- A. Aeration followed by filtration: Aeration oxidizes dissolved iron and manganese, forming precipitates that are then removed by filtration. Thus, it's used for the removal of iron (3). - B. Reverse Osmosis: This process uses a semipermeable membrane to remove dissolved salts and other impurities from water, effectively used for desalination or removal of excess salts (4). - C. Filtration through activated carbon: Activated carbon is highly effective at adsorbing organic compounds, chlorine, and other substances that cause color, odor, and taste in water. Thus, it's used for the removal of colour (1). - D. Treatment with UV light: Ultraviolet (UV) light treatment is a disinfection method that inactivates microorganisms like bacteria and viruses by damaging their DNA. Thus, it's used for the removal of microorganisms (2).