Microalgae cultivation in wastewater effluent from tilapia culture pond for enhanced bioethanol production

Abstract

The large number of wastewaters are generated because of the various production processes. Vegetable and fish processing can be considered an important industry for wastewater generation. The essential method for completing this waste is to digest the organic matter using anaerobic digestion followed by aerobic wastewater treatment processes. However, wastewater from tilapia culture pond retains great quantities of inorganic substances, particularly nutrients, i.e., nitrogen and phosphorus. The optimal conditions for cultivating Chlorella vulgaris from wastewater treatment effluent from tilapia culture pond were evaluated. The optimal conditions were found to be 10% initial stock suspension, 20 cm depth, and 12 days of culture conditions. C. vulgaris had an optical density of 0.649, a cell density of 17.68 × 105 cells/mL, and biomass of 0.376 ± 94.21 mg/L after cultivation. Discharged wastewater from the fishpond was utilized for the improved growth of microalgae and obtained biomass was used for bioethanol production. These results showed that fishpond wastewater is the best source of nutrients for algal mass production and biofuel applications.