Water

Water Disinfection

Ultraviolet and Chemical Treatment - Brockman Four Project, WA

Description

Water disinfection is a key factor in the process of providing quality water supply. ABCO water pump skids utilise ultraviolet and chemical treatments to produce a consistent quality of potable water supply.

Ultraviolet Treatment

Ultraviolet treatment has been used for over 70 years to eliminate disease-causing bacteria from industrial and commercial water supplies. The advantages of ultraviolet are that it wastes no water, requires no chemicals, and is inexpensive to maintain. A standard ultraviolet unit essentially comprises of a stainless steel casing and a mercury vapour lamp. The lamp is made with a clear quartz globe which transmits over 90% of ultraviolet energy to the surrounding water. The system incorporates a cleaning bracket which travels along the length of the lamp and prevents the buildup of biological organisms on the globe.

The ultraviolet systems used by ABCO require very little maintenance. General duties are limited to confirming the correct function of the UV unit’s operation. Each unit has built in technology to self-check and notify via a liquid crystal display of any system errors.

Ultraviolet lights run at very high temperatures and rely on a constant supply of cool water to avoid damage to the system. By installing a temperature-controlled bypass system across all ultraviolet units, ABCO eliminates this danger and ensures that no further components are damaged by over-heated water.

Chemical Treatment

Chemical treatment of potable water incorporates both pH adjusting and sterilizing chemicals. The chemicals used for pH adjustment vary based on the type of water entering the water treatment system. Most installations are fed by bore water, which can be either basic or acidic in nature depending on the location and mineral concentrations in the surrounding earth.

Chemical treatment can be used to adjust the water to a nominal potable quality of pH7.2. For acidic bores the standard chemical for pH adjustment is low concentration sodium hypodroxide while basic bores can be treated by low concentration hydrochloric acid. Sterilization is achieved by dosing the water with liquid chlorine. This serves to remove any contaminating biological organisms from the water prior to camp use. Chlorine levels should be continuously monitored to prevent over-dosing of chlorine, as this can lead to skin irritation and/or pain. Typical chlorine levels for potable water should be limited to 0.3 ppm.

Ozone Treatment

Ozone treatment has been a continuously advancing technology over the past 40 years. As the technology is refined it has become more viable for small to mid scale water treatment facilities. The primary advantage of ozone treatment is that it has no residual effect on the product water; the only by-product of the oxidation and disinfection being oxygen. The other key advantage is that ozone generators can be installed on site which eliminates the need for chemical supply and storage.

ABCO encourages the incorporation of ozone treatment into its future waste water treatment plants as an alternative to traditional chemical treatments.