Abstract:

Atmospheric dust precipitates are one of the most common mass exchanges between earth and atmosphere. Due to its easy settlement, the dust precipitates carrying pollutants cause contamination in the area near the pollution sources. They can also be distributed at distant places by the strong wind. The characteristics and levels of the pollution strongly depend on the sources of dusts. Accurate control of artificial emission sources is essential to reduce dust pollution. The local industrial structure and layout affect the type, number and distribution of dust sources. Therefore, the correlation analysis between the industrial sources and pollutants on dust particles could reveal the causes of local dust, and provide theoretical and practical advice for accurate control of the dust pollution and improve the air quality. This research focused on the dust pollution of a typical heavy industry area in Jinan, Shandong. Two sampling sites (1# and 2#) were set up in the industrial area, while one sampling site (3#) in non-industrial area and one sampling site (4#) in remote control area were used for comparison. All the dust samples were collected in spring and analyzed for the dust flux, concentrations of water-soluble ions (SO₄^2-, Ca²⁺, etc.) and metal elements (Fe, Hg, As, etc.). The correlation between the concentrations of elements and ions and the industrial characteristics were also determined. The dust flux in the industrial area was 20.6% and 12.6% higher than that in non-industrial and control areas, respectively. It could mainly be caused by the large number of steels, coking, building material factories and coal-fired boilers. The metal elements also implied the environmental impact of the steel enterprises: The concentrations of Fe, Mn and Hg in the industrial area were 47.2 mg∙g^-1, 0.791 mg∙g^-1 and 0.415 μg∙g^-1, respectively, which were 2.05, 1.35 and 1.14 times of that in non-industrial area, respectively. The results could be attributed to the combined influence of mercury discharged from coal-fired factories and cement factories. The amount of SO₄^2- on dust was 3.5 times of that at the non-industrial site, owning to the large number of coal-fired boilers in the industrial area. This study provides theoretical support for accurate control of dust pollution.

Key words: heavy industry area, dust, pollution characteristics, industrial structure, source analysis

摘要：

大气降尘是地球表层地气系统物质交换的常见形式,因其容易沉降,所载带的污染物极易造成近源污染,当风速较大时也能造成远源污染,其污染特征、危害水平与降尘的来源密切相关。精准控制人为排放源是减轻区域降尘污染的关键,而区域的产业结构与布局特点决定了尘源企业的类型、数量与分布,因此将降尘污染特点与区域产业特性进行关联分析,探究降尘污染的成因,对控制区域的颗粒物污染,改善空气环境质量,具有一定理论和实践意义。以位于济南市的一典型重工业区为研究区域,采用布点采样监测对比研究方法,在典型重工业区设置2个采样点（1#和2#）,在非工业区和清洁对照区各设置1个采样点（3#和4#）,采集春季降尘样品并进行降尘通量以及尘载SO₄^2-、Ca²⁺等8种水溶性离子和Fe、Mn等20种元素的测定,并将降尘载带的元素与离子的质量分数与产业特点进行关联分析。结果表明,典型重工业区的春季降尘通量分别高出济南市平均水平和非工业区20.6%和12.6%,主要是钢铁、焦化、建材等尘源企业和燃煤锅炉数量多且分布较集中所致;重工业区降尘载带的金属元素反映出钢铁企业集聚分布的环境效应,主要体现在Fe和Mn明显高于非工业区,二者的平均质量分数分别为47.2 mg∙g^-1和0.791 mg∙g^-1,分别为济南市区（3#）的2.05倍和1.35倍;重工业区降尘中Hg明显偏高,平均含量为0.415 μg∙g^-1,为济南市区点位的1.14倍,从产业特点分析得出这主要是受到燃煤Hg和水泥Hg的叠加影响;重工业区降尘中的SO₄^2-质量分数为非工业区的3.5倍,明显偏高的主要原因是区域内燃煤锅炉数量大且分布集中。

关键词: 重工业区, 降尘, 污染特征, 产业结构, 成因分析