Phytoremediation

Phytoremediation defines a technique of reducing and cleaning pollutants concentrations in contaminated soils, water, or, with plants. This technique differs to bioremediation in that the former  uses plants while the later uses biological (plant or bacterial). Such as bioremediation, phytoremediation technologies are based on two methods: ex-situ and in-situ. Ex-situ method requires removal of contaminated ground for treatment on or of site, and returning the treated ground to the resorted site while in-situ method defines a remediation without excavation of contaminated site. Phytoremediation has advantages and limitations. Like bioremediation, the cost of phytoremediation is lower than that of traditional remediation both in situ and ex situ. However it requires a longer treatment period. It is effective if land contamination is limited to within 0.9144 meters (3 feet) of the surface, and if groundwater is within 3,048 meters (10 feet) of the surface. Sites must be low to moderate soil contamination over large areas, and to sites with large volumes of groundwater with low levels of contamination.
Phytoremediation and Ecological architecture,  urbanism, and engineering
The architectural and engineered technological reflection on environmental pollution is revived in recent work. Several research on building skins indicate a technological direction with the integration of phyto-remediation to reduce, if not to say to resolve, environmental pollution. Two representations of terraforming building skins that are related to phytoremediation are the Active Modular Phytoremediation Systems and the Detox Towers. The former proposal, represented by Anna Dyson and Skidmore Owings and Merrill's Center for Architecture Science and Ecology (CASE), explores the ability of the envelope to clean up air pollution.

The Active Modular Phytoremediation Systems (AMPS), 2008, © Anna Dyson and Skidmore,
Owings and Merril for CASE

AMPS © Anna Dyson and Skidmore, Owings, and Merrill

The envelope integrates a smart system that imitates the air cleaning capacity of plants. This AMPS is a bio-mechanical hybrid system that aims to improve indoor air quality while minimizing both energy consumption and exposure to outdoor air pollution thanks to a phytoremediation process.

AMPS © Anna Dyson and Skidmore, Owings and Merrill

AMPS © Anna Dyson and Skimore, Owings, and Merrill

The later representation is the BIOMSgroup/Maria-Paz Gutierrez's design proposal Detox Towers for the eVolo 2011 Skyscraper Competition. BIOMSgroup and Maria-Paz Gutierrez proposes a next-generation of high residence which will be responsible to reduce increasing issues on ecosystems. More than a skyscraper, this proposal presents a next-generation building technologies adaptable to environmental constraints. These so-called technologies consist of a smart membrane system based on phytoremediation methods of mitigating pollutants concentrations. This active detox membrane comprises of an internal (Part A) and an external (PartB) membrane system that incorporates algae and lichen which aim to clean up air pollution and reduce energy consumptions as the diagram shows below.

Detox Towers © BIOMSgroup/Maria-Paz Gutierrez. Originally appeared on eVolo

The diagram explains the mechanism of mitigating air of BIOMSgroup and Maria-Paz Gutierrez's detox Towers. The membrane absorbs toxic air (CO2, methane emissions etc.) and, then, excretes clean air, such as plants.

Detox Towers © BIOMSgroup/Maria-Paz Gutierrez. Originally appeared on eVolo

Phytoremediation can be useful to terraform contaminated water environment or soils reducing the impact of sites that have been highly contaminated or are suffering of chronic pollution. However, such as bioremediation, numerous question remain about the effectiveness of this method to restore contaminated soils in a large scale. Many metals can be tied up in insoluble forms which make them less available. As we have seen with the AMPS and Detox Towers, phytoremediation technologies are still in research and development phase.

> Bioremediation, terraforming, Landscraping, Recombinant, Photosynthesis