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

Abstract

This 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 the major pollutants 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 mg/L), cyanide (0.3–1 mg/L) and NH4+ (100–200 mg/L), termed as simulated secondary treated coke-oven wastewater. Maximum removal was observed with individual solutions of phenol (4 mg/L), cyanide (0.6 mg/L) and NH4+ (175 mg/L), while maximum removal in simulated secondary treated coke-oven wastewater was observed at higher concentrations of phenol (8 mg/L) and cyanide (0.8 mg/L) and the same concentration of NH4+ (175 mg/L). A 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 per day) and carrying capacity (1,330 mg/L) 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 the present consortium.; Biomass and biomolecules were extracted and estimated.; A consortium was found effective for real wastewater treatment.;

Keywords

• biomolecules
• coke-oven wastewater
• consortium
• phycoremediation
• poultry litter
• tertiary treatment