RSI-MO工艺对沼气脱硫的影响及微生物种群分析

为实现剩余污泥厌氧消化沼气原位深度脱硫，采用向反应器中嵌入最佳剂量（20g/L）废铁屑并引入微氧条件，构建废铁屑-微氧（RSI-MO）消化工艺，探索其对原位脱硫的影响.研究分7阶段，P1阶段对照组，P2阶段加入RSI，P3~P7阶段逐步提高O₂剂量.结果表明，MO效应激发硫氧化菌（SOB）生物脱硫，促发RSI化学腐蚀而生成铁硫沉淀物.P1~P7阶段，RSI与MO交互作用可促进水解酸化，但O₂剂量过高会抑制产甲烷微生物活性，造成VFAs积累.为研究RSI与MO交互作用对微生物群落多样性和丰度的影响，取P1、P2和P6阶段污泥样品进行高通量测序发现，RSI投加有益于产氢型微生物（Syntrophobacter fumaroxidans）、产乙酸型微生物（Roseomonas lacus、Sporomusa silvacetica）、产甲烷微生物（Methanoculleus palmolei、Methanolinea tarda、Methanosarcina mazei、Methanosaeta concilii、Methanococcus aeolicus）的生长.MO效应可激活SOB的活性，强化生物脱硫作用.

Influence of RSI-MO process on biogas desulfurization and analysis of microbial communities

To achieve in-situ deep desulfurization of biogas derived from waste-activated sludge (WAS) anaerobic digestion, an integrated approach of optimal rusty scrap iron addition (20g/L) with micro-oxygen injection (RSI-MO) was constructed to disclose their combined influences on the performance of in-situ desulfurization. The operation of semi-continuous anaerobic/microaerobic reactor included seven stages (P1~P7). The operation of first stage (P1) was set as the control. The addition of RSI was started at the second stage (P2). The oxygen was introduced in P3 stage, and the concentrations were gradually increased from P3 to P7 stages. The results showed that MO induced the microbial sulfide oxidation by stimulating sulfur-oxidizing bacteria (SOB), and simultaneously promoted the chemical corrosion on iron to generate iron-sulfide precipitation. From P1 to P7, the synergistic effects of RSI and MO contributed to the hydrolytic-acidogenic efficiency. However, the overdose of oxygen inhibited the activities of methanogenic microorganisms, which caused the accumulation of VFAs. To demonstrated the combined effects of RSI and MO on the microbial diversity and abundance, the microbial communities in sludge samples of P1, P2 and P6 were analyzed via the high-throughput sequencing technology. The microbial analysis suggested that the RSI addition stimulated the activity of hydrogen-producing microorganisms (Syntrophobacter fumaroxidans), acetate-producing microorganisms (Roseomonas lacus, Sporomusa silvacetica) and methanogenic microorganisms (Methanoculleus palmolei, Methanolinea tarda, Methanosarcina mazei, Methanosaeta concilii, Methanococcus aeolicus) while the MO stimulated the activity of SOB for biological desulphurization enhancement.