Post treatment of microalgae treated pharmaceutical wastewater in photosynthetic microbial fuel cell (PMFC) and biodiesel production

Abstract

Microalgae can utilize the pollutants from wastewater as substrate and act as a renewable feedstock for biodiesel production. In this study, the pharmaceutical wastewater was pretreated in photobioreactor (PBR) using microalgae Scenedesmus abundans. The pretreated effluent was further treated in a photosynthetic microbial fuel cell (PMFC) for production of biomass and electricity. The biomass generated in PBR and PMFC was used for biodiesel production. At the end of pretreatment process, maximum 77 ± 3% of the COD was removed along with nitrate and phosphate removal of 82 ± 0.5 and 65.9 ± 0.4%, respectively. In continuation of the treatment process, in PMFC a maximum of 88 ± 3% COD was removed resulting in 97.24% total COD removal. Overall (97.12% Nitrate and 93.71% phosphate) were also removed. A maximum voltage of 745.96 mV and power density of 838.68 mW/m2 were achieved. The amount of biomass produced in PBR and PFMC process was 0.97 ± 0.01 g/L and 0.94 ± 0.01 g/L, respectively. Fatty acid profile of Scenedesmus abundans from both the processes has shown the presence of ample amount of saturated and unsaturated fatty acids with C16 and C18 carbon chain. This study indicates that the integration of microalgal pretreatment may help in an efficient bioremediation process of pharmaceutical wastewater as well as bioelectricity production. © 2019 Elsevier Ltd