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1.
The effect of sediment size on metals bioleaching from bay sediments was investigated by using fine (< 45 μm), medium (45-300 μm), and coarse (300-2000 μm) size fractions of a sediment sample contaminated with Cr, Cu, Pb, and Zn. Chemical speciation of the metals in bulk and size fractions of sediment were studied before and after bioleaching. Microbial activity was provided with mixed cultures of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans. The bioleaching process was carried out in flask experiments for 48 days, by using 5% (W/V) of solid concentration in suspension. Bioleaching was found to be efficient for the removal of selected heavy metals from every size fraction of sediments, where the experiments with the smaller particles resulted in the highest solubilization ratios. At the end of the experimental period, Cr, Cu, Pb and Zn were solubilized to the ratios of 68%, 88%, 72%, and 91% from the fine sediment, respectively. Higher removal efficiencies can be explained by the larger surface area provided by the smaller particles. The changes in the chemical forms of metals were determined and most of the metal releases were observed from the reducible and organic fractions independent from grain size. Higher concentrations were monitored in the residual fraction after bioleaching period, suggesting they are trapped in this fraction, and cannot be solubilized under natural conditions.  相似文献   

2.
Coarse (>2 μm) and fine (<2 μm) atmospheric particulate material was collected in the Zabadani Valley, near Damascus, in August 1985, and analyzed for sulfate, nitrate, and about 40 elements. Individual particles were analyzed for chemical and morphological parameters. Particle number concentrations and size distributions were also measured. The physical aerosol characteristics, and particularly the chemical composition indicate that the airborne particles in this arid region are predominantly due to desert soil dispersion, but that there is also some contribution from anthropogenic sources. The crustal elements exhibit atmospheric concentrations which are comparable to those in urban and industrial areas. The anthropogenic elements, on the other hand, are clearly less abundant in the Zabadani Valley than in industrialized regions. The individual particle analysis indicated that there are two major soil dust components with respectively a shale-like and a limestone composition. The data set with the bulk atmospheric concentrations (sum of coarse and fine) was subjected to chemical mass balance receptor modeling in order to assess the impact of the various plausible aerosol sources. It was found that desert soil dispersion is responsible for at least 90% of the total suspended particulate mass concentration, and that the shale and limestone components contribute in about equal proportions.  相似文献   

3.
Size distributions of aerosol particles in the radius range of 0.006–0.53 μm were measured over the Pacific Ocean along the 150° longitude from about 20°N to 55°S. Throughout the tropical trade wind region, the size distribution of fine particles was relatively stable and exhibited a double-peaked characteristic with one peak at about 0.1 μm and the other in the 0.02–0.04 μm region, separated by a minimum at about 0.06 μm. The total concentrations of particles were in the 150–300 cm−3 range with 60–150 cm−3 residing in the accumulation mode (0.06<r<0.5 μm). South of the trade wind region, the measured size distributions and meteorological conditions were more diverse. Periods with very low concentrations in the accumulation mode were associated with regions of large-scale precipitation. Large increases in the number of nucleation mode particles were found in air masses with low concentrations of particles in the accumulation mode.  相似文献   

4.
Between 15 January and 26 February 1987, 51 fine and coarse mode aerosol samples were collected at the Universidad de Santiago de Chile Planetarium using a dichotomous sampler. The samples were analyzed by X-ray fluorescence for up to 17 elements (Mg, Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb). Aerosol particles were individually studied by Electron Probe Microanalysis (EPMA) and Laser Microprobe Mass Analysis (LAMMA). The data set consisting of aerosol elemental concentrations and meteorological variables was subjected to Principal Factor Analysis (PFA), allowing the identification of six fine mode particle source classes (soil, industrial, sulfate particles, traffic, residual oil, wood-burnings), and five coarse mode particle source classes (soil, industrial, traffic, residual oil, sulfate particles). Both PFA solutions explained about 81 and 90% of the total variance in the data set, respectively. The regression of elemental mass concentrations on the Absolute Principal Factor Scores allowed the estimation of the contribution of the different source classes to the Santiago aerosol. Within the fine fraction, secondary SO42− particles were responsible for about 49% of the fine mode aerosol mass concentration, while 26, 13, 6.4 and 5.6% were attributed to wood-burning/car exhausts, residual oil combustion, soil dust/metallurgical, and soil dust/wood-burning releases, respectively. The coarse fraction source apportionment was mainly dominated by soil dust, accounting for 74% of the coarse mode aerosol mass concentration. A composite of soil dust and industrial release accounted for 13%; a composite of secondary sulfates contributed with 9%; a composite of soil dust and automotive emissions, and secondary sulfates were responsible for 4 and 0.03% of the coarse aerosol mass concentration, respectively. EPMA results are in satisfactory agreement with those from the bulk analysis and allowed the identification of eight particle types in both fine and coarse mode aerosols, pertaining to different source classes, namely soil, seaspray, secondary SO42−, metallurgical emissions and biomass burning release. EPMA also evidenced that one of the most abundant particle types corresponded to marine aerosol, having an average diameter of 0.7 μm for the fine mode and 2.2 μm for the coarse mode aerosol. LAMMA results indicate that, in fact, seaspray has been transported into the city of Santiago de Chile airshed, suffering several transformations and a sulfur enrichment. This analytical technique also provided evidence of the abundance of carbon-rich particles, which were not detected by either the bulk X-ray analysis or EPMA; they are probably due to fossil-fuel combustion releases.  相似文献   

