---
title: "Major pollutants of water"
subject: "Engineering Chemistry"
chapter: 3
key: "semester_2/engineering_chemistry:water-pollutants-list"
source: https://www.bctengineer.com/q/semester_2/engineering_chemistry/water-pollutants-list
site: BCT Engineering
---

# Major pollutants of water

Engineering Chemistry · Chapter 3: Environmental Chemistry

- Asked in: 2067 Chaitra, 2 marks
- Video: [What Is Water Pollution | Environmental Chemistry | Chemistry | FuseSchool](https://www.youtube.com/watch?v=Zk1J2EW-nmQ) — FuseSchool - Global Education
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_2/engineering_chemistry/water-pollutants-list
- Whole chapter: https://www.bctengineer.com/md/semester_2/engineering_chemistry/chapter-3

## Question

Mention the major pollutants of water.

## Short answer

Major water pollutants: pathogens, organic wastes, pesticides, nitrates, heavy metals (lead, mercury, cadmium, arsenic), acids, alkalis, salts, suspended solids, oil, thermal effluents, and radioactive substances.

## Answer

- **Pathogens:** bacteria, viruses, protozoa from sewage and animal waste.
- **Organic wastes:** sewage, food waste, detergents, oils and phenols.
- **Agricultural chemicals:** pesticides (DDT) and fertilisers (nitrates, phosphates).
- **Heavy metals:** Pb, Hg, Cd, As, Cr from industry and mining.
- **Acids, alkalis and salts** from industrial effluents.
- **Suspended solids and silt**, **oil** from spills, **thermal** (hot water), and **radioactive** wastes.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which pollutant category includes bacteria, viruses and protozoa from sewage?
   A. Pathogens
   B. Heavy metals
   C. Organic wastes
   D. Radioactive wastes
   Answer: A. Disease-causing organisms from sewage and animal waste are pathogens. (Key point: Pathogens)

2. Which are classed as agricultural chemical pollutants of water?
   A. Pb and Hg
   B. DDT, nitrates and phosphates
   C. Phenols and oils
   D. Acids and alkalis
   Answer: B. Pesticides such as DDT and fertilisers (nitrates, phosphates) are agricultural chemicals. (Key point: Agricultural chemicals)

3. Which group lists heavy metal pollutants?
   A. Na, K, Ca
   B. Cl, Br, I
   C. Pb, Hg, Cd, As, Cr
   D. N, P, S
   Answer: C. Pb, Hg, Cd, As and Cr come from industry and mining. (Key point: Heavy metals)

## Related in Engineering Chemistry

- [Water pollution, pollutants and adverse effects](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollutants-effects) — Engineering Chemistry, chapter 3
- [Water pollutants, harmful effects, control measures](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollutants-effects-measures) — Engineering Chemistry, chapter 3
- [Water pollutants, sources; oxides making water acidic](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollutants-acidic) — Engineering Chemistry, chapter 3
- [Organic/inorganic water pollutants, effects, remedies](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollution-substances-effects-remedies) — Engineering Chemistry, chapter 3, asked 2×
- [Sources, effects and remedies of water pollution](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollution-sources) — Engineering Chemistry, chapter 3, asked 2×
- [Point and non-point sources; waste water treatment](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Apoint-nonpoint-waste-water) — Engineering Chemistry, chapter 3

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- [Indoor air pollutants and their sources](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aindoor-air-pollutants-sources) — Environment and Pollution Control, chapter 3
- [Water pollution: sources and effects](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Awater-pollution-sources-effects) — Environment and Pollution Control, chapter 4
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