Brownfield

Brownfield sites are abandoned or underused industrial and commercial facilities available for re-use. Expansion or redevelopment of such a facility may be complicated by real or perceived environmental contamination. Innovative remedial techniques used at distressed brownfields in recent years include bioremediation and in situ oxidation. Often, these strategies are used in conjunction with each other or with other remedial strategies such as soil vapor extraction.In this process, vapor from the soil phase is extracted from soils and treated, which has the effect of removing contaminants from the soils and groundwater beneath a site. Some brownfields with heavy metal contamination have even been cleaned up through an innovative approach called phytoremediation, which uses deep-rooted plants to soak up metals in soils into the plant structure as the plant grows. After they reach maturity, the plants – which now contain the heavy metal contaminants in their tissues – are removed and disposed of as hazardous waste.
A newer technology for remediating brownfields involves an in situ injection of an iron-embedded organosilica material that creates a permanent soft curtain barrier underground. Groundwater passes through the barrier, which absorbs toxins and solvents while the iron dechlorinates them to non-toxic
products. Research is under way to see if some brownfields can be used to grow crops, specifically for the production of biofuels.

( from wikipedia)










An excellent example of remediation of brown field is the Gasworks Park in Seattle. The site previously belongs to the former Seattle Gas Light Company. It is located on the north shore of the Lake Union, having a good view of Seattle city. Through bio-phyto-remediation techniques the soil and water is cleaned and "greened". And the old plants, structures and paths are preserved to honor the rich industrial history. Now the park holds a lot of different public activities.
(Pictures from wikipedia)