Active Ceramics

Active Ceramics

What is an ‘active’ ceramic?

Most basic ceramics such as glass, porcelain, clay ware, and brick, are based on natural aluminium silicates, which are ‘inactive’ electrical and thermal insulators.

New technology has led to a range of ‘special’ or ‘active’ ceramics which display physical properties of semi-conductivity, thermal and ultra-sound conductivity, magnetic properties, and light emission, achieved by the addition of various selected transition elements and sintering at very high temperatures.

These ‘active’ ceramics, used for the treatment of water and other liquids, are produced as spheres.

The material of the spheres is approved by the Water Research Centre under the Water By-laws scheme for use in contact with potable water.

They present no hazard to health or body in either their use, handling, storage or transportation (COSHH Regulations and Occupational Exposure Limits).

How Do They Work?

Most bacteria have a short life expectancy and, deprived of nutrition or the wrong environmental conditions, quickly expire.

They reproduce by one of two methods; binary fission, where individual cells continually divide into two identical cells, and sexual, where two cells merge before producing progeny by division or ‘budding’.

The function of any bacteriostat is to prevent or inhibit both types of reproduction.

Disinfection can be achieved by physical or chemical means, involving the destruction of the information required by the cell to survive (the DNA complex), or of the membrane enveloping the cell.

Physical methods include heat (wet or dry), electromagnetic radiation (infra-red, ultra-violet, rays), ultra-sound etc. These can kill all living microorganisms, the result being termed `Sterilisation’.

Chemical methods include strong oxidising agents such as chlorine and its oxides, bromine, iodine, hydrogen peroxide and its derivatives.

Also specific organic compounds such as pesticides, phenolic compounds, organochlorine and phosphorus.

These tend to act in a general fashion by attacking the cell as a whole, or selectively by altering the genetic structure, and can vary in strength from mild to strong. These are termed `Disinfectants’.

Active ceramics are a recent development in the production of specially designed, dedicated ceramics.

When immersed in the water these Active Ceramics display physical properties of semiconductivity, magnetic properties and light emission (in the far infrared spectrum).

The effect is similar to a miniature electric cell, the current flow causing hydroxyl ions (OH) to convert to oxygen gas (O2). At the same time, the formation of hydroxyl and anolyte result in a neutral pH.

The radiation emitted by the spheres in the infrared region of the electromagnetic spectrum is too low to cause sterilisation but is sufficient to excite the molecules in the water, thereby stimulating the oxidisation process.

The oxidisation (and production of chlorine) by the electrolysis of water acts as a potent disinfectant, with the anaerobic bacteria (amongst which are Legionella and E.Coli) being the most sensitive to attack and, therefore, most quickly controlled or eliminated. Aerobic bacteria can also be affected but the protective enzymes they produce considerably extend the time taken to achieve the same result.

Bacteria are attracted to the chemical activity and extensive substrate of the Active ceramics where they attach themselves to the surface. There the products of the electrolytic process destroy the D.N.A. and/or the membrane enveloping the cell, whereupon their ability to thrive and reproduce is ended.

The Electro-Chemical Action of ‘Active’ Ceramic Spheres

Application of an electrical voltage of a certain value across two inert electrodes immersed in water will cause current to flow involving ions (not electrons as in metals and semiconductors), the positive hydrogen ions (H+) collecting at the Cathode (-ve) where electrons convert the ions to hydrogen gas (H2).

This is only possible if a corresponding process takes place at the Anode, which transfers electrons from the water, achieved by the Hydroxyl ions (OH) converting to oxygen gas (O2). Impurities in the water increase the electrical conductivity of the water and reduce the potential at the electrodes.

The region around the cathode is called the catholyte and is generally alkaline (high pH) due to the formation of the hydroxyl while the region around the anode is the anolyte, which is acidic (low pH) and is where the oxidising entities are formed. When catholyte and anolyte mix the result is a pH which is neutral, while some of the active species lose their potency.

Using natural water with a degree of mineralisation, for example, NA+, K+, Ca+, Mg2+, C1-, SO42-, HCO32-, etc..

ANOLYTE

pH = 3 à7 ORP = +700 à+1200 mV

Active products synthesised: HO2, HO*2, O3, O*2, H2O2, O2, H+ (H3O+), O*, OH*, Cl2O, C1O2, HC1O, C1O*, C1* C12, S2O82-, C2O62-
.
CATHOLYTE

pH = 10 à11 ORP = - 500 à - 800 mV

Active products synthesised: NaOH, KOH, Ca(OH)2, Mg(OH)2, HO*, H3O2*, HO*2, H2O*2, O*2, HO-, O22-, O2-.

Note: * = free radical

Properties

The Active Ceramics transmit radiation, in the far-infra red region of the electromagnetic spectrum, of low intensity and energy (of relatively low energy compared, say, to that of ultra-violet), too low to cause sterilisation but capable of exciting the molecules of water by vibration and rotation, and so increasing their mobility (by lowering viscosity) and thereby facilitating the oxidising process.

However, it is the electrochemical property, which achieves disinfection. Over the surface of the ceramic minute cells are formed, comprising pairs of cathodes and anodes, where water is electrolyzed, splitting into its component hydrogen and oxygen albeit in a complex manner.

While the hydrogen readily escapes, the oxygen so produced provides a powerful oxidising reagent capable of inhibiting the growth of micro-organisms and, indeed, killing them.

This is akin not only to the physical sterilisation performed by heat, ultra-violet, "X"and "Y" [special characters missing] radiation and ultrasound, but also the disinfecting properties of such powerful oxidants as chlorine, bromine, iodine, chlorine dioxide, peroxide and ozone, without leaving the latter group's obnoxious and often hazardous residues.