5.
Size distribution data obtained during the U.S.S.R.-U.S. dust experiment make it possible to propose a general conception about the size distribution of dust aerosols within the size range 0.005–100 μm. The microstructure for the optically active fraction of arid aerosol is approximated in the form of a log-normal distribution with parameters D = 3.5−6 μm, δ2 = 0.5−0.8, which can be used when estimating radiative calculations.  相似文献   

6.
In a study to differentiate between municipal refuse incinerator particles and other particles in urban air, samples were collected on Teflon and nuclepore filters in dichotomous samplers and analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry. The samples included ambient aerosol from two sites in the Philadelphia area, representing different meteorological conditions. The same samples were previously analyzed by bulk techniques including X-ray fluorescence and instrumental neutron activation analysis.Particles emitted from incinerators rich in Zn, Cl and K were clearly identified in ambient samples, both in the coarse (2.5–10 μm) and fine aerosol fraction (<2.5 μm). The contribution of incinerators emission was from zero up to 10% of the coarse aerosol mass. Similar particles that contained also Zn and Cl were observed, but they did not originate in refuse incineration. Minerals and biologicals were the most dominant components of the coarse aerosol fraction; sulfates dominate the fine fraction. One of the case studies provided evidence for the missing chlorine in the fine fraction. Apparently fine chlorides emitted from incinerators reacted with ambient sulfates to form mixed sulfates of Zn and K. Good agreement was obtained between the measured coarse aerosol mass concentration and the one estimated by electron microscopy.  相似文献   

7.
The vertical distribution of background atmospheric aerosols was measured over south-central New Mexico as a part of the Atmospheric Lidar Verification Experiment (ALIVE) during four research field periods in the summers and winters of 1989 and 1990. Aerosol size distribution was measured from the surface up to 4500 m above sea level (asl) over the particle size range 0.1∼32 μm, using two Particle Measuring Systems (PMS) probes mounted on the wings of the NOAA King Air research aircraft. Vertical profiles of aerosol number concentrations of both fine- (0.1–2.0 μm) and coarse- (>2.0 μm) particle modes show seasonal differences, with higher number concentrations and higher mixed layer heights during summers. The measured aerosol size distribution data of each ALIVE intensive were averaged for boundary layer and free troposphere regions. These data mostly exhibit bi-modal distributions, typical for the continental atmospheric aerosols. Exceptions were the free troposphere size distributions measured during December 1989 (ALIVE III) and June 1990 (ALIVE IV), which resemble Junge's power-law distribution. Each of the averaged aerosol size distributions was approximated by the sum of log-normal distributions. Different characteristics of aerosol size distribution were observed between the two summer measurements of 1989 and 1990. Back-trajectory analysis revealed that decreased aerosol concentrations were observed during June 1990 when the air mass was transported from the southwestern U.S.A.  相似文献   

