Statement I: Activated carbon is a good and an attractive tool to remove pollutants from effluent streams and to remediate contaminants from various industries.
Statement II:Activated carbon exhibits a large surface area and a strong potential for adsorbing heavy metals.
Statement III: Activated carbon can be easily synthesized from environmental wastes with high carbon content.
Which one of the following is correct in respect of the above statements?
(a) Both statement II and Statement III are correct and both of them explain Statement I
(b) Both Statement II and Statement III are correct but only one of them explains Statement I
(c) Only one of the Statements II and III is correct and that explains Statement I
(d) Neither Statement II nor Statement III is correct.
Ans-c
Explanation
Activated carbons are produced from carbon of vegetable origin (peat, lignite, coal or nutshells). The activation process creates an extensive pore structure that allows considerable adsorption onto an active surface area above 400 m2/g.
Activated carbon products can be put to a range of uses, including the purification, concentration and separation of gases from liquids, purifying drinking water, waste water and sewage treatment as well as controlling emissions. They also have further applications in the food, chemical and pharmaceutical industries.
Hence statement 2 is correct
The production method of activated carbon consists of the following main process steps:
Devolatilization and Carbonization of raw material
The Carbonization process comprises heating of the raw material to a temperature around 600 °C. This process also removes volatiles from the raw material
Activation of the carbonized material
The carbonized material is activated at temperatures around 950 °C with a gasification agent (usually steam) which removes a proportion of the carbon atoms by gasification
The steam activation process steps are performed in reactors such as rotary kilns, multiple hearth kilns, shaft kilns, and other high temperature kilns.
So It cannot be easily synthesised , it involves substantial costs .
Hence statement 3 is incorrect
So Only Statements II is correct and that explains Statement I
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