Adsorptive Performance of Walnut Shells Modified with Urea and Surfactant for Cationic Dye Removal

Adsorption of cationic dye crystal violet (CV) onto a modified walnut shell (WS) adsorbent was investigated. Combined treatment WS using urea and sodium dodecylsulfate (SDS) carried out. Surface modification adsorbents confirmed by FTIR analysis, pHpzc measurements, elemental SEM-EDX analysis. In order to optimize the adsorption conditions, effect solution pH, dose CV concentration studied means central composite face-centered design (CCFD). The highest correlation between experimental model data obtained for pseudo-second-order (PSO) kinetic model, assuming an ion exchange mechanism adsorption. A satisfactory fit from Langmuir isotherm, supporting single layer According results, can be considered as low-cost, efficient environmentally compatible biosorbent removal pollutants aqueous solutions.