WASTEWATER TREATMENT AND CO 2 FIXATION THROUGH REVOLVING ALGAL BIOFILM PHOTOBIOREACTOR

Abstract

In the view of elevating global CO 2 level and water scarcity, the wastewater treatment integrated with microalgae production pose to be a viable option. In this study, lab scale Revolving Algal Biofilm photobioreactor was operated using cotton rope as an attachment material. Tetradesmus obliquus was immobilized on RABP using synthetic produced municipal wastewater under 2, 4 and 6 days HRT and 12:12, 14:10 and 16:08 h photoperiods. Maximum removal rates for NH 4 + - N, NO 2 - -N, PO 4 3- and COD of 80.81, 99.39, 97.56 and 84.9% was observed at 6 days HRT while highest removal per day was observed at 2 days HRT. Maximum biomass productivity of 1.921 g m -2 d -1 was observed at 2 days HRT along with highest CO 2 biofixation rates of 3.79 g m -2 d -1 . Similarly, highest nutrient removal rates for NH 4 + -N, NO 2 - -N, PO 4 3- and COD of 64.4, 99.46, 61.94 and 98.19% were observed at 14:10 h photoperiod. Results showed highest biomass productivity and CO 2 biofixation of 0.539 g m -2 d -1 and 1.06 g m -2 d -1 at 16:08 h photoperiod. Results showed the applicability of RABP for nutrient removal and microalgal growth performance along with CO 2 biofixation at low light intensity areas under varying HRTs and photoperiods.