Removal of Toluenel from aqueous solutions by NanoChitosan extracted from shrimp shell: isotherm and adsorption kinetics

Toluene, with the chemical formula C6H5CH3, is one of the toxic and cancerous combinations of petroleum products and is one of the most important contaminants in the water. The high cost and low efficiency of some refining processes has created limitations in the elimination of these compounds. In the present study, the process of adsorption of toluene from aqueous solutions is investigated by nanocytosine adsorbent extracted from shrimp shell as a natural, inexpensive, and environmentally friendly adsorbent. Nano-chitosan is purchased from Sigma Aldrich USA. To determine the concentration of toluene, the Photonix Ar 2015 UV-Vis Array spectrophotometer is used at a wavelength of 206 nm. In order to determine the optimal conditions for the toluene adsorption capacity by nanocytosins, the effect of different pH parameters in the range of 3 to 8 and contact time in the range of 5 to 120 minutes is investigated in a laboratory scale in a discontinuous system. The optimal values ​​for these parameters are 5 and 35 minutes, respectively. The Freundlich model with R2 = 0.92 corresponded more to the balance data of toluene adsorption. The quasi-first-order and pseudo-second order kinetics models are used to test the kinetics of the reaction. Results indicated that the pseudo-second-order model with correlation coefficient of R2 = 0.99 had better fit with experimental data. The results showed that nanocytosins have a very good ability to use in the process of toluene removal from aqueous solutions.