Preparation and Characterization of Chitosan-Zeolite Molecular Sieve Composite for Ammonia and Nitrate Removal

Abstract

A new zeolite molecular sieve modified with chitosan was prepared and employed for the adsorption of ammonia and nitrate from underground water. Batch of experiments were performed to investigate the effects of various conditions on chitosan/ zeolite molecular sieve(CTS-Z) preparation, including the concentration of acetic acid, the concentration of chitosan, the stirring time and the stirring temperature. Characteristic of CTS-Z adsorption particles were analyzed by Scanning electron microscopy (SEM), Specific surface area (BET), Fourier infrared spectroscopy (FTIR) and X ray photoelectron spectroscopy (XPS). Experimental results showed that the optimum preparation processes for the chitosan / zeolite molecular sieve were as follows: the concentration of acetic acid was 4%, the concentration of chitosan was 7g / L, the stirring time was 10h and the stirring temperature was 30°C. And adsorption capacity of adsorption particles for ammonia and nitrate were 0.636 mg/g and 1.952 mg/g, and the removal rates were 81.60 % and 40.28 % respectively. The surface morphology of the particles showed more protrusions and micropores, the specific surface area of the particle was 391.516 m2/g. FTIR analysis showed that CH3- and NH2- have been loaded into the basic framework of zeolite molecular sieve and XPS analysis showed that the element O 1s played an important role in the attachment of chitosan to zeolite molecular sieves. Therefore, the results of the research can provide a theoretical basis for the upgrading of the water purification plants in the cold region of northern China.