Water and Environmental Engineering

CHARECTERISTICS OF WASTEWATER

Download - Click Here

Physical characteristics

1.Solids  

       Composed of floating matter, settleable matter, colloidal matter and

       matter in solution.

Total Suspended Solids (TSS)

ØTotal suspended solids (TSS) include all particles suspended in water which will not pass through a filter.

ØAs levels of TSS increase, a water body begins to lose its ability to support a diversity of aquatic  life.

ØSuspended solids absorb heat from sunlight, which increases water temperature and subsequently decreases levels of dissolved oxygen

Total Dissolved Solids (TDS)

TDS are passed through the filter. TDS comprised of

colloidal and dissolved solids. Colloids are typically in the

size range from 0.001 to 0.45μm

Volatile Suspended Solids (VSS)

Those solids that can be volatilized and burned off when the TSS are ignited. Volatile suspended solids data is critical in determining the operational behavior and biological concentration throughout the system.

2.Turbidity

       Measure of the light-transmitting properties of water, is another

       test used to indicate the quality of waste discharges and natural waters with respect to colloidal and residual suspended matter.

Units – NTU (Nephelometric Turbidity Units)

Equipment using to measure - electronic turbidity meter or a turbidity tube

3.  Colour

ØAge of the waste water is determined qualitatively by its colour and

  odour.

ØFresh wastewater is usually a light brownish- gray colour. 

ØTravel time of the collection system increases anaerobic conditions develop and colour of the waste water changes sequentially for gray to dark gray, and ultimately to   black.

ØThis black colour is due to the metallic sulfides which formed under the anaerobic conditions.

4.  Absorption / Transmittance

ØThis is measure of the amount of light, of a specified wave length, that is

  absorbed by the constituents in a solution.

ØAbsorbance measure using the spectrophotometer.

5.Temperature

ØThe temperature of waste water is commonly higher due to the addition of warm water from households and industrial activities.

ØTemp. is effects on chemical reactions and reaction rates, aquatic life and the suitability of the water.