Two Marks Questions and Answers

TWO MARK QUESTION AND ANSWERS

 

1. What are the types of trickling filters?

• Conventional trickling filter

• High rate trickling filter

 

2. What are the operational troubles in trickling filter?

• Fly nuisance

• Odour nuisance

• Ponding troubles

 

3. Define sludge age.

The sludge age is defined as the average time for which particles of suspended soil remain under aeration.

 

4. Define sludge volume index.

Sludge volume index is defined as the volume occupied in ml by 1 gm of solids in the mixed liquor after settling for 30 minutes and is determined experimentally.

 

5. What are the methods of disposing the sewage effluent?

• Disposal in water (dilution)

• By disposal on land

 

6. What are the different types of sewage treatment?

• Contact beds

• Intermittent sand filters

• Trickling filters

• Miscellaneous type of filters

 

7. Define sludge digestion

The sludge is first stabilized by decomposing the organic matter under controlled anaerobic condition. The process of stabilization of the sewage particles are called sludge digestion

 

8. What are the stages in the sludge digestion process?

• Acid fermentation

• Acid regression

• Alkaline fermentation

 

9. What is meant by ripened sludge?

The ripened sludge is nothing but the digested sludge is collected at the bottom of the digestion tank and it is alkaline in nature.

 

10.  What are the factors affecting sludge digestion and their control?

• Temperature

• pH value

• mixing and stirring of raw sludge with digested sludge

 

11. What are the types of incinerators has primary designed?

• Multiple hearth furnaces      

• Fluid bed furnace and infra red furnace

 

12. What are the methods of aeration?

• Diffused air aeration

• Mechanical aeration

• Combined aeration

 

13. What is meant by sludge concentrator unit?

The sludge obtained in a sludge digestion plant contains too much of moisture and is therefore very bulky may be reduced in its moisture content by sending into sludge thicker unit (or) sludge concentrator unit

14. Give different types of thicker unit.

• Gravity thickener

• Floating thickener

• Centrifugal thickener

 

15. What is Coagulation?

The fine mud particles and other colloidal matter present in waste waters gets absorbed in flows, forming the bigger sized flocculated particles. The process of bolla addition and mixing of chemicals is called coagulation.

 

16. What is biological treatment?

Biological treatment is carried out by changing the character of the organic matter, and thus converting it into stable forms (like nitrates, sulphates) by oxidation or nitrification.

 

17. What is biological film (or) slime layer.

As the sewage percolates through the filtering media, fine colloidal organic matter to mois trapped in the voids between the particles of the filtering media.

 

18. What is sloughing?

The break up or detachment of the biomass (biological solids) from the slime layer is known as sloughing.

19. What are the methods of disposal of septic tank effluent?

• Soil absorption system

• Biological filters

• Up flow anaerobic filters feesn

 

20. Define percolation rate.

Peculation rate is defined as the time in minuets required for sewage of water through that ground by one cm.

 

21. What are the soil absorption system?

• Dispersion trench

• Seepage pit (or) soak pit

 

22. What is meant by de oxygenation curve?

The curve which represents (or) showing the depletion of D.O with time at the given temperature.

 

23. What are the methods of applying sewage effluents to forms?

• Surface irrigation

• Free flooding

• Border flooding

• Check flooding

 

24. Name the biological zone in lakes.

• Euphonic zone

• Littoral zone

• Benthic zone.

 

25. What is meant by re -oxygenation?

In order to counter balance the consumption of D.O due to the de- oxygenation, atmosphere supplies oxygen to the water and the process is called the re-oxygenation.

 

26. What is meant by oxygen sag curve?

The amount of resultant oxygen deflect can be obtained by algebraically adding the de -oxygenation and re -oxygenation curves. The resultant curve so obtained is called oxygen sag curve.

 

27. What is meant by zone of recovery?

The zone in which the river water tries to recover from its degraded conditions to its former appearance is called zone of recovery.

 

28. What is meant by sewage sickness?

The phenomena of soil getting clogged when the sewage is applied continuously on a piece of land is called sewage sickness.

 

29. What are the preventive methods for sewage sickness?

• Primary treatment of sewage

• Choice of land

• Under drainage of soil

• Giving rest to land and Rotation of crops

 

30. Define dilution factor.

The dilution factor is defined as the ratio of the amount of river water to the amount of the sewage.

 

31.What is meant by self purification?

The automatic purification of natural water is known as self purification.

 

32. List various natural forces of self purification.

• Physical forces

• Chemical forces