Filtration Aggregates Specifier – Process
Filtration
Groundwater is filtered naturally through aquifers, often layers of sand and gravel, and only needs to be disinfected with chlorine before it is safe to use. This natural process can be replicated in treatment works to remove solids from surface or stored water, before disinfection.
The sands in varyng sizes are supported by gravel beds and act as a giant filter collecting contaminents in the upper sand layer, periodically these are back washed and cleaned to keep the process operating effectively. Eventually these are replaced with new gravels and sand.
In addition sand beds are used during the last stages of sewage treatment works as a final filter and cleaning process before the water is released into watercourses. In some cases reed beds are used at this stage, the reeds will be grown on gravel to allow the fluids to seep through the reed bed without blocking.
Water Filtration