方案详情文
智能文字提取功能测试中
Water Air Soil Pollut (2015) 226: 403DOI 10.1007/s11270-015-2666-1 Water Air Soil Pollut (2015) 226: 403403Page 2 of 13 Conception of the Mercury Deposition Coefficient Basedon Long-term Stream Intensity Measurements of MercurySpecies TGM and TPM Bartosz Nowak· Marianna Czaplicka Abstract For many years, atmospheric mercury hasbeen perceived as a global pollutant. Transport of mer-cury compounds in the atmosphere and its deposition onthe earth’s surface is an important issue that requiresknowledge regarding the circulation of the variousforms of this metal between environmental components.There are many numerical models that can be used tostudy and image this phenomenon. These models arebased on data concerning mercury emission sources,concentrations of this contaminant on modelling areasand meteorological data to assess air mass inflow on aregional and global scale. A method to assess mercurydeposition fluxes on a local scale based only on streamintensity analysis of mercury is proposed in this study.Mercury deposition fluxes (bulk) that were assessed bythe MDC method at the Zloty Potok station (regionalbackground station for the Silesian Agglomeration) var-ied from 22.8 ugmyear(an 8-month period in2013) to 54.2 ugmyearin2012. Developing pro-cedures to estimate the mercury deposition coefficient(MDC) is useful in areas where only meteorologicalparameters and mercury concentrations in the atmo-spheric air are measured. The obtained deposition coef-ficient values enable quantification of a selected B. Nowak ()Institute for Ecology of Industrial Areas, 6 Kossutha Str.,40-844 Katowice, Polande-mail: nowak@ietu.katowice.pl M. Czaplicka Institute of Non-Ferrous Metals, 5 Sowinskiego Str.,44-100 Gliwice, Poland pollutant concentration and its potential impact resultingfrom deposition. Keywords Mercury deposition coefficient ·Atmospheric mercury species·Mercury wet and dry deposition 1 Introduction There are several reasons that justify environmentalmercury as a global concern. The first reason is thatonce mercury is introduced into the environment, itremains forever and does not degrade; the second reasonis that mercury can be transported over a long distancein a simple way due to the physical properties of themetal. Even small amounts of mercury in the environ-ment may cause negative health effects. Therefore, tak-ing action to reduce mercury emission and focusing onexpanding the knowledge about mercury circulation inthe environment are very important. In the last fewyears, mercury release,spread and changes in the envi-ronment have awakened significant interest, but despitenumerous studies regarding these issues, many of thephenomena remain unexplained. Concentrations of totalgaseous mercury (TGM) in ambient air in uncontami-nated areas ofAsia and North America range from 0.52to 21.03 ng'm’ (Fu et al. 2008; Choi et al. 2009;Nakagawa and Hirooto 1997; Lynam and Keeler 2006;Fu et al. 2009; Mazur et al. 2009; Liu et al. 2002).Additionally, in unpolluted areas in Europe, the TGMcontents in ambient air range from 0.66 to 6.20 ng'm. Average concentrations of TGM in ambient air in un-contaminated areas of Europe range from 1.96 to33.8 ngm(Kock et al. 2005; Berg et al. 2001;Zielonka et al. 2005; Pyta et al. 2009). Almost all ofthese previous research articles showed that concentra-tions ofTGM in winter seasons are significantly higherthan in summer seasons, with only a few exceptions incoastal zones, such as Cabo de Creus (Spain); Meze,Thau Lagoon (France); Piran Marine (Slovenia); NeveYam, Israel; Halifax (Canada) (Marks and Beldowska2001;Beldowska et al. 2006;Ebinghaus et al. 2006) andthe Silesian Region of Poland (Nowak et al. 2014).European legislation and internal regulations in variouscountries outside of the EU devote much attention tothis pollutant. Many actions have been specifically di-rected at reducing mercury emissions into the environ-ment and phasing-out certain mercury-containing prod-ucts (European Commission 2004; European Parliament2005).According to EU legislations, mercury should beconstantly monitored and is included in directives andprotocols, such as