Open AccessEffects of sludge properties in a combined process of mesophilic anaerobic-aerobic digestion
Author(s) -
Zehua Zhao,
Xiaowei Xu,
Yuanshun Xu,
Tianfeng Wang,
Houhu Zhang,
Jing Hua
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/675/1/012055
Subject(s) - anaerobic digestion , chemistry , digestion (alchemy) , retention time , aerobic digestion , mesophile , anaerobic exercise , mand , activated sludge , chromatography , extracellular polymeric substance , pulp and paper industry , food science , sewage treatment , waste management , bacteria , biology , methane , biofilm , physiology , psychology , developmental psychology , organic chemistry , autism , engineering , genetics
The combined medium-temperature anaerobic digestion and medium-temperature aerobic digestion (MAND/MAD) is a strategy that is suitable for the disposal of conventional activated sludge. The MAND/MAD sludge stabilization process was performed at three retention times (17, 24, and 38 days) of anaerobic digestion (AND-time) with further duration up to 22 days of the MAD process. The retention time of the MAND process had an important role in sludge stabilization. Its extension enhanced sludge stability in the aerobic digestion stage. During a MAD process, values of volatile/total solids ratio (VS/TS) presented the lowering course for the three investigated retention AND-times. The relatively long retention time of MAND leads to a higher level of soluble organic compounds (SCOD) and extracellular polymers (EPS) in the supernatant. Due to the shorter capillary uptake time at the end of digestion in the MAND/MAD system, the sludge with an AND-time of 38 days was extremely susceptible to dewatering compared to the sludge with an AND-time of 17 and 24 days.