8.
The mass-particle size distributions of up to 17 trace elements in aerosol particle samples from dust storm and non-dust storm periods were determined for three sites in or near the source regions of Chinese dust. The mass of particulate material in the atmosphere at the sites is dominated by mineral aerosol particles. An absolute principal component analysis of the non-dust storm elemental data for the loess region allows the estimation of the mass contributions from two coarse-particle classes (soil dust and dust associated with pollutants), and two fine-particle classes (soil dust and anomalously enriched). For most elements (Al, Si, Ca, Fe, Ti, K, S and As), the mass-particle size distributions (MSDs) were approximately log-normal. The mass-median diameters (MMDs) of the soil-derived elements tended to decrease with distance from the desert region and when the dust storms subsided. Total dry deposition velocities were calculated by fitting a log-normal distribution to the aerosol data and calculating deposition rates for 100 particle-size intervals using a two-layer deposition model. The mean dry-deposition rates and fluxes were highest during dust storms over desert regions. In thloess region, the calculated dry deposition velocities of soil derived elements (Al, Si, Ca, Fe and Ti) during non-dust storm periods were from 3.1 to 3.7 cm s−1. From the estimated mass-particles size distributions, the coarser and finer mineral particles were found to benriched with Ca, Fe, Ti and K relative to Al or Si. On a yearly basis, the dry atmospheric input to the Loess Plateau was mainly attributable to normal transport processes, i.e. non-dust storm conditions. Wet deposition fluxes estimated from scavenging ratios indicate that dry deposition dominated the total atmospheric deposition of mineral aerosol. The deposition of aerosol particles associated with coal burning or other anthropogenic sources also was considerable on the Loess Plateau.  相似文献   

9.
Cigarette smoking is a particle-related exposure. Studying the characteristics of the particle size distribution of cigarette smoke can aid in providing knowledge of smoke aerosol attributes. We used an electrical low pressure impactor (ELPI) to measure the particle size distribution of mainstream cigarette smoke generated by a smoking machine and provided a continuum of particle sizes of cigarette smoke from a whole cigarette. The results showed that the aerodynamic diameters (D, geometric mean of a channel) of particles ranged from 0.021 to 1.956 ~m, and the number concentrations were on the order of 105-109 cm-3 for different sizes of particles. The particle number of the size category below 0.1 p,m approximated that of the category 0.1-2.0 Ixm, and the particles in the size category of 0.1-2.0 μm contributed extremely heavily to total particulate mass. In addition, the results with small samples indicated that the tar yields normalized per milligram of nicotine showed an approximately linear increase with increasing concentration of total particles.  相似文献   

10.
为更好地理解大气颗粒物中糖类的来源及其环境影响,利用微孔撞击式采样器(MOUDI)采集了上海市宝山区2012年11月—2013年8月四季节代表性时段18 μm以下11个不同粒径段的大气颗粒物样品,利用硅烷化衍生和GC-MS对10种脱水糖、单糖和糖醇类化合物进行了分析. 结果表明:上海大气颗粒物中所检测的10种糖类化合物的质量浓度之和在春、夏、秋、冬四季采样期的平均值分别为120.3、104.0、292.9和206.0 ng/m3,脱水糖在秋、冬季占主导地位,单糖和糖醇的质量浓度在冬季最低. 绝大部分脱水糖存在于粒径≤1.8 μm的颗粒中,冬、夏季质量浓度最高的粒径段(峰值粒径)为>0.32~0.56 μm,而春、秋季峰值粒径为>0.56~1.0 μm. 单糖和糖醇类化合物在春、夏季时主要存在于粒径>1.8 μm的颗粒中,而秋、冬季时在粒径≤1.8 μm的颗粒中质量浓度较高. 应用PMF(正定矩阵因子分析法)解析出了大气颗粒物中糖类的3个来源——生物质燃烧、植物源土壤有机质和微生物源土壤有机质. 脱水糖全部来源于生物质燃烧,单糖主要来源于植物源土壤有机质,而糖醇主要来源于微生物源土壤有机质;秋、冬季时生物质燃烧对山梨糖醇之外的单糖和糖醇有较大贡献.   相似文献   

