摘要
剩余污泥的水解破壁是其厌氧消化的限速步骤。投加Fe(Ⅲ)氧化物可富集具有异化铁还原功能的Fe(Ⅲ)还原菌,强化复杂有机物的分解,是一种促进剩余污泥水解破壁的有效手段。然而,在实际工程中,连续投加Fe(Ⅲ)氧化物不经济。亚硝酸盐作为反硝化中间产物,被报道能促进污泥水解破壁,同时可将污泥中的Fe(Ⅱ)化学氧化为Fe(Ⅲ),但对于亚硝酸盐引发的Fe(Ⅱ)氧化和Fe(Ⅲ)还原过程对污泥水解破壁及后续厌氧消化的影响却鲜有报道。向剩余污泥中添加亚硝酸盐,发现其中97.3%的Fe(Ⅱ)被氧化为Fe(Ⅲ),进而参与异化铁还原。扫描电镜和三维荧光光谱结果表明,添加亚硝酸盐组污泥水解破壁明显,有机物大量释出;微生物群落分析表明,添加亚硝酸盐组反硝化细菌和Fe(Ⅲ)还原菌显著富集。厌氧消化结束后,相比对照组(未添加亚硝酸盐),添加亚硝酸盐组污泥减量化和累积甲烷产量分别提高21%和86%。
Hydrolysis including the cell disintegration is the rate-limiting step of anaerobic digestion of waste activated sludge.Adding Fe(Ⅲ)oxides to enrich the Fe(Ⅲ)-reducing bacteria via the dissimilatory iron reduction can enhance the decomposition of complex organic compounds,which is considered as an effective method to promote the hydrolysis and cell disintegration of waste activated sludge.However,the continuous addition of Fe(Ⅲ)oxides is uneconomical in the practical engineering.Adding nitrite,the intermediates in the denitrification,has been reported to promote the hydrolysis and cell disintegration of waste activated sludge.In the meantime the Fe(Ⅱ)in the sludge can be chemically oxided to Fe(Ⅲ).However,there are few reports on the effects of nitrite induced Fe(Ⅱ)oxidation and Fe(Ⅲ)reduction processes on sludge hydrolysis and cell disintegration and subsequent anaerobic digestion.In this study,adding nitrite into the waste activated sludge caused the oxidation of Fe(Ⅱ)with an efficiency of 97.3%.The produced Fe(Ⅲ)further drove the dissimilatory iron reduction.Analysis of scanning electron microscope and three dimensional fluorescence spectrum indicated that the hydrolysis and cell disintegration of waste activated sludge were significantly enhanced in the nitrite-added group,accompanied by the release of large amounts of soluble organic compounds.Analysis of microbial community showed that,both denitrifying and Fe(Ⅲ)-reducing bacteria were significantly enriched in the nitrite-added group.After anaerobic digestion,the sludge reduction and accumulative methane production in the nitrite-added group were 21%and 86%higher than that in the control group without nitrite,respectively.
作者
孟雨桐
赵智强
高金索
张耀斌
MENG Yutong;ZHAO Zhiqiang;GAO Jinsuo;ZHANG Yaobin(School of Enviromental Science and Technology,Dalian University of Technology,Dalian 116024,Liaoning,P.R.China)
出处
《土木与环境工程学报（中英文）》
CSCD
北大核心
2021年第6期155-164,共10页
Journal of Civil and Environmental Engineering
基金
国家自然科学基金(21777016),辽宁省“兴辽英才计划”(XLYC1902075)。
关键词
剩余污泥
水解破壁
异化铁还原
亚硝酸盐
Fe(Ⅱ)氧化
waste activated sludge
hydrolysis and cell disintegration
dissimilatory iron reduction
nitrite
Fe(Ⅱ)oxidation
