Simultaneous biodiesel and bioelectricity generation utilizing dairy and rice mill wastewater by freshwater microalgal isolate: An integrated energy-efficient approach

Abstract

A negative impact is posed on the environment because of the rapid depletion of non- renewable feedstocks. Microalgae are excellent candidates that can be used as sustainable feedstock for biodiesel production. Implementing wastewater treatment along with bioenergy (biodiesel and bioelectricity) generation by cultivating microalgae in wastewater is a practical solution. This work concentrates on microalgal biodiesel production, bioelectricity generation, and wastewater treatment using Chlorella sorokiniana KP. Dairy Wastewater (DWW) and Rice Mill wastewater (RMWW) were utilized as substrates for optimization studies of biodiesel and bioelectricity production. Chlorella sorokiniana KP produced better biodiesel yield in DWW than RMWW, thus, DWW was employed as a substrate for further integrated bioelectricity studies. An “H-type” cathodic microalgal-based microbial fuel cell (MMFC) was used in the study as a novel system with Klebsiella pneumoniae FA2 utilizing 80% food wastewater (FWW) at pH 5.5 in the anode chamber and 50% DWW at pH 6 with Chlorella sorokiniana KP in the cathode chamber. The microalgal biomass generated in the cathodic chamber of the MMFC was used for biodiesel production. The current investigation reports that the microalgal strain Chlorella sorokiniana KP can successfully utilize DWW to produce high-quality biodiesel and bioelectricity production by coupled MMFC with wastewater treatment.