- (a). Aluminium Smelting
- (b). Cement
- (c). Paper
- (d). Steel
Bauxite is the principal ore refined and smelted to produce aluminium.
(a) Aluminium Smelting
- (a). Steel
- (b). Electronic
- (c). Aluminium Smelting
- (d). Information Technology
The electronics industry manufactures products including telephones, televisions and computers.
(b) Electronic
Definition grounded in the chapter opening.
Manufacturing is producing goods in large quantities by processing raw materials into more valuable finished or semi-finished products, usually with labour, power, machinery and capital.
Grounded in the classification by role.
Basic industries supply raw material to other industries. The iron and steel industry is basic because its products are inputs for machinery, transport, construction and engineering industries.
Organised by the chapter’s air, water, land, noise and thermal pollution categories.
Industries pollute air through smoke, dust, sulphur dioxide, nitrogen oxides and toxic gases from factories and power plants. They pollute water by discharging organic waste, chemicals, dyes, acids, salts and hot water into rivers and ponds. Solid wastes such as slag, ash and hazardous residues degrade land and contaminate groundwater. Machinery, generators and drilling produce noise that harms hearing and causes stress. Thermal pollution lowers dissolved oxygen in water and damages aquatic life. Pollution can therefore spread beyond the factory through air currents, drainage and food chains, affecting workers, nearby communities, crops and ecosystems.
Grounded in the chapter’s pollution-control measures and NTPC example.
Industries should minimise water use by reusing and recycling it through successive stages, harvest rainwater and treat hot water and effluents before discharge. Primary, secondary and tertiary treatment can remove solids, biological waste and toxic chemicals. Factories should use cleaner fuels and processes, fit electrostatic precipitators, scrubbers and filters to chimneys, and recover or safely dispose of solid waste. Machinery can be redesigned, maintained and enclosed to reduce noise; generators can use silencers. Green belts around plants absorb dust and noise. Energy efficiency, waste recovery, continuous monitoring and enforcement of environmental standards reduce pollution at its source.