Wastewater Flashcards
1
Q
Wastewater Treatment
A
Wastewater is water that is discharged after household or industrial use and that is polluted as a result of human activities.
2
Q
Wastewater Contaminants
A
- Sand and suspended particles
- Pathogens
- Decomposing organic waste
- Nutrients that stimulate the excessive growth of algae, cyanobacteria and aquatic plants.
3
Q
Wastewater treatment Plants
A
- Expensive to build
- Usually in urban areas
- Where sewer systems exist
4
Q
Septic Tanks
A
- Wastewater is drained into a container
- Solid waste settles at the bottom = sludge
- Collect the sludge and treat it
- Liquid part drains out of tank into surrounding land i.e. Drainage field
- Can use microorganisms to treat the liquids in the water or the soil
5
Q
3 Major Processes of Waste Water Treatment
A
1) Primary or physical Treatment
2) Secondary or biological Treatment
3) Disinfection
6
Q
Primary/physical Treatment
A
- Involves settling sedimentation of solid waste
- Wastewater in passed through several tanks
- At the end of this process bigger particles are removed and only organic matter should be left.
7
Q
Secondary/Biological Treatment
A
- Removes dissolved and suspended biological matter.
- Aeration and sludge pumped into the water.
8
Q
Disinfection
A
- Uses chemicals
- Clorein disinfection: kills off bacteria
- Ultraviolet: Scrables DNA so cannot multiply
