Drinking Water and fresh air are the unavoidable reasons for life. More than 70% of human body is composed by water. But unfortunately, only 3% of water available across the globe is fresh water and only half of that is available to humans. In developing countries population growth combined with industrial development is hard pressing on water demand resulting in the shrinkage of water table.
The shrinkage water table, bad industrial waste management practices, improper sanitation are mostly responsible for the deteriorating drinking water quality. The most essential requirement to ensure good quality drinking availability to all is regular testing of drinking water.
Nonpotable water Testing
Non-potable water is water that is not of drinking quality, but may still be used for many other purposes, depending on its quality.Potable water is water of a quality suitable for drinking, cooking and personal bathing. The standards that define potable water are described in the Australian Drinking Water Guidelines.Unless water is known to be of potable quality it should be regarded as non-potable and used appropriately.
The colours of water indicates the presence of a range of chemical and organic pollutants such as copper from plumbing systems, rust from iron pipes, algae, bacteria, and so on. This means that colour testing is an effective way to determine the nature of water pollution.Colour in water can be measured by eye.
If the water has no odour, the likely source is the sink drain. If it does have an odour, the source could be organic matter in your drinking water. Although harmless, this material can affect the taste and smell of your drinking water even at very low concentrations.
A numerical limit for taste in water has not been established because there is no objective method for numerical measurement of taste and because there is considerable variation among consumers as to which tastes are acceptable. In many cases, sensations ascribed to the sense of taste may actually be odours.
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Turbidity is also applied to transparent solids such as glass or plastic.
Hard water is water that has high mineral content . Hard water is formed when water percolates through deposits of limestone, chalk or gypsum which are largely made up of calcium and magnesium carbonates, bicarbonates and sulfates. Hard drinking water may have moderate health benefits, but can pose critical problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling towers, and other equipment that handles water. In domestic settings, hard water is often indicated by a lack of foam formation when soap is agitated in water, and by the formation of limescale in kettles and water heaters. Wherever water hardness is a concern, water softening is commonly used to reduce hard water’s adverse effects.
Water containing ferrous iron is clear and colorless because the iron is completely dissolved. When exposed to air in the pressure tank or atmosphere, the water turns cloudy and a reddish brown substance begins to form. This sediment is the oxidized or ferric form of iron that will not dissolve in water.
Fluorine is a common element that does not occur in the elemental state in nature because of its high reactivity. It accounts for about 0.3 g/kg of the Earth’s crust and exists in the form of fluorides in a number of minerals, of which fluorspar, cryolite and fluorapatite are the most common. The oxidation state of the fluoride ion is -1. Fluoride is usually determined by means of an ion-selective electrode, which makes itpossible to measure the total amount of free and complex-bound fluoride dissolved in water. The method can be used for water containing at least 20 µg/litre (Slooff et al.,1988). For rainwater in which fluoride was present at a concentration of 10 µg/litre, a detection limit of 1 µg/litre was reported (Barnard & Nordstrom, 1982).
Phenol is an organic compound appreciably soluble in water, with about 84.2 g dissolving in 1000 mL (0.895 M). Homogeneous mixtures of phenol and water at phenol to water mass ratios of 2.6 and higher are possible. The sodium salt of phenol, sodium phenoxide, is far more water-soluble.
Some cyanide in water will be transformed into less harmful chemicals by microorganisms or will form a complex with metals, such as iron. The half-life of cyanide in water is not known. Cyanide in water does not build up in the bodies of fish. Cyanides are fairly mobile in soil.
Metals are introduced in aquatic systems as a result of the weathering of soils and rocks, from volcanic eruptions, and from a variety of human activities involving the mining, processing, or use of metals and/or substances that contain metal pollutants. The most common heavy metal pollutants are arsenic, cadmium, chromium, copper, nickel, lead and mercury. There are different types of sources of pollutants: point sources (localized pollution), where pollutants come from single, identifiable sources. The second type of pollutant sources are nonpoint sources, where pollutants come from dispersed (and often difficult to identify) sources. There are only a few examples of localized metal pollution, like the natural weathering of ore bodies and the little metal particles coming from coal-burning power plants via smokestacks in air, water and soils around the factory.