Potential Application of Earthworm for the Phytoremediation of Soils Contaminated by Heavy Metals

Phytoremediation to remediate heavy metal-contaminated soils has been widely accepted as a cost-effective,environmental-friendly technology. The primary objective of this technology is to maximize the transfer of heavy metals to plant so that the greatest total mass of contaminant is removed by each cropping.Slower growth rate and lower biomass production of hyperaccumulators plant may limit the phytoremediation technology application,and the availability of heavy metals in soil for plant uptake also restrains its success.The paper discussed the toxicity of heavy metals to earthworms and the tolerance of earthworms to heavy metals.There are abound evidences that earthworms have the capability to enhance plants yield and increase the concentrations of available heavy metals in soil.It is most likely that earthworm activity can increase phytoremediation efficiency by improving soil conditions and enhancing plant growth and the uptake of heavy metals by plant.Further investigation is necessary to study the interaction mechanisms between earthworms and heavy metals in rhizosphere.