Sewage Treatment

Question 1

is the mainly liquid waste containing some solids produced by humans, typically consisting of washing water, urine, feces, laundry waste, and other material that goes down drains and toilets from households and industry

Answer 1

Sewage

Question 2

is the process of removing contaminants from wastewater and sewage. It includes physical, chemical and biological processes to remove physical, chemical and biological contaminants. Its objective is to produce a waste stream and a solid waste or sludge suitable for discharge or reuse back into the environment.

Answer 2

Sewage Treatment

Question 2

• ______ is created by residences, institutions, hospitals and commercial and industrial establishments.
• It can be treated close to where it is created (in ________), or collected and transported via a network of pipes and pump stations to a municipal treatment plant.

Answer 2

• Sewage
• septic tanks

Question 2

Sewage Treatment Systems

1. Rural and suburban areas - ______

Answer 2

septic tank

Question 3

Sewage Treatment Systems

2. Urban areas -________
   * __________ - physical process
   * __________ - biological process
   * __________ - bleaching and disinfection

Answer 3

• wastewater treatment plants
• Primary treatment
• Secondary treatment
• Chlorination

Question 4

• common in areas with no connection to main sewage pipes
• It is 4000 - 7500 litres in size

Answer 4

Septic tank

Question 4

The five parts of a sewage disposal system are:

Answer 4

(1) the house plumbing,
(2) the sewer line from house to septic tank,
(3) the septic tank,
(4) the septic tank outlet sewer pipe,
(5) the final soil treatment unit, which may be a soil absorption unit

Question 4

The material in the septic tank separates into three distinct layers:
A top layer of floating ______
A middle ______
A bottom layer of ____

Answer 4

• scum
• liquid zone
• sludge

Question 5

keep the septic tank and soil absorption unit at least 100 feet away from any ________ that is less than 100 feet deep, and at least ________ from wells more than 100 feet deep

Answer 5

private well
50 feet away

Question 5

Sewage Treatment Plant
* ________
* Pre-treatment may include a ____________ where the velocity of the incoming wastewater is adjusted to allow the settlement of sand, grit, and stones

Answer 5

• Grit removal
• sand or grit channel or chamber

Question 6

_____________
* Settle solids for 2-3 hours in a static, unmixed tank, commonly called “________” or “__________”. The tanks are used to settle sludge while grease and oils rise to the surface and are skimmed off

• Sludge is directed towards the base of the tank where it is pumped to sludge treatment facilities

Answer 6

Primary Treatment
* “primary clarifiers” or “primary sedimentation tanks”

Question 7

__________
* Sludge from the sedimentation tanks is digested anaerobically in large tanks, In the sludge digesters the sludge is kept at 370C and mechanically mixed to ensure optimum operation.

• When the sludge leaves the digesters it has undergone a _____ volume reduction

Answer 7

Secondary Treatment
* 50%

Question 8

The ______ are either sent directly to open-air oxidation ponds

Answer 8

liquids

Question 8

In the pond, algae use ____ to produce oxygen from carbon dioxide and water, and bacteria use ____ to break down the remaining organics to simple molecules such as carbon dioxide and ammonia. The sun also destroys ________, while the wind ensures even mixing so that all parts of the ponds are ______.

Answer 8

• solar energy
• oxygen
• pathogenic bacteria
• aerobic

Question 9

After ________ all effluent, both solid and liquid, is sufficiently safe to be released into the environment

Answer 9

secondary treatment