50
Question 50
Consider the following statements :
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?
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?
AOptions
A
A) Both Statement-II and Statement-III are correct and both of them explain Statement-I
B
B) Both Statement-II and Statement-III are correct but only one of them explains Statement-I
C
C) Only one of the Statements II and III is correct and that explains Statement-I
D
D) Neither Statement-II nor Statement-III is correct
BSolution
Statement-I is correct. Activated carbon is widely recognized and used as an effective adsorbent for removing a broad range of pollutants (organic, inorganic, dissolved gases) from various media, including water (effluent streams), air, and for remediation of contaminated sites across industries. Its porous structure and high surface area make it an attractive and versatile tool.
Statement-II is correct. The effectiveness of activated carbon stems from its highly porous structure, which gives it an extremely large internal surface area (typically 500 to 1500 m²/g or more). This vast surface area, combined with its surface chemistry, provides numerous sites for the adsorption of pollutants, including heavy metals, through various mechanisms (e.g., electrostatic interactions, chelation, surface complexation).
Statement-III is correct. Activated carbon can be (and often is) synthesized from a wide variety of carbon-rich precursors, including environmental wastes such as agricultural residues (nut shells, wood waste), municipal solid waste, and industrial by-products (e.g., coal, discarded tires). This process, often involving carbonization followed by activation (physical or chemical), makes it a sustainable option.
Both Statement-II (large surface area, adsorption potential) and Statement-III (synthesis from wastes) contribute to activated carbon being a "good and attractive tool" (Statement-I). Statement-II explains *why* it can remove pollutants effectively, and Statement-III explains *why* it's an 'attractive' (e.g., sustainable, cost-effective from waste) tool. Thus, both explain Statement-I.
Statement-II is correct. The effectiveness of activated carbon stems from its highly porous structure, which gives it an extremely large internal surface area (typically 500 to 1500 m²/g or more). This vast surface area, combined with its surface chemistry, provides numerous sites for the adsorption of pollutants, including heavy metals, through various mechanisms (e.g., electrostatic interactions, chelation, surface complexation).
Statement-III is correct. Activated carbon can be (and often is) synthesized from a wide variety of carbon-rich precursors, including environmental wastes such as agricultural residues (nut shells, wood waste), municipal solid waste, and industrial by-products (e.g., coal, discarded tires). This process, often involving carbonization followed by activation (physical or chemical), makes it a sustainable option.
Both Statement-II (large surface area, adsorption potential) and Statement-III (synthesis from wastes) contribute to activated carbon being a "good and attractive tool" (Statement-I). Statement-II explains *why* it can remove pollutants effectively, and Statement-III explains *why* it's an 'attractive' (e.g., sustainable, cost-effective from waste) tool. Thus, both explain Statement-I.
CStrategy
For questions on environmental technologies, understand the mechanism of action and the benefits. For adsorbents like activated carbon, key features include large surface area and the ability to be derived from sustainable/waste sources. Connect these features to their effectiveness.
DSyllabus Analysis
Environment & Ecology: Pollution Control Technologies (Water Treatment, Air Purification), Waste Management. Science & Technology: Materials Science, Green Chemistry.
EQuestion Analysis
This is a factual and conceptual question from Environment and Science & Technology. All three statements accurately describe activated carbon's properties and applications in pollution control. Statement II provides the scientific basis for its effectiveness, and Statement III highlights its sustainable nature, both of which make it an attractive tool (Statement I). Easy difficulty.