In the UK, brown field sites are defined as being “previously developed land” that has the potential for being redeveloped. It is often (but not always) land that has been used for industrial and commercial purposes and is now derelict and possibly contaminated.
There are various reasons that owners of brown field sites have for the reclamation the land. Owners of such sites include manufacturing plants, petrochemicals and utilities and these businesses may require reclamation based on decisions made about the future use of the land. Such decisions may depend on whether to better the land in its current state in order to keep it operational or whether it will be sold off for public or private development, such as housing.
Land reclamation for sites that have previously been used for industrial processes may, on investigation, identify contamination of soils and groundwater, the processing of which may also involve dealing with difficult natural background chemistry such as, for example iron. Iron may be oxidised during the process, thus complicating the treatment process, particularly where petroleum hydrocarbons are also present.
Remediation of such sites can require the extraction of contaminated groundwater using submersible pumps and the treatment and disposal of these segregated wastes. This may necessitate the bespoke design and engineering of a treatment plant capable of handling the contaminants and local groundwater chemistry.
In order to undertake effective water particulate separation to handle effective filtration of the oxidized iron high efficiency sand filtration has been developed for this purpose. The ancillary use of such water filtration technology as part of the overall treatment process can reduce operational costs and be highly efficient.
Treatment plants are more often than not designed to run 24/7 for the continual remediation of land. Previous water filtration methods can lead to the requirement for continuous or very frequent site presence to service plant works and keep them operational.
Through applying high efficiency water filtration as a bolt on to the overall operation of the plants, the backwash process becomes very efficient and reliable. With the volume of water needed for a successful backwash being less and because it is automatic, operative site visits can be reduced significantly.
Costs are also significantly reduced whilst increasing the operation of the plants which ultimately becomes of benefit to the land owner.
The water filtration technology necessary for this purpose filters below 1.0 micron – reliably – even achieving down to 0.45 micron to ensure cleaner process water. Such technology has been shown to provide a high efficiency removal rate of over 86% at 1.0 micron in one single pass whereas conventional filters have to undertake multiple passes to get anywhere such efficiency.