CHROMIUM (VI) REMOVAL FROM WASTEWATER BY ION EXCHANGE RESINS (AMBERLITE IR 400, DUOLITE A378)

 Chromium (VI) is commonly found in large quantities in wastewater, which is toxic to animals and humans and known to be carcinogenic, and that is why the recovery of chromium content in wastewater is necessary for environmental and economic reasons.Experimental measurements have been tested for prepared solution and the effluent of the General Company for Electrical Industries in batch ion exchange
system using two types of anion exchange resin, weak base anion resin Duolite A378 and strong base anion resin Amberlite IR400. The effect of various process parameters on chromium removal in terms of adsorption capacity was evaluated.The stated parameters were initial concentration of solute in the range 80-140 mg/ l, initial pH of the sorption medium in the range 4-10, mass of the resin 0.2-1.2 g for Duolite A378 and 0.05-0.2 g for Amberlite IR400, agitation speed in the range 0-850 rpm and stirring time 2-90 min.The adsorption isotherms were described by means of the Langmuir and Freundlich isotherms, Freundlich isotherm was found to adequately describe the equilibrium relation between the resin and liquid phase of the ion exchange reaction for two types of resin. Kinetic data were tested using pseudo first order and pseudo second order kinetic models, Doulite A378 follows pseudo second order model while Amberlite IR400 shows better fit for pseudo first order.The chromium removal was examined through the column experiments for both synthetic and industrial wastewater by varying the flow rate at the range 5-15 ml min ^-1 , it was observed that the breakthrough point and breakthrough time decreased when increasing the flow rate. The result exhibit that the removal efficiency of synthetic solution is higher than industrial wastewater, the maximum removal in batch system for prepared solution is 98.7 %, while it was 77.6 % for industrial wastewater.