Remediation of Heavy-Metal-Contaminated Soil by a CAM Plant
Li, T., Tao, Q., Han, X. and Yang, X. 2013. Effects of elevated CO2 on rhizosphere characteristics of Cd/Zn hyper-accumulator Sedum alfredii. Science of the Total Environment 454-455: 510-516.
In doing their part to help achieve this worthy goal, Li et al. conducted a pot experiment to contrast the effects of elevated CO2 (800 vs. 350 ppm) on rhizosphere characteristics of a hyper-accumulating ecotype (HE) and a non-hyper-accumulating ecotype (NHE) of Sedum alfredii, which is the only Crassulacean acid metabolism (CAM) species that is known to be a Zn/Cd hyper-accumulator.
In describing their results the four researchers say they "clearly showed that HE has a great potential for removal of Cd and Zn from contaminated soil," for "after a growth period of 45 days, phytoextraction efficiency of Cd and Zn by HE was increased significantly (by 52.8% for Cd and 42.6% for Zn, respectively) by elevated CO2."
Noting that their results are in accordance with those of previous reports (Zheng et al., 2008; Wu et al., 2009; Jia et al., 2010), Li et al. say they collectively demonstrate that "elevated CO2 can be developed as a potential useful phytoremediation tool to clean up soils contaminated with heavy metals by enhancing the hyper-accumulation of metal."
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