DBDMH

DBDMH is a disinfectant used for drinking water purification, recreational water treatment, as a bleaching agent in pulp and paper mills, and for treating industrial/commercial water cooling systems. It is a white crystalline compound with a slight bromine odor. DBDMH is an excellent source of bromine as it produces no hypochlorous acid as an intermediate to generation of hypobromous acid. Chemically, DBDMH works in the following manner:

Where R = 5,5-Dimethylhydantoin:
 * Br2R + 2 H2O → 2 HOBr+ H-R-H

Hypobromous acid partially dissociates in water (pKa = 8.6):
 * HOBr  H+ + BrO-

Hypobromous acid produces bromide ions when disinfecting or oxidizing:
 * HOBr + Live Pathogens → Br- + Dead Pathogens

The resulting bromide ions can then undergo oxidation to hypobromous acid in the presence of an oxidizer of sufficient strength e.g. ozone, hypochlorous acid, potassium monopersulfate. This process is commonly called "activation" of the bromide ion.
 * Br- + HOCl → HOBr +  Cl-