Evaluation of nano chitosan efficiency in removal of benzene from aqueous solutions

Benzene is an aromatic compound with the formula C6H6. This substance is highly toxic and cancers and is one of the pollutants in the refinery wastewater. Due to the pollution of water resources with this combination, it is very important to remove this material from the environment. For this purpose, the aim of this study was to synthesize a porous nano adsorbent using chitosan as an inexpensive and environmentally friendly adsorbent to remove benzene from aqueous solutions.

Chitosan nano particles are made from chitosan powder made by Sigma Aldrich and 1% acetic acid solution. The effect of different pH parameters, initial concentration of benzene solution, adsorption dose and contact time are investigated. The concentration of benzene was determined by a UV-Vis Array spectrophotometer, Photonix Ar 2015, at 254 nm wavelength and analyzed using Excel and SPSS software.

According to the results, the optimum amount of benzene adsorption was obtained at pH 4. By increasing or decreasing the pH of the solution, the efficiency of benzene removal decreased. Also, with increasing contact time from 5 to 120 minutes, the efficiency of benzene removal decreased from 96.86 to 89.28%. By increasing the initial concentration of benzene, the removal efficiency had a upward trend and the highest removal percentage was obtained at a concentration of 70 mg / l, equal to 78.57%. Also, the results showed that by increasing the absorbent dose, the removal efficiency of benzene was decreasing and the highest percentage of removal in the absorbent dose was 0.01 g, 82.85%. In optimal conditions, the highest percentage of benzene removal was determined to be 85.66%.

The results of this study showed that nano chitosan adsorbent has a high efficiency in adsorption of benzene from aqueous solutions. Due to the fact that nano chitosan have a natural origin, it can be used as an environmentally friendly and inexpensive absorbent from other adsorbents to remove aromatic compounds from aqueous solutions.