ELECTROLYSIS TREATMENT OF AMMONIUM CHLORIDE WASTEWATER BY DOUBLE CHAMBER MEMBRANE PROCESS

Abstract

Aiming at the problem that ammonium chloride wastewater generated from the rare earth and fertilizer industries is difficult to treat, combining with the actual case of a factory in Guangdong province that produced a large amount of ammonium chloride waste solution in the treatment of alkaline copper chloride etching liquid, this paper put forward the method of electrolysis to treat ammonium chloride wastewater and probed into the optimal experimental conditions. It was found that the anion exchange membrane was used to separate the electrolytic cell into a bipolar chamber, which could prevent the contact between chlorine gas and ammonium ion from producing explosive nitrogen trichloride, ensure the safety of operation, and effectively separate chlorine gas from the anode and hydrogen from the cathode, so as to facilitate products collection. On this basis, through exploring the impact of anode chamber and electrolyte concentration, cathode chamber ammonium chloride solution concentration, electrolytic time on treatment effect, optimized experimental condition was as follows:20 mL 5 g/L sodium chloride solution in the anode chamber, 20 mL 100 g/L of ammonium chloride solution in the cathode chamber, constant current of 0.3 A, and electrolysis time of 3 hours, then 93% of chloride ions were transformed into chlorine and sodium hypochlorite. Under this condition, the factory could make an income of at least RMB 1950 by treating 15 t of ammonium chloride waste liquid per day. The membrane electrolysis method could effectively remove chloride ions from ammonium chloride wastewater and produce chlorine gas, sodium hypochlorite and ammonia water. Compared with the traditional electrochemical treatment technology, it had the advantages of simple device and high removal rate, with controllable reaction rate.