Utilizing the eutrophication in bioresources recovery and biogas production - a case study in Egypt

In this work, the nutrients and eutrophication problem are integrated into a nature-based solution by incorporating microalgae-based nutrient removal from wastewater and collecting the residue in an anaerobic digestion plant to produce biogas that is directly exported to an existing gas-fired power plant and closes the bioresource loop. El Burullus lake in Egypt was selected as a case study because it is rich in nutrients and suitable for the integrated system. The theoretical results were promising as for one-hectare, nutrient pollution could be reduced with a total nitrogen removal rate of 4 kg d-1, a total phosphorus removal rate of 1.1 kg d-1, and a total COD removal rate of 9.3 kg d-1. The digester volume corresponding to the biomass produced was 120 m3 per hectare of algae pond and the methane yield (Y) from anaerobic digestion was 73 m^3 d^(-1).