Water quality results reinforce need for action
Hundreds of water samples taken from Ōtūwharekai Ashburton Lakes and streams over the past year confirm that water quality remains a concern, according to Environment Canterbury.
The Iron Out System from Longveld, based around a floating polymer media is capable of dealing with iron levels up to 50ppm, and producing from 12,000 to 200,000 litres of clean water per day.
In practice contaminated water is first passed through an aerator where hydrogen sulphide, the “bad egg” smell, and other gases are removed.
The aeration process causes the iron content to precipitate out as an insoluble compound, which is carried into the main separation area, and is trapped by the floating polymer filtering media. After passing through the media the “clean water” flows by gravity to a storage area.
Over time the media will become clogged and restrict water flow, which results in a drop in water level in the main tank, and an increase in the level of the main feed pipe, which in turn creates a vacuum, which instigates a “back-wash” cycle.
At this point flow is reversed and clean water flows back through the media and takes any collected impurities with it to a back wash collector, and away to waste. As the media is refreshed water flow increases, and the level rises and the cleaning cycle recommences.
As well as being fully automatic and very low maintenance, the process is chemically stable, impervious to bacteria, and the expected lifespan of the cleansing media is about 15 years.
