Rhizofiltration

Rhizofiltration is a form of phytoremediation that involves filtering contaminated groundwater, surface water and wastewater through a mass of roots to remove toxic substances or excess nutrients.

Rhizofiltration is a type of phytoremediation, which refers to the approach of using hydroponically cultivated plant roots to remediate contaminated water through absorption, concentration, and precipitation of pollutants.

[citation needed] This process is very similar to phytoextraction in that it removes contaminants by trapping them into harvestable plant biomass.

[citation needed] Rhizofiltration may be applicable to the treatment of surface water and groundwater, industrial and residential effluents, downwashes from power lines, storm waters, acid mine drainage, agricultural runoffs, diluted sludges, and radionuclide-contaminated solutions.

Plants suitable for rhizofiltration applications can efficiently remove toxic metals from a solution using rapid-growth root systems.

[3] A system to achieve this can consist of a “feeder layer” of soil suspended above a contaminated stream through which plants grow, extending the bulk of their roots into the water.

The feeder layer allows the plants to receive fertilizer without contaminating the stream, while simultaneously removing heavy metals from the water.

Their roots penetrate microscopic scale pores in the soil matrix and can cycle 100 L of water per day per tree.

[5] Willows have been successfully used as “vegetation filters” for nutrient (e.g. nitrogen and phosphorus) removal from municipal wastewater [6] and polluted groundwater.

[5] Plants grown on polluted water and soils become a potential threat to human and animal health, and therefore, careful attention must be paid to the harvesting process and only non-fodder crop should be chosen for the rhizofiltration remediation method.