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 economics environment pollution strategies to control environmental pollution strategies to control pollution strategies to control environmental pollution and green chemistry

The function of sedimentation tank in sewage treatment is to:

  1. disinfect the sewage

  2. aerate the sewage

  3. remove water content

  4. remove suspended solids
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A sedimentation tank allows suspended particles to settle out of water or wastewater as it flows slowly through the tank, thereby providing some degree of purification. A layer of accumulated solids, called sludge, forms at the bottom of the tank and is periodically removed.

Multiple choice economics environment pollution strategies to control environmental pollution strategies to control pollution strategies to control environmental pollution and green chemistry

Treatment of waste water involves physical, chemical, and biological processes, which remove _______ matter that contaminates waste water.

  1. physical

  2. chemical and biological

  3. both $A$ and $B$

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

Physical treatment of water includes-filtration, sedimentation, separation etc. Chemical and Biological treatment includes coagulation, flocculation, ion-exchange, absorption, also aerobic treatments and anaerobic treatments. By these treatments, all physical, chemical and biological matter that contaminates wastewater, can be removed 

Multiple choice zoology pollution - a rising environmental problem sources of water pollution marine life water pollution

Which one of the following impurities is easiest to remove from wastewater ?

  1. Bacteria

  2. Colloids

  3. Dissolved solids

  4. Suspended solids
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Suspended solids in water refer to various impurities like sand, slit, small stones, etc. These are heavy ad get submerged at the bottom of water. They do not easily mix or dissolved easily with water. So, they can be separated from water by various means like sedimentation, water filter, etc. 
  • Bacteria are very minute organisms that are not even visible to naked eyes and thus their removal becomes very difficult. Proper disinfection is required to remove them. 
  • Colloids and other suspended impurities also need special filtration and purification techniques to be separated from the water.
  • So, option D is the correct answer.
Multiple choice evs - i methods of preserving food food spoilage and food preservation chemicals in food food chemistry
Muddy water can be purified through coagulation by using :
  1. $\text{common slat}$
  2. $\text{alums}$
  3. $\text{sand}$
  4. $\text{lime}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Muddy water can be purified through coagulation by using alums. 


It is added to the water so that the negatively charged colloidal particles clump together into Flocks which then float to the top of the liquid settle to the bottom of the liquid, or can be more easily filtered from the liquid, prior to further filtration and disinfection of the water.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

The salt we get from sea water can have many impurities in it. These impurities can be removed by :

  1. sedimentation

  2. crystallisation

  3. centrifugation

  4. all of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Crystallisation is used to obtain pure solid from impure solid sample. It is used to purity solids, e.g., purification of salts that we get from sea.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Which of the following method is used for water treatment?

  1. Centrifugation

  2. Sedimentation

  3. Evaporation

  4. Crystallization
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sedimentation is a physical water treatment process using gravity to remove suspended solids from water. Solid particles entrained by the turbulence of moving water may be removed naturally by sedimentation in the still water of lakes and oceans.

Multiple choice chemistry air and water pollution control smoke, dust and other air pollutants, acid rain air pollutants and its effects air and air pollution

Which of them is used to remove hydrogen sulphide from water?

  1. Continuous chlorination

  2. Aeration

  3. Heating

  4. Hydrodesulfurization
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation
Removal of $H _2S$ from water can be done by:
(I) Chlorination and filteration.
(ii) Manganese greensand iron filter.
(iii) Aeration.
(iv) Alternative systems.
Multiple choice geography pollution - types and sources study of water pollution threats to water resource major hazards in india and prevention pollution and environment

Best management practices for water pollution include approaches to reduce the quantity of water use and improvement in water quality. One of the water pollution control method is:

  1. using biogas

  2. use of public transport/ CNG

  3. planting more trees

  4. treatment of industrial waste water by effluent treatment plant (ETP)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Wastewater effluent treatment is important way to control pollutants reaching in water bodies.

Multiple choice solid waste management environmental management biology

One of the method for the treatment of industrial wastes is chemical method and it involves chemical oxidation and flocculation processes.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The industrial wastes can be treated by the chemical method is which chemicals with a positive charge are added to water. The positive charge of these chemicals called coagulants neutralizes the negative charge of dirt and other dissolved particles in water. The particles then bind with water and form large particles called floc. The anionic flocculant is added to these flocs. Because the flocculants react against the positively charged mixture, it either neutralizes the particle groups or creates bridge between them to bring particles into larger groups. After this sedimentation is used to remove the particles from the mixture. 

Thus, the correct answer is option A. 

Multiple choice business organisation and correspondence waste and its management sources of waste protecting our environment rules are for everyone

Which of the following is used to speed up the rate of degradation of a contaminant?

  1. Biological augmentation

  2. Biostimulation

  3. Biosensor

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Biological augmentation or bioaugmentation is the process of addition of bacterial cultures to speed up the rate of degradation of a contaminant. It is also called as biological augmentation.

Thus, the correct answer is option A.