DefinePK

Abstract

Industrial wastewater poses a significant global environmental challenge due to the presence of various organic pollutants and heavy metals at elevated concentrations. This study investigated the potential of microalgal biomass for the treatment of industrial wastewater from the industrial estate in Hayatabad, Peshawar. A total of 25 different microalgal species were collected and morphologically characterized using light microscopy. Out of the 25 microalgal strains, Chlorella ellipsoidea , Oscillatoria curviceps , O. rubescens , O. tenuis , Spirogyra collinsii , S. crassa , Closterium strigosum , C. pritchardianum , and C. lunula successfully proliferated in BG-11 medium. These strains were subsequently transferred to agar media to establish pure cultures, which were then cultivated in both autoclaved and unautoclaved industrial wastewater. Biomass production was evaluated based on Total Volatile Suspended Solids (TVSS). In unautoclaved industrial wastewater, the highest growth rate (0.89 ± 0.03 day⁻¹) and biomass productivity (1.83 ± 0.05 g/L/day) were observed for C. ellipsoidea , S. crassa , and O. curviceps , while C. strigosum exhibited the lowest growth rate (0.79 ± 0.05 day⁻¹). O. rubescens and C. strigosum produced the lowest biomass (1.66 ± 0.10 g/L/day). In the control (autoclaved wastewater), C. ellipsoidea again recorded the highest growth rate (0.89 ± 0.05 day⁻¹), while C. pritchardianum showed the lowest (0.60 ± 0.07 day⁻¹). Nutrient removal efficiency by C. ellipsoidea was notably high, with reductions in COD (90.16%), ammonia (67.26%), and nitrate (94.93%). Moreover, O. curviceps was highly effective in removing sulfate and lead. Overall, the study demonstrates that C. ellipsoidea and O. curviceps are promising candidates for nutrient and pollutant removal from industrial wastewater due to their high biomass productivity and remediation efficiency.