Evaluation of Clinoptilolite Modified by Cationic Surfactant for Nitrate Removal from Aqueous Solutions

Nitrate contamination of surface and groundwater is considered as one of the more serious problems in throughout the world. High nitrate concentration in water (higher than standards) is very dangerous, consuming such polluted water can lead to Methemoglobinemia disease in children and the formation of the carcinogenic nitrosamines in adults. . The aim of this study was to investigate the possibility using of Modified clinoptilolite Zeolite by Cationic Surfactants adsorbent in nitrate removal from aqueous solutions.
In this empirical study, the effects of different independent variables including adsorbent dose (1-3 g/l), initial concentration of nitrate (50-150 mg/l), pH (4-10) and contact time (15-120 min) on elimination of nitrate was investigated. Also, adsorption kinetic along with Langmuir and Freundlich isotherms was studied.
The obtained results showed that the maximum removal efficiency of NO3 was in the initial nitrate concentration of 50 mg/L, pH of 4, adsorbent dose of 3 g/l, and contact time of 90 min. Also, the results indicate that the nitrate adsorption by modified Clinoptilolite zeolite was fitted well with Freundlich isotherm (R2=0.9951), and second- order kinetics (R2=0.9998).
According to the attained results, the Clinoptilolite zeolite can be considered as an appropriate and economical adsorbent for elimination of nitrate from aqueous solutions. Concerning its simple modification method and low cost, it can be applied as an adsorbent for other anionic pollutions. .