the CAFE Directive and Protocol onHeavy Metals (Directive 2004/107/EC). In 2014, theMinamata Convention on Mercury was entered, whichhas been signed by 128 and ratified by 10 countries sofar. The main goals of the convention are to providecomprehensive protection of the environment and hu-man health against the release of mercury into the atmo-sphere, water and soil. The provisions of the agreementgovern issues related to extraction of the metal, trade inproducts containing mercury and use of this metal inproducts and industrial processes. The Minamata Con-vention also established principles for safe managementof waste containing mercury and also regulated issuesrelated to mercury-contaminated sites (Minamata Con-vention 2014). Transport of mercury compounds in the atmo-sphere and its deposition on the earth’s surface isan important issue that requires knowledge regard-ing the circulation of the various forms of this metalbetween environmental components. There are manynumerical models that can be used to study andimage this phenomenon. These models are basedon data about mercury emission sources, concentra-tions of this contaminant on modelling areas andmeteorological data to assess air mass inflow. Oneof the basic models used to simulate pollutant trans-port in ambient air is the Advanced Statistical Tra-jectory Air Pollution model (ASTRAP) (Shannonand Volder 1995). More complex models describing the transport of various forms of mercury that arebased on air mass analysis also exist. One of thesemodels is the Regional Lagrangian Model of AirPollution (RELAMP) (Eder et al. 1986). This modelassumes that reactions in the gas phase are veryslow, including oxidation and reduction reactions,and therefore, reactions that may occur in raindropscontained within clouds are included in the calcula-tions. All of the numerical models require meteoro-logical and precision data regarding the types ofemission sources present in the modelling area(Travnikov 2005; Tsiros and Ambrose 1999;Bullock 2000). These models can describe not onlythe transport ofmercury in the atmosphere but alsothe wet and dry depositions and amounts of thesecontaminants exchanged between various elementsin the environment. To further understand the prin-cipal mechanisms governing mercury dispersion andcycling in the environment, a global observationsystem for mercury (GMOS) was created. This sys-tem was based on the ECHMERIT and GLEMOSglobal models and Regional Chemistry TransportModels (CTMs). The GMOS system utilizes datafrom ground-based stations at high altitudes andsea level locations, ad-hoc oceanographic cruisesover the Pacific, Atlantic and Mediterranean andfree tropospheric mercury measurements. Applica-tion of the GMOS can supplement direct measure-ments of mercury concentrations and depositionlevels, providing more comprehensive and detailedinformation on the global cycle of mercury(Bencardino et al. 2014; Pirrone et al. 2013;Gencarelli et al. 2014). A large number of emissionsources, such as point, linear and area sources, aswell as natural processes occurring in the environ-ment are so complex that without a detailed inven-tory of emission sources, the models cannot accuratelycapture the specificity ofthe phenomena that can occuron a local scale. Determining the actual mercury inflowat local measurement points is possible based only onanalysing the inflow of mercury streams in the immedi-ate area of the tested point. Although there are methodsto analyse contaminant stream inflows that include localand regional scales, simple tools for assessing mercurydeposition fluxes on a local scale based on commonlyavailable data are still lacking. Developing a method toassess contaminant deposition fluxes on a local scalebased only on stream intensity analysis of those pollut-ants is one of the challenges of environmental engineering.Accordingly, the primary goal ofthis studywas to develop a procedure to determine Hg depositionfluxes on a local scale based on mercury stream inten-sities measured in local ambient air monitoringprograms. 