Evaluation removal of uranium ion from nuclear wastes by means of some zeolitic exchangers (preliminary results)

Liquid radioactive wastes (LRW) produce as a result of the operation, repair and disposal of nuclear energy installations can be classified in different ways (1). Use of selective sorbents in liquid radioactive waste management is widely spread in the field of different nuclear objects liquid waste decontamination (2). The presence of uranium in the environment not only originates from the nuclear industry but also from other anthropogenic activities such as lignite burning in power stations, ore processing and the use of fertilizers (3). A number of studies have promoted the potential use of in-situ reactive barriers for the remediation of contaminated groundwater. Although, one of the major applications of natural zeolitic materials is the removal of radionuclides from aqueous environments and especially the radio-cesium and radio-strontium decontamination of polluted water and waste water streams (4) Due to their large surface areas, high cation exchange capacities, favorable hydraulic characteristics, and low cost zeolites, are a major category of materials being considered for the removal of uranium isotopes from liquid medium (5). The main aim of this project is to determine the capability several natural, synthetic and modified Iranian zeolites as well as some zeolitic based composite would enhance the ability of up taking of uranium ions from nuclear wastes. obtained data the ion-exchange isotherms were plotted and distribution coefficients (Kd) on the different exchanger were calculated using batch operation method, from the extracted results it can be conclude that among the investigated exchangers the composite which was prepared by potassium nickel hexacyanoferrate- loaded Iranian natural clinoptilolite and relevant synthetic zeolite-P (6) are more effective ion-exchangers and could be good candidate for sorption of uranium ion (uranyl ion) from nuclear waste streams. The obtained results will be present and discuss. (author)