| As a result of rapid economic growth and energy demand, air pollution in Shanghai is a complex of oil pollution and coal-burning pollution. In recent years, atmospheric particulate matter has become an important part of air pollution in Shanghai. Bromine and iodine are trace elements in the atmosphere, as the atmosphere of active halogen, to participate in the many environmental pollutants in atmospheric chemical reactions. So trace elements Br, I in atmospheric aerosol catch scholars'attention.During the study period from February 2008 to January 2009, we collected 24 TSP samples, 24 PM10 samples and some Parts of the source of atmospheric dust particles. Based on the laboratory analyzing and statistic illustration, this work has studied the seasonal variations of trace elements Br, I and the soluble Br, I in those aerosols, including the factors affecting their distribution, as well as major weather factors, with emphasis on the elements Br, I. In this paper, the following aspects of work carried out:(1) Using high pressure and closed microwave digestion technology, atmospheric aerosol samples were digested quickly with mixed acids of nitric acid, hydrofluoric acid, and hydrogen peroxide solution, with the help of Inductively Coupled Plasma Mass Spectrometer (ICP-MS), a method was established for simultaneous determination of trace elements bromine (Br) and iodine (I) in atmospheric aerosol samples. The low detection limits were in the range of 0.1–5.0 ng/ml with relative standard deviations of 1.5%–12.0%, and the recoveries were in the range of 80%–130%. The analysis results were satisfactory.(2) Seasonal variations of bromine and iodine in particulate matter all showed a summer minium and a winter/autumn maximum. The water-soluble Br, I and the acid–soluble Br, I concentrations exhibited a similar variation.(3) The correlation analysis showed that no obvious correlation between bromine and iodine in TSP, but a significant positive correlation between the concentration of bromine and iodine in PM10. That suggested that bromine, iodine in Shanghai fine atmospheric particulate matter were from marine sources. The concentration of gross iodine positively correlated with the concentration of SO2 and NOX. The negative correlation between Br/I ratio in aerosols and the air quality illuminated that the ratio affected by local man-made pollution so that it could reflected local environmental quality to some extent.(4) Water-soluble and acid-soluble bromine, iodine in the particulate matter have shown the tendency to enrich in fine particle. The magnification of acid-soluble bromine, iodine was lager than the coefficient of water-soluble bromine, iodine and the elements bromine, iodine. By acid extraction, bromine, iodine in particulate matter dissolved in a sharp increase, especially for the fine particulate matter. When the acidity increases, bromine, iodine concentration in the water environment will bring the potential harm.(5) Analysis of meteorological factors showed that the concentration of bromine, iodine in particles in the wind flow to the shore were lower than that in the offshore flow. Correlation analysis results showed that the main meteorological impact factors in the bromine of particulate matter was atmospheric pressure, while major factors in iodine were atmospheric pressure, relative humidity and temperature. In addition, the correlation analysis results showed that relative humidity was not the main meteorological factor for the water-soluble and acid-soluble bromine, iodine. |
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