بررسی کارآیی حذف کروم شش‌ظرفیتی از محلول‌های آبی، با استفاده از جاذب طبیعی پوسته سبز بادام و خاکستر حاصل از آن

Background and Aim: Hexavalent chromium is a metal, which causes harmful effects in surface and ground water, Its removal from contaminated water and waste water has received a great deal of interest in recent years. Thus, theaim of the presentstudy was a comparative analysis of the application of green almond hull and its resultant ash inremovingchromium from aqueous solutions. Materials and Methods: In this experimental study, the effects of variables such as pH of adsorbent dose, initial chromium concentration, contact time, temperature, and adsorbent characteristics of almond hull and its resultant ash on removing of chromium from aqueous solutions were investigated. Experiments were intermittently performed in batch reactor on Shaker. Finally, in order to assess the obtained samples colorimetricmethod using UV/V Spectrophotometer T80+ set, at a wavelength of 540, was applied. Results: The most efficient removal of hexavalent chromium occurred when pH was 2. Furthermore, it was found that removal percentage increased parallel to contact time and temperature. But, when the bioabsorbent and the resultant ash were used, a decrease in the initial hexavalent chromium density from 100 to 10mg/lit led to a decrease in the removal percentage from 99/66% to 61/19% and 78/93% to 37/01%, respectively. It was found that by increasing the absorbent dose (i.e. the bioabsorbent) the removing percentage tended to its extreme level (100%). However, when the absorbent ash was used, removing percentage increased at first, but then it decreased. Conclusion: Both almond green hull and its resultant ash are agents which cause effective removing of hexavalent chromium from aqueous solutions.