三氯生对剩余污泥碱性发酵及微生物群落结构的影响

Effect of triclosan on alkaline fermentation and microbial community structure of excess activate sludge

考察了三氯生(TCS)对剩余污泥碱性发酵(pH 10)产酸效果的影响。当TCS投加量为400 mg/kg(以TSS计)且发酵5 d时,短链脂肪酸(SCFA)的产量最高,为2740.96 mg/L(以COD计),相比未投加TCS时提高了352.54 mg/L;该体系中,乙酸在SCFA中的占比最高(质量分数达36.73%),以VSS减少率表征的有机质减少率最大(达40.50%),有助于污泥资源化利用。TCS促进了污泥碱性发酵的溶解、水解和酸化过程,同时增强了水解酶的活力,为产酸微生物提供更多底物。TCS显著强化了厚壁菌门和放线菌门微生物在污泥碱性发酵过程中的富集,尤其是厚壁菌门的厌氧醋酸菌属和泰氏菌属微生物(相对丰度分别达15.88%和6.12%),有利于SCFA的积累。

The effect of triclosan(TCS)on acid production in alkaline fermentation(pH 10)of residual sludge was investigated.When the TCS amount is 400 mg/kg(calculated by TSS)and the fermentation time is 5 d,the highest yield of short-chain fatty acid(SCFA)is achieved at 2740.96 mg/L(calculated by COD),which is 352.54 mg/L higher than that without TCS;The system has the highest percentage of acetic acid in SCFA(36.73%of mass fraction)and the highest reduction rate of organic matter(40.50%,characterized by VSS reduction rate),which contributed to the resource utilization of sludge.TCS promoted the dissolution,hydrolysis and acidification processes of sludge alkaline fermentation,while enhancing the activity of hydrolytic enzymes and providing more substrates for acidproducing microorganisms.TCS significantly enhanced the enrichment of Firmicutes and Actinobacteria in the alkaline sludge fermentation process,especially the Acetoanaerobium and Tissierella of Firmicutes(with the relative abundance of 15.88%and 6.12%,respectively),which facilitate the accumulation of SCFA.