Inclined algal biofilm photobioreactor (IABPBR) for cost-effective cultivation of lipid-rich microalgae and treatment of seawater-diluted anaerobically digested effluent from kitchen waste with the aid of phytohormones.

Previous study has demonstrated that freshwater can be replaced with seawater for dilution of feed to algal production and wastewater treatment, but high harvest cost in suspended-growth systems is still a troublesome limitation for large-scale production. Therefore, a novel inclined algal biofilm photobioreactor (IABPBR) was constructed for algal bioproduct production and treatment of seawater-diluted anaerobically digested effluent (SA) in this study. Fluffy polyester was selected as the best carrier for the algal biofilm among ten discarded materials. With the help of phytohormones, the viability of SDEC-18 was clearly enhanced and an algal biomass productivity of 5.66 g/m/d was achieved. The SDEC-18 biofilm provided removal capacities of 0.65, 0.25 and 3.31 g/m/d for TN, TP and COD. Phytohormones clearly enhanced the lipid biosynthesis, with an extraordinary lipid productivity of 3.98 g/m/d being achieved. Moreover, an automatic harvesting system was designed for the efficient harvesting process during large-scale production.