Fe3O4对含盐废水厌氧处理系统的影响

通过在固定的水力停留时间下(24h)逐步提升盐度,并设置有无Fe₃O₄的平行反应器作对照,考察不同盐度水平下Fe₃O₄对厌氧系统运行效能和厌氧污泥颗粒化进程的影响。结果表明,在0~2%的NaCl盐度水平下,Fe₃O₄的加入均能有效提升厌氧系统的处理效率并保证其稳定进行。Fe₃O₄对产甲烷过程的促进作用在不同盐度水平下有所差异,当盐度分别为0,0.5%,1%,2%时,实验组的甲烷产量分别为对照组的1.08,1.36,1.33和1.17倍,低盐环境下的促进效果更为显著。污泥特性和胞外聚合物的分析结果发现,Fe₃O₄的引入有利于形成结构更为紧密的厌氧颗粒污泥,进而强化厌氧污泥颗粒化进程。微生物群落结构分析结果表明,随着盐度提升,氢型产甲烷菌得以快速富集,同时主要细菌类型和代谢途径均发生了改变。而Fe₃O₄对厌氧系统中微生物菌群结构和代谢途径的影响在低盐度(0.5%)和较高盐度(1%,2%)下也存在显著差异。

Influence of Fe3O4 on the anaerobic treatment system of saline wastewater

The salinity was stepwise increased at fixed hydraulic retention time of 24h, two parallel anaerobic reactors with and without Fe₃O₄ were applied to investigate the influence of Fe₃O₄ on operational performance and sludge granulation of anaerobic system. The addition of Fe₃O₄ could effectively enhance the anaerobic treatment efficiency and ensure the stable operation at all tested salinity. The improvement of Fe₃O₄ on methane yield differed significantly at salinity varying from 0~2%. At salinity of 0, 0.5%, 1% and 2%, the methane yield of Fe₃O₄-supplemented reactor was 1.08, 1.36, 1.3 and 1.17-fold of the contrast reactor, the enhancement of Fe₃O₄ on methane yield was more significant under low salinity. In addition, the sludge properties and extracellular polymer substances secretion during the operation process were simultaneously analyzed as well. The results showed that the addition of Fe₃O₄ facilitated the formation of closely-packed anaerobic granular sludge, thus enhanced the anaerobic granulation process. According to the microbial community structure analysis, hydrogenotrophic methanogens were rapidly enriched with the increase of salinity, while the main bacterial consortium and metabolic pathways were changed as well. The effects of Fe₃O₄ on the microbial community structure and metabolic pathway of anaerobic system were also observed obviously distinct under low salinity (0.5%) and high salinity (1%, 2%).