The effect of slime accumulated in a long-term operating UASB using crude glycerol to treat S-rich wastewater  

作　　者：Xudong Zhou Eva Fernández-Palacios Antoni DDorado Javier Lafuente Xavier Gamisans David Gabriel 

机构地区：[1]Key Laboratory of Urban Pollutant Conversion,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China [2]GENOCOV Research Group,Department of Chemical,Biological and Environmental Engineering,Escola d’Enginyeria,Universitat Autònoma de Barcelona,08193 Bellaterra,Spain [3]Department of Mining,Industrial and ICT Engineering,Universitat Politècnica de Catalunya,Avinguda de les Bases de Manresa 61-73,08242 Manresa,Spain

出　　处：《Journal of Environmental Sciences》2024年第1期353-366,共14页环境科学学报（英文版）

基　　金：the Spanish Government,through the project RTI2018-099362-B-C21 MINECO/FEDER,EU,for the financial support provided to perform this research;the China Scholarship Council (CSC,201706300052)for financial support。

摘　　要：An up-flow anaerobic sludge blanket(UASB)reactor targeting sulfate reduction was operated under a constant TOC/S-SO2-4ratio of 1.5±0.3 g C/g S for 639 days using crude glycerol as carbon source.A filamentous and fluffy flocculant material,namely slime-like substances(SLS),was gradually accumulated in the bioreactor after the cease of methanogenic activity.The accumulation of SLS was followed by a decrease in the removal efficiencies and a deterioration in the performance.Selected characteristics of SLS were investigated to explore the causes of its formation and the effect of SLS on the UASB performance.Results showed that glycerol fermentation and sulfate reduction processes taking place in the reactor were mainly accomplished in the bottom part of the UASB reactor,as the sludge concentration in the bottom was higher.The accumulation of SLS in the UASB reactor caused sludge flotation that further led to biomass washout,which decreased the sulfate and glycerol removal efficiencies.Batch activity tests performed with granular sludge(GS),slime-covered granular sludge(SCGS)and SLS showed that there was no difference between GS and SLS in the mechanism of glycerol fermentation and sulfate reduction.However,the specific sulfate reduction rate of GS was higher than that of SLS,while SLS showed a higher glycerol fermentation rate than that of GS.The different rates in GS and SLS were attributed to the higher relative abundances of fermentative microorganisms found in SLS and higher relative abundances of sulfate reducing bacteria(SRB)found in GS.

关 键 词：Sludge flotation Granular sludge Slime-like substances Glycerol fermentation Sulfate reduction Removal efficiency 

分 类 号：X703[环境科学与工程—环境工程]