ABSTRACT
With the rapid development of industrialization, urbanization, and human activities, more and more soils were polluted by heavy metals. Heavy metal-contaminated soil has been a widespread global problem. The restoration of heavy metal-contaminated soils is a global hot issue. Currently, there are physical, chemical, and biological remediation technologies, but the traditional physical or chemical methods can be very costly and also destructive to the soil. Phytoextraction, one way of bioremediation, is recognized the green eco-friendly in situ remediation method (Zaier et al. 2010b). However, the ef—ciency of phytoextraction is generally considered as too slow duo to the inherent characteristics of hyperaccumulator plants: the hyperaccumulator plants grows slowly, the long growth cycle and the small biomass, leading to the small quantity of heavy metals in the shoot, affecting the actual practice value. So the researchers begin to study the more effective method: using the general plant with fast growing and large biomass and other assistive technologies to strengthen the extraction, such as the chemistry-plant and the microorganism-plant joint reparation (Kim et al. 2010). In the chemistry-plant joint remediation, the chelating agents are widely used. The chelate can increase the bioavailability of heavy metals and the plant absorption, improving the effectiveness of the phytoextraction.
