Advanced Oxidation Process for Water Filtration

Advanced Oxidation Process DMI-65 is an extremely powerful silica sand based catalytic water filtration media that is designed for the removal of Iron and Manganese without the use of potassium permanganate. The unique microporous structure of DMI-65 efficiently removes dissolved iron to the almost undetectable levels as low as 0.001 PPM and manganese to 0.001 PPM. DMI-65 acts as an oxidation catalyst with immediate oxidation and filtration of the insoluble precipitates derived from this oxidation reaction. DMI-65 can also remove Arsenic, Aluminium and other heavy metals and Hydrogen Sulfide under certain conditions.

Lowest Whole of Life Cost Solution

Low Cost Iron and Manganese Treatment
DMI-65 significantly reduces the operating costs of iron and manganese removal in water filtration due to the following performance features:

Regeneration Not Required
The media operates with a continuous injection of sodium hypochlorite at low residual levels (0.1 to 0.3 ppm) which eliminates the need for regeneration with Potassium Permanganate which both cost and time expensive

Long Life
DMI-65 is not consumed in the process giving it an expected operational life of up to 10 years, providing considerable advantages over other processes or media. The media does not display a decaying capacity to do its catalytic work. Over the 5 to 10 year period, through many backwashing operations of the bed to remove retained solids, an attrition loss of the media occurs by contact between particles and mechanical abrasion.

High Load Capacity
Because of the increased surface area owing to the micro-porous structure of the matrix material, DMI-65 has higher iron and manganese load capacity which can extend the duration of filter runs and the time between backwashing, thereby reducing downtime, operating expense and wastage.

Reduced Total Water Treatment Solution costs

The use of DMI-65 in a water treatment solution for the removal or iron and manganese contributes to a reduction in the capital investment cost of the water filtration solution:

High Flow Rates
The infused technology of DMI-65 promotes the highest oxidation rate of any catalytic filtration media. This permits a significantly higher water flow rate to achieve the same level of iron and manganese removal. DMI-65 can operate at linear filtration velocities up to twice that of conventional media with a corresponding reduction in capital equipment costs.

Reduce Redundancy
Iron and Manganese contamination can materially reduce the performance of water treatment systems. The effectiveness of DMI-65 in removing iron and manganese contamination levels allows the water filtration system to function closer to rated levels thereby reducing the amount of costly overcapacity that would be acquired to achieve required output levels.

Wide Operating Environment
Stable and satisfactory performance at pH 5.8 to 8.6. and a maximum operating temperature of 113° F (45°C) reduces the need for investment to alter the operating environment.

DMI-65 Advanced Oxidation Process

Our Advanced Oxidation Process (“AOP”) uses the highly reactive catalytic material DMI-65 to boost the reduction/oxidation (redox) processes in water. This material promotes stronger oxidation than molecular oxygen and ordinary oxidants. Under certain conditions heavy metals may be difficult to oxidise to insoluble hydroxides, however our DMI-65 based AOP increases the rate of reaction and achieves a higher degree of purification.

In essence, the oxidants and the media work together to oxidize a dissolved solid into a suspended solid that is then filtered out in the depth of the media bed. If an element can’t be oxidized and precipitated the media can’t remove it. The media “helps” chemical reactions to occur by interacting with the oxidation reaction without being permanently altered.

Iron and manganese exist in bore water as bicarbonate. DMI-65 acts as an oxidation catalyst in the true meaning of the word and facilitates oxidation – precipitation – filtration. Strictly speaking, the media facilitates chemical reactions and does not explicitly remove anything, though once oxidised, the depth filtration aspect of the media removes the solids created by the oxidation that are then periodically backwashed out of the filter vessels.

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. Other oxidants such as hydrogen peroxide (H2O2), chlorine dioxide (ClO2) or ozone can also be used so long as a residual can be measured and maintained. Choice of oxidants needs to be subject to detailed analysis as performance varies according to the operating environment.

Another function of the Chlorine is that it keeps the media free from bacterial bio fouling or slime growth which reduce its performance. The need to add an oxidizer as part of the DMI-65 process also means that the final stage of the disinfection process of water treatment is also addressed.

For effective treatment results, DMI-65 Advanced Oxidisation Process is integrated into a complete treatment system. The treatment processes are arranged in three stages: pretreatment-conditioning, DMI-65 catalytic AOP treatment and post DMI-65 catalytic AOP treatment.

The DMI-65 Advanced Oxidation Process will work in most vertical filtration configurations.
Pre-treatment allows flexible implementation of a range of traditional processes; however significant performance improvements and cost reductions are generally achieved from the integration with the next stage, AOP. Post DMI-65 catalytic treatment stage may include fine filtration comprising 5 and 1 micron filters, a secondary filtration barrier using fine resolution filters.

Arsenic Removal
The media can also be used to remove Arsenic (As). In this case, the media does not actually remove the As but rather relies on the fact that Arsenic and Iron (Fe) readily form a complex and when the media takes out the Fe it takes the As with it. If water has As present but no Fe it will be necessary to add ferric chloride to the water. It should be noted that this only applies to inorganic As (As III and V) since not all organic As readily bonds with the Fe. As Arsenic is extremely poisonous (classified as a group 1 human carcinogenic substance), water treatment plant design must be proven through pilot testing to establish correct settings, or the use of already proven DMI-65 based arsenic removal systems.

Hydrogen Sulphide Removal
The media can also be used as a simple and low-cost technology to remove H2S. The DMI-65 Advanced Oxidation Process acts as an oxidation catalyst and facilitates the oxidation of any H2S not oxidized by the chlorine injection. The sulfur is then filtered in the media bed.

Uses

In addition to the basic human right to have access to clean and safe drinking water, most industries that use water in their production require water purification to ensure integrity of their products of the highest quality and that the performance of their processing or manufacturing equipment is not compromised.
Water for consumption or used in food processing industries needs to be clean, with iron and manganese well below regulated levels, low in hardness and alkalinity and free of undesirable taste, odours and chlorine.

Water used in processing industries and systems need water that is treated for the removal of iron and manganese in order to achieve the highest possible performance from their systems. This performance can be a measure of output or downtime for maintenance.
Impact on the environment must also be addressed. Spent water, or output from dewatering operations must have excess iron and manganese removed in order to avoid damage to the ecosystem output areas. Facilities must be compliant, chemical reduced, discharges recycled and minimised.