Using Scenedesmus sp. for the Phycoremediation of Tannery Wastewater

Abstract

Wastewater from the leather tannery industry contains high concentrations of heavy metals, especially chromium, as well as high values of inorganic nutrients and organic matter which, if not treated prior to discharge, may alter the quality of surface water bodies. As an alternative treatment to these industrial effluents, we propose the use of microalgae, due to their ability to remove contaminants. This study evaluates the growth of the microalga Scenedesmus sp. in three different concentrations of wastewater (20%, 50%, and 100%) at a tannery in Bogota, Colombia, for a period of 15 days, and assesses the removal of chromium, nutrients, and organic load. Results indicate a growth proportional to the concentration of the effluent, with greater biomass in undiluted wastewater. Likewise, the procedure achieved the removal of over 80% of hexavalent chromium, nitrates and phosphates, and organic load, measured as BOD. Thus, the microalga Scenedesmus sp. exhibited a phycoremediation effect on tannery wastewater.