Biogas from Co-digestion of Sewage Sludge and Microalgae

Microalgae cultivated in waste water could contribute to increased biomass production at municipal waste watertreatment plants. The biomass could be utilized for biogas production when co-digested with sewage sludge. In thispaper previous published results on co-digestion of sewage sludge and microalgae are summarized and remainingknowledge gaps are identified. The available batch tests in literature mostly concern digestion at mesophilicconditions. Some of those tests indicate a synergetic effect for the co-digestion. Investigations at thermophilicconditions and of semi-continuous processes are scarce. The available results show good possibilities for co-digestionof sewage sludge and microalgae. Further investigations are needed to find optimal conditions for biogas production.MAASIC