NaCl对反硝化脱硫工艺运行效果的影响

Effect of NaCl on denitrifying sulfide removal process

采用UASB反应器研究当NaCl质量浓度为2~35 g/L时对反硝化脱硫工艺以及微生物群落结构的影响。结果表明:NaCl从2 g/L增加至35 g/L的过程中,提高S∶C∶N至1∶3∶1可以保持高的单质硫产率;反应器内异养反硝化菌属所占比例随NaCl质量浓度的增加而减小,而自养反硝化菌属所占比例却随之增加;NaCl存在时,有机物的增加能够影响亚硝酸盐还原速率,从而使硫化物氧化停留在单质硫阶段,且高质量浓度NaCl条件下兼性自养反硝化微生物能同时参与硫化物的氧化、硝酸盐的反硝化和有机物的降解,使反硝化脱硫工艺维持较好的处理效果。

The UASB reactor was used to investigate the effects of NaCl on denitrifying sulfide removal process performance and microbial community structure when concentration of NaCl ranges from2g/L to35g/L in this study.The results show that high production rate of S in the process could be maintained by increasing the ratio of S∶C∶N up to1∶3∶1when concentration of NaCl is increased from2g/L to35g/L.It is also found that with the increase of NaCl concentration,the proportion of heterotrophic denitrification bacteria decreases instead of the proportion of autotrophic denitrification bacteria increases.When there is NaCl,the increase of organic compounds could influence the reduction rate of nitrite,which keeps the sulfide oxidation at the elemental sulfur stage.Also,the autotrophic denitrification microorganism can simultaneously participate in the sulphide oxidization,denitrification of nitrate,and degradation of organic compounds at high NaCl concentration,which lead to the good results of the denitrifying sulfide removal process.