The ____ process is used in the water industry primarily for the removal of ______.

The ____ process is used in the water industry primarily for the removal of ______.

• A. absorption, organic substances
• B. adsorption, inorganic substances
• C. absorption, inorganic substances
• D. adsorption, organic substances

Answer: (D)

Adsorption is the process where molecules stick to the surface of a solid rather than being taken into its interior. In water treatment, activated carbon is widely used because it has a vast surface area and many pores, allowing it to attract and hold organic molecules from water—such as taste- and odor-causing compounds and precursors to disinfection byproducts. This surface adhesion makes adsorption the primary method for removing organic substances. Absorption would involve solutes entering the bulk of a material, which isn’t how carbon filters operate to remove organics. Inorganic substances are typically removed by other mechanisms like precipitation, ion exchange, or filtration, so adsorption is not the main approach for them.

Adsorption is the process where molecules stick to the surface of a solid rather than being taken into its interior. In water treatment, activated carbon is widely used because it has a vast surface area and many pores, allowing it to attract and hold organic molecules from water—such as taste- and odor-causing compounds and precursors to disinfection byproducts. This surface adhesion makes adsorption the primary method for removing organic substances. Absorption would involve solutes entering the bulk of a material, which isn’t how carbon filters operate to remove organics. Inorganic substances are typically removed by other mechanisms like precipitation, ion exchange, or filtration, so adsorption is not the main approach for them.