What is absorption?

The correct understanding of absorption, particularly in the context of water treatment, is best described as the process of taking in fluids or gases. Absorption refers to the phenomenon where one substance is taken up or assimilated into another, typically through a material's pores or interstitial spaces. For example, in water treatment, certain chemicals or pollutants can be absorbed by filter media which helps in purifying the water by removing contaminants.

Option B, while conveying a related concept of being engrossed, does not capture the specific scientific process being referred to in the context of water treatment. The focus in this industry is on how substances interact physically and chemically to improve water quality, which makes the other options more relevant to the discussion of absorption in that field.

Understanding absorption in water treatment is crucial because it can directly influence the efficiency of purification processes and the overall effectiveness of treatment systems employed to ensure safe and clean water.