Introduction

The quality of the water being used in your home is directly releated to your health. Recent water quality issues in certain areas of the country have highlighted the health risks associated with a poor quality supply.

Filtration is the general term used to describe a range of water treatment solutions. A filter removes suspended matter from water by mechanical "screening". Basic filters usually are porous beds of insoluble material. Other examples include cast forms, plates of sheet material, synthetic membranes, finely perforated plastic or specially sized beds of inert particles. Suspended silt, clay, colloids, and some micro-organisms are removed by the filtration process. Simple cartridge filters may be effective for low levels of turbidity.

A water treatment system is one way to improve the water you use in your home for cooking and drinking.

Water Treatment Systems - Installation Options

Water treatment technology for the home is an effective method of improving the quality the water you use on a day-to-day basis. Treatment products are typically offered under two categories:

• Domestic Under-Sink Filtering
• Whole House Filters

Then, within these two categories,there exists a broad number of treatment options

• Reverse Osmosis Filtering
• Water Softening
• Ultra Violet Irradiation
• Iron Treatment
• Bacteria Treatment
• Carbon Treatment

Domestic Under-Sink Filtering - General

Domestic Under-Sink filtering systems are familar to many as a tap-mounted system and only service a single tap/sink in your home. They install neatly under the sink and linked to a single tap (usually in the kitchen for cooking/drinking purposes etc.)

Whole House Filtering Filtering - General

Whole House filtering systems are installed at the main water intake pipe for your home. In this way they provide treated/filtered water to the every tap in the house.

How does Reverse Osmosis work?

Reverse Osmosis filtration is used today by bottling plants that require ultra-refined water in manufacturing. This water filter technology is also available as a home water filtering system. It works using a semipermeable membrane to separate two bodies of water. A semipermeable membrane allows some atoms or molecules but not others to pass through it. Saran wrap is a membrane that is impermeable to many water-borne molecules. Gore-tex fabric is a commercial example of a semipermeable membrane that contains an extremely thin plastic film into which billions of small pores have been cut. The pores are big enough to let water vapour through, but small enough to prevent liquid water from passing.

In water filtration the membrane allows passage of water molecules but not larger material molecules via osmotic pressure. Osmotic pressure is the natural flow of water from the clear/clean side of the membrane to the contaminated/un-treated side - this occurs because a natural ‘pressure draw’ is established as a result of some of the pores on the un-treated side becoming clogged with molecules.

In Reverse Osmosis, the principle is to use the membrane to act like an extremely fine filter to create drinkable water from contaminated or untreated water. The un-treated water is put on one side of the membrane and pressure is applied to stop, and then reverse, the osmotic process. It generally takes a lot of pressure and is fairly slow, but it works.

Reverse Osmosis is the most effective of all drinking water treatments systems. Each type of filtering system removes specific contaminants. RO systems remove a wider variety of pollutants than other methods. These filters use a porous membrane to strain very fine particles. The number of chemicals, microorganisms and pollutants removed by this process is large. These systems work effectively by removing 99% of chlorine, fluoride, iron, lead, and organisms such as giardia, e-coli and cryptosporidium.

Bacteria Treatment

Bacteria are tiny organisms occurring naturally in water. Not all types of bacteria are harmful. Many organisms found in water are of no health concern since they do not cause disease. Biological contamination may be separated into two groups:

• Pathogenic (disease causing)
• Non-pathogenic (not disease causing)

Pathogenic bacteria cause illnesses such as typhoid fever, dysentery, gastroenteritis, infectious hepatitis, and cholera. All water supplies should be tested for biological content prior to use and consumption.

E.Coli (Escherichia Coli) is the coliform bacterial organism which is looked for when testing the water. This organism is found in the intestines and fecal matter of humans and animals. If E.Coli is found in a water supply along with high nitrate and chloride levels, it usually indicates that waste has contaminated the supply from a septic system or sewage dumping, and has entered by way of runoff, a fractured well casing, or broken lines.

If coliform bacteria is present, it is an indication that disease causing bacteria may also be present. Four or fewer colonies / 100 ml of coliforms, in the absence of high nitrates and chlorides, implies that surface water is entering the water system.

Carbon Filtration

Activated Carbon Filtration systems involve the adsorption (adhesion) of one material on the surface of a second solid substance based on opposing electrical charges of each material. These systems are widely used to eliminate certain hazardous compounds related to industrial wastes, chemicals and pesticides. This treatment method can also remove unpleasant tastes and odours caused by decaying organic matter, dissolved gases, and residual chlorine. Activated carbon is placed on a filter medium or installed in treatment tanks and adsorbs the taste and odour impurities in water, leaving the water taste- and odour-free.

Adsorption filtration does not treat microorganisms and should also include a method of chemical disinfection. It is recommended that water be chlorinated before passing through an activated carbon filter. The purpose of the chlorination is to assist in the removal of substances causing taste and odour, and more important, to prevent bacteriological growth on the filter.