ZVI对剩余污泥与柑橘废渣厌氧共发酵产酸研究

Effects of ZVI on the production of volatile fatty acids from waste activated sludge and citrus waste by anaerobic co-fermentation

考察了零价铁(ZVI)对剩余污泥与柑橘废渣共发酵系统的产酸性能影响.结果表明:投加ZVI可以提高共发酵系统中挥发性脂肪酸(VFA)产量和甲烷累积产量,当ZVI投加量为5 g·L^(-1)时,VFA产量和甲烷累积产量分别是空白组的1.48倍和1.52倍;ZVI能提高厌氧发酵系统的pH值和降低厌氧发酵系统的ORP值,且对厌氧发酵各阶段(增溶、水解、产酸和产甲烷)均有一定的促进作用,相关酶活性明显提高.微生物群落分析发现,投加ZVI能提高梭状芽胞杆菌纲(Clostridia)的相对丰度,促进厌氧发酵的水解过程;降低欧陆森氏菌属(Olsenella)的相对丰度,提高了乙酸含量;甲烷球形菌属(Methanosphaera)和甲烷杆菌属(Methanobacterium)的相对丰度较空白组分别提高了28.84%和8.80%,ZVI有利于氢营养型产甲烷菌生长,对产甲烷过程有一定促进作用.研究结果为提高剩余污泥于柑橘废渣厌氧共发酵系统产酸性能提供理论依据.

The effects of zero-valent iron(ZVI)on the production of volatile fatty acids from waste activated sludge and citrus waste by anaerobic cofermentation were investigated.The results indicated that the presence of ZVI enhanced the volatile fatty acid(VFA) yield and methane(CH4) yield in the co-fermentation system.When the concentration of ZVI was 5 g·L^(-1),the VFA production and methane cumulative production were 1.48 times and 1.52 times higher than that those of the control group,respectively.ZVI could increase the pH value and decreased the ORP value of the anaerobic fermentation system,and had a certain effect on the all stages of anaerobic fermentation(solubilization,hydrolysis,acid production and methane production),with a significant increase in the activities of related enzymes.Microbial community analysis revealed that the addition of ZVI could increase the relative abundance of Clostridia and promote the hydrolysis process of anaerobic fermentation,reduce the relative abundance of Olsenella and promote acetic acid content;the relative abundance of Methanosphaera and Methanobacterium increased by 28.84% and 8.80% compared with that of the control group.The introduction of ZVI demonstrated a favorable impact on the growth of hydrogenotrophic methanogens and promoted the methanogenesis process.The research results provide a theoretical basis for improving the acid production performance of the anaerobic co-fermentation system of waste activated sludge and citrus waste.