Common Pond Microorganism UV Dosages
Target Microorganism
The size, biological make up and life cycle of a microorganism all play a critical part in successful germicidal disinfection. By way of comparison, there are
approximately 65,000 known protozoa and only 4,500 bacteria of which all require their own specific UV-C dose. A microorganism's size plays a significant roll in the
UV dose required to irradiate it. Protozoa is often many times larger than bacteria and therefore requires a much higher
UV dose. The speed (flow rate) at which the
waterborne microorganism travels through the UV housing (across the UV lamp field) establishes the UV dose (µWs/cm²) received.
(see charts 1 & 2 below)
click either chart to enlarge
Microorganism Life Cycle
Life Cycle is another critical factor that requires consideration when applying UV Sterilization. The marine parasite Cryptocaryon (salt water white spot)
is an excellent example of how complex a microorganim's life cycle can be. Cryptocaryon has a four part life cycle. A warm water parasite, cryptocaryon can be lethal to
many species of marine fish. Diagram A is very descriptive, showing the many characteristics of this microorganism. The aquaculture community has waged battles against
cryptocaryon and have lost, specifically at the encysted (Tomont) stage, simply due to its evasiveness by attaching itself to its substrate. Disease outbreaks still
occur even with filtering the water column using extremely fast flow rates.
Prerequisites of achieving successful UV disinfection
- Identify the "Target Microorganism", consider its physical and life cycle characteristics
- Determine its Required UV Dose
- Determine the condition of the water to be treated
(water temperature & UV Transmissibility).
- Contact your UV Manufacturer, ask questions regarding their UV Equipment's capacity compared to your specific needs
- Select the UV Sterilizer model that best suits your application requirements
|
