Numerical study of the oxidation process of dimethylsulfide in the marine atmosphere   总被引：1，自引：0，他引：1  

Seizi Koga  Hiroshi Tanaka 《Journal of Atmospheric Chemistry》1993,17(3):201-228

A box model, involving simple heterogeneous reaction processes associated with the production of non-sea-salt sulfate (nss-SO ₄ ^2– ) particles, is used to investigate the oxidation processes of dimethylsulfide (DMS or CH₃SCH₃) in the marine atmosphere. The model is applied to chemical reactions in the atmospheric surface mixing layer, at intervals of 15 degrees latitude between 60° N and 60° S. Given that the addition reaction of the hydroxyl radical (OH) to the sulfur atom in the DMS molecule is faster at lower temperature than at higher temperature and that it is the predominant pathway for the production of methanesulfonic acid (MSA or CH₃SO₃H), the results can well explain both the increasing tendency of the molar ratio of MSA to nss-SO ₄ ^2– toward higher latitudes and the uniform distribution with latitude of sulfur dioxide (SO₂). The predicted production rate of MSA increases with increasing latitude due to the elevated rate constant of the addition reaction at lower temperature. Since latitudinal distributions of OH concentration and DMS reaction rate with OH are opposite, a uniform production rate of SO₂ is realized over the globe. The primary sink of DMS in unpolluted air is caused by the reaction with OH. Reaction of DMS with the nitrate radical (NO₃) also reduces DMS concentration but it is less important compared with that of OH. Concentrations of SO₂, MSA, and nss-SO ₄ ^2– are almost independent of NO _x concentration and radiation field. If dimethylsulfoxide (DMSO or CH₃S(O)CH₃) is produced by the addition reaction and further converted to sulfuric acid (H₂SO₄) in an aqueous solution of cloud droplets, the oxidation process of DMSO might be important for the production of aerosol particles containing nss-SO ₄ ^2– at high latitudes.  相似文献   

The biogeochemical sulfur cycle in the marine boundary layer over the Northeast Pacific Ocean   总被引：1，自引：0，他引：1  

T. S. Bates  J. E. Johnson  P. K. Quinn  P. D. Goldan  W. C. Kuster  D. C. Covert  C. J. Hahn 《Journal of Atmospheric Chemistry》1990,10(1):59-81

The major components of the marine boundary layer biogeochemical sulfur cycle were measured simultaneously onshore and off the coast of Washington State, U.S.A. during May 1987. Seawater dimethylsulfide (DMS) concentrations on the continental shelf were strongly influenced by coastal upwelling. Concentration further offshore were typical of summer values (2.2 nmol/L) at this latitude. Although seawater DMS concentrations were high on the biologically productive continental shelf (2–12 nmol/L), this region had no measurable effect on atmospheric DMS concentrations. Atmospheric DMS concentrations (0.1–12 nmol/m³), however, were extremely dependent upon wind speed and boundary layer height. Although there appeared to be an appreciable input of non-sea-salt sulfate to the marine boundary layer from the free troposphere, the local flux of DMS from the ocean to the atmosphere was sufficient to balance the remainder of the sulfur budget.  相似文献   

On the scavenging of SO2 by cloud and rain drops: IV. A wind tunnel and theoretical study of the absorption of SO2 in the ppb(v) range by water drops in the presence of H2O2     

A. Waltrop  S. K. Mitra  A. I. Flossmann  H. R. Pruppacher 《Journal of Atmospheric Chemistry》1991,12(1):1-17

An experimental study involving the Mainz vertical wind tunnel is described where the rate of SO₂ removed from the air by freely suspended water drops was measured for SO₂ concentrations in the gas phase ranging between 50 and 500 ppb, and for various H₂O₂ concentrations in the liquid phase. In a first set of experiments, the pH inside the SO₂ absorbing drops was monitored by means of colour pH indicators added to the drops. In a second set of experiments, the amount of SO₂ scavenged by the drops was determined as sulfate by an ionchromatograph after the drops had been removed from the vertical air stream of the wind tunnel after various times of exposure to SO₂. The results of our experimental study were compared with the theoretical gas diffusion model of Walcek and Pruppacher which was reformulated for the case of SO₂ concentrations in the ppbv(v) range for which the main resistance to diffusion lies in the gas phase surrounding the drop. Excellent agreement between experiment and theory was obtained. Encouraged by this agreement, the theory was used to investigate the rate of sulfate production inside a drop as a function of pH. The sulfate production rate, which includes transport and oxidation, was compared with the production rate based on bulk equilibrium, as cited in the literature.  相似文献   

The effect of gas-phase chemistry on aqueous-phase sulfur dioxide oxidation rates     

