Nutrients removal from raw municipal wastewater using Chlorella vulgaris microalgae

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.

Keywords:

Chlorella vulgaris , Microalgae , Photobioreactor , Municipal wastewater , Bacteria