Selection of optimum combination via comprehensive comparison of multiple algal cultures for treatment of diverse wastewaters

In spite of several studies on algal wastewater treatment, comparison of performances is difficult due to differences in parameters such as algal culture, wastewater, photobioreactor employed, temperature, light intensity etc. Keeping this in mind, present study was focused on phycoremediation potential of eleven algal cultures (seven isolated cultures and four procured cultures) in three different wastewaters [(sewage treatment plant wastewater (STP), dairy processing industry (DWW) and slaughter house wastewater (SWW)]. Most of the algal cultures exhibited exemplary performance in terms of biomass production (0.78-1.16 g L-1) and nutrient removal with removal efficiencies reaching maximum in case of isolated algal culture PA9 in dairy wastewater (sCOD: 93.4%, NO3-N: 82.1%, NH4(+)-N: 92.2%, PO43+-P: 100%) and PA4 in slaughterhouse wastewater (sCOD: 73.2%, NO3-N: 88.5%, NH4(+)-N: 90.3%, PO43--P: 84.8%), respectively. In sewage treatment plant wastewater, procured culture, Chlorella vulgaris performed best in terms of nutrient removal efficiency (sCOD: 79.6%, NO3-N: 95.0%, NH4(+)-N: 97.6%, PO43--P: 99.3). Results clearly established that specific solutions are required for effective wastewater treatment and highlight the importance of utilization of native microalgal community over axenic microalgal species. While all the wastewater parameters went below the discharge limit for STP and DWW, most of the contaminants were above the discharge limit in treated SWW. DWW turned out to be better nutrient medium as compared to STP and SWW. (C) 2020 Elsevier B.V. All rights reserved.