Question

A scrubber in the exhaust of a chemical industrial plant removes
A. Gases like sulphur dioxide
B. Particulate matter of size 5 micrometre or more
C. Gases like ozone and methane
D. Particulate matter of size 5.5 micrometre or less

Answer 1

Hint: Scrubbers are used to remove particulate matter and harmful components such as nitrogen dioxide and sulphur dioxide generated from the engines as a result of combustion. These scrubbers help in reducing pollution in the environment and they filter out the harmful components.

Complete answer:
Scrubbers are connected to the streams of exhaust which cleans the dirty gases and components and releases the clean gas. Scrubbers are of two types:- Wet Scrubber and Dry Scrubber. The wet scrubber uses liquid such as Water. This water is allowed to flow within the dirty gases and all the effluents then get collected in the water and form an emulsion. In the dry scrubber, we use a dry reagent to filter the dirty gas. The dirty gases include the sulphur dioxide and nitrogen dioxide which if released in unfiltered form into the atmosphere is harmful.
The scrubber used in the exhaust of chemical industries is meant only to remove harmful components from the gas, so it doesn’t filter out the particulate matter. Hence the option B and Option D are wrong statements.
The chemical industries on the other hand release only gas like Sulphur dioxide and nitrogen dioxide and hydrogen peroxide etc and not other gases like ozone and methane. So option C is also Wrong.

So, option A ( gases like sulphur dioxide) is the correct option.

Additional information: scrubbers, on ships as an alternative to switching to cleaner low-sulphur fuel, has been a seriously debated issue since the global ship fuel sulphur regulations were brought to control by the International Maritime Organization (IMO) for more than ten years ago. Ship operators have different options available to achieve sulphur limits. The most straightforward option is to change to using compliant lower-sulphur fuel oil, i.e. with a sulphur content less than the mandatory limit values.

Note:
Removal potency of pollutants is improved by increasing continuance time within the scrubber or by the rise of the surface area of the scrubber solution by the utilisation of a twig nozzle, packed towers or an aspirator. Scrubbers can also be used for heat recovery from hot gases by flue-gas condensation. They are additionally used for the high flows in solar, PV, or LED processes