11.
Partial clarification of water by coagulation and sedimentation done prior to
fiItration is known as ____________________.
12.
If used, plain sedimentation always includes:
a. FiItration.
b. Disinfection.
c.
Chemically induced disinfection.
d. Chemically assisted filtration.
13.
What is floc?
a. A fluffy white, sticky substance, which floats on the surface.
b. A transparent, gelatinous and sticky mass, which makes the water very
viscous.
c.
An insoluble, jelly-Iike substance that entraps turbid particles to form fast
settling clumps.
d. A chemical compound, which reduces surface tension, thereby assisting in the
filtration process.
14.
What are the three critical essentials to proper flocculation?
b. Continuous aeration.
c.
Thorough and uniform mixing.
d. Carefully controlled temperature.
e. Carefully controlled chemical feeding.
f.
Carefully controlled depth of the water.
MD0160
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