Study of surfaces and sorption properties of natural sorbents

The surfaces of tuffs materials, perlite, mordenite and clinoptilolite type of zeolite and its chemical modifications were studied by physical adsorption of nitrogen at the temperature of liquid nitrogen by volumetric method. Specific surface of materials was determined by standard BET isotherm. Specific volume of micropores and specific surface of mesopores together with external surface were assessed using t-plot. Total pore volume was calculated from volume of adsorbed nitrogen at relative pressure 0,98. The experiments show the double increase of specific surface along with increasing of diameter of mesopores and total volume of pores only for zeolites chemically modified. The results confirm also the formation of secondary mesopore structure after modification with NaOH solution. The kinetic of Cs and Co sorption with given materials was studied by static radioindicator isotope method and radioactivity of solutions and loaded materials was measured by gamma spectrometry. From experimental dates were calculated some sorption characteristics. It was determined that primary tuffs do not contribute to sorption capacity of clinoptilolite and the influence of NaOH solutions on the clinoptilolite type of zeolite increases mainly the sorption of multivalency and hydrated cations. (authors)