What constitutes the most effective approach for eliminating low-concentration organic contaminants (< 200 mg/litre) from polluted water ?
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Answer: B. Activated carbon adsorption
Explanation
Activated carbon possesses an enormous internal surface area and excellent adsorption capacity. This porous structure attracts and holds low-concentration organic molecules effectively. It represents the most efficient technology for polishing water contaminated with trace organics. Adsorption involves molecules adhering to the internal surface of solid activated carbon media. Granular and powdered carbon forms are widely used in municipal and industrial water treatment. Spent carbon can often be thermally reactivated for repeated industrial use.
Drinking water treatment plants use carbon beds to remove taste and odor compounds. Industrial facilities polish wastewater streams to remove persistent synthetic organic chemicals. Activated carbon adsorption successfully captures trace pharmaceutical residues from water. Lagooning utilizes large open ponds and requires long residence times for biodegradation. Biological oxidation ponds are effective for higher organic loads rather than trace concentrations. Chemical coagulation targets suspended colloids rather than dissolved low-concentration organics.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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