Extraction heavy metals from contaminated water using chelating agents

Abstract

Water pollution caused by toxic elements is one of the most important environmental problems in the world. Heavy metals are toxic to human and dangerous for the environment. The objectives of this study were: the effects of chelating agents on heavy metals extraction from polluted water were carried out to examine. In different concentrations: 0.01, 0.05, 0.1 mg/l of Chelating agents: Ethylenediamine tetra acetate (EDTA), oxalic acid (OA) and citric acid (CA) were tested respectively . The effects of operating parameters, such as pH and extraction time were examined. The results showed that the extraction ability for mercury and copper from the polluted water decreased as follows: OA > CA > EDTA. Removal of metals was dependent on the concentration of extracting agent and raised with increasing concentration of chelating agents. the rate of metals removal were very rapid during first 50 min, and the removal decreased when the pH value of the solution increasing.