School of Engineering/Environmental Sciences, University of Applied Sciences Upper Austria, Stelzhamerstraße 23, A-4600 Wels, Austria.
Environ Pollut. 2018 Aug;239:522-531. doi: 10.1016/j.envpol.2018.04.063. Epub 2018 Apr 21.
The concentration of heavy metals in urban road-deposited sediments (RDS) can be used as an indicator for environmental pollution. Thus, their occurrence has been studied in whole road dust samples as well as in size fractions obtained by sieving. Because of the limitations of size separation by sieving little information is available about heavy metal concentrations in the road dust size fractions <20 μm. In this study air classification was applied for separation of dust size fractions smaller than 20 μm from RDS collected at different times during the year. The results showed only small seasonal variations in the heavy metals concentrations and size distribution. According to the Geoaccumulation Index the pollution of the road dust samples deceased in the following order: Sb » As > Cu ≈ Zn > Cr > Cd ≈ Pb ≈ Mn > Ni > Co ≈ V. For all heavy metals the concentration was higher in the fine size fractions compared to the coarse size fractions, while the concentration of Sr was size-independent. The enrichment of the heavy metals in the finest size fraction compared to the whole RDS <200 μm was up to 4.5-fold. The size dependence of the concentration decreased in the following order: Co ≈ Cd > Sb > (Cu) ≈ Zn ≈ Pb > As ≈ V » Mn. The approximation of the size dependence of the concentration as a function of the particle size by power functions worked very well. The correlation between particle size and concentration was high for all heavy metals. The increased heavy metals concentrations in the finest size fractions should be considered in the evaluation of the contribution of road dust re-suspension to the heavy metal contamination of atmospheric dust. Thereby, power functions can be used to describe the size dependence of the concentration.
城市道路沉积物（RDS）中重金属的浓度可用作环境污染的指标。因此，已经对整个道路灰尘样本以及通过筛分获得的大小分数进行了研究。由于筛分的尺寸分离有限，因此有关道路灰尘<20μm 大小分数中重金属浓度的信息很少。在这项研究中，空气分类法用于从一年中不同时间收集的 RDS 中分离小于 20μm 的灰尘大小分数。结果表明，重金属浓度和大小分布的季节性变化很小。根据地质累积指数，道路灰尘样本的污染程度按以下顺序递减：Sb>As>Cu≈Zn>Cr>Cd≈Pb≈Mn>Ni>Co≈V。对于所有重金属，细颗粒分数中的浓度均高于粗颗粒分数，而 Sr 的浓度与粒径无关。与整个 RDS <200μm 相比，最细颗粒分数中重金属的富集高达 4.5 倍。浓度的粒径依赖性按以下顺序降低：Co≈Cd>Sb>（Cu）≈Zn≈Pb>As≈V>Mn。通过幂函数对浓度的粒径依赖性进行近似非常有效。所有重金属的粒径与浓度之间的相关性都很高。在最细颗粒分数中增加的重金属浓度应在评估道路灰尘再悬浮对大气灰尘重金属污染的贡献时加以考虑。在此，可以使用幂函数来描述浓度的粒径依赖性。
