Cl^- concentration as 10000 mg·L^-1. The community structure of the anaerobic granular sludge was analyzed using high-throughput sequencing when the Cl^- concentration was 0 and 5000 mg·L^-1. The results show that the salinity stress produced different dominant groups. The dominant species were Methanobacterium, Methanospirillum, Methanothrix, and Paludibacter when the Cl^- concentration was 5000 mg·L^-1, but Methanoregula and Longilinea were the dominant species when the Cl^- concentration was 0.