Contribution to Tannery Waste Water Treatment for Chromium Removal/Recycle by Means of Cation Exchange Resins

Abstract

This work deals with the methodology of choosing a combination of processes for optimal treatment of tannery waste water, aiming at chromium removal/recycle through adsorption and cation exchange. The methodology we have developed, under the form of an algorithmic procedure, consists of 22 activity stages and 8 decision nodes. A case example has been used to illustrate certain features of the functionality of this procedure, concerning the adsorption of Cr³⁺ on and cation exchange with Amberlite IR 120-H (CAS: 39389-20-3, MSDS), a strongly acidic exchange resin of gel type, with sulphuric acid as functional group and styrene-divinylbenzene as matrix. The thermodynamic equilibrium of this process has been studied through adsorption isotherms and the kinetics has been examined by applying several models of various order under batch conditions while for the continuous flow regime the Bohart Adams model and its relevant modifications were used.