Anaerobic digestion of aerobic granular sludge and flocculent activated sludge: Degradation kinetics and characteristics variations of alginate-like extracellular polymeric substances
To understand the degradation kinetics and the variation in mechanical properties of sludge during the anaerobic digestion (AD),a comparative batch experiment on AD of aerobic granular sludge (AGS) and flocculent activated sludge (AS) was carried out for 44 days.Alginate-like extracellular polymeric substances (ALE),being responsible for the aggregation of sludge,were extracted from both types of sludge during the AD process.Their chemical and mechanical properties were measured and compared.Based on the biochemical methane potential (BMP) tests,the simulated results using a two-substrate model revealed that the hydrolysis rate during the AD process of AGS was significantly lower than that of AS,although the overall methane potential of both types of sludge were comparable.Meanwhile,the extracted ALE from both AGS and AS contributed to 13.04 % and 14.35 % of the total sludge VS reduction,respectively.The results of the second derivative fourier transform infrared (FT-IR) and three-dimensional excitation and emission matrix (3D-EEM) analysis showed that the changes in the spectra of ALE isolated from the AGS presented substantial difference with that from AS during the AD process.Moreover,the variation of mechanical properties of ALE was measured by gelation tests using Ca2+-ALE hydrogel and it was found that the reduction in mechanical strength of ALE from AGS was less than that from AS upon AD.These evidences indicated that (1) pretreatment for the AGS is recommended in order to enhance hydrolysis of AGS during the AD process,(2) the mechanical structure of granules is more difficult to be destroyed compared to that of sludge flocs due to the less degradation of polysaccharides and proteins in ALE from AGS during the AD process and (3) given the limited strength reduction after AD,ALE could be extracted from the digestate of AGS digestion for product recovery.
Anaerobic digestion Aerobic granular sludge Activated sludge Degradation kinetics Alginate-like extracellular polymeric substances Gel-forming property
H.Guo J.Fang S.Felz Y.Lin J.B.van Lier M.de Kreuk
Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Te Department of Biotechnology, Faculty of Applied Science, Delft University of Technology, Van der Maa
国际会议
The 15th IWA World Conference on Anaerobic Digestion( 第15届IWA世界厌氧大会)
北京
英文
487-490
2017-10-17（万方平台首次上网日期，不代表论文的发表时间）