University of Copenhagen, Department of Plant and Environmental Sciences, Frederiksberg DK-1871, Denmark.
Cranfield University, School of Water, Energy and Environment, Cranfield MK43 0AL, UK.
Sci Total Environ. 2019 Feb 20;652:744-754. doi: 10.1016/j.scitotenv.2018.10.244. Epub 2018 Oct 18.
The physico-chemical factors affecting the distribution, behavior and speciation of chromium (Cr), copper (Cu) and arsenic (As) was investigated at a former wood impregnation site (Fredensborg, Denmark). Forty soil samples were collected and extracted using a sequential extraction technique known as the Chemometric Identification of Substrates and Element Distributions (CISED) and a multivariate statistical tool (redundancy analysis) was applied. CISED data was linked to water-extractable Cr, Cu and As and bioavailable Cu as determined by a whole-cell bacterial bioreporter assay. Results showed that soil pH significantly affected the solid phase distribution of all three elements on site. Additionally, elements competing for binding sites, Ca, Mg and Mn in the case of Cu, and P, in the case of As, played a major role in the distribution of these elements in soil. Element-specific distributions were observed amongst the six identified soil phases including residual pore salts, exchangeable, carbonates (tentative designation), Mn-Al oxide, amorphous Fe oxide, and crystalline Fe oxide. While Cr was strongly bound to non-extractable crystalline Fe oxide in the oxic top soil, Cu and notably, As were associated with readily extractable phases, suggesting that Cu and As, and not Cr, constitute the highest risk to environmental and human health. However, bioavailable Cu did not significantly correlate with CISED identified soil phases, suggesting that sequential extraction schemes such as CISED may not be ideally suited for inferring bioavailability to microorganisms in soil and supports the integration of receptor-specific bioavailability tests into risk assessments as a complement to chemical methods.
在丹麦弗雷登斯堡的一个前木材浸渍现场，研究了影响铬 (Cr)、铜 (Cu) 和砷 (As) 分布、行为和形态的物理化学因素。采集了 40 个土壤样本，使用一种称为化学计量学识别底物和元素分布 (CISED) 的顺序提取技术进行提取，并应用了一种多变量统计工具（冗余分析）。将 CISED 数据与水可提取的 Cr、Cu 和 As 以及通过全细胞细菌生物传感器测定的可利用的 Cu 相关联。结果表明，土壤 pH 值显著影响了现场所有三种元素的固相分布。此外，与 Cu 竞争结合位点的元素（Ca、Mg 和 Mn）和与 As 竞争结合位点的元素（P）在这些元素在土壤中的分布中起主要作用。在确定的六个土壤相中观察到元素特异性分布，包括残留孔隙盐、可交换、碳酸盐（暂定）、Mn-Al 氧化物、无定形铁氧化物和结晶铁氧化物。虽然 Cr 强烈结合于氧化层中不可提取的结晶铁氧化物，但 Cu 尤其是 As 与可提取的相有关，这表明 Cu 和 As 而不是 Cr 对环境和人类健康构成最高风险。然而，可利用的 Cu 与 CISED 确定的土壤相没有显著相关性，这表明顺序提取方案（如 CISED）可能不适合推断土壤中微生物的生物利用度，并支持将受体特异性生物利用度测试整合到风险评估中，作为化学方法的补充。
