Using Modified Clinoptilolite to Remove Sulfate and Nitrate Ions from Aqueous Solution in Adsorption Process

Clinoptilolite is a cheap and abundant zeolite. They are alumino-silicate that play important role in water and wastewater treatment. The clinoptilolite are characterized by using XRD, FT-IR. The best method of modification and operating conditions were detected. Clinoptilolite was papered from Manzarieh (Qom Province) and then was crushed by ball milling to reduce the size to below 400 nm. The spectrophotometer was utilized to detect the removal efficiency. Addition of adsorbent to solution containing nitrate and sulfate ions has been carried out with the thorough investigation of main parameters such as type of modification, the amount of adsorbent to pollutant concentration, contact time and pH. The results show that clinoptilolite has important characteristics in removing ions from water. Furthermore modification of zeolite can improve the efficiency of adsorbent. Type of modification plays an important role in removing total iron and phosphate ions. The modified zeolite can remove nitrate up to 94% and sulfate ion up to 98 % at different pH and concentrations. Increasing contact time could improve removal efficiency. The ratio of adsorbent to initial concentration and pH were investigated as important factors. The study shows that clinoptilolite can be used as a promising and low-cost adsorbent for removal of nitrate and phosphate ions from aqueous solution.