1. The PH value of fresh sewage is usually
                 a.       Equal 5Â
                b.       5 to 7Â
                c.       More than 7Â
                d.       Less than 7Â
More than 7Â
2. The rate of accumulation of sludge in septic tanks is recommended as
                a.       25 liters / person / yearÂ
                b.       28 liters / person / yearÂ
                c.       35 liters / person / yearÂ
                d.       30 liters /person/year Â
30 liters /person/yearÂ
3. What is the slope of semimetal tank
                a.       1:20Â
                b.       1:40Â
                c.       1:60Â
                d.       1:80 Â
1:20Â
4. The danger for workers descending into a deep sewer is due toÂ
                a.       Deficiency of OxygenÂ
                b.       Toxic gassesÂ
                c.       Inflammable gassesÂ
                d.       All of the above  Â
All of the aboveÂ
5. The release time for the domestic septic tank
                a.       1 to 3 yearsÂ
                b.       2 to 3 yearsÂ
                c.       2 to 5 yearsÂ
                d.       2 to 4 yearsÂ
 2 to 5 yearsÂ
6. The drop manholes are generally provided in sewers for
                a.       Industrial areasÂ
                b.       Large townshipsÂ
                c.       Hilly townshipsÂ
                d.       Cities in grasslandsÂ
  Large townshipsÂ
7. De-sludging of Septic Tank is needed when
                a.       ½ tank occupiedÂ
                b.       ¼ tank occupiedÂ
                c.       ½ to 2/3 tank occupiedÂ
                d.       None of theseÂ
½ to 2/3 tank occupiedÂ
8. Trickling filters are used to remove
                a.       Suspended solidsÂ
                b.       Colloidal solidsÂ
                c.       Organic matterÂ
                d.       Pathogenic bacteria
Organic matterÂ
9. What is the last stage of sewage treatment plant
                a.       Sludge treatment
                b.       Screen Treatment
                c.       Trickling Treatment
                d.       None of these
Sludge treatment
10. What is the factor affecting hardness of water
                a.       Magnesium & Calcium
                b.       Magnesium only
                c.       Calcium only
                d.       None of these
Magnesium & Calcium
11. Activated sludge is the
                a.       resultant sludge removable from the aeration unit
                b.       sludge settled in the humus tank
                c.       sludge in the secondary tank post-aeration rich in microbial mass
                d.       sludge in the secondary tank post aeration, rich in nutrientsÂ
Sludge in the secondary tank post-aeration rich in microbial mass
12. What is the correct order of processes in a wastewater plant
                a.       Screens , grit chamber, primary clarifier, secondary clarifier, trickling filter, chlorine and metal removal system
                b.       Screens , grit chamber, primary clarifier, trickling filter, secondary clarifier, chlorine and metal removal system
                c.       Screens , grit chamber, primary clarifier, trickling filter, chlorine and metal removal system, secondary clarifier.
                d.       Primary clarifier, trickling filter, screens , grit chamber, chlorine and metal removal system, secondary clarifier
Screens , grit chamber, primary clarifier, trickling filter, secondary clarifier, chlorine and metal removal system
13. The water supply to a house begins with the connection of the service pipe with the municipal water mains. The connections comprises
                1.       Stopcock
                2.       Goose neck
                3.       Ferrule
                4.       Water meter
The correct statement of these connections is :
                c.       1, 2, 3, 4
                c.       3, 1, 2, 4
                c.       3, 2, 1, 4
                d.       1, 2, 4, 3
3, 2, 1, 4
14. Viewing watershed as a system, which one of the following assumptions is made in the unit graph theory
                a.       Non-linearity
                b.       Both linearity and time variance
                c.       Both time invariance and non-linearity
                d.       Both linearity and time invariance
Both linearity and time variance
15. The PH value of fresh sewage is usually
                a.       More than 7
                b.       More than 6
                c.       Less than 7
                d.       None of these
 More than 7
16. Problems of nutrients
                a.       Taste & odor in drinking water
                b.       Can be toxic, especially to farm animals
                c.       Fouling
                d.       All of above
All of above
17. Pollutants are measured by oxygen demand potential or total organic content
                a.       Biochemical Oxygen Demand (BOD)
                b.       Theoretical Oxygen Demand (TOD)
                c.       Chemical Oxygen Demand (COD)
                d.       All of above
All of above
18. Coagulation
                 a.       Process of adding chemicals and rapid mixing
                b.       Chemical treatment process that destabilizes colloidal particles
                c.       All of above
                d.       None of these
All of above
19. Sedimentation basin (primary treatment
                a.       Waste water is held in a quiet tank for several hours allowing the particles to settle to the                Â
                b.       bottom and the greases to float to the top
                c.       The solids drawn off the bottom and skimmed off the top receive further treatment as sludge
                d.       All of the above
All of above
20. Water hardness is principally caused by
                a.       Calcium ions
                b.       Magnesium ions
                c.       both a and b
                d.       none of these
both a and b
21. Dis-advantages of hardness
                 a.       Excessive soap consumption during laundering
                b.       Scale-formation in hot water heaters and pipes
                c.       both a and b
                d.       none of theseÂ
both a and b
22. Filtration
                a.       The final step in removing particles
                b.       Removal of those particles that are too small to be effectively removed during sedimentation
                c.       both a and b
                d.       none of theseÂ
 both a and b
23. Rapid sand filtration
                a.       As particles are removed, filter become clogged- head loss increases, turbidity increases
                b.       Must back-wash once per day
                c.       Must design to handle flow with one filter out of service
                d.       both a, b and c
                e.       none of these Â
both a, b and c
24. How do treatment plants protect our water
                a.       Remove solids
                b.       Reduce organic matter & pollutants
                c.       Restores oxygen
                d.       All of the above Â
 All of the above
25. A major flood has resulted in contamination of hundreds of domestic water wells and the distribution system of a small town. The pH should be controlled to less than 7 because
                a.       It reduces the growth of viruses
                b.       PH of less than 7 will kill bacteria
                c.       The chlorine will be in the CI2 form primarily
                d.       The chlorine will be in the HOCI form primarily  Â
PH of less than 7 will kill bacteria