Determination of ion adsorption by radioactive tracer technique

Abstract

The slight linear decrease of the “per mole of AgI adsorbed amount” (¯C) of the coagulating ion with the increasing pI at a constant concentration of the coagulating ion was proved and explained by the linear decrease of the specific surface. The adsorbed amount of the coagulating ions at a constant concentration and at a given pI decreases with the increasing concentration in which the AgI precipitate was formed. Ions of different valencies are adsorbed in equivalent amounts which are independent of their concentrations which were higher than their coagulation values. The correctness of the desorption-adsorption formula logc″/c′=(z′−z″ a+ logx/(−x) respectivelyS=c″ (1−x)/c′x= 10(z′−z″)a was confirmed (x the fraction of the adsorbed amount of the ion of valencyz″ and concentrationc″, 1−x the fraction of the adsorbed amount of the ion of valencyz′ and concentration c′,S the selectivity coefficient of ion exchangers). Therefore the coagulated AgI can be considered as an ideal ion exchanger. The constanta in the above formula is equal to the slope of the line “log coagulation value-valency” of theSchulze-Hardy rule.