An inverse Gaussian plume approach for estimating atmospheric pollutant emissions from multiple point sources

A method is developed for estimating the emission rates of contaminants into the atmosphere from multiple point sources using measurements of particulate material deposited at ground level. The approach is based on a Gaussian plume type solution for the advection–diffusion equation with ground-level deposition and given emission sources. This solution to the forward problem is incorporated into an inverse algorithm for estimating the emission rates by means of a linear least squares approach. The results are validated using measured deposition and meteorological data from a large lead–zinc smelting operation in Trail, British Columbia. The algorithm is demonstrated to be robust and capable of generating reasonably accurate estimates of total contaminant emissions over the relatively short distances of interest in this study.     

基于遗传算法的大气污染总量控制新方法

提出一种利用遗传算法进行大气污染总量控制的新方法,并以柳州市SO2总量控制为例说明这种方法的具体运用.遗传算法具备自适应全局搜索寻优特点,从控制点浓度推算源强分布,该源强分布满足总量控制的根本要求.该方法的具体实现是:将区域内各污染源的排放量编码为染色体,让染色体群体在模拟的进化环境下按生物进化规律进行优胜劣汰的自然选择,经过若干代的进化,最终得到的最优个体即代表最佳的源强分布.研究结果表明,这种方法是有效的和可行的.     

Effective pollutant emission heights for atmospheric transport modelling based on real-world information

Emission data needed as input for the operation of atmospheric models should not only be spatially and temporally resolved. Another important feature is the effective emission height which significantly influences modelled concentration values. Unfortunately this information, which is especially relevant for large point sources, is usually not available and simple assumptions are often used in atmospheric models. As a contribution to improve knowledge on emission heights this paper provides typical default values for the driving parameters stack height and flue gas temperature, velocity and flow rate for different industrial sources. The results were derived from an analysis of the probably most comprehensive database of real-world stack information existing in Europe based on German industrial data. A bottom-up calculation of effective emission heights applying equations used for Gaussian dispersion models shows significant differences depending on source and air pollutant and compared to approaches currently used for atmospheric transport modelling.     

基于大气环境监测数据的工业园区污染物排放总量实时反演核算方法

工业园区既是重要的社会经济发展单元,也是主要的大气污染排放单元。综合利用环境监测数据和数值模拟方法,开展工业园区污染排放的动态精准管控,有助于提升工业园区大气环境管控效果,统筹园区经济发展与环境优化。以某工业园区为例,探索了基于环境监测数据,利用高斯大气扩散模型和源参数反演技术,实现小时级别的园区大气污染物排放总量反演核算的技术可行性。结果表明：1) 监测站点布设方案显著影响反演核算精度,网格化布点方案有效提高了反演核算精度;2) 监测数据的随机误差显著影响反演核算精度,在简化布点方案下,园区监测站点对VOCs质量浓度监测误差应控制在0.1 mg∙m⁻³以下;3) 园区总排放强度对反演核算精度存在一定影响,总排放量大的园区反演核算精度较高;4) 反演核算精度与实时气象条件有关,当气象条件不适宜模型模拟污染物扩散或不适宜监测站点对污染物分布进行有效采样时,可能造成反演精度的下降。以上结果表明,在工业园区开展基于环境监测数据的大气污染物排放总量核算研究具有可行性,但需要在监测站点布设方案比选、监测站点数据质量控制等方面进行精细化管理,以达到最优反演核算效果。     

Global emission of mercury to the atmosphere from anthropogenic sources in 2005 and projections to 2020

This paper presents the 2005 global inventory of anthropogenic emissions to the atmosphere component of the work that was prepared by UNEP and AMAP as a contribution to the UNEP report Global Atmospheric Mercury Assessment: Sources, Emissions and Transport (UNEP Chemicals Branch, 2008).It describes the methodology applied to compile emissions data on the two main components of the inventory – the ‘by-product’ emissions and the ‘intentional use’ emissions – and to geospatially distribute these emissions estimates to produce a gridded dataset for use by modelers, and the results of this work.It also presents some initial results of work to develop (simplified) scenario emissions inventories for 2020 that can be used to investigate the possible implications of actions to reduce mercury emissions at the global scale.     

