DISINFECTION OF WATER BY N-HALAMINE BIOCIDAL POLYMERS

Two novel polymers have been tested in a filter application for biocid al efficacy for flowing aqueous solutions of microorganisms. A laborat ory water pump was employed in the experiments to provide contact time s on the order of 1-2 s/mL. The two polymers are N-chlorinated and N-b rominated derivatives of a polystyrene hydantoin. The variables of pH, temperature, flow rate, and dilution with inert sand have been examin ed. The N-bromamine polymer (Poly-IB) was generally more effective tha n the N-chloramine polymer (Poly-I), probably because N-bromamines and free bromine are more biocidal under a given set of conditions than a re their N-chloramine and free chlorine analogs. Once the biocidal eff icacies of the polymers were exhausted due to chemical reaction with m icroorganisms or organic load, they could be regenerated by exposure t o circulated free chlorine or bromine. This demonstrated that the poly mer materials were not permanently damaged by the exhaustion process.