Bioadsorption of heavy metals using microalgae isolated from Mosul city wastewater

Abstract

This study examined the ability of two genera of microalgae chlorosarcinoopsis and Dietyosphoerium Sp. The presence of heavy metals in wastewater as hazardous environmental pollutants has led to the consideration of bioremediation as a means to mitigate this risk. Accordingly, microalgae isolated from wastewater belonging to the Chlorophyta division (green algae) and morphologically identified as Dictyosphaerium sp. and Chlorosarcinopsis eremi. These isolates demonstrated the ability to adsorb the heavy metals examined in this research (Cr, Ni, Cu). It was observed that Dictyosphaerium sp. exhibited an optimal capacity for nickel adsorption at 0.03599, whereas Chlorosarcinopsis eremi achieved the highest adsorption percentage for chromium at 0.3282. The biosorption mechanism of such pollutants is based on the functional groups' binding sites found within the cell wall of the microalgae. In this work, Dictyosphaerium sp. cell wall contained amino, alkane, carboxyl, amidic, and sulfonate groups as well as alcohol and phenol groups. The same functional groups were detected in the cell wall of Chlorosarcinopsis eremi namely amino, alkene, carboxylic acid, aldehyde, sulfonate, alcohol, and phenol groups. There was a variation in the number of these chemical functional groups prior to and subsequent to the heavy metal treatment of the isolates, and they were analyzed using Fourier Transform Infrared (FTIR) spectroscopy.