What is the most favorable soil condition for removing viruses?

The most favorable soil condition for removing viruses is fine loamy sand over coarse sand and gravel. This combination provides a balance of both filtration and adsorption properties that are effective at trapping viruses.

Fine loamy sand contains smaller particles which can create a larger surface area for microbial interactions, including adsorption. The presence of loam helps retain moisture while also allowing for some permeability, which is essential for the movement of water through the soil. The coarse sand and gravel underneath provide good drainage and help maintain aeration, but they also contribute to the overall structure that can capture and hold onto contaminants.

This layering allows for effective filtration, as the finer particles can trap smaller viruses while the coarser materials still facilitate adequate water movement. As a result, this type of soil structure optimizes both the physical and chemical processes necessary for virus removal in groundwater or wastewater applications.

In contrast, clay soil with low permeability might hinder movement of water, which can lead to less effective filtration as water may not pass through adequately. Sandy soil with high permeability could allow viruses to move too quickly through it without sufficient contact time to achieve removal. Rocky soil with large voids may not provide enough surface area for adsorption, allowing viruses to pass through untrapped. Thus, while all soil