2 Experimental 2.1 Total Gaseous Mercury (TGM) Measurements TGM concentrations in ambient air were measured usinga RA-915+ LUMEX analyser (Lumex Analytics GmbH,Naher str., 558 Wakendorf II, Germany). The analyseroperation is based on the differential Zeeman atomicabsorption spectrometry technique, which is implement-ed using the direct Zeeman effect (Zeeman atomic ab-sorption spectrometry using high frequency modulationof light polarization,ZAAS-HFM). The analyser wasoperated in a continuous mode (time of individual mea-surement 60 s). Air samples were collected at a level of2.2 m above the ground. A new calibration method basedon preparing reference gas samples of mercury vapours inthe concentration range of LOQ-67.6ngmwas appliedto validate the analytical procedure for detecting mercuryvapours in the concentration range that occurs in ambientair (Nowak et al. 2014). The developed analytical proce-dure can be characterised by the following parameters:detection limit of 0.24 ng'm, limit of quantification of0.48 ngm’, working range from 0.48 to 67.6 ngm,linearity of 0.999, repeatability of 5.3 %, recovery from98.9 to 107.5 % and expanded uncertainty of 19.7 %.Application of this methodology over a long period oftime required stable operation of the analyser. At the inletof the analyser, a fibre filter was used to absorb particlesfrom the air. For the blank signal control, an effectivecarbon filter (CF 32 A2B2E2K2Hg-P3) was used toadsorb approximately 99.99 % of the mercury vapourpresent in the air. Using the carbon filter for blank signalcontrol significantly decreased the level of noise anddirectly affected the accuracy and precision of the analyt-ical procedure. The limits of detection and quantificationwere also improved by the significantly decreased back-ground noise. 2.2 Total Particulate Mercury (TPM) Measurement Particulate matter samples were collected on 47-mm Teflon filters (0.45-mm pore size) housed in acid-cleaned Teflon filter packs at a nominal flowrate of 10 1 min(Zielonka et al. 2005).Next, theends of the sampling filters were placed into acid-cleaned Petri dishes and stored in a refrigerator.Upon completion of the measurements, the filterswere brought to the laboratory for analysis. TheFilters and the particulate matter collected on theirsurfaces were placed into Teflon vessels for miner-alization in a microwave oven (Multiwave 3000-Anton Paar, Austria) using concentrated nitric acidand hydrochloric acid (1:1) (Hg≤0.000001 %, proanalysis, Merck, Germany). The concentrations ofmercury were determined by the cold vapor atomicabsorbtion spectrometry (CV-AAS) method usingan RA-915+ analyser equipped with an RP-91 at-tachment provided by Lumex Ltd. The operation ofthe analytical system was checked using appropri-ately prepared calibration solutions with referencematerial in the concentration range from 0 to500 ng1. The linear correlation coefficient ofthe calibration curve was R-=0.974. The methoddetection limit for TPM was approximately 5 pg'm for a 24 h sample at the applied flow rates. 2.3 Wet and dry deposition measurements Rainfall samples were collected on the bulk sampler.The sampler was made with an acid-washed open boro-silicate glass bottle and a 30-cm funnel composed of aninert material. The funnel was supported in a thermo-static housing system and the system protected the sam-ples from solar radiation and high temperatures. On thedays without rainfall, the dry deposit collected on theopen collector was washed with deionized water on thesite. After sampling, the filters with dry deposits wereplaced into acid-cleaned Petri dishes and stored in therefrigerator. The filters with dry deposits were analysedfollowing the same procedure as the TPM filters(Zielonka et al. 2005;Nowak et al. 2013). The wetdeposition samples were preserved with 1 ml of stabi-lizing solution (nitric acid and potassium dichromate;5g K2Cr207+500 ml HNO3/1000 ml) and stored in aTeflon bottle in the refrigerator. After the measurementswere completed, samples were mineralized in a waterbath for 2 h at a temperature of 95 °C using the follow-ing solutions: 0.2 ml (25g.1) of potassium permanga-nate, 0.2 ml of nitric acid (concentrated) and 0.5 ml(40 g.1) of potassium