William R. Stockwell 《Journal of Atmospheric Chemistry》1994,19(3):317-329

The rates and mechanisms of both gas and liquid phase reactions for the oxidation of sulfur dioxide play an important role in the production of atmospheric acids and aerosol particles. Rhodeet al. (1981) concluded that sulfate production rates were highly non-linear functions of sulfur dioxide emission rates. Their modelling study used an HO _x termination mechanism for the HO—SO₂ reaction in the gas-phase. Stockwell and Calvert (1983) determined that one of the products of the overall reaction of HO with sulfur dioxide was an HO₂ radical. The National Research Council (1983) using a version of the Rhodeet al. (1981) model modified to include HO₂ production from the HO—SO₂ reaction concluded that sulfate production becomes much more linear with respect to reductions in sulfur dioxide emissions. However, the cause of this increased linearity was not explained by the National Research Council report. It is demonstrated that the increased linearity is due to the coupling of gas-phases and aqueous phase chemistry. The gas-phase sulfur dioxide oxidation mechanism has a very significant effect on hydrogen perodide production rates.  相似文献   

氢化物发生-原子荧光光谱法则定锑精矿中的微量砷     

韦山桃  卢启余 《矿产与地质》2007,21(4):482-486

使用氢化物发生—原子荧光光谱法测定锑精矿中的微量砷在国内外报道较少。文章在锑干扰状况试验、高锰酸钾溶液消除干扰的最佳条件选择试验、锑精矿中共存元素的干扰和消除试验的基础上,对样品进行了实测,并就其灵敏度、准确度和精密度进行了讨论。研究表明,该方法是测定锑精矿中微量砷的有效方法。  相似文献   

古交矿区主要可采煤层煤中硫的赋存规律     

张正喜 《中国煤田地质》2002,14(4):15-16,66

应用扫描电镜对煤中不同显微组分中有机硫进行了测定。应用XPS方法测定了8号煤中有机硫的存在形态，评述了煤中硫的变化规律。论述了古交矿区主要可采煤层中黄铁矿硫的形态特征和分布规律。  相似文献   

燃煤烟气中SO2治理方法综述   总被引：2，自引：0，他引：2  

余江  陈攀江  龙炳清  宋薇薇  赵仕林 《地质灾害与环境保护》2001,12(2):45-48

对燃煤烟气中SO2的脱除方法进行综述和分析。  相似文献   

西范坪铜矿成矿作用初步研究——兼论还原硫对斑岩铜矿成矿的制约   总被引：1，自引：1，他引：1  

王奖臻  胡瑞忠  李泽琴  孙燕 《矿物岩石地球化学通报》2001,20(3):183-186

对西范坪斑岩铜矿的蚀变作用、流体包裹体特征等进行了研究,指出该矿床是由两期岩浆流体叠加作用所形成的.第一期热液作用形成了磁铁矿化和黑云母化,并形成了无矿石英脉;第二期热液形成了阳起石化;早晚两期热液的混合引起了钾长石化及强烈的矿化.由于第二期流体的叠加,将还原硫(H2S)带到浅部,并与第一期富铜的高盐度流体相混合,从而形成铜硫化物的沉淀.第二期富含还原硫流体的加入,是西范坪斑岩铜矿床形成的重要控制因素之一.  相似文献   

高峰100号矿体硫、铅同位素特征   总被引：1，自引：0，他引：1  

李蘅 《矿物岩石地球化学通报》2001,20(4):334-336

10 0号矿体的成矿物理化学环境为 :成矿温度 30 0± 30℃ ;成矿压力为 84.2× 10 5Pa ;LogfO2 =- 30 .4～- 35 .6 ,LogfCO2 =- 2 .5 5～ +0 .36 ,LogfS2 =- 8.3～ - 11.0 ,pH =4.2～ 4.9。同位素的分析结果 :硫化物的硫同位素为 6 4‰～ 12 .3‰ ,δ3 4 SΣS 值为 6 6～ 13 8;2 0 6Pb 2 0 4Pb值为 17 4 91～ 18 96 0 ,2 0 7Pb 2 0 4Pb值为 15 5 39～15 940 ,2 0 8Pb 2 0 4Pb值为 37 95 7～ 39 4 90。表明 10 0号矿体的硫源是混合硫 ,铅源是两种异常铅混合的结果。  相似文献   

布雅煤矿一井田煤中硫的特征及脱硫方法     

徐进  敬益武 《煤田地质与勘探》2001,29(5):14-16

从宏观、微观和煤化学几个方面 ,研究了新疆和田县布雅煤矿一号井田主采煤层中硫的赋存形态、含量、变化规律及成因。并提出几种脱硫方法 ,对煤矿生产出质量好的洁净煤 ,有一定的参考价值  相似文献