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

What cant be removed after distillation of water?

  1. Suspensions

  2. Precipitates

  3. Volatile liquids like alcohol

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

Distillation is the process of purifying water by removing contaminants.

A volatile liquid has a comparatively smaller boiling point than the water thus it becomes difficult to separate them. 

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

Silt in water remains suspended. It is removed by sedimentation and filtration. For increasing its sedimentation aluminium sulphates and calcium hydroxide (slaked lime) are added. As a result sticky aluminium hydroxide.

  1. Destroys slit particles

  2. Attracts the particles of slit

  3. Mixes with slit particles

  4. Makes slit particles increases in size and deposit at the bottom
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The silt in $H _2O$ remains suspended. To attract some more silt particles, $Al(OH) _3$ is used. It is used to absorb the silt particles and make the liquid more pure.

Multiple choice biology rain: where does it come from sources of water and water cycle availability and forms of water the water cycle

Which of the following processes is unsuitable for softening water possessing temporary hardness?

  1. Adding calcium hydroxide

  2. Filtration

  3. Boiling

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

If you added calcium oxide to water, it would react and make calcium hydroxide. Calcium hydroxide is produced, however, when calcium oxide is mixed (or slaked) with water. Overall, nothing significant happens when you mic Ca(OH)2 with water, certainly no reaction occurs. So, the correct option is "A" (Adding calcium hydroxide).

Multiple choice waste management - need for management of waste sanitation and solid waste management pollution, sources, effects and preventive measures man and environment geography treatment and disposal of waste waste generation and management - methods of safe disposal of waste

A mechanical means of treating industrial effluents is called _______.

  1. Sedimentation

  2. Rainwater harvesting

  3. Recycling of waste water

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

Treatment of industrial effluents can be done in three phases.

  • (a) Primary treatment by mechanical means. This involves screening, grinding, flocculation, and sedimentation. 
  • (b) Secondary treatment by biological process. 
  • (c) Tertiary treatment by biological, chemical and physical processes. This involves recycling of wastewater.

Multiple choice zoology applications of biotechnology genetically modified organism transgenic organisms genetic modification and biotechnology

Heavy metals like nickel can be removed from water with the help of

  1. Filtration

  2. Carbomethylchitosan

  3. Biological treatment

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

The conventional methods which are commonly used for the removal of nickel from water are physico-chemical methods, such as chemical coagulation, chemical oxidation or reduction, active carbon adsorption, filtration, ion exchange and membrane technologies. Nickel behaves the same as iron, and can be removed by a strong acid cation exchanger. Activated-carbon filtration can be used to reduce the amount of nickel in drinking water, but may not remove it all. Reverse osmosis will remove 97 - 98% of the nickel from drinking water.

So, the correct answer is option A.

Multiple choice biology environmental pollution control of water pollution protecting our environment rules are for everyone

Water pollution can be controlled by

  1. Treating sewage or factory wastes to remove harmful organisms and compounds

  2. Using biodegradable fertilizers and pesticides

  3. Both A and B

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

Water pollution is the increase in the concentration of the undesirable harmful compounds in the water resources. The water pollution can be controlled by many ways. The sewage and the factory wastes which contain the pollutants and high number of microbes can be treated before letting the water discharged into water bodies. Biodegradable form of fertilizers and pesticides can be used for the reduction of the soil and water pollution, and eutrophication. 

Thus, the correct answer is option C. 

Multiple choice biology environmental pollution control of water pollution protecting our environment rules are for everyone

Which of these methods is/are used to control water pollution?
(i) Preventing the release of factory wastes into nearby streams.
(ii) Educating society about the dangers of water pollution.
(iii) Using biological control in agricultural areas instead of using pesticides.

  1. Only (i) and (ii)

  2. Only (ii) and (iii)

  3. Only (i) and (iii)

  4. (i), (ii) and (iii)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The methods that can be used to control water pollution are:
(i) Avoiding the use of chemical substances freely.
(ii) Educating society about the dangers of water pollution.
(iii) Using biological control in agricultural areas instead of using pesticides.

Multiple choice biology environmental pollution control of water pollution protecting our environment rules are for everyone

Which one of the following is not used for disinfection of drinking water?

  1. Chlorine

  2. Ozone

  3. Chloramine

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

Disinfectants are the antimicrobial agents which is mainly used to stop the growth of pathogen on the non-living organism. It may affect the substances on which it is applied. Phenyl is a disinfectant which cannot be used for purification of drinking water because it will kill the pathogens of the bacteria but the quality of the water will  degrade as it is poisonous for the living organisms. It has a pungent odour. All the other options are used as disinfectant because they do not have an adverse effect on the quality of water.

So, the correct answer is option D.

Multiple choice biology environmental pollution control of water pollution protecting our environment rules are for everyone

Treatment of waste water is done by the :

  1. Autotraphic microbes

  2. Heterotrophic microbes

  3. Chemoautotrophic microbes

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

Autotrophs of greatest significance in sanitary engineering are the nitrifying, sulfur, and iron. Because these bacteria use CO$ _2$ as the carbon source and oxidize inorganic compounds for energy. 

So the correct option is ' heterotrophic microbes'.

Multiple choice biology environmental pollution control of water pollution protecting our environment rules are for everyone

FOAM and the biologists from humboldt state university, california created an integrated waste water treatment, they use plants for purify mainly :-

  1. Sludge from water

  2. Nitrate and phosphate from water

  3. Heavy metals from water

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

The main purpose of FOAM is to treat wastewater around a place called Arcata and the surrounding bay through a natural system.

So, the correct option is 'Sludge from water'.

Multiple choice biology wastewater story sewage treatment wastewater treatment - need and methods conservation

Which of the following can kill water purifying microbes?

  1. Paints

  2. Cooking oils

  3. Vegetable peels

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The chemical present in paints, Solvents, Insecticides, motor oils, medicines may kill microbes that help purify water. So do not throw them down the drain.
  • Hence Paints can kill water purifying microbes.
  • So, the correct answer is 'Paints'.