School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China.
Environ Sci Pollut Res Int. 2019 Jan;26(3):2794-2805. doi: 10.1007/s11356-018-3836-7. Epub 2018 Nov 28.
Variability of background concentration of toxic trace metal(loid)s in sediments can often lead to under/over-report of contamination level, even in detailed scale. In this study, both surface (5-10 cm) and subsurface (> 10 cm) sediments were collected at many sites in a small lake (0.528 km) with multi-function (irrigation, aquaculture, and watercourse) in an industrial area. Total concentration of trace metal(loid)s (Cd, Cr, Co, Cu, Ni, Sb, Pb, and Zn) and potential reference elements (Ti, Zr, Rb, and Li) were analyzed. The results showed that although the trace metal(loid)s were mainly lithogenic in subsurface sediments, the variability of baseline concentration was significant. For Sb, this variability was a result of alteration in hydrological parameters as well as sediment properties including Fe/Mn oxide contents, particle size distribution, and organic matter contents. Comparison of the normalized Sb concentration in samples from two sediment cores indicated that Ti is the best reference element for normalizing Sb to reduce the impact from particle size and natural source. Enrichment assessment using modified EFs (Ti as reference element) and I index (measured baseline concentration) suggested that about 70% of the surface sediments were at least moderately polluted by Sb in the lake, as a result of recent anthropogenic input, mainly from nearby industries, e.g., concrete factory and textile factory. Modified EFs should be used, instead of I index, when Sb enrichment was relatively low in sediment. The anomalies of Sb background concentration may need regulator attention when assessing the level of sediment contamination.
背景中有毒痕量金属（类金属）浓度的变异性往往会导致污染水平的低估/高估，即使是在详细的尺度上。在这项研究中，在一个具有多功能（灌溉、水产养殖和水道）的工业区的一个小湖（0.528 平方公里）中，在许多地点采集了表层（5-10 厘米）和次表层（>10 厘米）沉积物。分析了痕量金属（类金属）（Cd、Cr、Co、Cu、Ni、Sb、Pb 和 Zn）和潜在参考元素（Ti、Zr、Rb 和 Li）的总浓度。结果表明，尽管痕量金属（类金属）在次表层沉积物中主要来源于岩石，但背景浓度的变异性非常显著。对于 Sb，这种变异性是由于水文参数以及沉积物特性的变化造成的，包括 Fe/Mn 氧化物含量、粒度分布和有机质含量。对两个沉积物岩芯中 Sb 浓度的归一化比较表明，Ti 是 Sb 归一化的最佳参比元素，可以减少粒径和自然源的影响。利用改进的 EF（Ti 作为参比元素）和 I 指数（实测基线浓度）进行的富集评估表明，由于最近的人为输入，主要来自附近的工业，如混凝土厂和纺织厂，湖中约 70%的表层沉积物至少受到 Sb 的中度污染。当 Sb 在沉积物中的富集程度较低时，应使用改进的 EF，而不是 I 指数。Sb 背景浓度的异常可能需要监管机构在评估沉积物污染水平时加以关注。
