Industrial water pollution and industrial air pollution arise from different processes but share a common underlying cause. (i) Identify one industry that contributes to BOTH air and water pollution and explain how it causes each. (ii) Explain one control measure that is specific to air pollution and one that is specific to water pollution.
Generated by claude-sonnet-4-6 · 2026-06-26 13:38 · grounding rag
Model Answer
(i) Industry contributing to BOTH air and water pollution: Petroleum Refinery
A petroleum refinery causes air pollution by emitting sulphur dioxide, carbon monoxide and smoke during the refining of crude oil. It causes water pollution by discharging oily effluents, acids, salts and toxic chemicals into nearby rivers and water bodies.
(ii) Control measures:
- Air pollution (specific): Fitting smoke stacks with electrostatic precipitators, scrubbers or fabric filters reduces particulate matter released into the air. Using oil or gas instead of coal also reduces smoke.
- Water pollution (specific): Industrial effluents must be treated in three phases before discharge — primary (mechanical: screening, sedimentation), secondary (biological process), and tertiary (biological, chemical and physical recycling of wastewater) — before releasing into rivers or ponds.
Source: Industrial Pollution and Environmental Degradation; Control of Environmental Degradation — Chapter 6
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Explanation
- Examiners expect a named industry with a clear two-part explanation (air + water) for part (i) — petroleum refinery or paper/pulp industry both work well from the passage.
- For part (ii), the two control measures must be distinct and correctly matched to air vs. water — mixing them up loses marks.
- The three-phase effluent treatment is a frequently asked point; name all three phases with their methods.
- Keep answers precise; avoid vague statements like "factories should reduce pollution."