1. In water filtration, van der Waals forces:
a. keep colloidal particles dispersed
b. are electrostatic repulsive forces
c. are electrostatic attractive forces
d. a and b
e. all of the above
2. With multimedia water filters, the more difficult particle size to remove from the water tends to be about:
a. 0.01microns
b. 0.1 microns
c. 1.0 microns
d. 10 microns
e. no differences among above particle size
3. Glauconite is more commonly known as:
a. silica sand
b. greensand
c. manganese dioxide
d. resin
4. To remove iron, manganese and hydrogen sulfide, greensand is covered or coated with:
a. manganese oxide groups
b. iron oxide groups
c. sulfonation groups
5 & 6. Reduced forms of iron, manganese and sulfur are 5)_____________, and oxidized forms are 6)____________ in water:
a. soluble
b. insoluble
c. dissolved
d. suspended particulates
e. a and c
f. b and d
7. Greensand is an excellent filter medium to remove suspended particulates from water. (True or False)
8. The capacity of manganese greensand is the greatest for removal of:
a. iron
b. manganese
c. hydrogen sulfide
9. Sodium hypochlorite (chlorine) can be injected into the water upstream of a manganese greensand bed. (True or False)
10. Hydrogen sulfide can strip the manganese oxide coating off of manganese greensand. (True or False)
