Influence of pathogenic bacterial activity on growth of Scenedesmus sp. and removal of nutrients from public market wastewater

Abstract

The present study aims to investigate the influence of Staphylococcus aureus, Escherichia coli and Enterococcus faecalis in public market wastewater on the removal of nutrients in terms of ammonium (NH4–) and orthophosphate (PO43) using Scenedesmus sp. The removal rates of NH4– and orthophosphate PO43– and batch kinetic coefficient of Scenedesmus sp. were investigated. The phycoremediation process was carried out at ambient temperature for 6 days. The results revealed that the pathogenic bacteria exhibited survival potential in the presence of microalgae but they were reduced by 3–4 log at the end of the treatment process. The specific removal rates of NH4– and PO43– have a strong relationship with initial concentration in the public market wastewater (R2 = 0.86 and 0.80, respectively). The kinetic coefficient of NH4– removal by Scenedesmus sp. was determined as k = 4.28 mg NH4– 1 log10 cell mL–1 d–1 and km = 52.01 mg L–1 (R2 = 0.94) while the coefficient of PO43– removal was noted as k = 1.09 mg NH4– 1 log10 cell mL–1 d–1 and km = 85.56 mg L–1 (R2 = 0.92). It can be concluded that Scenedesmus sp. has high competition from indigenous bacteria in the public market wastewater to remove nutrients, with a higher coefficient of removal of NH4– than PO43.