Phosphate and nitrate removal from municipal wastewater by algae Scenedesmus obliquus cultivation and production of algal biomass

Nitrate and phosphate are abundant in urban wastewater. We evaluated the efficiency of nitrate and phosphate removal from wastewater by Scenedesmus obliquus and its use as a medium for Scenedesmus obliquus. Samples were collected from the effluent of central wastewater treatment in Gorgan. This experiment was done by 3 treatments and 6 replications that effluent with 100%, 50% and 0% were diluted. The results showed that Scenedesmus obliquus could be grown in wastewater and 100% phosphate (group S100) and 100% nitrate (all of group) was removed. The highest biomass production (0.6 g/L), chlorophyll a (4.87 mg/L), the number of cells (106 cells/ml) was observed in the S0 group. Statistical analysis of the data with analysis of variance (one-way ANOVA) and the Duncan test at a 5% level of significance (SAS software version 9.2) indicated that the algae could be used to remove phosphates, nitrate and algal biomass in municipal wastewater filtration systems before they enter the environment. The municipal wastewater can be used as culture medium for mass production of algae.