The Effect of Operating Parameters on Bromine Extraction from Desalination Plant Discharge

A comprehensive utilization of concentrated seawater is crucial in order to promote the development of the desalination industry as a key solution to global freshwater. Debromination of the desalination plant effluent as well as the bromine product extraction are two parallel goals, which have been the subject of many research studies as well as industrial operations. In this investigation, bromine extraction is investigated experimentally form the effluent of the Konarak desalination plant located in Chabahar bay, Iran. For this purpose, an air blow-out method is used, and the effects of the operating parameters including the temperature, pH, and chlorine gas flow rate are examined in a continuous reactor. The parameters are optimized, and the trend is discussed in details. The bromine concentration of the sample collected from the Pozm Tiyab area, close to the plant discharge point, has been determined to be ۱.۱۷۲ g/L using ion chromatography. A pre-concentration procedure is conducted in order to reach a concentration of ۳.۱۰۰ g/L by evaporation. A reactor with the dimensions of ۶۰ mm × ۸۰۰ mm is designed and assembled for the experimental studies. In order to investigate the operating parameters, a central composition design (CCD) method is used. Among the factors studied, only the chlorine gas flow rate has a substantial effect on the bromine recovery, and the effects of the other two factors are negligible in the pH range of ۲-۳ and the temperature range of ۵۰-۷۰ °C. At the three chlorine concentrations of ۱, ۱.۵, and ۲ L/min, the bromine production increases almost linearly with the increasing chlorination injection rate. The Br۲ gas is recovered with a maximum rate of ۹۳.۸% and a bromine loss of ۱۸۵ mg/L in the mother liquid. The optimum operating parameters to achieve this recovery are a pH of ۲.۵, a temperature of ۶۰ ˚C, and a chlorine gas flow rate of ۱.۵ L/min.

کلیدواژه ها:

bromine ، air blow-out ، desalination plant discharge