Bioremediation of a pesticide and selected heavy metals in wastewater from various sources using a consortium of microalgae and cyanobacteria

Abstract

The presence of organophosphate pesticides and heavy metals in water are known to be toxic to aquatic organisms. Bioremediation makes use of naturally-occurring organisms to remove pollutants from the environment. This study explored the potential of using a consortium of microalgae and cyanobacteria (Chlorella vulgaris, Scenedesmus quadricuda and Spirulina platensis) to remove the organophosphate pesticide malathion and the heavy metals cadmium, nickel and lead from water samples taken from varying combinations of urban wastewater and agricultural drainage water in Egypt. The fastest algal growth observed in this study was in a treatment containing the microorganismal consortium, malathion and heavy metals cultured in water samples taken from agriculture drainage and urban wastewater. Microalgae in this study were able to remove malathion from samples of wastewater with up to 99% efficacy and were able to bioaccumulate nickel at up to 95% efficacy. Moreover, microalgae demonstrated the ability to uptake lead and cadmium at up to 89% and 88% efficacy respectively. The results from this study suggest that a consortium of Chlorella vulgaris, Scenedesmus quadricuda and Spirulina platensis can be effective in remediating the pesticide malathion and the heavy metals cadmium, lead and nickel from wastewater.