MODULE 2 PUBLIC WATER SUPPLY: SOURCES AND PURIFICATION PROCESS

Question 1

The 2 General Sources of Public Water Supply are:

Answer 1

surface water
ground water

Question 2

The 3 Watersheds identified as major water sources for Metro Cebu:

Answer 2

1. Kotkot Watershed
2. Lusaran Watershed
3. Mananga Watershed

Question 3

MCWD supplies only ____ of Metro Cebu’s population.

Answer 3

40%

Question 4

What is the Purification Process for Surface Water Supply Source?

Answer 4

1. Storage
2. Aeration
3. Coagulation / Flocculation
4. Sedimentation
5. Filtration

Question 5

Water is sprayed into the air or cascaded in order to release trapped gases & absorb additional oxygen for better taste. It also removes iron compounds.

Answer 5

aeration

Question 6

the chemical process in which the _____ reacts with the sediment to make it capable of combining into larger particles. Alum is the common coagulant used.

Answer 6

coagulation

Question 7

common coagulant used

Answer 7

alum

Question 8

is the physical process in which the sediment particles collide with each other and stick together.

Answer 8

flocculation

Question 9

This is the process by which suspended solids are removed from the water by gravity settling and deposition. The objective of this process is to remove most of the suspended solids and thus reducing the loads on the filters.

Answer 9

sedimentation

Question 10

Water is passed through a bed of fine sand in which the suspended matters that did not settle during sedimentation are trapped and held in place by the force of gravity or by the direction of flow.

Answer 10

filtration

Question 11

What are the types of Filters?

Answer 11

slow sand filter
rapid sand filter

Question 12

2 types of rapid sand filter

Answer 12

rapid gravity filter
rapid pressure filter

Question 13

The organic matter which accumulates on the surface of the sand forms a jelly-like film which does stops the passage of organisms. Cleaning of the filter bed is done through scraping off a thin layer of sand together with the surface film. There must be at least 2 filters in any filtration system.

Answer 13

slow sand filter

Question 14

When the filter requires cleaning, it is emptied down to the level of the waste channel. The sand is agitated from below by means of compressed air delivered through the same pipes which previously collected the filtered water. The cleaning is completed in a few minutes and the filter is ready for use again immediately.

Answer 14

rapid gravity filter

Question 15

This is generally used for the purification of water used in swimming pools. The cleaning process consists of reversing the flow of water through the filter and allowing the washings to flow through the washout valve. While the flow of water is reversed, the sand is agitated from below by mechanical stirrers or by compressed air injected from below the filter bed.

Answer 15

rapid pressure filter

Question 16

______ is the method of introducing a controlled amount of chlorine gas or chlorine salts to the water in order to attain a desired degree of disinfection. ______ kills any disease – producing organisms in the water.

Answer 16

chlorination

Question 17

Used in disinfecting wells

Answer 17

pot chlorinator