Phycoremediation of pollutants from secondary treated coke-oven wastewater using poultry litter as nutrient source: a cost-effective polishing technique

The present article focuses on the phycoremediation of pollutants from secondary treated coke-oven effluent through a green and economical route. A microalgal sample was collected and identified as a consortium of Chlorella sp. and Synechococcus sp. The culture cost was reduced by using poultry litter extract as supplementary material to BG-11 medium. Since major pollutants as present in real secondary treated coke-oven wastewater are phenol, ammoniacal-N (NH4+) and cyanide, several matrices were designed with these three major pollutants by varying their initial concentrations such as phenol (2-10 mgL(-1)), cyanide (0.3-1 mgL(-1)) and NH4+ (100-200 mgL(-1)), termed as simulated secondary treated coke-oven wastewater. Maximum removal was observed with individual solutions of phenol (4 mgL(-1)), cyanide (0.6 mgL(-1)), and NH4+ (175 mgL(-1)) while maximum removal in simulated secondary treated coke-oven wastewater was observed at higher concentrations of phenol (8 mgL(-1)) and cyanide (0.8 mgL(-1)) and the same concentration of NH4+ (175 mgL(-1)). Consortium was found effective to meet statutory limits of pollutants. Kinetic model was developed for predicting growth of consortium and observed that the poultry litter extract enriched BG-11 medium showed higher values of maximum specific growth rate (0.56 day(-1)) and carrying capacity (1,330 mgL(-1)) than that in BG-11 medium only. HIGHLIGHTS A consortium was identified for tertiary treatment of coke-oven wastewater. Poultry litter extract was found effective as a growth medium for consortium. Phycoremediation of NH4+, phenol, and cyanide was examined with present consortium. Biomass and biomolecules were extracted and estimated. Consortium was found effective for real wastewater treatment.