11.
12.
Sulfate, nitrate and ammonium(SNA) are the dominant species in secondary inorganic aerosol, and are considered an important factor in regional haze formation. Size-fractionated aerosol particles for a whole year were collected to study the size distribution of SNA as well as their chemical species in Shanghai. SNA mainly accumulated in fine particles and the highest average ratio of SNA to particulate matter(PM) was observed to be 47% in the fine size fraction(0.49–0.95 μm). Higher sulfur oxidation ratio and nitrogen oxidation ratio values were observed in PM of fine size less than 0.95 μm. Ion balance calculations indicated that more secondary sulfate and nitrate would be generated in PM of fine size(0.49–0.95 μm). Sulfur K-edge X-ray absorption near-edge structure(XANES) spectra of typical samples were analyzed. Results revealed that sulfur mainly existed as sulfate with a proportion(atomic basis) more than 73% in all size of PM and even higher at 90% in fine particles. Sulfate mainly existed as(NH4)2SO4 and gypsum in PM of Shanghai. Compared to non-haze days, a dramatic increase of(NH4)2SO4 content was found in fine particles on haze days only, which suggested the promoting impact of(NH4)2SO4 on haze formation. According to the result of air mass backward trajectory analysis, more(NH4)2SO4 would be generated during the periods of air mass stagnation. Based on XANES, analysis of sulfate species in size-fractionated aerosol particles can be an effective way to evaluate the impact of sulfate aerosols on regional haze formation.  相似文献   

13.
Study of the particle size distribution of an urban aerosol has revealed associations between polycyclic aromatic hydrocarbons (PAHs) and inorganic elements. Two particle size distribution families coexist: the first, having mean particle size less than 1 μm, corresponds to lead and to relatively non-volatile PAHs; the second, with mean particle size greater than 1 μm, corresponds to anthropogenic iron, anthropogenic manganese and to volatile PAHs except fluoranthene.Factor analysis shows that the existence of these two families implies two different mechanisms of particle formation, which both depend on the volatility of the compounds: adsorption of PAHs on preexisting particles corresponding to the fine fraction of aerosols (0.7 μm) and condensation of gaseous compounds leading to the formation of bigger particles (1.5 μm).These results are applied to the evaluation of the relative importance of parameters which determine the PAH concentration variations during meso-scale transport between the source zone and the western Meditteranean Sea: the effect of the specific reactivity of each PAH is predominant while the differences on the deposition rates related to particle size are of minor importance.  相似文献   

14.
During a joint U.S./U.S.S.R. research cruise from 3 May to 27 July 1987 both total and fine (< 2 μm) particulate material was sampled. This cruise started in the Hawaiian Islands and then proceeded to the Kamchatka peninsula, south to Wellington, New Zealand, south of Australia into the Indian Ocean, to Singapore and then returned to the Hawaiian Islands by sailing just north of the Equator. Particulate samples, collected on quartz fiber and Teflon filters, were analysed for organic and elemental carbon by transmission thermo-optical carbon analysis and for trace elements by energy dispersive X-ray fluorescence.In the Northern Hemisphere the total particulate, organic carbon and elemental carbon concentration ranges were, respectively, 10–25, 0.5–2.5 and 0–0.3 μg m−3. In the Southern Hemisphere they were, respectively, 5–10, <0.6 and <0.02 μg m−3. In the Northern Hemisphere the fine particulate concentration range was 2–15 μg m−3 and the fine fraction varied from 20 to 80% of total aerosol loading. In the Southern Hemisphere the fine particulate loading was 1.2–1.7 μg m−3 and was usually less than 20% of the total particulate mass.Chemical mass balance (CMB) modeling was used to determine possible anthropogenic particulate contributions to the ocean aerosol. Readily available source profiles were used for CMB modeling. Sea-salt aerosol was represented by either the conventional EPA marine source profile or by the average of ambient ocean aerosols sampled in very clean mid-ocean regions. Usually 60–90% of ambient particulate mass was “explained” by the CMB model. Sources such as soil, catalytic auto emissions and wood-burning emissions were found to be possible contributors to the ocean aerosol, especially in the Northern Hemisphere. Anthropogenic contributions were estimated to contribute from 10 to 30% of oceanic aerosol mass. Emissions from a hugh forest fire that burned in northern China during the spring of 1987 were possibly detected, but the CMB model cannot distinguish this source from emissions from heating and cooking with wood.Since anthropogenic emissions are mainly combustion emissions which usually contain a large carbon component, carbon data is essential to CMB modeling. The relatively good CMB results obtained in this study suggest that it might be useful to develop source profiles for major emission sources in those countries which contribute most directly to oceanic aerosols. Perhaps characteristic national or regional source profiles could be developed.  相似文献   

