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

Desalination is the process of what?

  1. Removing the salt from ocean and sea water

  2. Adding salt to fresh water

  3. Pumping water from underground aquifers

  4. Purifying water contaminated with pollutants
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Desalination is the process of removing mineral components, specifically salt, from saline water. This is commonly used to produce fresh water from seawater for human consumption or irrigation.

Multiple choice

Primary treatment of sewage involves

  1. Production of biogas

  2. Physical removal of particles by filtration and sedimentation

  3. Formation of floc

  4. Digestion of floc by anaerobic microbes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Primary treatment of sewage is a physical process that involves the removal of large and small particles through filtration and sedimentation. Biological processes like floc formation occur during secondary treatment.

Multiple choice

Activated sludge has the ability to settle quickly this enables it to

  1. be rapidly pumped back from sedimentation to aeration tank.

  2. absorb pathogenic bacteria while sinking to the bottom of the settling-tank

  3. anaerobically digested and be discarded.

  4. absorb colloidal organic matter.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Activated sludge consists of a mass of bacteria and fungi that settle quickly. This allows a portion of it to be recycled back into the aeration tank as an inoculum for further treatment.

Multiple choice

Passage of effluents into oxidation tank is for

  1. Primary treatment

  2. Secondary treatment

  3. Tertiary treatment

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

Primary treatment involves physical removal of particles. Secondary treatment is a biological process where microorganisms in an oxidation tank or aeration tank break down organic matter in the effluent.

Multiple choice

In a water treatment plant what is removed in secondary treatment?

  1. all solids

  2. sediment

  3. mostly nitrogen

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

Secondary treatment in a wastewater plant is a biological process that uses microorganisms to break down organic matter, which includes nitrogen and phosphorus compounds, rather than just physical solids.

Multiple choice chemistry metals chemical properties and uses of metals and non-metals introduction to metals physical properties of non-metals

Which of the following non-metal is commonly used for purifying water?

  1. Sulphur

  2. Oxygen

  3. Chlorine

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

Chlorine is one of the most commonly used disinfectants for water disinfection. Chlorine can be applied for the deactivation of most microorganisms and it is relatively cheap. Although several methods eliminate disease-causing microorganisms in water, chlorination is the most commonly used. Chlorination is effective against many pathogenic bacteria, but at normal dosage rates it does not kill all viruses, cysts, or worms. When combined with filtration, chlorination is an excellent way to disinfect drinking water supplies.