The Efficiency of Grape Seeds in Removal of Hexavalent Chromium from Aqueous Solutions

Chromium (Cr6) is a heavy metal which is present in industries sewages likecladding, mining, and in various concentrations. Cr6 compared with Cr3 is so toxic, carcinogenic,and mutagenic. Thus the aim of this study was to evaluate the efficiency of 3 types of grape seeds in adsorbing Cr6 from aqueous solutions and determining its isotherms and kinetics.
This was an experimental study. The seeds of the three types of grapes were used as adsorbent. In this study the effects of different variables such as pH, initial chromium concentration, adsorbent dosage, and contact time were studied in a batch system. Measuring the concentration of hexavalent chromium was performed using a spectrophotometer at 540 nm.
The results showed that the removal efficiency decreases with increasing pH and contact time. Alternatively, by increasing adsorbent dosage, efficiency increases for 3types of adsorbents. So that all three types of adsorbents in dosage of 0.3 mg showed 80% removal efficiency Also in the initial chromium concentration, using adsorbent in dosage of 0.2 mg/L in the pH = 3, the obtained efficiency was more than 80% for each absorbent.
According to the results, the grape seeds can be effective adsorbents for the removal of hexavalent chromium from their aquatic environment. Likewise using this adsorbent is much easier and cheaper comparedwith many other natural and artificial adsorbents, which marks its priority.