Anaerobic co-digestion of microalgae Chlorella sp and waste activated sludge

作者：Wang Meng; Sahu Ashish K; Rusten Bjorn; Park Chul^*

来源：Bioresource Technology, 2013, 142: 585-590.

DOI：10.1016/j.biortech.2013.05.096

• Chlorella
• Waste activated sludge
• Anaerobic co-digestion
• Extracellular polymeric substances (EPS)
• Dewaterability

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 262 mL/gVS(fed) after 45 days 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.

• 出版日期2013-8