Two novel polymers have been tested in a filter application for biocidal efficacy for flowing aqueous solutions of microorganisms. A laboratory water pump was employed in the experiments to provide contact times on the order of 1-2 s/mL. The two polymers are N-chlorinated and N-brominated derivatives of a polystyrene hydantoin. The variables of pH, temperature, flow rate, and dilution with inert sand have been examined. The N-bromamine polymer (Poly-IB) was generally more effective than the N-chloramine polymer (Poly-I), probably because N-bromamines and free bromine are more biocidal under a given set of conditions than are their N-chloramine and free chlorine analogs. Once the biocidal efficacies of the polymers were exhausted due to chemical reaction with microorganisms or organic load, they could be regenerated by exposure to circulated free chlorine or bromine. This demonstrated that the polymer. materials were not permanently damaged by the exhaustion process. @ Abstract published in Advance ACS Abstracts, September 15, 1995.
A new insoluble N‐halamine polymeric disinfectant material has been tested in a water filter application to determine (1) its tendencies to leach undesirable decomposition products, (2) its range of potential applicability, and (3) its regenerability. In flowing water tests, poly‐1,3‐dichloro‐5‐methyl‐5‐(4‘‐vinylphenyl)hydantoin (Poly‐I) leached only small amounts of total organic carbon, free and total chlorine, anions, and volatile organics such as trihalomethanes. Furthermore, Poly‐I provided bactericidal efficacy over the pH range 4.5 to 9.5 and at temperatures as high as 37°C. Poly‐I is deactivated by reducing agents such as sodium thiosulfate and by ethanol; following deactivation, it can be regenerated by exposure to flowing aqueous free chlorine. Poly‐I appears suitable for use as a biocidal filter for small potable and recreational waters, for it is effective over a wide pH and temperature range and is readily regenerable. It would not be useful, however, for disinfection of large bodies of water such as in city treatment plants because of its cost and the large amount of the material that would be necessary.
The N-chloramine compound 3-chloro-4,4-dimethyl-2-oxazolidinone (agent I) has been compared with calcium hypochlorite as to its efficacy as a bactericide for the treatment of water. The study included concentration, contact time, pH, temperature, and water quality as controlled variables. The species of bacteria tested were Staphylococcus aureus, Pseudomonas aeruginosa, and Shigella boydii. In general, for highly pure, demand-free water, calcium hypochlorite was the more rapid disinfectant at a given total chlorine concentration, although for water containing a controlled amount of organic load, agent I was the better disinfectant. The differences in efficacy of each of the two disinfectants can be attributed primarily to their different stabilities in water at various controlled conditions.
The preparation and biocidal efficacies of eight new N-halamine polymers have been reported. The polymers are in the classes known as dichlorohydantoins, trichlorotriazinediones, and dichloropyrimidinones. They were synthesized from the commercial polymers polystyrene, poly(methyl vinyl ketone), and polymethacrylamide. All of the polymers were insoluble in water and leached only small amounts (less than 0.5 mg/L) of free chlorine into flowing water. It was demonstrated that the bacterium Staphylococcus aureus in water flowing through filters made of these polymers was inactivated. These materials show considerable commercial potential as biocidal water filters, especially the dichloro-poly(styrene-hydantoin) because of its inexpensive synthetic route.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.