What happens to the concentration of contaminants as sediment is diluted?

When sediment is diluted, the concentration of contaminants does indeed decrease. This dilution occurs because the contaminants are spread out over a larger volume of water or sediment, which effectively reduces their concentration. Buffering, in the context of water quality, typically refers to the ability of a solution to resist changes in pH when acids or bases are added. Though buffering can play a role in stabilizing certain chemical properties of the solution, it is not directly related to the concentration of contaminants due to dilution.

The fundamental principle at play here is that concentration is defined as the amount of solute (or contaminants, in this case) per unit volume of solvent (or the total volume). When sediment is diluted, the volume increases while the amount of contaminants remains the same, leading to a lower concentration. Thus, understanding the relationship between dilution and concentration is crucial in environmental science, particularly when assessing the risks and impacts of contaminants in water or soil systems.