Element Case Studies: Cadmium and Zinc

Sedum plumbizincicola (Crassulaceae), a new Sedum species, was originally discovered in 2005 in Zhejiang Province, eastern PR China, and was identified as a Cd-Zn hyperaccumulator in 2007. During the past decade, great efforts have been made to understand its metal-accumulating capacities, physiological and molecular mechanisms for metal hypertolerance and hyperaccumulation, and enhanced measures of phytoextraction, as well as field applications of phytoremediation practice and disposal of harvested biomass. This chapter provides a brief review of the progress on phytoremediation of Cd- and Zn-contaminated soils using this species. Agronomic measures to enhance Cd and Zn phytoextraction efficiency using S. plumbizincicola were studied, including cultivation management, intercropping with other plant species, and nutrient management. Changes in soil and plant metal uptake were investigated during long-term and repeated phytoextraction of Cd- and Zn-contaminated soils using S. plumbizincicola. Field assessment results confirm that phytoextraction using S. plumbizincicola is a promising technique for the remediation of slightly Cd-polluted soils without the need to halt normal agricultural production.