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 commercial studies waste generation and management e-waste management e-wastes waste generation

Finely divided solid, remaining either with in solution or in suspension is known as

  1. Settaleable Solids

  2. Dissolved Solids

  3. Suspended solids

  4. Colloidal Solids
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Colloidal solids are particles that are finely divided and remain in suspension or solution due to their small size, preventing them from settling easily by gravity. Settlable solids settle quickly, while dissolved solids are in true solution.

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.

Multiple choice geography pollution - types and sources environmental risks of economic development tundra climatic region effects and successes of environment conservation

The stage in which the biological processes is used to purify water in a wastewater treatment plants is called :

  1. secondary sewage treatment

  2. wastewater reduction

  3. biochemical reduction

  4. primary sewage treatment
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Secondary treatment is a waste water management technique which uses physical phase separation and a biological process.

Physical phase separation removes suspended solids. Biological process is employed to remove organic matter. 

Example: Bacteria and protozoa consume biodegradable soluble organic contaminants

Multiple choice biology aids to health immunization, treatment and antibiotics antibodies and antitoxin prevention and treatment of disease

Disinfectants are

  1. Biological

  2. Enzymes

  3. Hormones

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

These are strong chemical substances that are applied on spots and places where germs thrive an multiply and places where germs thrive and multiply.commonly used disinfactants are cresol, phenol, Lysol,40% formalin, lime, Bordeaux mixturr, DDT etc. Precaution-all disinfectants are strong and should not come in contact with the human skin. Strong heat and boiling also destroy germs and may be called physical disinfectants.deodorants are neither antiseptics nor disinfectants.they only serve to mask a bad smell.
So, the correct answer is D
Multiple choice biology aids to health immunization, treatment and antibiotics antibodies and antitoxin prevention and treatment of disease

Identify the correct definition of a disinfectant.

  1. Chemicals that kill or prevent infection and damage living tissues.

  2. Chemicals that kill or prevent infection without damaging living tissues.

  3. Chemicals that can only kill or prevent infection on non-living objects.

  4. Chemicals that can only kill or prevent infection on animals.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Disinfectants are chemical antimicrobial agents used to kill microbes from inanimate objects and surfaces or non-living objects e.g., phenol, cresol etc.

Multiple choice biology aids to health immunization, treatment and antibiotics antibodies and antitoxin prevention and treatment of disease

Ozone is passed through swimming pool because it

  1. Absorbs UV radiations

  2. Acts as disinfectant
  3. Easily available from $O _2$

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

Ozone is an effective disinfectant. It is passed through the swimming pool and is used in water treatment units because of the following reasons:

1. It improves the smell and visibility of the water.
2. It destroys bacteria and viruses by causing their oxidation.
3. It oxidises metals like manganese, iron and sulphur into the soluble particles and so these can be easily filtered out.
4. It has a bleaching effect on the discoloured water.
Hence, the correct answer is 'Acts as disinfectant'.

Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Bleaching powder is disinfectant for purification of water when water born germs are killed. But disinfectant activity is destroyed. It is due to its disproportionation into:

  1. $ CaCl _2$ and $Cl _2 $
  2. $ CaCl _2$ and $Ca(ClO _3) _2 $
  3. $ CaO$ and $Cl _2 $
  4. $ CaO, Cl _2$ and $CaCl _2 $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Bleaching powder is disinfectant for purification of water when water born germs are killed. But disinfectant activity is destroyed because of the degradation of high grade of bleaching powder.
These include disproportionation to give $Ca(ClO _3) _2$ and $CaCl _2$, and with the evolution of $Cl _2$ or $O _2$ depending on the presence or absence of water.

Option B is the correct answer.

Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Uses of bleaching powder is/are:

  1. It is used as a disinfectant in sterilization of water

  2. It is used to bleach straw, ivory

  3. It is used as an oxidising agent in industry

  4. It is used for making wool unshrinkable
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
Explanation

Following are the uses of bleaching powder.
(A) It is used as a disinfectant in sterilization of water
(C) It is used as an oxidising agent in many chemical reactions in industry
(D) It is used for making wool unshrinkable
Bleaching powder is useful in preparation of organic solvent chloroform which is also used as an anesthetic.
Bleaching action is possible on cotton in textile industry, wood pulp in paper factories and washed clothes in laundary.

Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Bleaching powder has several uses, some of which are mentioned here. Pick the false one.

  1. For decolourising sugar

  2. For bleaching paper pulp

  3. For sterilizing water

  4. For making chloroform
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bleaching powder is used for bleaching dirty clothes in the laundry, as a bleaching agent for cotton and linen in the textile industry. It is a strong oxidizing agent hence used as an oxidizer in many industries. It is used as a disinfectant which is used for disinfecting water to make potable water.It is also used for bleaching paper pulp,sterilizing water,making chloroform.

It is not used to decolourize sugar and hence option A is false one.

Multiple choice chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

Which of the following procedures will give you water free from all impurities?

  1. Adding chlorine tablets

  2. Distillation

  3. Boiling

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

Distillation procedures will give us water free from all impurities. The distillation process removes almost all impurities from water. Distillers are commonly used for removing nitrate, bacteria, sodium, hardness (dissolved solids), most organic compounds, heavy metals and radionuclides from water. Distillers remove about 99.5% of the impurities from the original water.

Multiple choice zoology environmental issues air pollution and its control air pollution - effects and control not for breathing not for drinking

Bag filters are used for removal of pollutants from

  1. Exhaust emissions

  2. Effluent water

  3. Sewage water

  4. Both B and C
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A. Exhaust emissions are the substances or gases that are released on burning of fuels.
B. Effluent water is the wastewater which is released in water bodies after treatment in sewage treatment plant so that harmful contaminants get removed from it.
C. Sewage water is the wastewater which is produced by a community of people.
Bag filters are the equipments used to control air pollution. They control the level of exhaust emissions such as sulphur dioxide and other gases.
So, the correct answer is 'Exhaust emissions'.
Multiple choice zoology not for breathing not for drinking air pollution and its control air pollution - effects and control environmental issues

Photocatalysis of effluents is carried out with the help of

  1. Polymeric adsorbents

  2. Titanium dioxide

  3. Resins

  4. UV radiations
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Photocatalysis is the reaction in presence of a catalyst that accelerates the rate of reaction which in turn, is occurring in presence of light i.e. photoreaction. Photocatalysis of effluents discharged from industries is done to remove organic pollutants from them. The catalyst used in the reaction is either zinc oxide or titanium oxide. Titanium oxide is a photocatalyst. When it is illuminated by light, an electron and positive hole pair is produced. The positive hole reacts with water to break it into hydrogen gas and hydroxyl ion whereas the negative electron reacts with oxygen to form superoxide.
So, the correct answer is 'Titanium oxide'.
Multiple choice chemistry hydrogen and its compounds heavy water study of heavy water hard water and soft water

Organic ion exchange resins purify hard water to yield :

  1. Distilled water

  2. Only decalcified water

  3. Deionised water
  4. Water having relatively high concentration of $OH^{-}$ion
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Organic ion exchange resins are used for water softening. In this process, the $Ca^{+2}$ and $Mg^{+2}$ ions which cause hardness are exchanged for $Na^{+}$ or $K^{+}$ ions due to which the water becomes decalcified or hardness free. Therefore, organic ion exchange resins purify hard water to yield only decalcified water