TY - JOUR
T1 - Thermophilic anaerobic digestion of coffee grounds with and without waste activated sludge as co-substrate using a submerged AnMBR
T2 - System amendments and membrane performance
AU - Qiao, Wei
AU - Takayanagi, Kazuyuki
AU - Shofie, Mohammad
AU - Niu, Qigui
AU - Yu, Han Qing
AU - Li, Yu You
N1 - Funding Information:
This work was partially supported by Japan Society for the Promotion of Science ( 24-02053 ) and Ministry of Science and Technology of China ( 2010DFA22770 ).
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2013/12
Y1 - 2013/12
N2 - Coffee grounds are deemed to be difficult for degradation by thermophilic anaerobic process. In this research, a 7L AnMBR accepting coffee grounds was operated for 82days and failed with pH dropping to 6.6. The deficiency of micronutrients in the reactor was identified. The system was recovered by supplying micronutrient, pH adjustment and influent ceasing for 22days. In the subsequent 160days of co-digestion experiment, waste activated sludge (15% in the mixture) was mixed into coffee grounds. The COD conversion efficiency of 67.4% was achieved under OLR of 11.1kg-COD/m3d and HRT of 20days. Tannins was identified affecting protein degradation by a batch experiment. Quantitative supplements of NH4HCO3 (0.12g-N/g-TSin) were effective to maintain alkalinity and pH. The solid concentration in the AnMBR reached 75g/L, but it did not significantly affect membrane filtration under a flux of 5.1L/m2h. Soluble carbohydrate, lipid and protein were partially retained by the membrane.
AB - Coffee grounds are deemed to be difficult for degradation by thermophilic anaerobic process. In this research, a 7L AnMBR accepting coffee grounds was operated for 82days and failed with pH dropping to 6.6. The deficiency of micronutrients in the reactor was identified. The system was recovered by supplying micronutrient, pH adjustment and influent ceasing for 22days. In the subsequent 160days of co-digestion experiment, waste activated sludge (15% in the mixture) was mixed into coffee grounds. The COD conversion efficiency of 67.4% was achieved under OLR of 11.1kg-COD/m3d and HRT of 20days. Tannins was identified affecting protein degradation by a batch experiment. Quantitative supplements of NH4HCO3 (0.12g-N/g-TSin) were effective to maintain alkalinity and pH. The solid concentration in the AnMBR reached 75g/L, but it did not significantly affect membrane filtration under a flux of 5.1L/m2h. Soluble carbohydrate, lipid and protein were partially retained by the membrane.
KW - Anaerobic co-digestion
KW - Coffee grounds
KW - Membrane reactor
KW - Sludge
KW - Thermophilic
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U2 - 10.1016/j.biortech.2013.10.002
DO - 10.1016/j.biortech.2013.10.002
M3 - Article
C2 - 24177158
AN - SCOPUS:84886550413
VL - 150
SP - 249
EP - 258
JO - Bioresource Technology
JF - Bioresource Technology
SN - 0960-8524
ER -