Quantification of variability and uncertainty in air pollutant emission inventories: method and case study for utility NOx emissions

The quality of stationary source emission factors is typically described using data quality ratings, which provide no quantification of the precision of the emission factor for an average source, nor of the variability from one source to another within a category. Variability refers to actual differences caused by differences in feedstock composition, design, maintenance, and operation. Uncertainty refers to lack of knowledge regarding the true emissions. A general methodology for the quantification of variability and uncertainty in emission factors, activity factors, and emission inventories (EIs) is described, featuring the use of bootstrap simulation and related techniques. The methodology is demonstrated via a case study for a selected example of NOx emissions from coal-fired power plants. A prototype software tool was developed to implement the methodology. The range of interunit variability in selected activity and emission factors was shown to be as much as a factor of 4, and the range of uncertainty in mean emissions is shown to depend on the interunit variability and sample size. The uncertainty in the total inventory of -16 to +19% was attributed primarily to one technology group, suggesting priorities for collecting data and improving the inventory. The implications for decision-making are discussed.     

我国移动源主要大气污染物排放量的估算

在考虑我国移动源主要大气污染物排放标准变化的基础上,分别对我国2000-2012年道路移动源和非道路移动源主要大气污染物（CO、NOx、HC、PM2.5）的排放量进行了估算。研究表明：2000-2012年间,我国移动源主要大气污染物排放总量呈现先增后减的趋势,2005年达到最大值,为4 233万t,其中道路移动源的排放量占80%以上;各类大气污染物的排放量的差异性较大,CO和NOx的排放量较多,占排放总量的87%以上,从整体趋势上来看,CO的排放量逐年较少,NOx的排放量逐年增大,而HC和PM2.5变化不大;摩托车和重型柴油货车是道路移动源主要排放源,农业机械是非道路移动源的主要排放源;移动源排放的主要大气污染物在地区间的分布极不平衡,2012年排放量最高的5个省份依次是山东、河北、河南、广东和江苏;排放强度较大的地区主要集中在环渤海经济圈、长三角地区和珠三角地区,其中又以上海、北京、天津3个直辖市的排放强度最大。     

某燃煤超低排放机组非常规污染物脱除

燃煤电厂非常规污染物的排放尚未引起足够的重视。为全面表征燃煤电厂非常规污染物脱除性能,针对某1 000 MW燃煤超低排放机组,分别采用FPM和CPM一体化采样系统、安大略法(OHM)、控制冷凝法、HJ 646-2013规定的有机物测试方法,系统研究了CPM、Hg、SO₃、PAHs等非常规污染物的梯级脱除特性。结果表明：100%、75%负荷时低-低温电除尘系统对CPM脱除率分别为87.15%、92.20%,湿法脱硫分别为49.65%、45.55%,不同负荷下FPM分别为3.6、4.4 mg·m⁻³,但CPM却分别达14.2、15.3 mg·m⁻³,CPM的浓度远超FPM;低-低温电除尘系统脱Hg效率为64.81%,整个系统的脱Hg效率为75.5%,Hg^p全部被脱除,剩余的是难以脱除的Hg⁰、Hg²⁺,脱除率分别为为63.01%、64.29%,Hg⁰排放浓度为5.4 μg·m⁻³,Hg²⁺排放浓度为0.5 μg·m⁻³;SCR脱硝催化剂将SO₂氧化成SO₃的转化率约为0.7%,低-低温电除尘系统可脱除88.7%的SO₃,湿法脱硫对SO₃的脱除率为29.63%,最终SO₃排放浓度为1.9 mg·m⁻³;全系统对16种PAHs脱除率达94.25%,其中,气相、固相脱除率分别为91.61%、99.27%,最终气相、固相PAHs排放浓度分别为2.39 μg·m⁻³和0.11 μg·m⁻³。现有超低排放设备对非常规污染物均有不同程度的协同脱除效果,满负荷条件下该机组CPM、Hg、SO₃、PAHs排放浓度分别为14.2 mg·m⁻³、5.9 μg·m⁻³、1.9 mg·m⁻³、2.5 μg·m⁻³,Hg的排放浓度满足火电厂大气污染物排放标准(GB 13223-2011)中30 μg·m⁻³的要求,CPM、SO₃、PAHs尚无国家强制排放标准。本研究结果可为燃煤电厂后续非常规污染物的控制提供参考。     

