Environmental Studies · Chemistry

Water and Wastewater Treatment

1,423 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

What is the function of a water treatment plant?

  1. It filters the water and makes water fit and safe for drinking purpose.

  2. It recycles the water.

  3. Water treatment plant saves energy as it helps the industrial units to consume less electricity.

  4. It acts upon the harsh chemicals and toxic materials which are present in water and converts them into less toxic and easily decomposable materials.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The function of a water treatment plant is that. It acts upon the harsh chemicals and toxic materials which are present in water and converts them into less toxic and easily decomposable materials. They pump in raw untreated water from a well, lake or river. Remove the odor and bad taste by aeration remove settable solids, disinfect the water, adjust the PH of the water, filter the water, then pump it out for your use. 

Multiple choice

What is primary treatment?

Water pollution can be defined as an undesirable change in the physical, chemical and biological characteristics of water that will be harmful to humans, animals or plant life and productivity. It is customary to consider the treatment of polluted water in three phases- Primary treatment, Secondary treatment and Tertiary or advanced treatment.

  1. The process in which the waste water is passed over stones or racks of plastic surface.

  2. The process where waste water is passed through a series of wire-meshes of decreasing size.

  3. Process that is carried out by a biological system where microorganisms decompose organic matter.

  4. The process in which waste water is mechanically stirred in a tank in presence of increased oxygen with help of electronic pump.

  5. The process in which different chemical components like phosphate, nitrogen, ammonia, poly-electrolytes, etc. are removed in treatment plants.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In primary treatment, different suspended and floating pollutants of water like plastic, paper, solid substances, etc. are passed through a system of screening and degrading, grease and scum removal, sedimentation, sludge thickening. The waste water passed through a series of wire-meshes of decreasing size where suspended and floating solid are maintained in a large water body in stagnant condition where sedimentation and precipitation occur.

Multiple choice

Which of the following is the correct method of reusing used water?

  1. Using water that was used to clean vegetables for drinking

  2. Using stale water for washing clothes

  3. Using water from factories for cooking

  4. Using the water after bathing to water plants

  5. Using the water after washing clothes to wash vegetables
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

We can use water after bathing to water plants, as plants do not need clean and purified water.

Multiple choice

Which method is used to remove water from crude oil?

  1. Cotrell process

  2. Bergius process

  3. Newton's process

  4. Berthelot process
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Cotrell process uses electrical precipitation to remove water and suspended solids from crude oil. Bergius process is for coal liquefaction, while Newton's process and Berthelot process are not relevant to crude oil dehydration. The Cotrell precipitator charges water droplets which are then attracted to opposite electrodes.

Multiple choice

What is water cycle?

  1. It is a device used to recycle water in industry.

  2. It is used in water treatment plants.

  3. It is a continuous process for circulation of water in nature.

  4. It is a cycle used for doing exercises in the morning.

  5. It is a type of water sport.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Circulation of water from the earth's surface to the atmosphere and back to the Earth is called the water cycle.

Multiple choice

Which of the following can be used to treat polluted water and make it safe for drinking?

  1. Ozone treatment

  2. Filtration

  3. Chlorine treatment

  4. Distillation

  5. By adding disinfectant

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ozone is a powerful oxidizing agent, which kills all types of bacteria, virus, and protozoa present in the water and makes water safe to drink. Before the ozone treatment, the water must be cleared of all types of mud, sewage and chemicals. Ozone is a molecule formed by a combination of three oxygen atoms.

Multiple choice

Which of the following techniques cannot be used to make water germ free?

  1. Chlorination

  2. Sedimentation

  3. Ultraviolet purification

  4. By boiling

  5. Ozone treatment
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Depletion of oxygen is caused by different pollutions like chemical contamination, garbage contamination, and agricultural contamination, which kills aerobic bacteria that are eco friendly and develops anaerobic bacteria which are harmful bacteria.

Multiple choice

Which of the following is not a measure adopted to make water safe?

  1. Boiling

  2. STP’s

  3. Nutrients added to water

  4. Chlorination

  5. Using a filter
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nutrients added to water cause eutrophication which generally promotes excessive plant growth and decay, favouring simple algae and plankton over other more complicated plants, and causes a severe reduction in water quality.