Phytoremediation technologies

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a. If soil is contaminated with dioxin, what kind of phytoremediation may be successful in removing it and why?

It has been found in the past that dioxins are not always effectively taken up in phytoremediation processes. However, some exceptions apply. For the removal of PCDDs (Dioxins) has been found to somewhat effective through rhizodegradation. This is a process that takes place in the soil of groundwater immediately surrounding the plant roots. Exudates from plants stimulate rhizosphere bacteria to enhance biodegradation of soil contaminants. Studies have shown that microbial population capable of degrading dioxins and furans were selectively increased by the addition of dioxins in the rhizophere ( Wang and Oyaizu, 2009). However, though degradation does occur, it has been found to be limited in most other studies. While some bacterial consortia have the ability to degrade PBCs, a similar contaminants to dioxins and furans, must less studies have been able to show the same for the presence of dioxins (Schmidt, 1998).

Thus, another, and potentially more useful type of phytoremediation that can be used against dioxins is thought to be phytoextraction. The complex formation between a binding compound and TCDD is reversible. It could enhance the availability of dioxins for micro-organisms in soil, but there is no indication of biodegradation in the plant or in the medium (Campenella et al., 2002). The major application of this process for phytoremediation of hydrophobic pollutant is the phytoextraction (Campenella et al., 2002). Phytoextraction and rhizodegradation used together may be the most effective way to get rid of dioxins.

b. If soil is contaminated with TCE, can phytoremediation remove it ...