Study of the sorption and desorption processes of sulfites on the anion-exchange redoxites

Abstract

At present, one of the promising methods for conditioning natural waters is the stabilization that employs redoxites based on the ion-exchange materials. This method of water treatment makes it possible to significantly reduce corrosion aggressiveness of water. The use of modified cationites and anionites enables a more efficient process of purification, helps reduce economic expenses in the operation of water treatment equipment. We investigated dependence of sorption capacity of the high-base anionite in the salt form AB-17-8 for sulfites on the starting concentration of the latter in a solution. It is shown that sorption is determined by the concentration factor. Thus, at an increase in the concentration of sodium sulfite to 10 %, the anionite capacity increases to 4,200 mg-equiv./dm 3 . When using weakly-acidic anionites in the salt form and basic form (Dowex Marathon WBA and AMBERLITE IRA 96), the sorption capacity of ionites for sulfites increases with an increase in the concentration of solutions and reaches 5,000 mg-equiv./dm 3 . We estimated effect of the concentration of chlorides, sulfates in water, which is fed for deoxygenation, on desorption of sulfite-anions form the high-base anionite AB-17-8 and the low-base anionite Dowex Marathon WBA. It is demonstrated that during filtration of solutions of chlorides and sulphates with different concentration the washout of sulfites occurs through the given anionites. Therefore, to prolong the time of use of the obtained redoxites, modified with sulfites, it is recommended to utilize desalinated water or water with an insignificant content of anions