Hadis Mostafaei - Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Abdolreza Samimi - Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Soheila Shokrollahzadeh - Department of Chemical Technologies, Iranian Research Organization for Science and Technology, Tehran, Iran
Salma Karamad - Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Ali Sheikhinejad - 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 ۹۰%. Phosphate removal was particularly efficient in the photobioreactor, with a removal rate of ۹۱%, while the shaker- incubator had a removal rate of ۴۴%. 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 ۹۰% from ۲۶۴ to ۲۳.۱ mg/l. The microalgae also had a symbiotic effect on the bacterial colonies present in the wastewater, reducing their numbers by ۹۹% while allowing the microalgae to thrive. The final biomass concentration in the photobioreactor was ۲.۰۳ 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.

Chlorella vulgaris, Microalgae, Photobioreactor, Municipal wastewater, Bacteria