Application of Native Mix Algal Strain for Gray Water Treatment and Biofuel Production: Preliminary Study

Abstract

The application of native mixed algal strains for wastewater treatment will be investigated in this study. Native mixed algal strains will be collected from Khorda district, Odisha, India, and acclimatized to the secondary treated gray water in a stepwise manner. The algal species in the mixed strain were identified as Oscillatoria sp., Nannochloropsis limnetica, Dictyosphaerium ehrenbergianum, and Chlorella vulgaris. The mixed algal strains will be grown in different systems with combinations of natural light (N) or artificial light (A) and open system (O) or closed system (C). The mixed algal strains grew well in natural light compared with artificial light. The maximum algal biomass concentration of 0.99 and 0.79 g/L, respectively, were observed in the natural light open (NO) and natural light closed (NC) systems. In contrast, the algal strains grown in the closed system indicated improved gray water treatment compared with that of the open system. The organics [(measured as chemical oxygen demand (COD)], NO3−, and PO43− removal from gray water were 85.25%, 88.50%, and 73.12%, respectively, in the NC system. In addition, proximate analysis revealed that the biomass obtained from the NC system was slightly superior with the volatile matter, ash content, and fixed carbon of 28.5%, 69.9%, 29%, and 1.6%, respectively. In addition, the heating value of algal biomass obtained from the NC system (3.86 MJ/kg) was slightly higher than that of the NO system (3.52 MJ/kg).