Reverse Osmosis Protection Service
Reverse Osmosis Protection: DMI-65 is an extremely powerful silica sand based catalytic action water filtration media that is designed for the removal of Iron and Manganese without the use of potassium permanganate through an Advanced Oxidation Process.
- Substantial whole of life cost savings
- Reduce downtime
- Save on costly membrane cleaning and replacement
- Significantly improve system performance reducing initial system capital investment
In the context of Reverse Osmosis Protection, typical sources of iron fouling are
- Anoxic aquifers containing soluble divalent iron and/or manganese
- Hydroxide flocs of oxidized iron and/or manganese from raw water
- Natural organic matter (NOM) containing iron complexes
- Hydroxide flocs from coagulation process
- Corrosion products from piping materials used for the feed water
- Silicates containing iron
The following are symptoms of iron and manganese fouling:
- Discoloration of membranes.
- Poor salt rejection on individual membrane test data.
- Low flow on individual membrane test data.
- Possible high pressure differential on individual membrane test data.
- High iron or manganese values reported in feed-water.
- High pressure differential reported on first array.
Incorporation of DMI-65 pretreatment filtration will materially reduce these symptoms as well as benefitting the total RO system.
DMI-65 is infused technology and not just a surface coating technology, unlike other catalytic water filtration media, which removes the chance of any chemical leaching into the water stream.
In order to begin the process of oxidation of the iron (and manganese) in solution DMI-65 is designed to operate in the presence of chlorine or other oxidant. In this process the oxidant removes electrons and is consumed in the process. The operator needs to ensure that there is a 0.1 – 0.3 ppm free chlorine residual in the effluent water. Chlorine, fed as sodium hypochlorite or bleach (12.5% NaOCl), is the preferred oxidant since it is relatively inexpensive, readily available around the world and it is effective. It also performs the vast majority of any disinfectant process.
Unlike ion exchange resins where higher regenerate dosages will increase the ion exchange capacity, chlorine residuals or concentrations higher than required to oxidize the Fe and Mn do not increase the oxidative properties of the media. Additionally, a higher free chlorine residual in an RO system would require more extensive post treatment to reduce the residual and protect the membranes from chlorine attack.
DMI-65 has been certified to the US Standard of NSF/ANSI 61 for Drinking Water System Components and for use in England and Wales Under Regulation 31(4)(a) of the water supply (Water Quality) regulations 2010 and has also been tested by many other water treatment authorities and laboratories.
DMI-65 is manufactured in Australia.