东南沿海典型港口城市大气降水中的重金属

Heavy Metals in Atmospheric Precipitation from a Typical Seaport in Southern China

为研究中国东南沿海港口城市大气降水中重金属的污染特征及其与p H、电导率、降雨量、PM2.5及PM10等因子之间的相互关系,于2013年3月-2014年2月期间,在厦门市城区和郊区共布置4个降水采样点及1个地表水采样点。用ICP-MS分析其中的溶解态重金属含量,同时获取其他相关因子的监测数据。研究表明厦门地区降水中的重金属含量水平总体较低,呈现出春秋季较高,夏冬两季较低;郊区点位较高,城区点位较低的时空分布特征。降水中的Zn、Cd、Pb、Cu等元素的浓度高于地表水中相应重金属的浓度。降水中大部分重金属浓度与p H有负相关、与电导率有正相关的关系,降雨量则有一定的稀释作用。PM2.5和PM10与降水中大部分重金属的浓度明显正相关,大气颗粒物浓度的增加会造成降水中大部分重金属浓度的增加。富集因子研究发现降水中的Cr、Ni较少受到人类活动的影响,Mn、Ba受到了一定程度人类活动的影响。Cu、Zn、As、Cd、Pb这几种元素受到了人类活动的严重污染,应该是下一阶段深入研究和污染控制的主要对象。

To investigate the chemical characteristics of the heavy metals in atmospheric precipitation and its relationship between the factors about p H,EC,rainfall,PM2.5 and PM10,from a typical seaport in southern China, four precipitation sites and one surface water site on the urban area and rural area of Xiamen city were set,and sampled from March 2013 to February 2014. Using the ICP-MS to determined the heavy metals,and the monitoring data about the other factors were also obtained. The results expressed that the concentrations of the heavy metals in atmospheric precipitation in Xiamen was comparatively low as a whole. The concentrations were higher in spring and autumn than in summer and winter,and higher in rural area than in urban area. The concentrations of the heavy metals such as Zn,Cd,Pb,Cu were higher in precipitation than in surface water. Correlation analysis showed that the concentrations of mostly heavy metals in precipitation had a negative correlation with p H,and a positive correlation with EC,and the rainfall can dilute the concentrations to a certain extent. PM2.5 and PM10 had a strong positive correlation with the concentrations of mostly heavy metals in precipitation. The concentrations of atmospheric particulates can increase the concentrations of heavy metals in precipitation. Enrichment factors study indicated that the metals Cr and Ni had low influence from anthropogenic source,the metals Mn and Ba were influenced by anthropogenic source to a certain extent. And the metals Cu,Zn,As,Cd and Pb were deeply influenced by the anthropogenic source, which should be the important object for further study and pollution control.