Chromium is one of the heavy metals that is found in industrial effluents and is very toxic to humans and environment. In this work the removal of hexavalent chromium by adsorption onto strongly basic anion was investigated. Various parameters such as pH initial hexavalent chromium concentration, contact time resin dosage were studied. Experimental data were expressed by Langmuir and Freundlich isotherm Pseudo-first order, Pseudo-second order and modified Pseudo-first order kinetic models. The results showed chromium removal was increased by increase of contact time and resin dosage, while decreased by increase of pH and initial hexavalent chromium concentration. At contact time equal 120 minutes, resin dosage 0.2 g/100 mL and initial hexavalent chromium concentration of 30 mg/l, by increasing pH from 3 to 11, removal efficiency was decreased from 93.56% to 69.12%. In addition, by increasing contact time from 5 to 120 minutes, removal efficiency was increased from 39.51% to 94.41%. The results also showed hexavalent chromium sorption follows Langmuir isotherm model. Pseudo second order models best describe chromium removal by using of adsorption onto strongly basic anion resin. The results revealed that removal of hexavalent chromium from aqueous solution by using of adsorption onto strongly basic onion resins can be done quick and effective.
Authors: Siboni, Mehdi Shirzad; Samadi, Mohammad Taghi; Azizian, Saeed; Maleki, Afshin; Zarrabi, Mansour ;Full Source: Water & Wastewater 2011, 79, 10-18 (Persian) ;