Adsorption of Acid Violet 17 onto acid-activated pistachio shell: Isotherm, kinetic and thermodynamic studies

Abstract

The pistachio shell was modified using different chemical agents and utilized as an adsorbent for the adsorption of AV 17 dye in an aqueous solution. Maximum removal of 93.04% was obtained for pistachio shell activated with 10 N H2SO4. The physicochemical properties of activated pistachio shell were characterized by pHpzc, FTIR, BET, and SEM-EDX analysis. The results showed that the AV 17 adsorption capacity was positively correlated to the BET surface area. The best fit of kinetic data to pseudo-second-order kinetic was determined. The adsorption follows both the Langmuir and Temkin isotherms. The Langmuir adsorption capacity was determined to be 26.455 mg/g at the initial dye concentration of 160 mg/L. The endothermic nature of adsorption was confirmed by the acquired thermodynamic data. Maximum desorption of 97.33% was achieved in 0.2 M NaOH for AAPS in the first cycle. This is very important for the economic use of the adsorbent. The findings demonstrate that activated pistachio shell may be a good alternative for color removal from industrial effluents.