镍对餐厨垃圾厌氧消化中挥发酸降解的影响

Effects of Nickel on Volatile Fatty Acids Degradation during Anaerobic Digestion Process of Kitchen Waste

针对高浓度有机废物厌氧消化过程中易发生反应器酸化问题,通过投加镍(Ni^(2+))来强化挥发性脂肪酸(VFAs)降解,考察镍强化VFAs降解和产生物气的效果。试验结果表明,当镍投加量为0.5 mg/kg TS时,反应11 h后,VFAs浓度降低至80.9 mg/L,生物气产量明显升高。长期连续试验发现,在反应器中积累90 d的VFAs可在投加Ni^(2+)后的10 d内完全降解,系统稳定后的平均生物产气速率达到0.548 m^3/(kg VS·d)。对古细菌群落结构和VFAs组成结构的分析表明,投加Ni^(2+)以后Methanosarcina和Methanosaeta所占比例分别从25.5%和28.8%升高至30.3%和32.6%,促进了VFAs中乙酸和丙酸的降解。

For reactor acidification problem during anaerobic digestion of high concentration organ- ic waste, Ni2＋ was added to enhance volatile fatty acids （VFAs） degradation, and the effects of nickel enhancing VFAs degradation and biogas production were investigated. Results showed that the biogas pro- duction increased obviously after 11 hours when dosage of Ni2 ＋ was 0. 5 mg/kgTS and the VFAs concen- tration was decreased to 80.9 mg/L. During the long-term continuous test, VFAs accumulated in 90 days were completely degraded in 10 days after Ni2＋ addition, and average methane production rate was up to 0. 548 m3/（kgVS · d） after the system was stable. Comprehensive analysis of archaea and VFAs compo- sition indicated that the ratio of Methanosarcina and Methanosaeta increased from 25.5% and 28.8% to 30.3% and 32.6% respectively after Ni2＋ addition, which eventually led to the degradation of acetic and propionic acids.