%0 Journal Article
%T Adsorption of Chromium(VI) from Aqueous Solutions by Coffee Polyphenol-Formaldehyde/Acetaldehyde Resins
%A Khudbudin Mulani
%A Siona Daniels
%A Kishor Rajdeo
%A Sanjeev Tambe
%A Nayaku Chavan
%J Journal of Polymers
%D 2013
%R 10.1155/2013/798368
%X Removal of chromium(VI) from wastewater is essential as it is toxic. Thus, removal of chromium(VI) was performed using coffee polyphenol-formaldehyde/acetaldehyde resins as adsorbents. Adsorbent resins were prepared by condensation of decaffeinated coffee powder with formaldehyde/acetaldehyde and used for the removal of Cr(VI) ions from aqueous solutions. A simple and sensitive solid phase extraction procedure was applied for the determination of chromium at trace levels by spectroscopic method using 1,5-diphenylcarbazide reagent. The adsorption of Cr(VI) on the coffee polyphenol-formaldehyde/acetaldehyde resins was monitored by FTIR and EDX analysis. The metal adsorption parameters such as contact time, pH, Cr(VI) ion concentration, and adsorbent dose were investigated. For Cr(VI), the maximum adsorption capacity of coffee polyphenol-formaldehyde resins was 98% at pH 2. The experimental results showed that Cr(VI) bound strongly with coffee polyphenol-formaldehyde/acetaldehyde resins and utilization of resins could be improved greatly by reuse. 1. Introduction Metal ions such as Cd, Cr, Co, Cu, Zn, Pd, Hg, Ni, Ag, and Sr and metalloids such as Se, As, and Sb are toxic beyond trace levels. Most of these trace elements are transition metals with variable oxidation states and coordination numbers. Strong exposure to Cr(VI) causes cancer in the digestive tract and lungs. It may also cause gastric pain, nausea, vomiting, severe diarrhea, and hemorrhage [1, 2]. Treatment of wastewater generated by industrial processes today is of prime concern. Various technologies have been developed over recent years and are available for the removal of toxic metal such as chromium from wastewater [3]. Chromium bearing wastewater originates from a variety of industrial processes such as electroplating, dichromate and basic chrome sulphate manufacturing, tannery, anodizing, cutting tools, and chrome mining. Many of these industrial processes usually produce a large volume of wastewater with a chromium concentration ranging from less than 1£¿ppm to 10£¿ppm. The two common oxidation states of chromium observed in natural water are Cr(III) and Cr(VI). Cr(III) is not a significant groundwater contaminant, whereas Cr(VI) is approximately 100 times more toxic than Cr(III) [4]. Conventional methods used for removing Cr(VI) ions from industrial wastewater include reduction followed by chemical precipitation, adsorption on activated carbon, solvent extraction, freeze separation, reverse osmosis, ion exchange, and electrolytic methods. These methods have found limited applications
%U http://www.hindawi.com/journals/jpol/2013/798368/