Impact of UV disinfection on microbially available phosphorus, organic carbon, and microbial growth in drinking water.

UV irradiation at a wavelength of 253.7 nm (UV(254)) is commonly used for drinking water disinfection. UV radiation is known to convert organically combined phosphorus to orthophosphate and to degrade natural organic matter. We studied if UV disinfection increases the amount of microbially available forms of organic carbon and phosphorus in drinking waters with different characteristics, and if these changes in water chemical quality could enhance the microbial growth in drinking water. The UV(254) dose (15-50 mWs/cm(2)) used in waterworks reduced the concentration of assimilable organic carbon and the sum of the molecular size fractions. The release of microbially available phosphorus needed higher doses (204 mWs/cm(2)) of UV(254) radiation. Of bacteria in drinking water, 90% were inactivated with UV(254)-irradiation doses below 50 mWs/cm(2). A high dose (501 mWs/cm(2)) of UV(254) radiation inhibited the microbial growth in water.

[1]  T. Vartiainen,et al.  The use of TSK size exclusion columns in determination of the quality and quantity of humus in raw waters and drinking waters , 1987 .

[2]  P. Martikainen,et al.  A New Sensitive Bioassay for Determination of Microbially Available Phosphorus in Water , 1999, Applied and Environmental Microbiology.

[3]  P. Backlund,et al.  Bacterial growth in humic waters exposed to UV-radiation and simulated sunlight , 1998 .

[4]  Dirk van der Kooij,et al.  Determining the concentration of easily assimilable organic carbon in drinking water , 1982 .

[5]  P. Martikainen,et al.  Phosphorus and bacterial growth in drinking water , 1997, Applied and environmental microbiology.

[6]  P. M. Williams,et al.  Photo-oxidation of Organic Matter in Sea Water by Ultra-violet Radiation, Analytical and Other Applications , 1966, Nature.

[7]  E. M. Thurman,et al.  Organic Geochemistry of Natural Waters , 1985, Developments in Biogeochemistry.

[8]  P. Martikainen,et al.  Microbially available organic carbon, phosphorus, and microbial growth in ozonated drinking water. , 2001, Water research.

[9]  Kazuo Yamamoto,et al.  Role of inorganic phosphorus in controlling regrowth in water distribution system , 1997 .

[10]  P. Backlund.  DEGRADATION OF AQUATIC HUMIC MATERIAL BY ULTRAVIOLET LIGHT , 1992 .

[11]  V. Adams,et al.  Ultraviolet inactivation of selected bacteria and viruses with photoreactivation of the bacteria , 1987 .

[12]  J. Shaw,et al.  Effects of UV irradiation on organic matter , 2000 .

[13]  T. Källqvist,et al.  Algicidal and chemical effect of u.v.-radiation of water containing humic substances , 1991 .

[14]  P. Backlund,et al.  Degradation Products Formed during UV-Irradiation of Humic Waters , 1996 .

[15]  P. Backlund,et al.  Impact of UV254-radiation on aquatic humic substances , 1996 .

[16]  Kazuo Yamamoto,et al.  Floc size distribution and bacterial activities in membrane separation activated sludge processes for small-scale wastewater treatment/reclamation , 1997 .

[17]  Jennifer L. Clancy,et al.  Cost of advanced UV for inactivating crypto , 1998 .

[18]  H. Holtan,et al.  Phosphorus in soil, water and sediment: an overview , 1988 .

[19]  Marc J. Parrotta,et al.  UV disinfection of small ground water supplies , 1998 .

[20]  E. Geldreich,et al.  A new medium for the enumeration and subculture of bacteria from potable water , 1985, Applied and environmental microbiology.

[21]  V. Lund,et al.  Ultraviolet irradiated water containing humic substances inhibits bacterial metabolism , 1994 .

[22]  P. Martikainen,et al.  Molecular size distribution of natural organic matter in raw and drinking waters. , 2001, Chemosphere.

[23]  P. Martikainen,et al.  Determination of assimilable organic carbon in humus-rich drinking waters , 1999 .

[24]  Maaret Kulovaara.  Light-Induced Degradation of Aquatic Humic Substances by Simulated Sunlight , 1996 .

[25]  A. Edwards,et al.  Determination of dissolved organic phosphorus in soil solutions by an improved automated photo-oxidation procedure. , 1992, Talanta.