Physical characteristics
The principal physical characteristics of wastewater
are its solids content, colour, odour and temperature.
The total solids in a wastewater consist of the
insoluble or suspended solids and the soluble compounds
dissolved in water. The suspended solids
content is found by drying and weighing the residue
removed by the filtering of the sample. When
this residue is ignited the volatile solids are burned
off. Volatile solids are presumed to be organic
matter, although some organic matter will not burn
and some inorganic salts break down at high temperatures.
The organic matter consists mainly of
proteins, carbohydrates and fats.