Fe_(2)O_(3)提高高浓造纸污水厌氧颗粒污泥产甲烷性能的机理研究

Mechanism of Fe_(2)O_(3) to Enhance Methanogenesis of Anaerobic Granular Sludge from High Concentration Papermaking Wastewater

针对厌氧颗粒污泥反应器在处理高钙离子含量造纸污水时存在的钙化和失活问题,探究在厌氧反应器中添加Fe_(2)O_(3)对厌氧颗粒污泥胞外聚合物分泌的影响及颗粒污泥中微生物群落的变化。结果表明:Fe_(2)O_(3)的加入显著提高了胞外聚合物的含量(特别是多糖和蛋白质含量),促进了微生物聚集。胞外聚合物中腐殖质等氧化还原介质含量的增加可能参与了产甲烷菌和相互作用的细菌之间的种间直接电子转移,使得厌氧消化过程中甲烷的生成速率提高。添加15 g/L的Fe_(2)O_(3)可使甲烷产量比对照提高67.6%。此外,添加Fe_(2)O_(3)可以改变污泥中的微生物群落,促进产甲烷菌的生长,Fe_(2)O_(3)富集了功能微生物(如Tepidimicrobium),强化了铁的异化还原作用。本研究有助于提高厌氧反应器性能,延缓高钙污水中厌氧颗粒污泥的钙化。

To cope with calcification and inactivation of anaerobic granular sludge in the treatment of effluent with a high-calcium ion content in a paper mill,Fe_(2)O_(3) was applied in the anaerobic reactor.This study aims to investigate the role of Fe_(2)O_(3)on extracellular polymeric substance(EPS)secretion and microbial community structure variation during the anaerobic digestion.The results show that the addition of Fe_(2)O_(3)could increase the content of extracellular polymers significantly(especially polysaccharides and protein content)and promote microbial aggregation.The increase in the content of redox mediators like humus in the extracellular polymeric substance demonstrates that they might directly participate in the interspecies electron transfer(DIET)between methanogens and interacting bacteria.The rate of methanogenesis in anaerobic digestion was accelerated by sub-transfer.The results also show that adding Fe_(2)O_(3)15 g/L could increase methane production by 67.6%compared with the control.Fe_(2)O_(3)changed the microbial community in the sludge and promoted the growth of methanogens.Fe_(2)O_(3)enriches functional microorganisms(such as Tepidimicrobium)and strengthens the dissimi-latory reduction of iron.This study is conducive to improving the performance of an anaerobic reactor and delaying the calcification of anaerobic granular sludge in the effluent with high-calcium ions in a paper mill.