Top 250+ Solved Waste Water Treatment MCQ Questions Answer

From 121 to 135 of 211

Q. The optimum temperature for bacterial activity is in what range?

a. 25-35 degree Celsius

b. 50 degree Celsius

c. 20 degree Celsius

d. 40 degree Celsius

  • a. 25-35 degree Celsius

Q. The fluoride concentration for prevention of dental caries is ____________

a. 1mg/l

b. 2mg/l

c. 3mg/l

d. 4mg/l

  • a. 1mg/l

Q. In which process, the fluoride content of water is raised?

a. Chlorination

b. Fluoridation

c. Defluoridation

d. Flocculation

  • b. Fluoridation

Q. Which of the following is not used as a fluoride compound?

a. Sodium fluoride

b. Sodium silico fluoride

c. Hydrofluosilicic acid

d. Sodium fluro carbonate

  • d. Sodium fluro carbonate

Q. Which of the following is the pure compound?

a. Sodium fluoride

b. Sodium silico fluoride

c. Hydrofluosilicic acid

d. Sodium fluro carbonate

  • a. Sodium fluoride

Q. As far as safer handling is considered, which of the following is used for fluoridation?

a. Sodium fluoride

b. Sodium silico fluoride

c. Hydrofluosilicic acid

d. Sodium fluro carbonate

  • c. Hydrofluosilicic acid

Q. What happens when water contains 8-20 ppm of fluoride concentration?

a. Blue baby disease

b. Crippling fluorosis

c. Dental fluorosis

d. Mottling of teeth

  • b. Crippling fluorosis

Q. The process of reducing the fluoride content from water is called _____

a. Chlorination

b. Fluoridation

c. Defluoridation

d. Flocculation

  • c. Defluoridation

Q. Which of the following is not used for defluoridation?

a. Calcium phosphate

b. Copper sulfate

c. Alum

d. Bone charcoal

  • b. Copper sulfate

Q. At which temperature, the bone is calcinated during defluoridation with calcium phosphate?

a. 100-200oC

b. 200-300oC

c. 400-600oC

d. 500-800oC

  • c. 400-600oC

Q. Which material is used in contact filters for the removal of fluorides?

a. Calcium phosphate

b. Copper sulfate

c. Synthetic tri-calcium phosphate

d. Bone charcoal

  • c. Synthetic tri-calcium phosphate

Q. Which material is used for removing fluorides from hard water containing 3ppm of fluorides?

a. Lime

b. Copper sulfate

c. Synthetic tri-calcium phosphate

d. Bone charcoal

  • a. Lime

Q. Fluorex is a special mixture of ____________

a. Di-calcium phosphate and carbon

b. Tri-calcium phosphate and hydroxyapatite

c. Di-calcium phosphate and phosphoric acid

d. Tri-calcium phosphate and carbon

  • b. Tri-calcium phosphate and hydroxyapatite

Q. Which of these materials is not added to iron for improving its oxidation resistance?

a. Nickel

b. Chromium

c. Aluminum

d. Silicon

  • d. Silicon
Subscribe Now

Get All Updates & News