Fluoridation of potable water has long been an accepted practice for the prevention of tooth decay. Water is generally treated with either:
- Fluorosilicic acid (commercially available as a 22% solution)
- Sodium Silicofluoride (Powder, 60% active Fluoride)
- Sodium Fluoride (Powder, 40% active Fluoride)
While each fluoride product has associated risks with regards to handling, fluorosilicic acid is a particularly aggressive and hazardous chemical and requires specific operator training and awareness. In addition, specific fluoride system design, particularly with regard to equipment flushing, also needs to be considered. On the other hand, powdered fluoride products present their own health issues, specifically with regard to management of the dust problem when handling. This normally requires a reasonably complex and costly dust extraction/air filtration system. All of these OH&S issues can be overcome, but generally at a cost, which makes the application of fluoride to small water treatment facilities uneconomic.
Orica and Hydramet have recognised that there is a need for water authorities to be able to fluoridate water easily, economically and safely. Through collaboration, Orica and Hydramet have designed a novel fluoridation system that meets all the above criteria. Through use of our system, there is no need for personnel to come into direct contact with fluoride chemicals ever again.
| After 18 months operation with Water Corporation of WA at Christmas Island, both Ken Walker (Project Manager) and Graham Lawler (District Manager), concur that our fluoridation system provides significant advantages compared to other fluoridation systems. Both highlighted the systems simplicity, ease of operation and particularly emphasised the significant reduction of OH&S issues normally associated with fluoride dosing systems. |
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Sodium Fluoride readily saturates in solution at a constant 4.0%, largely unaffected by temperature. Therefore, accurate and controlled fluoride dosing within recommended limits is easily achievable. To overcome the previously mentioned dust problems normally associated with powdered material, this system utilises approved prepacked water soluble sachets (5kg) of sodium fluoride. The sealed bags of sodium fluoride are packaged in a sealed container with desiccant to retain the packaging integrity in moist or humid environments and have been approved by Western Australian Department of Health for use in potable water. When added to water, the sealed bags dissolve entirely within approximately two minutes, allowing the fluoride powder to dissolve within the tank.
The saturated constant solution is drawn from the tank as a colourless particulate free product via a fine (5 micron) filter and dosed to the water supply. Using the advantage of consistent saturation level, fluoride usage rate can be accurately determined by volumetrically measuring the make up water to the solution tank.
Standard fluoride dosing package systems include: - Saturation tank(s) with integral controls
- Chemical injection package (including metering pumps, valves etc.)
A system for applications to a typical water supply up to 25 ML/D is standard, with only the metering pump capacities and control method nominated to suit the specific duty |
A small package system, suitable to inject up to 0.9mg/l of fluoride to a water supply to 25ML/D would require the following site facilities or services:
- Housing for the package (weather protected and secure) - area requires nominal 3m x 3m
- Water supply (for solution make up)
- 240V 50Hz Single Phase 10Amp power supply
- System initiation/control signal
- Injection point to water supply main
> Fluoride Saturator Brochure
