【摘要】 粉煤灰经工厂废气排放进入大气,对人类健康和生态系统都造成了无法弥补的破坏.本文选取具有高空间分辨率优势的树叶作为收集粉煤灰的载体,对临汾市大气中可吸入颗粒物进行磁学参数和重金属含量监测.结果表明,磁化率最大值出现在工厂污染源附近,磁化率空间分布呈现随污染源距离增加而降低的趋势.工业区收集到的磁性颗粒以低矫顽力、粗粒度的磁铁矿为主.夏季磁性矿物来源单一,主要为人为影响.冬季大气中悬浮的磁性颗粒有部分来自于西北风/北风的自然尘降.同一采样点磁化率随时间变化特征表明,树叶的磁学性质可以灵敏和有效地反映较短时期内大气污染的现状.统计分析表明磁化率和重金属元素(铁,铬,镍,铜,铅,钴)之间存在显著相关性.污染负荷指数用于评估研究区域内重金属各元素综合污染的程度.结果显示,在废弃的旧工业区附近无大气污染指示,但在运营中的工厂集中的地区,大气均受到严重污染.污染负荷指数与表征磁性矿物含量的磁化率呈相关性(r2=0.66),因此树叶的磁性参数可以作为大气重金属污染的替代指标.更多还原

【Abstract】 Fly ash from industry makes irreparable destruction to human health and ecological system.Here,we applied tree leaves with a high spatial resolution of fly ash receivers to investigate air quality in Linfen city,northern China.The spatial distribution of magnetic susceptibility(MS)indicates that values decrease with their distance from the source ofcontamination.Magnetic particles around industrial areas are mainly low-coercivity magnetite,occurring in a larger grain-size range.In summer,magnetic particles all directly from anthropogenic emission,however in winter,magnetic particles are mainly from industrial discharge but few of them also from strong natural wind deposition.Temporal variation of MS shows leaf samples are sensitive and efficient to reflect the current state of atmospheric pollution.Strong correlation is obtained between MS and heavy metal(HM)contents(Fe,Cr,Ni,Cu,Pb,Co)by statistical analysis.Pollution load index(PLI)is used to evaluate the degree of contamination.The results showing that there is no air pollution risk in abandoned industrial area while in enterprise concentrated areas,there are heavily polluted.The PLI also shows correlation with MS(r2=0.66),which means magnetic properties of tree leaves can be seen as an indicator of atmospheric pollution of heavy metals.更多还原