K Azizi , Ar Mesdaghinia , F Vaezi , S Nasseri ,
Volume 1, Issue 1 (4-2003)
Abstract
Bromide which is present in many water resources has the potential to create adverse health effects after water disinfection by oxidizing agents, and it is considered to be the most important mineral in this respect. Bromide removal is not feasible in conventional water treatment plants. This survey with the aim of removing Br" from water has been accomplished by performing pilot tests in which a GAC fixed - bed contactor and two different resins have been employed. Synthetic water samples of known concentrations of Br" (1-10 mgL -&apos) and TDS (250 - 1000 mg/L-1) have been treated, at the first phase of this study.
Results showed that the best efficiency of GAC treatment was for samples having more than 1 mgL"1 Br" and less than 1000 mgL-1 TDS.
At the second phase of the study, a strong anionic-cathionic resin had been used for Br" removal. Either low or high concentrations of Br", in the influent a considerable reduction in Br" content was always observed at the first 5 minutes of contact.
At the third phase of the study a weak anionic resin (WBA) has been employed. Using this resin in the treatment of synthetic samples proved that WBA is also very effective for Br" removal during 10 min contact while , Br- was reached less than 0.4 mgL"1 . Simultaneous removing of TDS was also showed well efficiency. However, TDS has never decreased to near zero as it was possible for the strong resins.
Finally in the 4th phase of this research, natural samples from four water resources supplying potable water for the city of Qom have been chosen to continue the process of Br" removal by above-mentioned pilots. Despite of high levels of TDS of the samples, there was no important problem in the process of Br" treatment. The acceptable removal efficiencies of bromide were minimum 50% and maximum around 100% .
