Ion Exchange in the Dowex 50 Sulfocationite–Aqueous Nicotinic Acid–FeCl3 System
摘要
The equilibrium distribution of cations between Dowex 50 sulfocationite and an aqueous solution of nicotinic acid and iron chloride at pH 1−3 was studied experimentally. The concentrations of protons, iron cations, and their complexes with nicotinic acid in the ionite significantly depend on pH of solution. The content of doubly charged iron complexes with nicotinic acid in the polymer can reach the value corresponding to the total ion exchange capacity of the ionite. A method is proposed for calculating the counterionic composition of the sulfocationite phase from the equilibrium constants of binary exchange of the sulfocationite proton for the iron cation and of the protonated form of nicotinic acid or the doubly charged iron complex with nicotinic acid.