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United States Department of Agriculture

Agricultural Research Service

Research Project: SUSTAINABLE CROPPING SYSTEMS FOR IRRIGATED SPECIALTY CROPS AND BIOFUELS

Location: Vegetable and Forage Crops Production Research

Title: Phytoextraction of metals and rhizoremediation of PAHs in co-contaminated soil by co-planting of Sedum alfredii with ryegrass (Lolium perenne) or castor (Ricinus communis)

Authors
item Wang, Kai -
item Huang, Huagang -
item Zhu, Zhiqiang -
item Li, Tingqiang -
item He, Zhenli -
item Yang, Xiaoe -
item Alva, Ashok

Submitted to: International Journal of Phytoremediation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 10, 2013
Publication Date: April 19, 2013
Citation: Wang, K., Huang, H., Zhu, Z., Li, T., He, Z., Yang, X., Alva, A.K. 2013. Phytoextraction of metals and rhizoremediation of PAHs in co-contaminated soil by co-planting of Sedum alfredii with ryegrass (Lolium perenne) or castor (Ricinus communis). International Journal of Phytoremediation. 15:283-298.

Interpretive Summary: It is a major challenge to develop an effective strategy for removal of multiple pollutants from contaminated soils. Contaminated soils may have high concentrations of metals, such as cadmium (Cd), lead (Pb) and zinc (Zn), as well as polycyclic aromatic hydrocarbons (PAHs). Sedum alfredii has been shown as an effective hyperaccumulator of Cd, Zn, and Pb. Co-planting of ryegrass or castor with Sedum was investigated for its effectiveness of phytoremediation of the above metals and dissipation of PAHs. This co-planting technique significantly enhanced dissipation of PAHs. Sedum and ryegrass co0planting enhanced removal of Pb. This study demonstrated merit of planting ryegrass or castor with Sedum for enhanced removal of metals and PAHs from co-contaminated soils.

Technical Abstract: Main challenge of phytoremediation of co-contaminated soils is developing strategies for efficient and simultaneous removal of multiple pollutants. A pot experiment was conducted to investigate the potential for phytoextraction of heavy metals and rhizoremediaiton of polycyclic aromatic hydrocarbons (PAHs) in co-contaminated soil by co-planting a cadmium/zinc (Cd/Zn) hyperaccumulator and lead (Pb) accumulator Sedum alfredii with ryegrass (Lolium perenne) or castor (Ricinus communis). Co-planting with castor decreased the shoot dry biomass of S. alfredii as compared to monoculture. Cadmium concentration in S. alfredii shoot significantly decreased when grown with ryegrass or castor as compared to that in monoculture. However, no reduction of Zn and Pb concentrations in S. alfredii shoot was detected in co-planting treatments. In contrast monoculture or co-plantings had no significant influence on removal of either Cd, Zn or Pb (except enhanced Pb removal in S-R co-planting treatment). Co-planting of S. alfredii with ryegrass or castor significantly enhanced the pyrene and anthracene dissipation as compared to that in the bare soil or S. alfredii monoculture. Enhanced soil microbial population and activities were detected in both co-planting treatments. Co-planting of S. alfredii with ryegrass or castor provides a convenient and effective strategy to mitigate both metal and PAH contaminants from co-contaminated soils.

Last Modified: 9/23/2014