Study of Wastewater Treatment by Microalga from the Caspian Sea

In today's modern world, using water by man and different industries produces a large volume of effluents and wastewaters that are a serious threat to humans, environments, and ecosystems. Refining and treatment of the wastewaters are essential. This research investigated the potential of marine microalgae Fischerella sp. in refining nutrients from wastewater. Fischerella sp. was collected from the Caspian sea.Artificial wastewater was prepared by adding different amounts of NaCl (1, 5%), CaCl2 (35, 100 mg/L), MgSO4 (75,150 mg/L), NaNO3 (50, 2000 mg/L) and K2HPO4 (6,500mg/L) to BG110 medium in 12 runs according to Design expert. The growth and chlorophyll contents in various treatments were measured, and nutrient analysis of the medium was performed on the 10th and 20th days after algal culture. Results showed that maximum growth, chlorophyll and decreasing of Ca2+, Mg2+, NO3- and PO43-content were observed in 1% NaCl,35 and 100 mg/L CaCl2, 150 mg/L MgSO4, 2000 mg/L NaNO3 and 6,500 mg/L K2HPO4 . The most removing activity was shown in the stationary phase of algal growth. Also, these conditions observed a decrease in TDS, TOC, and COD. It can be concluded that Fischerella sp. is a suitable microalga decreasing nutrients in1% NaCl and the highest amount of N and P.