AWWA WQTC58847

Porphyrins are heterocyclic organic compounds that can be excited under irradiation with light,transferring energy collisionally to surrounding biomolecules. Porphyrins can be incorporatedinto various solid matrices, such as cellulose acetate membranes (CAMs). Hence, photodynamicproperties of porphyrins may be useful in situations where microbial inactivation is required,such as during the physical and chemical treatment of drinking water. No work has examined theefficacy of porphyrin inactivation on human enteric viruses such as hepatitis A virus (HAV) inwater. Experiments were conducted to evaluate the effect of cationic, anionic, and amphiphilicporphyrins on HAV in porphyrin-containing water or water-containing buffers exposed to long-wavelength(365 nm) ultraviolet (UV) light. Inactivation of poliovirus type 1 (PV1) and coliphage MS2 alsowas determined, and inactivation of the bacterium E. coli B was determined on porphyrin-containingmembranes. Results are expressed as the percent reduction in log10 infectious units attime (t) when compared to numbers of microbes not exposed to treatment with UV light. Whenporphyrin-containing CAMs were exposed to long wavelength UV light, E. coli B wasinactivated by about 90% in 300 minutes. In contrast, reductions of E. coli B in 0.01 mMcationic or anionic porphyrin solutions ranged from 97.5% after 10 minutes and was >99.999%after 90 minutes. Percent reductions of MS2 in cationic or anionic porphyrin solutions rangedfrom 99.8% to >99.99% after 10 minutes. Poliovirus was inactivated by >99.99% in 1 minute in0.01 mM cationic or anionic solutions, while reductions of HAV by 0.01 mM cationic porphyrinin water was 99% in 1 minute and >99.98% in 10 minutes. Amphiphilic porphyrins also resultedin rapid and extensive (>99.98% in 1 minute) inactivation of HAV in water. Concentrations ofporphyrins that inactivated viruses were minimally toxic to Chinese Hamster Ovary cells andnonmutagenic in the Ames test. These experiments show that porphyrin-containing water andmembranes can inactivate infectious viruses and bacteria. Includes 31 references, tables, figure.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

14

File Size:

1 file , 320 KB