硫酸盐生物还原过程中涉硫组分代谢特性

Characteristic of metabolism for sulfur-containing components during sulfate bioreduction process

通过硫酸盐生化代谢过程中涉硫组分(SO_4^(2-)、SO_3^(2-)、H_2S、S^(2-)、S_2O_3^(2-)、微生物含硫)等代谢特性模式研究,揭示了代谢过程中的主要限速步骤及过程代谢产物演替规律。SRB还原过程中限速步骤主要为亚硫酸根转化为硫化氢的过程,利用氮气吹脱硫化氢后,反应终点时各涉硫组分占总硫的51.38%,硫离子的量增加了2.09倍,硫酸根的去除率从83.5%提高到91.24%,亚硫酸根浓度呈现出降低的趋势;pH明显上升,并最终达到8.31,而无吹脱硫化氢的反应器最终pH为6.87。反应器中脱硫弧菌为优势菌,硫化氢被吹脱后,微生物在目、科、属水平上优势菌得到提高,硫化氢的存在抑制了优势菌的增殖。

The characteristic of metabolism for sulfur-containing components （SO4^2-, SO3^2-, H2S, S^2-, S2O3^2- and microbial sulfur） during sulfate bioreduction process was investigated, and rate-limiting step as well as the succession process of metabolites was illustrated. It was shown that the conversion of sulfite to hydrogen sulfide was regarded as the rate-limiting step in the process of sulfate reducing bacteria reduction. The amount of sulfur ion was increased by 2.09 times and the removal efficiency of sulfate radical was increased from 83.5% to 91.24% after blowing hydrogen sulfide by nitrogen, while the concentration of sulfite was decreased. The sulfur-containing components accounted for 51.38% of the total sulfur at the end of the reaction. Furthermore, it was indicated that the pH of the solution was increased significantly and eventually reached to 8.31. In contrast, the corresponding pH of 6.87 in the reactor was obtained without purging hydrogen sulfide. Besides, the results also demonstrated that Desulfovibrio sp was the dominant bacteria in the reactor, and the amount of these dominant bacteria were increased at the level of the order, family and genera after blowing off hydrogen sulfide. The presence of hydrogen sulfide was proved to inhibit the proliferation of the dominant bacteria.