Kandakji Tarek, Udeigwe Theophilus K, Dixon Ryan, Li Li
Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA.
Department of Environmental Health and Safety, Texas Tech University, Lubbock, TX, 79409, USA.
Environ Monit Assess. 2015 Nov;187(11):665. doi: 10.1007/s10661-015-4863-1. Epub 2015 Oct 3.
This study examined and compared arsenic (As) and other element [copper (Cu), iron (Fe), potassium (K), manganese (Mn), rubidium (Rb), and zinc (Zn)] distribution, as well as their interactions in historically irrigated and non-irrigated semi-arid agricultural soils of the Southern High Plains (SHP) in the USA, using findings from a portable X-ray fluorescence spectrometer. The portable X-ray fluorescence (PXRF) findings revealed that the concentrations of As (5.1 vs. 3.1 mg kg(-1)), Cu (7.2 vs. 6.2), Fe (7398 vs. 5677), K (8638 vs. 7061), Mn (80 vs. 68), Rb (36 vs. 27), and Zn (19.3 vs. 13.8) were higher in the historically irrigated field compared to the non-irrigated and, when examined within depths, were consistently and significantly higher (P<0.001) in the subsurface soils of the non-irrigated field, a trend not evident in the irrigated field. The strengths of the correlation among elements were higher in the non-irrigated field compared to the irrigated (average R of 0.60 vs. 0.54), suggesting a possible external input of these pollutants in the historically irrigated field which could have altered the natural background concentration and association among them. Furthermore, findings from principal component analysis (PCA) indicated that As, Mn, Rb, Fe, Zn, and K were more closely associated in the non-irrigated field and likely of lithogenic origin. The observed differences in elemental concentration and interaction between the irrigated and non-irrigated soils support the hypothesis that water from the local aquifer could be a potential source of pollutant addition to these semi-arid alkaline soils.
本研究利用便携式X射线荧光光谱仪的检测结果，对美国南部高平原（SHP）历史灌溉和非灌溉半干旱农业土壤中的砷（As）和其他元素[铜（Cu）、铁（Fe）、钾（K）、锰（Mn）、铷（Rb）和锌（Zn）]分布及其相互作用进行了检测和比较。便携式X射线荧光（PXRF）检测结果显示，与非灌溉土壤相比，历史灌溉土壤中As（5.1对3.1 mg kg⁻¹）、Cu（7.2对6.2）、Fe（7398对5677）、K（8638对7061）、Mn（80对68）、Rb（36对27）和Zn（19.3对13.8）的浓度更高，并且在按深度检测时，非灌溉土壤的次表层土壤中这些元素的浓度始终显著更高（P<0.001），而这一趋势在灌溉土壤中并不明显。与灌溉土壤相比，非灌溉土壤中元素之间的相关性更强（平均相关系数R为0.60对0.54），这表明在历史灌溉土壤中这些污染物可能存在外部输入，从而改变了它们的自然背景浓度及其之间的关联。此外，主成分分析（PCA）结果表明，在非灌溉土壤中，As、Mn、Rb、Fe、Zn和K的相关性更强，并且可能源于成岩作用。灌溉土壤和非灌溉土壤中元素浓度及相互作用的差异支持了这样一种假设，即当地含水层的水可能是这些半干旱碱性土壤中污染物添加的潜在来源。
