Quiznetik
Waste Water Treatment | Set 3
1. From which of the following methods can toxic chemicals be removed?
A. Sorption
B. Adsorption
C. Absorption
D. Dewatering
Correct : A. Sorption
2. What is the term used for reuse of sewage sludge?
A. Compost
B. Solids
C. Biosolids
D. Sludge
Correct : C. Biosolids
3. In which year was the term Biosolids introduced?
A. 1990
B. 1995
C. 1998
D. 2000
Correct : C. 1998
4. What is the first step in the sewage treatment process?
A. Dewatering
B. Thickening
C. Phosphorus recovery
D. Digestion?
Correct : B. Thickening
5. What is the amount of solids released into wastewater by human beings?
A. 30 gpcd
B. 40 gpcd
C. 60 gpcd
D. 70 gpcd
Correct : D. 70 gpcd
6. What is the percentage of aerobically digested sludge?
A. 0.2-0.5
B. 0.3-0.6
C. 1.0-2.0
D. 1.5-3.0
Correct : C. 1.0-2.0
7. Ws = Wsp + Wss What does Wsp stand for in the above equation?
A. Total dry solids
B. Raw primary solids
C. Suspended solids
D. none
Correct : B. Raw primary solids
8. Sludge from the primary clarifier is ______
A. Brown and flocculant like appearance
B. Dark in colour
C. Gray and slimy
D. Dark brown in colour
Correct : C. Gray and slimy
9. How does the chemical sludge appear?
A. Gray in colour and not slimy
B. Brown and flocculant like appearance
C. Red/grayish brown
D. Black in colour
Correct : C. Red/grayish brown
10. How does the activated sludge appear?
A. Gray
B. Red
C. Brown and flocculant like appearance
D. Greasy
Correct : C. Brown and flocculant like appearance
11. What is the % of dry solids assumed for a primary sludge from a settling tank at the outlet?
A. 12%
B. 5-7%
C. 8%
D. 9-11%
Correct : B. 5-7%
12. What is the percentage of dry solids assumed for the sludge at the outlet of a centrifuge?
A. 10-15%
B. 1-3%
C. 4-8%
D. 9-12%
Correct : C. 4-8%