珠江三角洲大气干沉降金属元素浓度和来源分析

本文对珠三角地区137个大气干沉降样品中金属元素含量和来源进行了分析。金属元素几何平均浓度高低依次为Fe>Zn>Mn>Pb>Cu>(Ni,Cr,Rb)>V>(Li,Y)>Co>(Cd,Cs)>Tl,其中Fe的浓度最高为31573mg/kg,Tl的浓度最低为1.0mg/kg,金属元素浓度主要与周边环境和当地发展类型影响有关,采样点位于工业区周边的金属元素浓度最高,城市居民区和近郊区次之,远离城市和工业地区的相对较低。富集因子分析表明Cd、Zn、Cu、Ni和Pb元素受人类活动影响显著,污染严重;相关性分析得出Cu、Pb、Zn具有显著性相关,Cr、Ni分别与Mn、Co、Li、Zn显著性相关,表明它们可能具有相同来源;因子分析得出Rb、Cs、Y、Mn、Ni、Li、Co主要受到土壤扬尘来源的影响,Pb、Cu、Cd及Ni、Cr与当地工业化和城市化过程密切相关,其中Pb元素主要受到燃煤和交通扬尘的污染,Cu和Cd元素主要来源于工业生产中产生的重金属污染。

Concentrations and Sources of Metal Elements of Dry Deposition in the Pearl River Delta, South China

The concentrations, spatial distribution and regional sources of metal elements (MEs) in 137 dry deposition samples were determined in this study. These samples were collected by passive sampling in ten locations in the Pearl River Delta (PRD), South China. The result showed that the geometric mean (GM) concentrations of MEs follow the order of Fe > Zn > Mn > Pb > Cu > (Ni, Cr, Rd) > V > (Li, Y) > Co > (Cd, Cs) > Tl, with the highest concentration of Fe (31573 mg/kg) and the lowest concentration of Tl (1.0 mg/kg). Different metals exhibit different spatial distributions and the concentrations of metals in dry deposition samples decrease from industrial areas to unban residential and suburban areas, and to rural area. As indicated by the enrichment factor analysis, Cd, Zn, Cu, Ni and Pb displayed large enrichments and thereby they have been significantly influenced by anthropogenical activities. Then, correlation analysis showed that Cu Pb and Zn are significantly positively correlated, and Cr and Ni are significantly correlated with Mn, Co, Li, and Zn. The strong correlations may suggest that they have similar source compositions. Principal factor analysis revealed that Rb, Cs, Y, Mn, Ni, Li and Co are mainly derived from soil particles, while Pb, Cu, Cd, Ni and Cr are polluted owing to rapid urban and industrial development, Pd is the trace metal from coal combustion and traffic emission, and Cu and Cd are mainly derived from industrial pollution sources.