Evaluation the efficiency of Scenedesmus obliquus, Chlorella vulgaris and a mixture of two algae in municipal wastewater treatment

Document Type: Primary Research paper

Authors

Abstract

This experiment was conducted over a 15-day period to determine efficiency of two algae species, Scenedesmus obliquus, Chlorellavulgaris, either singularly or in combination, in nutrient absorption from municipal wastewater. Algal cell counting was performed daily, but water nitrate, nitrite, phosphate, ammonia, chlorophyll a, algal biomass, BOD and COD levels were determined every other day. At the end of the experiment, water phosphate in treatments C0, M50 and S100 was zero. Also, water nitrate levels reached zero, only in treatment M50 and all groups of treatment S. The maximum algal biomass was observed in treatment S0 (0.6 gL-1; p<0.05) at the end of the experiment. Algal biomass of the treatment S groups was significantly lower than that of the other treatments (0.2 gL-1; p<0.05). The maximum chlorophyll a with significant difference was observed in treatment S0.  COD and BOD content showed constant trends among the treatments. The lowest COD and BOD was observed in treatments S and C respectively (4.1 mgL-1; p<0.05; 1.3 mgL-1; p<0.05). Overall, Sc. Obliquus was more efficient than Ch. vulgaris in biomass production, chlorophyll a concentration and nutrient absorption.

Keywords