**5. Six main subgroups in phytoremediation**


**35**

fertility/quality.

*Phytoremediation of Hazardous Radioactive Wastes DOI: http://dx.doi.org/10.5772/intechopen.88055*

**6. Factors affecting the uptake mechanisms**

metals and are discussed as below:

**6.1 Plant species**

**6.2 Properties of medium**

rate of uptake by plants [37].

ability of the dried soil [38].

**6.4 Addition of chelating agents**

such as chelating agents, and micronutrients [39].

metals, crude oil, explosives, and radionuclides [41].

**6.3 The root zone**

6.**Rhizodegradation:** Enhancement of naturally occurring biodegradation and destruction of contaminants in the soil through mineralization and transfor-

There are several factors which can affect the uptake mechanisms of radioactive

Plant species with superior remediation ability of the concerned radioactive waste are screened and carefully chosen. The success of phytoremediation tech-

Factors such as temperature, moisture content, pH, organic matter affect the

It can absorb contaminants and store or metabolize it inside plant tissue. An increase in root diameter and reduced root elongation as a response to less perme-

The increase of the uptake by crops can be influenced by increasing the bioavailability of radionuclides through addition of biodegradable physiochemical factors

In a stressed environment, the application of plants to remediate sites governed by mainly on the persistence capacity of the plant. All through phytoremediation, plants absorb pollutant from the soil, and mineralized it, thus preventing infection of groundwater and retaining system shield for human habitation. Efe and Elenwo reported that plants (e.g., *Axonopus compressus*) used as phytoremediation means, should have the capacity to adapt properly to the climatic condition and soil of the polluted sites, and retain high patience under stressed environments [40]. Several phytoremediation plant types have technologically advanced adaptive features for absorption, acceptance, transfer and degradation of pollutants for example heavy

The efficiency of the process is also dependent on the soil properties, type of contaminants and its bioavailability. Plant roots usually serve as interlinks providing enormous surface area for the absorption and accumulation of essential growth nutrient along with contaminants [42]. In metal contaminated sites, characterization of eco-toxicity (e.g., oxidative stress) is mostly determined through the formation of free radicals [43]. Some of the advantages of phytoremediation include risk containment, extraction of valuable metals (phytomining) and increased soil

Baker and Brooks [44] recommended that the metal hyperaccumulator must fulfill a standard that the concentration of an element stored in a plant can be higher than the soil [44]. Based on their classification, the transfer factor (TF)

nique depends upon the ability of the plant to accumulate [36].

mation of pollutants by plant roots and associated microbes [33–35].

6.**Rhizodegradation:** Enhancement of naturally occurring biodegradation and destruction of contaminants in the soil through mineralization and transformation of pollutants by plant roots and associated microbes [33–35].
