Algae mediated treatment and bioenergy generation process for handling liquid and solid waste from dairy cattle farm

In the present work four algae were tested for their biomass production potential in neat livestock wastewater. Chroococcus sp.1 was found to be the best for biomass production under controlled (2.13 g L–1) and outdoor conditions (4.44 g L–1) with >80% of nutrients removal. The produced biomass was then digested with cattle dung as cosubstrate. Interestingly, up to 291.83 ± 3.904 mL CH4 g–1 VSfed was produced during codigestion studies (C/N ≈ 13.0/1). In contrast to this, only 202.49 ± 11.19 and 141.70 ± 2.57 mL CH4 g–1 VSfed was recorded with algae (C/N ≈ 9.26/1) and cattle dung (C/N ≈ 31.56/1) alone, respectively. The estimated renewable power generation potential of the investigated coupled process was around 333.79–576.57 kWh d–1 for a dairy farm with 100 adult cattle. However, further scale-up and testing is needed to make this process a reality.