filtratielaag

Filtratielaag is a layer within soil, sediment, or engineered media that principally serves as a filtration medium when fluids move through it. As water or other liquids percolate, the particles in the layer trap suspended solids and, to some extent, adsorb dissolved substances on mineral surfaces. The result is a filtrate with reduced turbidity and particle load compared with the incoming flow.

Natural filtratielaag commonly consists of relatively well-sorted sand or a sand–gravel mix, with a thickness ranging from a few centimeters to decimeters. It lies above a less permeable layer that guides flow and enhances retention. In engineered systems, the filtratielaag is purposely constructed, for example as a rapid sand filter or a filtration bed in wastewater treatment, typically comprising sand, gravel, and sometimes finer layers to optimize porosity and hydraulic conductivity.

Key properties include grain size distribution, porosity, and hydraulic conductivity, which determine the filtration efficiency and the infiltration rate. The layer also tends to become clogged over time as solids accumulate; maintenance such as backwashing or sediment removal is required to restore performance.

Filtratielaag influences groundwater recharge, surface water quality, and the effectiveness of filtration-based treatment. It is discussed in soil science, hydrogeology, and environmental engineering contexts.