Bioresource Technology, Vol.273, 297-304, 2019
Cost-effective wastewater treatment in a continuous manner by a novel biophotoelectrolysis cell (BPE) system
Approaches to improve wastewater treatment by microalgae have objectives of greater culture control, efficient nutrient removal and increased lipid content. This work designed a bio-photoelectrolysis cell (BPE) system to modulate wastewater treatment by electric current. The electric current had the capacity to enrich entrapped cell weight with a 0.72-fold increase, which resulted in high daily nutrient removal, with 6.78 mg/L/d for nitrogen and 2.14 mg/L/d for phosphorus at 0.6 A/m2. As the nutrient removal was mostly dependent on cell growth, the 1.17-fold increase of lipid productivity was achieved. The harvesting at 6 A/m2 required lower energy input of 1.77 KVVh/kg. For the recyclability of treatment, BPE system could continuously treat the fresh wastewater for at least three cycles with biomass and lipid productivities of 68.67 and 22.04 mg/L/d, respectively. The nitrogen removal model of C = 45.52-5.52exp(0.45 t) and phosphorus removal model of C, = 12.54-1.48exp(0.45 t) were established to evaluate the stability of BPE system.
Keywords:Chlorella zofing ens s;Electric current;Nutrient removal;Lipid productivity;Recyclable wastewater treatment