投加颗粒活性炭和二氧化锰对剩余污泥厌氧消化的影响

厌氧系统添加碳和金属纳米材料是强化厌氧消化的有效策略.为考察投加GAC和MnO₂对剩余污泥厌氧消化过程的影响，设置了空白组（R0）、GAC组（R1）、MnO₂组（R2）以及GAC/MnO₂组（R3）4组间歇实验，研究GAC和MnO₂的投加对剩余污泥厌氧消化效率、微生物活性和微生物群落结构的影响.结果表明，反应器运行28 d后，与R0相比，R1和R3的产CH₄速率分别提高了68.18%和51.35%，R2的产CH₄量降低了21.25%.GAC和MnO₂的单独或者混合投加，对厌氧发酵过程均有促进作用.Mn²⁺与剩余污泥释放的磷酸盐生成磷酸盐沉淀对厌氧代谢通道的阻塞作用，造成R2产CH₄效率变低.GAC优良导电性、吸附能力和MnO₂/Mn²⁺的催化作用是R3产CH₄效率增强的主要原因.正常代谢条件下，投加GAC、MnO₂和GAC/MnO₂均可以提高污泥厌氧消化系统微生物活性.微生物群落分析表明，GAC和MnO₂促进了产甲烷菌Methanobacterium和Methanosaeta的富集，强化了发酵细菌和产甲烷菌的种间电子传递，促进了剩余污泥厌氧发酵过程和CH₄的产生.

Effect of Adding Granular Activated Carbon (GAC)/Manganese Dioxide (MnO2) for the Anaerobic Digestion of Waste Activated Sludge

The addition of conductive materials or metal oxide nanoparticles to an anaerobic system is an attractive strategy to enhance anaerobic digestion. The effect of granular activated carbon (GAC) and/or manganese dioxide (MnO₂) on waste activated sludge (WAS) anaerobic digestion was investigated by batch experiments. The experiments were provided in control, GAC, MnO₂, and GAC/MnO₂ groups, which were named R0, R1, R2, and R3, respectively. The sludge characteristics, microbial activity, and microbial community structure were systematically investigated. Results showed that CH₄ yield rate was evidently increased by 68.18% and 51.35% in R1 and R3, respectively, whereas the cumulative CH₄ production decreased by 21.25% in R2, compared with R0. Moreover, the fermentation process could be promoted with the addition of GAC and/or MnO₂. The phosphate precipitation generated by Mn²⁺ and phosphate released from WAS blocked the anaerobic metabolic channel and then decreased the production of CH₄ in R2. The increase in CH₄ yield rate in R3 was mainly attributed to the conductivity and adsorption of GAC and the catalysis of MnO₂. Additionally, the microbial activity could be promoted with the addition of GAC, MnO₂, and GAC/MnO₂ in anaerobic digestion. Microbial community structure analysis showed that the abundance of the Methanobacterium and Methanosaeta increased with the addition of GAC and MnO₂, which could enhance the interspecies electron transfer between fermenting bacteria and methanogens and boost fermentation and CH₄ production.