Environmental Pollution and Control Questions and Answers

Answer: B

Ozone in air is a secondary air pollutant.

Ground-level ozone is not emitted directly by any significant source. It forms in the atmosphere when oxides of nitrogen and volatile organic compounds react in sunlight, which is why it peaks on sunny afternoons downwind of cities, as part of photochemical smog.

Primary pollutants, such as sulphur dioxide, carbon monoxide and particulate matter, are emitted directly from sources. 'Tertiary' and 'fundamental' are not standard classes of air pollutant.

Answer: A

Influenza, measles and mumps are air-borne infections.

All three are viral diseases spread by droplets and aerosols released when an infected person coughs, sneezes or talks, and inhaled by others nearby. That is why they spread fastest in crowded indoor places and why measles, in particular, is highly contagious.

Water-borne infections include cholera, typhoid and hepatitis A; food-borne ones include food poisoning by salmonella; and soil-borne ones include tetanus and hookworm. None of these routes is the main one for influenza, measles or mumps.

Answer: A

The pulp and paper waste is Black liquor.

In kraft pulping, wood chips are cooked in white liquor (sodium hydroxide and sodium sulphide) to dissolve the lignin that binds the fibres. The spent cooking liquor, dark with dissolved lignin, is black liquor. It is the industry's main waste stream and is usually concentrated and burnt in a recovery boiler to regain chemicals and energy.

Spentwash is the effluent of molasses-based distilleries, and filter cake (press mud) is a residue of sugar mills. Since neither belongs to the paper industry, 'All of the above' is wrong.