Experimental and theoretical study of heavy metal complexation prior to elimination by ultrafiltration

The environment faces serious problems which may be caused by toxic heavy metals transported by industrial wastewater. If not treated, such wastewater can be a potential source of pollution of soil and groundwater. This may affect the quality of water supply where increasing concentrations of metal cations in the water constitute a severe health hazard, mainly due to their non-degradability and toxicity. This work deals with the removal and recovery of these pollutants by membrane-based processes, such as ultrafiltration. In order to be efficient, this technique should be preceded by a cation complexation process, with a judiciously chosen complexing agent. This will prevent the complex from passing through the semi permeable membrane, hence increasing the metal retention. The present study consists of two parts: experimental and theoretical where the effects of certain parameters, such as the initial concentration of the complexing agent, pH, temperature, and agitation speed, on the complexation reaction of certain heavy metals have been investigated. Through this study, the values of the parameters when cation elimination is maximum have been determined. The theoretical results obtained in the second part of the work showed excellent agreement with the experimentally measured values.