Document Type : Research Paper
Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Department of Chemical Technologies, Iranian Research Organization for Science and Technology, Tehran, Iran.
Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, Iran.
Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran
This study evaluated the ability of Chlorella vulgaris, a freshwater microalgae species, to remove nutrients from raw municipal wastewater. The wastewater was collected from the initial sedimentation-stage discharge of the treatment plant and used to cultivate the microalgae in both a shaker-incubator and a photobioreactor. The results showed that the microalgae effectively reduced the nitrate, nitrite, phosphate, and ammonium ion concentrations in the wastewater by over 90%. Phosphate removal was particularly efficient in the photobioreactor, with a removal rate of 91%, while the shaker- incubator had a removal rate of 44%. In addition to removing nutrients, the microalgae were also able to significantly reduce the wastewater’s chemical oxygen demand (COD), with a reduction of over 90% from 264 to 23.1 mg/l. The microalgae also had a symbiotic effect on the bacterial colonies present in the wastewater, reducing their numbers by 99% while allowing the microalgae to thrive. The final biomass concentration in the photobioreactor was 2.03 g/l, a higher value compared to similar studies. These results demonstrate the potential of Chlorella vulgaris and other microalgae species for use in wastewater treatment systems.