Influential parameters to produce iron-coated ZSM-5 zeolite including iron loading concentration, calcination temperature and time, synthesis temperature and mixing intensity were investigated. Results showed that the optimized iron-coated ZSM-5 nano-adsorbent is produced if 40 wt.% iron loading concentration at 30°C synthesis temperature under 60 rpm mixing intensity and 400°C calcination temperature for 3hrs are applied. Also, optimization of some parameters such as pH, adsorbent dose, contact time and temperature for removal of arsenite from aqueous solution with 400µg/L initial concentration was considered. Evidently, the highest adsorption of arsenite occurred under pH 7, adsorbent dose 2.5g/L, contact time 30min and temperature 40°C. Kinetic and isotherm models studied showed that arsenite adsorption by iron-coated ZSM-5 follows pseudo-third order equation and well fitted with Langmuir isotherm model. Evaluation showed that the optimized iron-coated ZSM-5 zeolite is able to remove up to 98.37 % of arsenite under the best condition in batch reactor. For column system, arsenite concentration range of 0.04-97.53µg/L in output at 1-35min interval was confirmed and the breakthrough curve represented that iron-coated ZSM-5 nano-adsorbent was saturated after 215min whereas Fe, pH and EC measured in output solution were 0.90 mg/L, 6.65 and 148.40 µs/cm, respectively.
