Retention Profile and Separation of Some Textile Dyes in Natural Water Employing Polyurethane Foams and Other Extracting Agents

Abstract

Recently, there have been an increasing interest of textile dyes entering into our environment. Many of these dyes are hazardous to human health and to the ecosystem. One of modem man's preoccupations. Therefore, in the present thesis we present a detailed survey on the essential background information and analytical methodology on the preconcentration and degradation of textile dyes in natural water. The overall work can be summarized as follow: 1- In chapter one, a brief review on the recommended methods for the degradation and preconcentration, of textile dyes is undertaken. Special attention is given to sunlight, photolysis and gamma-radiation for the dye degradation and for minimizing the dyes in natural water. The reported literature survey revealed that few studies on the preconcentration of textile dyes employing polyurethane foams are known. Hence, there is a need for reliable rapid and low cost solid sorbent for routine work for minimizing and removal of textile dyes species in natural and industrial eflluents. ii- The second chapter is concerned with the experimental part and the capacity measureme ts of the polyurethane foam towards the tested textile dyes in aqueous solutions. Investigation of the various parameters involving the retention, kinetics, and sorption isotherms employing batch mode of separation and the chromatographic behavior of tested dyes are undertaken. iii- Chapter three includes the kinetics of textile dyes onto the unloaded polyurethane foams (PUFs). The uptake of the dyes was found fast, reached equilibrium in few minutes and followed a first-order rate equation with an

overall rate constant K in the range of 0.05 - 0.055+0.008 min-1

The

dependence of the dyes uptake by polyurethane foam on the Ph, salt effect, etc., was explained in a manner consistent with a " solvent extraction " mechanism. However, the sorption data also followed Langmuir, Freundlish and Dubinin-Radushkevich (D-R) type sorption isotherms.