The Chemical Characteristics Study Of Heavy Metal In Atmospheric Particulates Based On The Chemical Analysis

The air in urban, an important part of the urban environment, has been stronglydisturbed by frequent transportation, the compact industrial production and humanactivities. And heavy metal, one of the main harmful components in atmosphericparticulates, has the effect of chronic poisoning, bringing about human body to cancer,the deformity and mutations. Because those are closely related to human health, theresearch about that at home and abroad are paid the great attention, and also becomesthe focus of research at home and abroad. Heavy metal in atmospheric particulatesmainly comes from the natural energy of burning use, car tail gas, and industrial dustemissions. Regarding East ring road of mutual interchange road in Xi’an as anobservation, this study will collect TSP, PM₁₀as the research object, and analyze theheating period and the non-heating season TSP, PM₁₀and pollution characteristicscontained in the heavy metal, the form of occurrence, and the mass density of heavymetals in different particle size and distribution of form, and explore biologicalvalidity that environmental impact of heavy metals in the different particle size ofatmospheric particulates produces. That provides theoretical basis and data support forthe management of environment.The heating period with the non-heating season TSP pollution characteristicsshow that the overall trend expression for TSP pollution is that the extent of theheating period pollution is greater than that of the non-heating season. The heatingperiod TSP pollution features as samples of spring is higher than that in fall samples,and the average monthly mass concentration is more than national secondary standard（0.3mg/m³）, of which spring sample is more than national level3standard （0.5mg/m³）, indicating that dust has a certain contribution rate to TSP. The heating period TSPpollution characters are progressive decrease, and the average monthly massconcentration is more than second secondary standard in national second grade district（0.3mg/m³） and some is more than three standard in national second grade district（0.5mg/m³）. Energy of burning has a dominant to the contribution of the heatingperiod TSP.Through analysis of the content of five kind heavy metal in the TSP, it is foundthat the content of five kind heavy metal in the TSP exist differences and overallsituation is that the heating period is higher than the non-heating season. In theheating period, Cu, Pb, Cd and Ni are mainly distributed in the carbonate combinationstate, and the advantage of Zn focuses on the exchange state. In the heating period, Cuand Ni mainly are distributed in exists in ferric-manganese oxidation state, and Pb thatis same in the non-heating season, mainly exists in carbonate combination state, andCd exists mainly as a form of scraps state. In the non-heating season, the averagecontent Cu, Pb, Zn, Cd and Ni respectively decreased by13.31%,15.35%,23.99%,3.06%and8.22%compared with in the heating period.The overall pollution tendency of PM₁₀is same as that of TSP. It is alsoconsidered that pollution extent of the heating period is greater than that of thenon-heating season, and the pollution characters of PM₁₀in the two sampling periodemerge same undulatory property.In the sampling period the mass concentration ofPM₁₀is not exceed the second secondary standard in national second gradedistrict（0.15mg/m³）.The heating period a PM₁₀pollution character is volatility and more than thenational secondary standard （0.1mg/m³） except in December2010. The non-heatingseasons PM₁₀pollutioncharacters also present some volatility and don’t exceed bid inrest months except in November2010flating to the second secondary standard innational second grade district.The content analysis of five kind heavy metals in PM₁₀shows that the overallsituation is that the level of five kind heavy metals in the heating period PM₁₀ishigher than in the heating period. In the non-heating season, the average content of Cu, Pb, Zn, Cd, and Ni was down by16.12%,51.00%,8.18%,6.44%and38.46%compared with in heating period. During the period of the non-heating season, Cu, Pb,Zn, Cd in PM₁₀are mainly distributed in the states of scraps, and Ni is mainlydistributed in the organic combination state. In the heating period, Cu in mainlydistributed in the organic combination state, and Pb, Zn, Cd and Ni exist mainly inscraps state.The analysis of biological effectiveness of heavy metal in atmosphericparticulates shows that biological effectiveness in all kinds of the heavy metal elementin TSP is greater than the biological effectiveness of the heavy metal element in PM₁₀.The characteristics of biological effectiveness in each of the heavy metal element inTSP are: Pb> Cu> Cd> Ni> Zn; the characteristics of biological effectiveness ineach of the heavy metal element in PM₁₀are: Pb> Cd> Zn> Ni> Cu.Through analysis to the share rate of PM₁₀and TSP, it shows that the share ratemainly concentrated in0.1-0.2and the share rate of the heating period is significantlyhigher than in the non-heating season; the share of rate in the spring of2011is higherthan that in the fall of2010. That is caused by the influence of the weather full ofsandy and wind in observation point in the spring weather. Five metals in TSP andPM₁₀have good statistics of correlation, which indicates that the change rules ofheavy metals in TSP and PM₁₀in environment air pollution are similar and mayfollow the same rules of movement and transformation and the same source.In the relationship analysis of distribution of concentration of elements andparticle size, it is found that distribution of mass density of Cu, Pb, Zn, Cd, Ni fivekinds of heavy metal decreases as particle size distribution quality increases. Thatshows that the metal elements in PM₁₀relatively richer than in TSP.