- Asked 2/16
- 2070 Magh · 3 marks
- 2068 Bhadra · 3+2 marks
Organic/inorganic water pollutants, effects, remedies
Short answer
Organic pollutants from sewage, farms, and industry cause oxygen depletion and disease; inorganic ones like heavy metals (Hg, Cd, Pb, As) and nitrates/phosphates cause toxicity, Minamata disease, arsenicosis, and eutrophication. Remedies: treat wastewater, use less fertiliser, enforce laws.
Give an account on the sources of organic and inorganic substances responsible for water pollution with its adverse effect and possible remedies.
Sources of organic and inorganic water pollutants
| Type | Pollutants | Source |
|---|---|---|
| Organic | Sewage, detergents, pesticides, oil, phenols, food waste | Households, farms, industries |
| Inorganic | Heavy metals (Pb, Hg, Cd, As), nitrates, phosphates, acids, alkalis, salts | Industries, mines, fertilisers |
| Biological | Bacteria, viruses, protozoa, worms | Sewage, animal waste |
| Physical | Suspended solids, heat, radioactive material | Erosion, power plants |
Sources in detail: domestic sewage and detergents; industrial effluents from tanneries, paper, textile, sugar and chemical mills; agricultural runoff of fertilisers and pesticides; mining and oil spills; solid waste dumping into rivers.
Adverse effects
- Health: waterborne diseases (cholera, typhoid, dysentery, hepatitis, diarrhoea); Hg causes Minamata disease, Cd causes itai-itai disease, As causes arsenicosis (found in groundwater of the Terai), Pb damages the brain; nitrate in water causes blue-baby syndrome.
- Eutrophication: excess nitrate and phosphate cause algal blooms; when the algae die, their decay uses up dissolved oxygen (high BOD, low DO) and fish die.
- Bioaccumulation and biomagnification of pesticides and metals in the food chain.
- Bad taste, smell and colour; water is unfit for drinking, irrigation and industry.
- Thermal pollution reduces oxygen solubility and disturbs aquatic life.
Possible remedies
- Treat sewage and industrial effluents before discharge (primary, secondary and tertiary treatment).
- Use less fertiliser and pesticide; use organic farming; ban phosphate detergents.
- Prevent dumping of solid waste in rivers; build proper sanitation and toilets.
- Cool hot water before discharge; recycle and reuse water.
- Strict laws (polluter pays), regular monitoring, public awareness and river-cleaning programmes (such as for the Bagmati).
✓ Answer checked by Claude Opus 5.5 (high effort)
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