陕西西部某工业园区采暖期大气降尘重金属特征

为了解陕西省某工业园区采暖期大气降尘重金属元素特征,于2012年11月20日至2013年3月20日,通过被动采样的方式,采集该区域采暖期的大气降尘样品,利用火焰原子吸收分光光度法测定其中重金属元素Cu、Pb、Zn、Cd、Ni、Cr和Fe的含量,并分别计算各元素采暖期的日沉降通量和富集因子.结果表明:研究区采暖期大气降尘量普遍较高,并且受园区人为污染源和道路扬尘影响明显;大气降尘中重金属含量分布不均,位于园区内部点位的重金属含量明显大于上风向点位和对照点;各元素之间也有很大的差异,其中,Fe的含量远高于其他6种元素,Pb、Zn含量次之,Cu、Cd、Ni、Cr的含量较小;从采暖期日沉降通量来看,Fe、Zn、Pb的沉降通量较大,Cu、Cr、Ni、Cd的沉降通量较小.而根据富集因子分析结果可知,Zn、Pb、Cu、Cd主要来自人为源,Fe、Cr、Ni与当地的自然地质背景有关.

Characteristics of heavy metals in atmospheric deposition in heating periods of an industrial park in western Shaanxi Province, China

In order to understand the characteristics of atmospheric heavy metal deposition in the heating periods in the industrial park in Shaanxi Province, the atmospheric dusts samples were collected in the heating periods from November 2012 to March 2013 (about 121 days). The contents of heavy metals including copper, lead, zinc, cadmium, nickel, chromium and iron in the atmospheric dust samples were determined by Flame Atomic Absorption Spectrophotometry, and both the daily deposition flux and the enrichment factors of heavy metals were calculated. It can be drawn from the results that the atmospheric dust flux is very high in the heating periods in the study area, and it is obviously impacted by the anthropogenic pollution sources and road dust. The heavy metal contents in the atmospheric dusts vary with the sampling locations. The heavy metal contents in the dust sample collected in the industrial park are much higher than those sampled upwind from the industrial park or at the reference points. The contents of different kinds of heavy metals in the atmospheric dusts samples are different. The content of iron in the samples is the highest, followed by lead and zinc, while the contents of copper, cadmium, nickel and chromium are much lower. The deposition fluxes of iron, zinc and lead are higher compared to those of copper, cadmium, nickel and chromium based on the daily deposition flux result in the heating periods. According to the enrichment factors, anthropogenic sources mainly contribute to the contents of heavy metals including zinc, lead, copper and cadmium, while the natural geological background has an evident impact on the contents of iron, chromium and nickel.