peroxidisulphate. To the obtain-ed solutions, 100g·1ofhydroxylamine hydrochloride was added dropwise to remove excess oxidizer. Theconcentration of mercury was determined by the CV-AAS method based on an RA-915+ analyser equippedwith an RP-91 attachment. The analyser was calibratedusing a mercury standard reference material in the con-centration range from 0 to 300 ng1. The linear corre-lation coefficient of the calibration curve was R2=0.97504. The detection and quantification limits for totalmercury in wet deposition samples were measured usingten independently prepared blank samples. LOD andLOQ amounted to 2 and 5 ng1, respectively. Therepeatability of this method was 9.4 %. The recoverieswere 100.4%. The laboratory glass and other glassequipment that were used in all conducted analyses werewashed in a laboratory washer (Miele G7883,Ontario).All calibration solutions and other reagents were pre-pared with high-purity deionized water, approximately0.5 uS/cm, Milli-Q(Millipore, Bedford, MA, USA).The nitric and hydrochloric acids used in the analysisshowed very low mercury contents (approximately Hg≤0.000001 %); therefore, its impact on the final resultswas neglected. The results were corrected using triplyprepared blank samples. 2.4 Meteorological Data Meteorological parameters were determined at allmeasurement sites. The meteorological stations inKatowice and Pszczyna were equipped with ultra-sonic anemometers (81000 YOUNG) used to mea-sure wind speed along the three axes x, y and z,which allowed determination of two horizontal ve-locities and one vertical velocity as well as air tem-perature and humidity. In other measuring points,meteorological conditions were measured accordingto the monitoring plan of the Silesian Inspectoratefor Environmental Protection. 2.5 Sampling Site The measurements were taken in the Upper Silesianregion (Southern Poland) from 2008 to 2010. Themeasuring points were located in the five followingSilesian cities (Fig. 1): Katowice, over 300 thou-sand inhabitants; Dabrowa Gornicza, approximately124 thousand inhabitants; Zabrze, approximately180 thousand inhabitants; Tychy, more than 128thousand inhabitants; Pszczyna, close to 26 thou-sand inhabitants..The measurements utilised to determine the deposition coefficient were taken attwo measuring points. The TGM and TPM mea-surements in the atmospheric air and the mercurycontents in dry and wet atmospheric precipitationswere taken in ten periods (each lasting 21 days) insummer and winter seasons; six measuring periodswere performed in Katowice and four in Pszczyna. 2.6 The Mercury Deposition Coefficient Method(MDC) This work showed that the mercury stream intensity(concentrations in ambient air and meteorologicalparameters) measured in routine air pollutant moni-toring programs can be used to assess mercury de-position. The MDC parameter allows for assessmentof mercury deposition. The main goal of this studywas to develop a procedure for determination of aHg deposition coefficient based on analysing mer-cury stream intensities and compare the obtainedresults with deposition values measured using chem-ical analysis. To calculate the deposition coefficientdata, the TGM and TPM stream intensities andmercury wet and dry deposition data collectedthroughout the measuring periods were used (tenmeasurement campaigns in Katowice and Pszczyna).The coefficient was calculated as a portion of themercury deposited on the land surface (mercuryvertical loads) in the amount of the pollutanttransported in the air in the form of TGM andTPM (stream intensity-mercury horizontal loads)within the entire measurement session (see Fig. 2).To determine the TGM and TPM stream intensities,high resolution data regarding the concentrations ofTGM and TPM as well as meteorological parameters(wind speed, wind direction) were used. Stream intensity is defined as a product of the pollut-ant concentrations and the vector opposite to the windspeed vector. The length of the inflow vector is equal tothe intensity of the pollutant stream inflow through thesurface that is perpendicular to the wind vector. Theinflow vector at the same time indicates the