الفهرس | Only 14 pages are availabe for public view |
Abstract Crystal violet dye, methylene blue dye, lead ions, and cadmium ions are toxic pollutants in aqueous media even present at low concentration. The aim of the current study was to synthesis some new tin and silicon nanostructures as novel adsorbent composites of these pollutants. These composites were synthesized via reaction of 2.407, 5.247, 7.195, 9.59 g of tin chloride dihydrate with 6 g of sodium metasilicate pentahydrate. The composites were abbreviated as T1, T2, T3, and T4 , respectively. The structure of these composites were characterized by XRD which confirmed that these composites consist of amorphous Sn/Si, sodium tin silicate, tin oxide, and sodium silicate. SEM which proved that all samples have irregular forms. TEM which proved that all samples consist of very tiny spherical particles. BET surface area which showed that surface area increases as follow: T4<T3<T2< T1. Different parameters were studied to increase the selectivity of adsorption as contact time, pH, temperature, initial concentration, and dose of adsorbent. More ever, thermodynamic parameters and kinitics study. 15 min, pH 6, and 298 K were regarded as the optimum conditions for the removal of studied pollutants. The adsorption process was fitted well with the Langmuir equilibrium isotherm and pseudo-second-order kinetic model. The thermodynamic parameters confirmed that the removal is chemical, spontaneous, and exothermic. The maximum adsorption capacity for methylene blue and crystal violet dyes onto T1 adsorbent was 30.13, 34.81 mg g-1, respectively. However, the maximum adsorption capacity onto T2 adsorbent was 29.33, 36.83 mg g-1, respectively.The maximum adsorption capacity for methylene blue and crystal violet dyes onto T3 adsorbent was 17.09, 29.46mg g-1, respectively. Additionally, the maximum adsorption capacity for methylene blue and crystal violet dyes onto T4 adsorbent was 13.43, 11.98 mg g-1, respectively. It was found that, the maximum adsorption capacity for Cd2+ (49.5, 49.25, 9.85, and 2.60) mg g-1, respectively.It was found that, the maximum adsorption capacity for pb2+ (74.50, 74.25, 47.55, and 27.15) mg g-1, respectively. |