Improved ammonium removal from industrial wastewater through systematic adaptation of wild type Chlorella pyrenoidosa

A single step process is proposed for ammonium removal from nitrogenous industrial effluents, with a concomitant generation of algal biomass. A microalgal strain found in the effluent treatment plant of a fertilizer industry in Mumbai, India was systematically adapted to remove up to 700 ppm of ammoniacal nitrogen from industrial wastewater, which is nearly four times higher than the ammonium tolerance reported in the literature as well as other algal strains tested in our laboratory. 18S rRNA sequencing revealed the strain to be Chlorella pyrenoidosa. Effects of process parameters such as pH, temperature and light intensity on cell growth and ammonium removal by the adapted cells were studied. Optimal conditions were found to be pH of 9, temperature of 30 °C and a light intensity of 3,500 Lux for the adapted cells.