directionof pollutant inflow (TGM and TPM) and their streamintensities. Based on the TGM and TPM streams intensities,which were measured at a height of 2.2 m during onemeasurement session, and based on mercury concentra-tion data in wet and dry deposits (deposition valuesobtained during one measurement session) collected at X- Routine measurement points used to assess deposition of mercury by proposed method (comparison studies); -Measurement points used to determination of the deposition coefficient. Fig. 1 Location of measurement points against the European map and the Silesian Voivodeship map a height of 1.5 m, mercury deposition coefficients werecalculated using the following equation (see below). where: SHgwet +SHgp is the sum of the wet and drymercury deposits and STGM+STPM is the sum of theTGM and TPM stream intensities. Fig. 2 Schematic diagram of mercury deposition coefficient 3 Results and Discussion 3.1 Overview of Mercury Species Concentrationsand Deposits from 2008 to 2010 Upper Silesia is an industrial region located in SouthernPoland. In this area, there are 21 mines, which belong totwo mining holdings. There are also many mines that donot currently function but contributed to degradation ofthe natural environment in this region in the past. Manyother industries, such as metallurgical, power, engineer-ing and chemical industries are also developed in thisarea. In the Silesian Voivodeship territory, the atmo-spheric air pollution situation, especially connected toparticles, has been categorised as class C (if the concen-tration of pollutants exceeds the limit levels as well asthe margin of tolerance). Analysing the frequency atwhich the average annual concentration of PM10 wasexceeded showed that at almost all of the measuringstations assessed, the average annual concentrationswere much higher than the admissible threshold of40 ugm(2008/50/EC). The poor air quality is espe-cially related to high levels of low emission in this area TGM streams intensity at the Katowice TGM streams intensity at the Pszczyna TGM streams intensity at the Pszczyna Fig. 3 Roses of TGM stream intensity at the monitoring stations in Katowice and Pszczyna during 2008-2010, mgm21 days that are connected with the burning of solid fuels indomestic heating units. This indicated that duringthe winter months, the concentrations of mercuryin the vapour and adsorbed on the particles aremuch higher than the concentration in the summermonths, which was also reflected in the depositionof this pollutant. The average TGM concentrationvalues obtained during the research conducted attwo sites (Katowice and Pszczyna) were very simi-lar to the concentrations previously measured invarious locations in Poland and Europe (Kocket al. 2005; Berg et al. 2001; Zielonka et al. 2005;Marks and Beldowska 2001: Beldowska et al. 2006: Ebinghaus et al., 2006;Nowak et al. 2014). Duringthe non-heating seasons (summer) that were moni-tored from 2008-2010, the average TGM concen-tration in Katowice was 3.49±1.12 ngm, but themean concentration of TGM in Pszczyna was ap-proximately 28 % lower and was approximately2.53±0.52 ng'm. In the middle of the heatingseason (winter), the mean TGM concentration inKatowice was2.70±0.71 ngm. During theheating seasons in Pszczyna, the TGM concentrationwas approximately 33 % lower and was1.84±0.41 ng'm. During the non-heating seasons mon-itored ffrom2008-2010, the;Imean TPM Table 1 Set of data necessary to estimate the mercury deposition coefficient and MDC results for the conducted measurement campaigns Measuring Season Measuring TGM streams TPM streams Wet deposition Dry deposition MDC point period intensity mg m intensity mgm ug'm ug'm . % 21 days -1 21 days 21 days 21 days Katowice Non-heating 20.08-09.09.2008 3.98 0.12 1.43 6.70 0.20 14.07-04.08.2009 4.82 0.21 2.41 1.23 0.07 19.05-09.06.2010 4.12 0.12 1.44 0.37 0.04 Heating 01.12-22.12.2008 4.85 1.40 1.93 1.92 0.06 09.03-30.03.2009 6.83 1.62 9.17 0.28 0.11 26.02-18.03.2010 8.11 0.49 0.91 0.55 0.02 Pszczyna Non-heating 18.05-08.06.2009 6.01 0.22 4.67 2.81 0.12 02.07-22.07.2010 6.35 0.19 1.20 0.83 0.03 Heating 20.10-10.11.2009 3.14 0.56 0.76 