“Water quality is commonly defined by its physical, chemical, biological and aesthetic (appearance and smell) characteristics. A healthy environment is one in which the water quality supports a rich and varied community of organisms and protects public health.”
The quality of drinking water is maintained by individual water bodies of all the metropolitan cities. Sydney Water and Hunter Water are the two large organisations that aim to provide high quality drinking water for all in these regions. Drinking water is treated to meet the Australian Drinking Water Guidelines (ADWG).
ADWG is concerned with the safety and aesthetic quality of drinking water for human consumption. Drinking water does not need to be absolutely pure to be safe, as water is such a good solvent, pure water containing nothing else is almost impossible to attain. What is required is that drinking water should be safe to drink for people in most stages of normal life, including children over six months of age and the very old. It should contain no harmful concentrations of chemicals or pathogenic microorganisms, and ideally it should be aesthetically pleasing in regard to appearance, taste and odour.
Water quality can be determined by a chemist by considering:
* Concentrations of common ions- which are monitored using two processes:
1. Atomic Absorption Spectrometry (AAS) is a common technique used to identify the concentration of metal ions. In testing water quality the concentration of the following cations are usually determined: sodium, magnesium, calcium and potassium.
2. Gravimetric analysis can be used to determine the quantities of both cations and anions, e.g. for chloride ions precipitated and weighed as silver chloride. Common anion concentrations measured include chloride, sulfate, bicarbonate and fluoride ions.
* Total dissolved solids- (TDS) are determined by evaporation to dryness of a known volume of a filtered sample. The...