Question 1

From which of the following methods can toxic chemicals be removed?&#10;A)Sorption&#10;B)Adsorption&#10;C)Absorption&#10;D)Dewatering

Accepted Answer

B  C  Sorption is a general term that encompasses both adsorption and absorption, which are processes used to remove toxic chemicals. Adsorption involves the adhesion of molecules to a surface, while absorption involves the uptake of substances into the volume of a material. Dewatering is not a method for removing toxic chemicals; it is a process for removing water.

Question 2

What is the term used for reuse of sewage sludge?&#10;A)Compost&#10;B)Solids&#10;C)Biosolids&#10;D)Sludge

Accepted Answer

Biosolids are treated sewage sludge that are intended to be reused, especially as fertilizer to improve and maintain productive soils and stimulate plant growth.

Question 3

In which year was the term Biosolids introduced?&#10;A)1990&#10;B)1995&#10;C)1998&#10;D)2000

Accepted Answer

1998&#10;

Question 4

What is the first step in the sewage treatment process?&#10;A)Dewatering&#10;B)Thickening&#10;C)Phosphorus recovery&#10;D)Digestion?

Accepted Answer

Thickening is the first step in the sewage treatment process, where the solid waste is concentrated to reduce its volume, making subsequent treatment processes more efficient.

Question 5

What is the amount of solids released into wastewater by human beings?&#10;A)30 gpcd&#10;B)40 gpcd&#10;C)60 gpcd&#10;D)70 gpcd

Accepted Answer

The answer of What is the amount of solids released...

Question 6

What is the percentage of aerobically digested sludge?&#10;A)0.2-0.5&#10;B)0.3-0.6&#10;C)1.0-2.0&#10;D)1.5-3.0

Accepted Answer

Aerobically digested sludge typically has a solids content of about 1.0-2.0%. This is because the aerobic digestion process reduces the volume of sludge by decomposing its organic matter, but not to the extent that it becomes very dry.

Question 7

Ws = Wsp + Wss What does Wsp stand for in the above equation?&#10;A)Total dry solids&#10;B)Raw primary solids&#10;C)Suspended solids&#10;D)none

Accepted Answer

Wsp stands for Raw primary solids in the context of wastewater treatment, where Ws represents the total solids, Wsp the raw primary solids, and Wss the suspended solids.

Question 8

Sludge from the primary clarifier is ______&#10;A)Brown and flocculant like appearance&#10;B)Dark in colour&#10;C)Gray and slimy&#10;D)Dark brown in colour

Accepted Answer

The answer of Sludge from the primary clarifier is ______&#10;A)Brown...

Question 9

How does the chemical sludge appear?&#10;A)Gray in colour and not slimy&#10;B)Brown and flocculant like appearance&#10;C)Red/grayish brown&#10;D)Black in colour

Accepted Answer

The answer of How does the chemical sludge appear?&#10;A)Gray in...

Question 10

How does the activated sludge appear?&#10;A)Gray&#10;B)Red&#10;C)Brown and flocculant like appearance&#10;D)Greasy

Accepted Answer

Activated sludge typically appears brown and has a flocculant-like appearance due to the aggregation of microorganisms and particulate matter.

Question 11

What is the % of dry solids assumed for a primary sludge from a settling tank at the outlet?&#10;A)12%&#10;B)5-7%&#10;C)8%&#10;D)9-11%

Accepted Answer

The answer of What is the % of dry solids...

Question 12

What is the percentage of dry solids assumed for the sludge at the outlet of a centrifuge?&#10;A)10-15%&#10;B)1-3%&#10;C)4-8%&#10;D)9-12%

Accepted Answer

The answer of What is the percentage of dry solids...

Deck 9: Sewage Sludge and Treatment Processes