2.24 0.08 08.10-29.10.2010 4.16 0.63 0.14 1.53 0.03 concentration in Katowice was 132.1±107.8 pg'mwhereas in Pszczyna this value was approximately97.18±61.33 pg'm. However, during the heatingseasons, the average TPM concentration was 531.7±324.1 pgmwhereas in Pszczyna this value wasapproximately 288.2±165.2 pgm. In the winterseasons in Katowice and Pszczyna, the content ofTPM in the atmospheric air was several times higherthan its content in the summer season. The differ-ence may result from increased combustion of solidfuels in the winter. In the winter season, the con-sumption of coal significantly increased. This wasalso confirmed by the approximately 50 % increasein PM10 average daily concentrations in ambient airduring the winter season in the Silesian Region.Based on the total annual precipitation amounts inthose locations and the average mercury concentra-tions in wet and dry deposits measured during theconducted studies, the total annual mercury wet anddry depositions were determined. The obtained re-sults are much higher than the literature results (Liet al. 2008; Sakata et al. 2005; Vanarsdale et al.2005; Gratz et al. 2009). The total average annualvalues of wet and dry deposition of mercury com-pounds measured in Katowice from 2008-2010were 32.1 and 28.2 ug'm,respectively. The totalaverage annual values of wet and dry depositionmeasured in Pszczyna were 11.3 and 31.6 pg·m,respectively. The differences between the observedmercury deposition values may be caused by diversetypes of air pollutant emission sources that occur atthe measuring points. ·3.2 Overview of TGM stream intensities from 2008to 2010 To assess mercury deposition using the MDC method,TGM and TPM stream intensity data were needed.Stream intensities of mercury compounds were calcu-lated based on high resolution data regarding the con-centration of TGM and TPM as well as meteorologicalparameters, such as wind speed and wind direction.During the measurement sessions in the non-heatingseason from 2008-2010, the average TGM stream in-tensity values were approximately 4.31 mg'm21 days, but this value was lower than the resultobtained for the heating seasons (6.60 mg'm ·21 days ) (see Fig. 3). Additionally, inverse relation-ships were noted at the air quality monitoring station inPszczyna. The average TGM stream intensity valuesduring the heating seasons were lower than during thenon-heating seasons and amounted to 3.65 and6.18 mgm221 days, respectively. At both leasur-ing stations in Katowice and Pszczyna as well as in allcases, the average TPM stream intensity values during2008-2010 were higher during the heating seasons thanin the non-heating seasons. At the mercury monitoringstation in Katowice, the average TPM stream intensitythat flowed through the measuring point from 2008-2010 was 1.17 mg*m2-21 days in the heating sea-sons. The result obtained for heating seasons was muchhigher than the value recorded for non-heating seasons,which was 0.15 mgm -21 days. This same trendwas observed in Pszczyna from 2009-2010. The TPMstream intensity values for this point in the heating and non-heating seasons were 0.60 and 0.21 mg'm21 days,respectively. 3.3 Calculation of the Mercury Deposition Coefficientand Analysis of Parameters Affecting Its Value In the next stage of this work, mercury deposition coef-ficients were calculated based on the recorded measure-ments and proposed methodology (see 2.6). The fulldata set needed for the MDC calculation is presentedin Table 1. The deposition coefficient that was calculated for themeasuring stations located in Katowice and Pszczyna inthe summer season ranged from 0.03 to 0.12%,whereasin the winter season these coefficients varied from 0.02to 0.20%.At both monitoring stations, the depositioncoefficient, which was defined as a portion of the mer-cury deposited on the land surface (dry and wet) to theamount of the pollutant transported with loads of air inthe form of TGM and TPM (stream intensity), did notexceed 0.2 %. As seen, the differences between theobtained MDC values are significant between measure-ment sessions, and this is important for understandingthe causes of these fluctuations in the next section. 