Technical Memorandum Report No. 54
Bruce H. Keswick, Robert S. Fujioka, Nathan C. Burbank Jr., Philip C. Loh
Bromine chloride (BrCl) was evaluated as an alternative to chlorine as a disinfectant of water and waste water by comparing the efficiency of these two chemicals to inactivate type l poliovirus seeded in various aqueous solutions. In a nitrogen-free buffer at pH 6.0, the minimum concentration of BrCl required to effectively inactivate poliovirus (4-log reduction after 15 min. at 25oC) was 0.15 mg/l, whereas 0.3 mg/l of chlorine was required to accomplish the same effect. The virus inactivating efficiency of BrCl was not interfered within the range of pH 6 to 10. Furthermore, the addition of various concentrations of glycine and NH4CI to the nitrogen-free buffer solutions more effectively interfered with the virus inactivating properties of chlorine than BrCl. To simulate waste water disinfection, 1 to 5 mg/l of BrCl and chlorine were added to activated sludge treated sewage effluent seeded with poliovirus, mixed well, and filtered after 15 min. at 25oC. The results show that the inactivating effects of 1, 2, and 3 mg/l, dose of both chlorine and BrCl were equivalent and inefficient. However, at a dose of 5 mg/l, BrCl inactivated 5 logs of virus, whereas chlorine inactivated only 2 logs of virus. These results indicate that BrCl should be seriously considered as a potential alternative to chlorine as a disinfectant.