Feng Huan, Qian Yu, Gallagher Frank J, Zhang Weiguo, Yu Lizhong, Liu Changjun, Jones Keith W, Tappero Ryan
Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07043, USA.
Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07043, USA.
J Environ Sci (China). 2016 Mar;41:172-182. doi: 10.1016/j.jes.2015.07.015. Epub 2015 Nov 1.
Liberty State Park in New Jersey, USA, is a "brownfield" site containing various levels of contaminants. To investigate metal uptake and distributions in plants on the brownfield site, Phragmites australis and Typha latifolia were collected in Liberty State Park during the growing season (May-September) in 2011 at two sites with the high and low metal loads, respectively. The objective of this study was to understand the metal (Fe, Mn, Cu, Pb and Zn) concentration and spatial distributions in P. australis and T. latifolia root systems with micro-meter scale resolution using synchrotron X-ray microfluorescence (μXRF) and synchrotron X-ray computed microtomography (μCMT) techniques. The root structure measurement by synchrotron μCMT showed that high X-ray attenuation substance appeared in the epidermis. Synchrotron μXRF measurement showed that metal concentrations and distributions in the root cross-section between epidermis and vascular tissue were statistically different. Significant correlations were found between metals (Cu, Mn, Pb and Zn) and Fe in the epidermis, implying that metals were scavenged by Fe oxides. The results from this study suggest that the expression of metal transport and accumulation within the root systems may be element specific. The information derived from this study can improve our current knowledge of the wetland plant ecological function in brownfield remediation.
美国新泽西州的自由州立公园是一个含有不同程度污染物的“棕地”场地。为了研究该棕地场地植物对金属的吸收及分布情况，2011年生长季节（5月至9月）期间，分别在自由州立公园金属负荷高、低的两个场地采集了芦苇和香蒲。本研究的目的是使用同步辐射X射线微荧光（μXRF）和同步辐射X射线计算机显微断层成像（μCMT）技术，以微米级分辨率了解芦苇和香蒲根系中金属（铁、锰、铜、铅和锌）的浓度及空间分布。同步辐射μCMT对根系结构的测量显示，表皮中出现了高X射线衰减物质。同步辐射μXRF测量表明，表皮与维管组织之间根横截面上的金属浓度和分布在统计学上存在差异。在表皮中发现金属（铜、锰、铅和锌）与铁之间存在显著相关性，这意味着金属被铁氧化物清除。本研究结果表明，根系内金属运输和积累的表达可能具有元素特异性。本研究获得的信息可增进我们目前对湿地植物在棕地修复中生态功能的了解。
