Table 4 Types of phytoremediation technologies
Technique principle | Technique principle | Characteristics | |
|---|---|---|---|
Phytodegradation | Degrade the absorbed contaminants into less toxic compounds, either by plant’s metabolic process or enzymes | Most suited for moderately hydrophobic organic chemicals | |
Phytoextraction | Absorb organic matter from the soil into the plant body through plants that have an enrichment effect on pollutants | Depends on the bioavailability of pollutants | |
Phytostabilization | Decrease the mobility and bioavailability of pollutants by root adsorption or insoluble compounds formed in the root zone, preventing pollutants leaching to ground water and the food chain | Does not reduce the concentration of pollutants but reduces the contamination of nearby media/area | |
Phytostimulation | Plants release specific root exudates (enzymes, organic acids, etc.) to enhance the growth and activity of microorganisms in the soil, accelerating the removal of pollutants | Cannot be done alone by the plant, always has close interaction between the microorganisms in rhizosphere | |
Phytovolatilization | Employs the plant-mediated uptake of pollutants, then transforms them into volatile compounds, and releases these compounds in the atmosphere by its metabolic and transpiration pull | Does not completely remove the pollutants from the environment | |
Rhizofiltration | Adsorption or precipitation of pollutants by plant roots | Requires a full understanding of the contaminant speciation and interactions of all contaminants and nutrients | |