Application of biosorption process by pomegranate seed powder in the removal of hexavalent chromium fromaqueous environment

Introduction: Because of heavy metals toxicity for the environmental, heavy metals are considered as environmental pollutants. The hexavalent chromium is one of the heavy metals that toxic and soluble in water. This study to remove of hexavalent chromium from aqueous solution by pomegranate seed powder has been done. Materials and Methods: This study was performed in laboratory scale and experimental. The adsorbent prepared in laboratory scale and pulverized by standard ASTM sieves (40-100 mesh). In this research, the effect of pH (2, 3, 4, 6), adsorbent dose (0.2 to 0.6 g/100 ml), contact time (15 to 180 min) at initial Cr (VI) concentrations of 2 and 10 mg/L, was studied. The results of adsorption equilibrium were analyzed to Langmuir and Freundlich isotherm models. The unknown Concentration of Hexavalent Chromium by spectrophotometer set (UV/VisibleSP-3000 Plus-Japan) at 540 nm based on standard methods for testing water and wastewater book determined. Results: The results showed that increasing the adsorbent dose and contact time led to increasing of the removal efficiency and increasing pH and initial chromium concentration led to reducing of removal efficiency. According to the results, the best removal efficiency occurred at acidic pH and adsorption equilibrium time was 120 min. In the absorbed dose of 0.6gr/100ml, pH = 2 and hexavalent chromium concentration 2 mg/l, the removal efficiency was achieved equal to 99.5%. In this study, chromium ions adsorption by pomegranate seed powder is follows Freundlich isotherm model. Conclusion: The obtained results showed that pomegranate seed powder is suitable natural adsorbent for the removal of chromium (VI).