15.
Our nucleation model of strong up-drafts over large fires (such as those ignited by nuclear blasts) show that many droplets in the size range of 1–10 μm are rapidly formed when the cloud becomes supersaturated. In this study we calculate aerosol/droplet collection kernels for electrical parameters commonly seen in cloud air. These kernels, which do not include Brownian diffusion, are used with aged droplet distributions to determine instantaneous scavenging rates of unwettable aerosols with cloud droplets. We find that within a portion of this parameter space the aerosol may be removed from the cloud air with time constants substantially below 1 h over the entire aerosol size range of 0.025–0.5 μm. For much of the parameter space, E-field enhanced attachment of charged aerosol is more rapid than that for Brownian diffusion.The aging of the droplet distribution incorporates the detailed microphysics of nucleation and condensation in a Lagrangian parcel with forced up-draft of 50 m s−1. We assume an initial aerosol distribution that is lognormal about a median radius of 0.05 μm with a geometric standard deviation of 2. Initially there are 106 insoluble aerosol particles per cubic centimeter of air with one-half of them being wettable and the other half being non-wettable.We present our results as a set of curves showing collection kernels and instantaneous scavenging rates vs aerosol radius and electric field strengths. The collection kernel curves are parametrically displayed for droplets of radii 1, 3 and 10 μm and electrical parameters typical of cumulus and thunderstorm clouds. The instantaneous scavenging curve vs aerosol radius is displayed as a function of electrical parameters.  相似文献   

16.
2002年春季沙尘暴对青岛大气气溶胶的影响   总被引:15,自引:0,他引:15       下载免费PDF全文
根据TSP,PM10,分级粒子质量浓度观测资料,分析了2002年春季发生于我国北方的2次沙尘天气过程对青岛大气环境的影响.在3月15-19日和21-23日的2次沙尘天气过程中TSP质量浓度分别为0.488和0.721 mg/m\+3,比平时增加了2.8和4.1倍.沙尘天气期间2~7 μm粒子为影响青岛的主要成分,在第2次沙尘暴期间该粒径的粒子质量浓度增加了30倍,其中2.1~3.3 μm粒子质量浓度达到0.13 mg/m\+3.根据地面气象资料和PM10连续监测资料发现,在地面风向转北之前,高空气流携带的沙尘首先影响到青岛.   相似文献   

17.
Size distributions of aerosol phase aliphatic and carbonyl groups were measured during the Southern California Air Quality Study. Samples were collected using a low pressure impactor equipped with ZnSe disks and the aerosol samples were analyzed directly using infrared (i.r.) spectroscopy. For the carbonyl absorbance, the ambient samples showed maxima in the 0.12–0.26 μm and the 0.5–1.0 μm size fractions. For the aliphatic carbon absorbance, the ambient samples generally showed maxima in the 0.076–0.12 μm size fraction. Factors contributing to these two absorbances were examined using principal component analysis. The results indicate that the carbonyl absorbance can be almost entirely attributed to products of atmospheric reactions and the aliphatic absorbances in particles smaller than 0.12 μm is correlated with automotive emissions.  相似文献   

18.
A 2-week intensive ambient aerosol study was conducted in December 1988 in Wuhan (Hubei Province), a city of nearly 2 million located on the Yangtze River in central China (P.R.C.). This is an industrial region where soft coal burning is widespread, and emission controls for vehicles and industrial facilities are minimal. The sampling site was located in one of the civic centers where residential and commercial density is highest. An Andersen dichotomous sampler was operated with Teflon membrane filters to collect fine (dp < 2.5 μmad) and coarse (2.5 ⩽ dp < 10 μmad) particles for total mass and element determinations. An annular denuder system (ADS) was used to collect fine fraction aerosols for analyses of ionic species including strong acidity (H+).The study was conducted between 18 and 30 December, which was rainless, consistently cool (3–10°C) and overcast, but without fog or acute stagnation. Fine particulate mass (PM, as μ m−3) averaged 139 (range 54–207); coarse PM averaged 86 (range 29–179). Trace element concentrations were also high. Crustal elements (Si, Al, Ca and Fe) were found primarily in the coarse fraction, while elements associated with combustion (S, K, Cl, Zn and Se) were enriched in the fine fraction. The concentrations of arsenic and selenium were evidence of a large source of coal burning, while vanadium levels (associated with fuel oil use) were not especially enriched.Despite the seemingly high PM loadings, ionic concentrations were not especially high. The average composition of soluble fine aerosol species (in neq m−3) were SO42−: 520 (range 180–980), NO3: 225 (range 50–470), Cl: 215 (range 20–640), and NH4+: 760 (range 280–1660). A deficit in accountable FP components (total mass compared to the total of ionic plus element masses) as well as the black appearance of collected materials indicate an abundance of carbonaceous aerosol, as high as 100 μ m−3. (total mass compared to the total of ionic plus element masses) as well as the black appearance of collected materials indicate an abundance of carbonaceous aerosol, as high as 100 μ m−3Aerosol acidity was negligible during most monitoring periods, H+: 14 (range 0–50 neq m−3, equivalent to 0–2.5 μm m−3 as H2SO4). Sulfur dioxide, measured by the West-Gaeke method for part of the study, concentrations were low. Although not directly measured, the aerosol measurments suggested that gaseous HCl (from refuse incineration) and NH3 (animal wastes) concentrations might have been high. Higher aerosol acidity might be expected if HCl sources were more prominent and not neutralized by local ammonia or other base components.  相似文献   

