Complexation study of heavy metal ion cu(Ii) with amino acids before elimination by ultrafiltration

Abstract

Nowadays one of the most critical issues for human life is the protection of the drinking water from contamination by heavy metals. They are toxic pollutants, which can be very dangerous for human health and the environment when they are present at high concentrations. The removal of these heavy metal ions from water has become a more than necessary issue. Ultrafiltration is considered a suitable molecular filter for the separation of big molecules, but it is still inefficient for the separation of free ions due to their weak sizes. Consequently, other methods including complexation reactions with organic ligands to trap the ions and to retain them by the membrane are considered. This work deals with the removal of toxic metallic ions by a combined complexation and-ultrafiltration process using Copper (II) ions and, amino acids as complexing agents. The complexation has been exhaustively studied by UV/visible absorbance spectrophotometry and Conductometric. The thermodynamic parameters (ΔH°, ΔG° and ΔS°) were derived and discussed for a complete description of the systems in solution and to demonstrate the importance of amino acids for trapping the metal cations by complexation processes.