The use of ultraviolet light (UV) for disinfection of drinking water is a
rapidly growing market because utilities are using UV to provide an
additional disinfection barrier to pathogens such as Cryptosporidium and
Giardia. Many lime-softening plants in the Midwestern United States are
interested in UV technology; however, there still remains some question
about the stability of lime-softened water and the impact it could have on
the fouling potential of the quartz sleeves of the UV reactor. Some studies
have been conducted to evaluate the impact of hardness on fouling of the
sleeves, but not many studies have looked at the long-term fouling
potential of lime softened water. The draft US Environmental Protection Agency (USEPA) UV Disinfection
Guidance Manual (UVDGM) recommends that systems that treat water
with high hardness and high iron concentrations evaluate the potential for
fouling by pilot or demonstration-scale testing. Water District No. 1 of
Johnson County, Kansas (WaterOne), is a large utility that supplies water
to approximately 340,000 people in the Kansas City metropolitan area. To
provide water of the highest quality to its customers, WaterOne is
considering the use of UV disinfection at the new facility, and retrofitting
its existing facilities with UV disinfection. Therefore, WaterOne
conducted a 6 month pilot study to evaluate the potential effects of lime-softened
water on the UV equipment. The pilot testing consisted of a side-by-
side comparison of low pressure high-output (LPHO) and medium
pressure (MP) UV lamps. Both systems were tested using pilot reactors
equipped with on-line UV intensity sensors and a sleeve wiping system.
The pilot testing protocol included long-term operation of the UV reactors
while wiper frequency was varied and the lamp outputs were being
monitored. In addition, periodically the quartz sleeves were removed and
the transmittance of the sleeves measured. Includes 3 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 530 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 11/01/2005 |