19.
Ambient aerosol in the size range 0.075–16 μm was sampled with Berner cascade impactors during the summer and fall intensive sampling periods of the Southern California Air Quality Study (SCAQS) of 1987. Deposits on the greased Tedlar stage substrates were extracted with deionized water and analyzed for inorganic anions and cations by ion chromatography. Stage mass data were inverted by a modified version of the Twomey nonlinear iterative algorithm and modes in the inverted size distributions were fitted with lognormal functions. Nine hundred size distributions of ionic species were obtained.Three modes, two submicron and one coarse, were sufficient to fit all of the size distributions. The smallest mode, at 0.2±0.1 μm, aerodynamic diameter, is probably a condensation mode containing gas phase reaction products. A larger mode, at 0.7±0.2 μm, is identified as a droplet mode. Evidence was obtained that the droplet mode grew out of the condensation mode by the addition of water and sulfate. During SCAQS, most of the inorganic particle mass was in the droplet mode except during a period of exceptionally low relative humidity. Nitrate was internally mixed with sulfate in the droplet mode. Since most of the aerosol fine mass is included in the ions analyzed, the observed condensation and droplet modes characterize the overall size distribution in the 0.1–1 μm range, previously described by Whitby as a single accumulation mode.  相似文献   

20.
为了探索土壤起尘后悬浮颗粒物对铅的携带特性与其矿物组成、粒径尺寸之间的关联,揭示土壤起尘矿物特性及其重金属污染赋存行为,并为雾霾矿物基源特性分析及后期治理提供理论参考.通过对土壤样品进行铅污染预处理,在实验室系统内模拟风速条件下进行起尘试验,利用悬浮颗粒采样仪对经过风吹起尘后的悬浮颗粒物(TSP)、吹前表层土、吹后表层土、吹后地表土及不同粒径悬浮颗粒物进行了收集,并对悬浮颗粒物、吹前表层土、吹后表层土、吹后地表土及不同粒径悬浮颗粒物中铅的赋存状态及矿物组成与含量进行了分析.结果表明:①土壤经过风吹起尘后,悬浮颗粒物中w(Pb)为2.584 mg/g,吹前表层土中w(Pb)为0.916 mg/g,悬浮颗粒物中w(Pb)约是吹前表层土中w(Pb)的3倍;②不同粒径悬浮颗粒物上的w(Pb)各不相同,>10.2 μm的粒径中w(Pb)为1.716 mg/g;>4.2~10.2 μm的粒径中w(Pb)为2.720 mg/g>2.1~4.2 μm的粒径中w(Pb)为3.937 mg/g>1.4~2.1 μm的粒径中w(Pb)为5.442 mg/g,w(Pb)随着粒径的增加而减小;③随着悬浮颗粒物粒径的减小,黏土矿物(伊利石+绿泥石)的含量在不断的增加.研究显示,土壤起尘过程是对Pb的一种高于本底浓度的迁移过程;起尘颗粒物中w(Pb)随着悬浮颗粒物的粒径的减小而增加,呈负相关;w(Pb)与黏土矿物(伊利石+绿泥石)含量在不同粒径悬浮颗粒物上的变化规律具有一致性,呈正相关,黏土矿物(伊利石+绿泥石)对Pb具有较好的吸附性.   相似文献   

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