partitioned into the airspaces within a plant and subsequently diffuses into the
ambient air, provided ambient air is less contaminated. For volatile organic compounds (VOCs), phytovolatilization is the major loss mechanism. Figure 5 presents
the phytovolatilization process, substantial dilution and photochemical decay of the
contaminant in the atmosphere. However, phytovolatilization may cause degradation of air quality and may lead to exposure of human beings to the contaminant
released to air and poses risk in the urban areas. Phytovolatilization of both inorganic
and organic contaminants have been reported. Volatile forms of several inorganic
compounds such as Se [49], As [69–71], and Hg [72] can be volatilized from plants.
In direct phytovolatilization, the contaminants that the plants uptake are
translocated and eventually volatilize from the stem/trunk and leaves. In indirect
phytovolatilization, volatile contaminant flux from the subsurface increases due to
plant root activities. Volatile contaminants like trichloroethylene (TCE) and
tetrachloroethylene (PCE) are reported to undergo phytovolatilization from traditional phytoremediation plants such as willow and hybrid poplar
[73]. Phytovolatilization of methyl tert-butyl ether (MTBE) in weeping willows
[74] and in hybrid poplar trees [75] has been reported.
Fig. 4 Phytostabilization
Phytoremediation of Soil for Metal and Organic Pollutant Removal
55
ambient air, provided ambient air is less contaminated. For volatile organic compounds (VOCs), phytovolatilization is the major loss mechanism. Figure 5 presents
the phytovolatilization process, substantial dilution and photochemical decay of the
contaminant in the atmosphere. However, phytovolatilization may cause degradation of air quality and may lead to exposure of human beings to the contaminant
released to air and poses risk in the urban areas. Phytovolatilization of both inorganic
and organic contaminants have been reported. Volatile forms of several inorganic
compounds such as Se [49], As [69–71], and Hg [72] can be volatilized from plants.
In direct phytovolatilization, the contaminants that the plants uptake are
translocated and eventually volatilize from the stem/trunk and leaves. In indirect
phytovolatilization, volatile contaminant flux from the subsurface increases due to
plant root activities. Volatile contaminants like trichloroethylene (TCE) and
tetrachloroethylene (PCE) are reported to undergo phytovolatilization from traditional phytoremediation plants such as willow and hybrid poplar
[73]. Phytovolatilization of methyl tert-butyl ether (MTBE) in weeping willows
[74] and in hybrid poplar trees [75] has been reported.
Fig. 4 Phytostabilization
Phytoremediation of Soil for Metal and Organic Pollutant Removal
55