The significant advantage of Active Ceramics over other (non sterilising) products currently available for prevention of the infestation of bacteria is that the electrolytic process (Bactericidal action) begins immediately upon immersion

...and is continuous and consistent thereafter, whatever the operating conditions. This compares with the effects of the most commonly used chemical treatments, which are transient and uncertain, requiring constant monitoring and re-dosing to ensure protection.

As the pH of the water treated is changed towards neutral the deposit of scale is immediately inhibited, and removed over time, downstream of the influence of the Active Ceramics. This is shown by the formation of fine deposits in waters of measurable ‘hardness’ (lime scale).

Disinfecting Capability

Most common disinfectants, such as sodium hypochlorite, take a significant time to kill the total number of microorganisms present, depending on their size and structure.

For example, a 1% (10,000 mg/litre) solution of free chlorine can take up to 10 minutes to achieve 100% eradication, while the normal 1mg/litre in municipal water supplies can take as much as 24 hours to give total kill, by which time it has been considerably diminished by side reactions.

The media will keep the water free from a number of pathogenic bacteria and organisms thereby keeping the water stored in a safe condition for extended periods of time. In fact, the HydroMaster™ Modules are long lasting, with a guaranteed lifespan of 5 years.

These composite modules have the additional property of balancing the pH, which precipitates the coagulation of many of the dissolved metallic species such as calcium, magnesium, iron, manganese, etc. inhibiting the build up of limescale or the formation of rust.

There are a number of different ‘Active Ceramic’ spheres made to various specific formulas. The spheres are designed for use in many different applications, including potable water treatment, grey water reclamation, sewage treatment, chlorine removal, red water and scale control.

There are clear advantages for the food industry where the ceramics will be used in plastics and work surfaces to control E-coli, Salmonella and other harmful organisms experienced in food preparation and storage.

The super water modules must be used as part of an ongoing preventative maintenance programme to avoid legionella. The modules will reduce both chemical and cleaning requirements.

FACTS, BENEFITS AND RESULTS

1. It provides background disinfection continually. Provides peace of mind.

2. Does not produce biofilm. Reduces maintenance costs (i.e. tank cleaning). Reduced costs - increased profits.

3. Balances pH. Prevents deposits of scale and effects of corrosion. Reduced costs - increased profits.

4. Non invasive - can be installed by a local plumber or DIY skilled customer. Minimum disruption of organisation reduced contract costs. A quality of life for customers and staff not affected. Reduced costs increased profits.

5. Non-toxic. Eliminates Known Risk associated with most other treatment currently available. Peace of mind.

6. Environmentally Friendly. Safe to handle, transport and for disposal. Conforming to popular ethical approach. Also complying with regulatory requirements.

Here is some brief information regarding Legionella Pneumophila.

Legionella Pneumophila

Legionella Pneumophila is a Gram-negative bacterium that is widely distributed in natural and manmade freshwater habitats.

All members of the genus have small rod-shaped cells 1-2 µm in length and 0.5 ?µm wide and require iron and cysteine for isolation.

They will initiate growth on artificial media only over a narrow pH range of 6.8-7.0 but can tolerate a pH range from 5.5-9.0 in natural habitats.

When Legionella Pneumophila was first isolated, it was found to be only distantly related to other bacteria and was placed in its own family, the Legionellaceae.

DNA-DNA hybridization experiments and 16S rRNA studies have shown that the species of Legionella are closely related to one another but distantly related to other bacteria.

The most closely related groups are the purple sulphur bacteria, the Enterobacteriaceae and Pseudomonas.

Legionella Pneumophila was identified in 1979 following an outbreak of ‘Legionnaire's Disease’ caused by the bacterium.

It was later learned that previous outbreaks of Legionnaire's disease had occurred as early as 1957.

Legionella Pneumophila was isolated in 1947 in a guinea pig that had been inoculated with blood from a patient with an unknown disease.

Legionnaires Disease

The first identified outbreak of Legionnaires Disease occurred during a Pennsylvania State Convention of the American Legion in 1976.

182 cases resulted in 29 deaths within the hotel. 38 cases were reported amongst passers by, resulting in a further 5 deaths.

In recent years 200 – 300 cases of the disease have been reported each year in England and Wales. The majority of outbreaks are associated with buildings such as Hotels, Factories, Hospitals, Nursing Homes and Office Blocks.

More research has been carried out in the United States where, according to the OSHA (Occupational Safety and Health Administration – part of the U.S. department of Labour), Legionnaire's disease is considered to be fairly common and serious, and the Legionella organism is one of the top three causes of sporadic, community-acquired pneumonia.

Because it is difficult to distinguish this disease from other forms of pneumonia, many cases go unreported.

Approximately 1,000 cases are reported annually to the CDC (Centre for Disease Control and Prevention), but it is estimated that over 25,000 cases of the illness occur each year and cause more than 4,000 deaths.

This is in excess of 25 times the number of reported cases, which would indicate that some 5000 – 7500 cases in England and Wales is, perhaps, a more accurate figure. There are sources in the UK that believe the true problem attributable to all of the 20+ different varieties of Legionella linked with human diseases, could be significantly higher than this.

In the UK, 180,000 people die from all of the different varieties of pneumonia each year. As many cases apply to people in susceptible groups (such as the elderly, smokers, alcoholics, cancer sufferers and other immunosuppressed patients) rarely is a full investigation of the true cause of pneumonia carried out.

How do people contract Legionella?

The most popular theory is that the organism is aerosolized in water and people inhale the droplets containing Legionella.

However, new evidence suggests that there is another way of contracting Legionella. It appears that "aspiration" may be the way the bacterium enters into the lungs.

Aspiration means choking such that secretions in the mouth get past the choking reflexes and instead of going into the oesophagus and stomach, mistakenly, enter the lung.

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