Characterization of Raw Zeolite and Surfactant-Modified Zeolite and their use in Removal of Selected Organic Pollutants from WaterAuthor(s): Maha M. Hussein, Khalil M. Khader and Salem M. Musleh
Increases in environmental pollutants led to use of natural low cost materials such as zeolite, which prove their effective in water treatment. Natural zeolite obtained from Jabal Hannoun (local) and imported zeolites, clinoptilolite-rich tuff obtained from U.S.A, Syrian zeolitic tuff, and synthetic faujasite- 13X were used as adsorbent. Characterization of raw and modified zeolite has been studied to verify their physical chemical and mineralogical properties, in order to note any changes occur during the modification of zeolite. The feasibility of using surfactant-modified zeolite to remove aniline and its derivatives from water in the broad band of concentrations (5-200 mg L-1) was evaluated by batch experiments. The results showed that a significant increase in aniline and its derivatives sorption capacity could be achieved at the loading level of hexadecyltrimethylammonium, a cationic surfactant, on zeolite surfaces at monolayer coverage. Adsorption equilibrium was carried out at different initial concentrations and different pH varies from 3 to 11. Langmuir and Freundlich adsorption isotherms were applied to the experimental data. The data best fitted the Freundlich model. It was found that the aniline removal efficiency by using clinoptilolite-rich tuff has the highest maximum adsorption 50% compared to the other zeolite. The maximum efficiency removal for N-Methylaniline reached upto 69.5% by using Syrianzeolite. A decrease in N,N-Dimethylaniline removal by surfactant-modified zeolite, and the maximum efficiency removal was 16% by using Jordanian-Faujasite. The results show that the optimum pH of the adsorption of aniline and its derivatives by surfactant-modified zeolite was almost in acidic and neutral pH conditions. Characterization of raw and surfactant-modified zeolite was carried out using several techniques such as cation exchange capacity, X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and Fourier Transform Infrared Spectroscopy. UV/VIS spectrophotometer was used in equilibrium analysis.