Introduction: One of the heavy metals is chromium which is used in trivalent and Hexavalent oxidation state in industries such as, glass, ceramic, tannery, leather especially in electroplating industries. Hexavalent Chromium has proven several health hazards such as a carcinogen. The aim of this study was to investigate the efficiency of Melia azedarach ash in the removal of hexavalent chromium from synthetic electroplating industry wastewater. Methods: This is an experimental study which investigates the effect of initial chromium concentration, adsorbent dose and reaction time on removal of chromium by Melia azedarach ash. The adsorbent was prepared in experimental conditions using electric oven in 550 0C at 2 hours and pulverized using ASTM standard sieves with a particle size range of 40–60 mesh. The study was performed on the synthetic samples containing 5and 10 mg/l concentration of chromium. The unknown concentration of Hexavalent chromium was detected by spectrophotometer set (UV/VisibleSP-3000 Plus-Japan) at 540 nm. Results: According to the results, removal efficiency increases by increasing adsorbent dose and reaction time and decreases with increasing initial concentration of chromium. Results of this study showed that Hexavalent chromium adsorption by Melia azedarach ash reaches equilibrium at 180 minutes. Conclusion: Melia azedarach ash is an effective adsorbent in removal of hexavalent chromium from synthetic electroplating industries wastewater. In addition, the use of this biosorbent in preparation and application aspects is simple and cheap compared to many other natural and man-made adsorbent.

Keywords: Melia azedarach, Hexavalent chromium, Surface adsorption, Electroplating industry

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