Assessment of Chlorella vulgaris, Scenedesmus obliquus, and Oocystis minuta for removal of sulfate, nitrate, and phosphate in wastewater

Abstract

AbstractApplication of wastewater for algal biomass production can not only lead to production of thousands of tons of biomass for subsequent biofuel production, but also can provide for significant removal of contaminants in wastewater. The aim of the present study is to evaluate the growth, contaminant removal, and biochemical component (lipid, carbohydrate, and protein) accumulation potential of Chlorella vulgaris, Scenedesmus obliquus, and Oocystis minuta cells in wastewater supplemented with different concentrations of sulfate, nitrate, and phosphate. The results show maximum biomass productivity of 33, 19, and 98 mg dw/L/d for C. vulgaris, S. obliquus, and O. minuta, respectively. Phosphate removal (more than 90%) was highest in the culture with O. minuta; about 93% nitrate was removed by C. vulgaris, and the highest sulfate removal of 36% was observed in the culture with S. obliquus. The biochemical composition of the microalgae cells is in the ranges of 22–65% carbohydrate, 19–38% protein, and 8–17% lipid. This indicates that carbohydrate and protein are preferentially accumulated as compared to lipids under the growth conditions investigated for each of the microalgae strains.