3.4 Chemometric analysis Variation of the TPM and TGM concentrations be-tween the winter and summer seasons and alter-ations in the meteorological parameters betweenthe seasons contributed to differences in the obtain-ed results. However, additional causes for thesefluctuations also exist, which we tried to prove inthe next stage of the analysis. These analyses willhelp determine whether the MDC method can beused to estimate mercury deposition based on com-monly available monitoring data regarding mercuryconcentrations in ambient air. Meteorological data, such as wind speed, tempera-ture, precipitation height and number of days with pre-cipitation influencing the DMC values were analysedusing two independent chemometric techniques i.e.principal component analysis (PCA) and Ward clusteranalysis. All of the meteorological data collected duringthe measurement periods are presented in Table 2. ThePCA technique detects existing relations betweenanalysed variables. PCA analysis is based ontransforming the originally measured data into a newlinear combination of uncorrelated variables, which arecalled principal components. Clearly interpreting these Table 2 Statistical characteristics of meteorological parameters causing MDC fluctuation Measuring Season Measuring Parameter Wind speed Temperature Precipitation Number of days MDC% point period ms °C1 mm with precipitation Katowice Non-heating 20.08-09.09.2008 Mean±SD 0.57±0.27 16.4±2.42 4.00±6.52 5 0.20 Range 0.2-1.2 11.9-20.9 0.10-15.5 14.07-04.08.2009 Mean±SD 0.60±0.31 19.6±3.64 14.7±17.0 7 0.07 Min-Max 0.1-1.1 13.2-25.3 0.35-51.8 19.05-09.06.2010 Mean±SD 0.68±0.28 12.9±3.40 6.10±9.57 14 0.04 Min-Max 0.3-1.3 5.70-20.1 0.16-36.7 Heating 01.12-22.12.2008 Mean±SD 0.91±0.47 1.59±2.33 3.92±4.34 11 0.06 Min-Max 0.3-2.1 -1.3-6.5 0.30-11.8 09.03-30.03.2009 Mean±SD 1.16±0.65 2.48±3.78 4.84±4.63 14 0.11 Min-Max 0.3-2.5 -1.9-12.6 1.02-15.3 26.02-18.03.2010 Mean±SD 1.25±0.69 -2.28±3.94 2.88±3.08 11 0.02 Min-Max 0.1-2.8 -7.8-4.3 0.11-10.4 Pszczyna Non-heating 18.05-08.06.2009 Mean±SD 1.72±0.67 14.3±3.56 3.83±5.12 13 0.12 Min-Max 0.8-3.1 8.0-21.8 0.25-18.8 02.07-22.07.2010 Mean±SD 1.34±0.48 22.1±3.55 8.21±4.71 4 0.03 Min-Max 0.7-2.5 15.8-26.1 4.08-13.9 Heating 20.10-10.11.2009 Mean±SD 1.07±0.47 5.05±3.26 2.77±1.94 9 0.08 Min-Max 0.5-2.2 -1.0-10.7 0.42-6.45 08.10-29.10.2010 Mean±SD 1.47±0.69 5.61±1.75 1.95±2.32 6 0.03 Min-Max 0.5-3.0 2.3-10.2 0.46-6.54 Dendrogram Height of precipitation Average wind speed [m/s] Fig. 4 Visualisation of the result of a hierarchical clustering calculation for the meteorological parameters shaping the MDC values components (chemical or physical) is very difficult;therefore, the data are appropriately rotated. The pur-pose ofthis rotation is to obtain a transparent system ofthe significance of individual factors characterised byhigh values of selected variables and low values ofothers variables. In this analysis, Varimax rotation wasused.The analysed data were transformed into a normaldistribution. Because each variable was characterised byan individual variation range, it was necessary to stan-dardize the data to correct the proportions, which is called autoscaling (Einax et al. 1997). In the PCA anal-ysis, three factors that explained greater than 65 % ofthedata variability were analysed. The conducted PCA analysis showed that the firstfactor explained approximately 35 % of the systemvariability. Analysing the weight of each factor showeda statistically significant positive correlation betweenthe MDC values and temperature(r=0.80) and precip-itation height (r=0.34). This relation was confirmed bythe increase of both the MDC and height of precipitation Table 3 MDC values by bulk and wet deposition depending on meteorological parameters MDC i5k [ng'm-2.s-/ngms] MDC we Percentile Height of precipitation Wind speed Temperature lng'm-2.s-/ngm.s] mml [m·s1 rc1 0.00035 0.00018 25 <1.5 >1.3 <3.1 0.00062 0.00031 50 1.5
还剩11页未读,是否继续阅读?
继续免费阅读全文产品配置单
美诺中国 Miele China为您提供《大气中汞沉降系数,大气汞形态,汞干沉降和湿沉降检测方案(洗瓶机)》,该方案主要用于空气中(类)金属及其化合物检测,参考标准《暂无》,《大气中汞沉降系数,大气汞形态,汞干沉降和湿沉降检测方案(洗瓶机)》用到的仪器有德国美诺PG8583清洗机。
我要纠错相关方案