Abstract
Previously Sr2+ion-exchange isotherms were obtained from the surface drinking water and the corresponding Sr2+ distribution coefficients (Kd) were calculated for linear part of the isotherms of the studied CLT. The comparative kinetic data of Sr2+ ion-exchange sorption on NH4+- forms of the clinoptilolite-containing tuffs from deposits of Russia and Bulgaria on the sample of the surface drinking water was investigated in detail with the known method of the "thin layer". It was shown, that the kinetic process of the Sr-sorption on the clinoptilolite- containing tuffs is characterized with the features and includes 3 stages. The first stage is described with the particle diffusion law, the second stage –a slowing down, the ion-exchange process reaches a plateau, then an increase of Sr2+ sorption is observed again. The particle diffusion coefficients of Sr2+ describing the first stage of the sorption process on CLT of different deposits were calculated. The obtained data are the initial one for the development of a mathematical model of the dynamic ion-exchange process on NH4+-form of the clinoptilolite- containing tuffs from the surface drinking waters, that makes possible to generate the computer program and thereupon to calculate the break-through curves of Sr2+ sorption on NH4+- clinoptilolite- containing tuffs for the different dynamic conditions, including the sorption dynamic conditions on the permeable reactive barrier
Highlights
Natural clinoptilolites – the clinoptilolite-containing tuffs (CLT) are characterized by the high selectivity for a number of ions, including Sr2+, and are used in purification of the natural surface and ground water from the radioactive and stable Sr2+ [1,2,3]
Earlier we proposed a mathematical model of sorption dynamics, which takes into account both kinetic stages and makes possible to determine the corresponding coefficients [10,11]
Earlier we have studied Sr2+ sorption kinetics on Na-CLT (Khonguruu deposit, Russia) from the surface drinking water (CSr2+ = 0.18-0.20 mg/L) using the “thin layer” method [13]
Summary
Natural clinoptilolites – the clinoptilolite-containing tuffs (CLT) are characterized by the high selectivity for a number of ions, including Sr2+, and are used in purification of the natural surface and ground water from the radioactive and stable Sr2+ [1,2,3]. The scale of the ion-exchange processes taking place in the geochemical barriers and at variety of the environmental conditions (ground water concentration, contact time of CLT with solution, etc.) determine the necessity of their mathematical modeling. The ion exchange process on CLT is described by 2 kinetic stages - relatively fast stage and slower one [9]. Earlier we proposed a mathematical model of sorption dynamics, which takes into account both kinetic stages and makes possible to determine the corresponding coefficients [10,11]. The model was based on the experimental breakthrough curves of Sr2+ on CLT from Khonguruu deposit (Yakutiya), obtained for the natural solutions of the different composition in a continuous mode and with the periodic interruptions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
