Match List-I with List-II and select the correct answer using the code given below : List-I (Process) A. Aeration followed by filtration B. Reverse Osmosis C. Filtration through activated carbon D. Treatment with UV light List-II (Contaminant) 1. Removal of colour 2. Removal of microorganism 3. Removal of iron 4. Removal of excess salts Code : A B C D

The matching of water purification processes to their respective contaminants is as follows: (A) Aeration followed by filtration is primarily used for the removal of iron and manganese. Aeration introduces oxygen, which oxidizes dissolved ferrous iron into insoluble ferric iron precipitates that are subsequently removed via filtration [t2][t5][t6]. (B) Reverse Osmosis (RO) is a membrane-based technology widely used for desalination, effectively removing excess salts and dissolved solids from water [t1][t4]. (C) Filtration through activated carbon is the standard method for removing organic compounds that cause unpleasant tastes, odors, and color in water [t5]. (D) Treatment with UV light is a disinfection process that inactivates or removes microorganisms by damaging their nucleic acids, preventing reproduction [t4]. Therefore, the correct sequence is A-3, B-4, C-1, D-2.

Sources

1. [1] https://www.sciencedirect.com/science/article/pii/S1944398624203921