Isomorphous Substitution of P(V) in Natural Clinoptilolite: Evalution of the Product for Removal of NO_3~-, NO_2~- and F~- from Aqueous Solutions

摘要

Nitrate is an anion of major importance particularly in biological areas. Excessive amounts in water supplies indicate pollution from sewage or agricultural effluents. The effects of excessive quantities of nitrate in water are well known. In this research structural modification of natural clinoptilolite by isomorphic substitution was performed. Isomorphously substituted zeolite was prepared under melting conditions from natural clinoptilolite. It was characterized by XRD, XRF, DTG and SEM techniques. The characterization process revealed that product is different from AlPo. Ion exchange property of the modified product was studied for NO_3~-, NO_2~- and F~- ion. The uptake of F~- was higher than those of NO_3~- and NO_2~-. Anion exchange isotherms were constructed for NO_3~- and discussed. The ion exchange chromatography and neutron activation technique were used to study the extent of the exchange.