Environmental Studies · Chemistry

Water and Wastewater Treatment

1,345 Questions

This topic deals with water purification, wastewater treatment methods, and industrial effluent management. It includes questions on filtration, disinfection, and water hardness removal. These concepts are tested in environmental science and engineering exams.

Water purificationWastewater treatmentBioremediation strategiesWater hardness removalIndustrial effluent management

Water and Wastewater Treatment Questions

Multiple choice

WWTP stands for

  1. Waste Water Therapy Plant

  2. Waste Water Treatment Plant

  3. Waste Water Travel Plant

  4. Waste Water Tremendous Plant
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

WWTP - Waste water treatment plant

Multiple choice

Which process is used to obtain common salt from sea water?

  1. Filtration

  2. Decantation

  3. Evaporation

  4. Sedimentation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Evaporation refers to the conversion of a liquid into vapor state. A mixture of sugar and water can be separated by evaporation as water can evaporate but sugar cannot. Also, common salt is separated from sea water by the same process. 

Multiple choice

A flocculant is a soluble material that is added to a glaze to increase the viscosity and increase the time it takes for the glaze to settle. Among the following ------------------ is used as a flocculant, in water and sewage treatment.

  1. calcium gluconate

  2. calcium hexaboride

  3. calcium hydride

  4. calcium hydroxide
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Calcium hydroxide, traditionally called slaked lime, is an inorganic compound with the chemical formula Ca(OH)2. It is a colourless crystal or white powder and is obtained when calcium oxide is mixed with water. One significant application of calcium hydroxide is as a flocculant, in water and sewage treatment.

Multiple choice

Which one of the following cannot help remove the permanent hardness of water?

  1. Boiling

  2. Application of caustic soda

  3. Distillation

  4. Adding of soda
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Permanent hardness of water is caused by the presence of dissolved chlorides and sulfates of calcium and magnesium, which cannot be removed by simple boiling. Boiling only removes temporary hardness caused by bicarbonates. Methods like distillation, adding washing soda, or caustic soda treatment are required for permanent hardness.

Multiple choice

The most common way of purifying city water supply is to

  1. filter it

  2. treat it with potassium permanganate

  3. chlorinate it

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chlorination is the most common and effective method for disinfecting city water supplies to kill bacteria and other pathogens.