TY - JOUR
T1 - Anaerobic co-digestion of microalgae Chlorella sp. and waste activated sludge
AU - Wang, Meng
AU - Sahu, Ashish K.
AU - Rusten, Bjørn
AU - Park, Chul
N1 - Funding Information:
The authors would like to thank the Research Council of Norway and Biowater Technology AS, Norway for their financial support on this research.
PY - 2013/8
Y1 - 2013/8
N2 - The study investigated the growth characteristics of environmental algal strain, Chlorella, in the modified Zarrouk medium and its anaerobic co-digestion with waste activated sludge (WAS). Analysis of extracellular polymeric substances (EPS) in algal culture and WAS indicated that Chlorella secreted more EPS into the surrounding liquid than formed floc-associated EPS as in activated sludge. Mesophilic anaerobic digestion of algae alone required extended digestion period to produce methane, with biogas yield at 262mL/gVSfed after 45days of digestion. When algae was co-digested with varying amounts of WAS, 59-96% in mass, not only biogas yield of microalgae improved but the gas phase was reached more quickly. The dewaterability of co-digestion products were also better than two controls digesting WAS or algae only. These results suggest that anaerobic co-digestion of algae and sludge improves the digestibility of microalgae and could also bring synergistic effects on the dewaterability of digested products for existing anaerobic digesters.
AB - The study investigated the growth characteristics of environmental algal strain, Chlorella, in the modified Zarrouk medium and its anaerobic co-digestion with waste activated sludge (WAS). Analysis of extracellular polymeric substances (EPS) in algal culture and WAS indicated that Chlorella secreted more EPS into the surrounding liquid than formed floc-associated EPS as in activated sludge. Mesophilic anaerobic digestion of algae alone required extended digestion period to produce methane, with biogas yield at 262mL/gVSfed after 45days of digestion. When algae was co-digested with varying amounts of WAS, 59-96% in mass, not only biogas yield of microalgae improved but the gas phase was reached more quickly. The dewaterability of co-digestion products were also better than two controls digesting WAS or algae only. These results suggest that anaerobic co-digestion of algae and sludge improves the digestibility of microalgae and could also bring synergistic effects on the dewaterability of digested products for existing anaerobic digesters.
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U2 - 10.1016/j.biortech.2013.05.096
DO - 10.1016/j.biortech.2013.05.096
M3 - Article
C2 - 23770998
AN - SCOPUS:84879449771
SN - 0960-8524
VL - 142
SP - 585
EP - 590
JO - Bioresource technology
JF - Bioresource technology
ER -
