School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China; Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology, Jiangnan University, Wuxi, 214122, China.
Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
J Environ Manage. 2022 May 15;310:114774. doi: 10.1016/j.jenvman.2022.114774. Epub 2022 Feb 23.
The in-situ hydrogen supply by nano zero-valent iron (nZVI, nFe) corrosion provided a feasible way to improve the efficiency of biogas biological upgrading. This work studied the effects of nZVI at different dosages (0, 2, 4, 6, 8 and 10 g/L) on anaerobic digestion of kitchen wastewater by two buffer systems 2-[4-(2-hydroxyethyl) piperazin-1-yl] ethanesulfonic acid (HEPES) and sodium hydrogen carbonate (NaHCO). The addition of nZVI improved the content of methane (CH) and stability of anaerobic digestion process. In HEPES buffer system, the CH was all increased and the maximum reached 90.51% with 10 g/L nZVI, higher than 32.25% compared to the control. The maximum hydrogen enrichment (HE) was 113 ppb after nZVI addition, indicating the mass transfer efficiency of hydrogen (H) was improved. Microbial community analysis showed that the total relative abundance of Methanobacterium and Methanolinea at 10 g/L nZVI was 53.72%, which was 1.62 times of the control group. However, in the NaHCO buffer system with 10 g/L nZVI addition, the content of CH and the loosely bound extracellular polymeric substances (LB-EPS) was lower than the control. The results indicated that the addition of nZVI was feasible for biogas upgrading, and the bidirectional effect of nZVI on the promotion or inhibition of bio-methanation might be related to the buffer system of the anaerobic process.
纳米零价铁（nZVI，nFe）腐蚀原位提供氢气为提高沼气生物升级效率提供了一种可行的方法。本工作研究了不同剂量（0、2、4、6、8 和 10 g/L）的 nZVI 对两种缓冲体系 2-[4-(2-羟乙基)哌嗪-1-基]乙磺酸（HEPES）和碳酸氢钠（NaHCO3）厌氧消化厨房废水的影响。添加 nZVI 提高了甲烷（CH）的含量和厌氧消化过程的稳定性。在 HEPES 缓冲体系中，CH 全部增加，添加 10 g/L nZVI 时达到 90.51%，比对照提高 32.25%。添加 nZVI 后最大氢富集（HE）达到 113 ppb，表明氢（H）的传质效率提高。微生物群落分析表明，添加 10 g/L nZVI 时 Methanobacterium 和 Methanolinea 的总相对丰度为 53.72%，比对照组高 1.62 倍。然而，在添加 10 g/L nZVI 的 NaHCO3 缓冲体系中，CH 的含量和松散结合的胞外聚合物物质（LB-EPS）低于对照。结果表明，添加 nZVI 可用于沼气升级，nZVI 对生物甲烷化促进或抑制的双向作用可能与厌氧过程的缓冲体系有关。