关于硝酸工业污染物排放标准的研究

中国近10年来硝酸工业快速发展,但该行业的污染治理和环境管理情况却没有得到同步发展和应有的重视,对环境已造成了严重污染.现行综合排放标准已无法对硝酸工业污染起到控制作用.分析了硝酸工业污染排放情况和国内外相关的排放标准,针对中国实际情况提出了该行业污染物排放标准制定思路,严格控制硝酸工业NOx 和总氮排放,并建议利用国际清洁发展机制对温室气体N2O实施减排控制.     

Developing and evaluating techniques for localizing pollutant emission sources with open-path Fourier transform infrared measurements and wind data

This paper presents the simulation and field evaluation results of two approaches to localize pollutant emission sources with open-path Fourier transform infrared (OP-FTIR) spectroscopy. The first approach combined the plume's peak location information reconstructed from the Smooth Basis Function Minimization (SBFM) algorithm and the wind direction data to calculate source projection lines. In the second approach, the plume's peak location was determined with the Monte Carlo methodology by randomly sampling within the beam segment having the largest path-integrated concentration. We first conducted a series of simulation studies to investigate the sensitivity of using different basis functions in the SBFM algorithm. It was found that fitting with the beta and Weibull basis functions generally gave better estimates of the peak locations than with the normal basis function when the plumes were mainly within the OP-FTIR's monitoring line. However, for plumes that were symmetric to the peak position or spread over the OP-FTIR, fitting with the normal basis function gave better performance. In the field experiment, two tracer gases were released simultaneously from two locations and the OP-FTIR collected data downwind from the sources with a maximum beam path length of 97 m. For the first approach, the release locations were within the 0.25- to 0.5-probability area only after the uncertainty of the peak locations was included in the calculation process. The second approach was easy to implement and still performed as satisfactorily as the first approach. The distances from the sources to the best-fit lines (i.e., the regression lines) of the estimated locations were smaller than 10 m.     

秸秆成型燃料锅炉污染物排放规律试验研究

根据锅炉烟尘测试方法(GB 5468-91)及锅炉大气污染物排放标准(GB 13271-2001),在不同风门的工况下,分别对设计的双层炉排秸秆成型燃料锅炉污染物排放规律进行试验.试验表明,在较好工况下,双层炉排锅炉排烟中CO等中间产物及烟尘含量低于单层炉排锅炉,其排烟中CO、NOx、SO2和烟尘浓度等指标远远低于燃煤锅炉,符合国家关于工业锅炉大气污染物排放标准要求,有较好环保效益.     

Design of network experiments for regional-scale atmospheric pollutant transport and transformation

Design criteria for the selection of regional-scale network sites, sampling times, and sampling intervals are investigated in terms of the verification requirements for various numerical models. Network experiments are classified into tracer experiments to test the physical and chemical mechanisms of atmospheric pollutant transformation and transport, and air quality experiments to evaluate the extent of air pollution. For the tracer experiments, two lines of five stations are recommended. The spatial separation between the lines is about 400 km, and the distances between stations are 170 km for the upstream line and 200 km for the downstream line. For air quality measurements, more than 13 stations are needed to recover the annual pattern of the pollutant concentration.     

Isotopic evidence of pollutant lead sources in Northwestern France

Ratios of stable lead isotopes (²⁰⁴Pb, ²⁰⁶Pb, ²⁰⁷Pb, ²⁰⁸Pb) are used to characterize both spatial and temporal variations in anthropogenic emissions of industrial lead aerosols to the atmosphere of northwestern France. Differences in isotopic compositions of aerosols collected from a rural area (Wimereux) in the Nord-Pas de Calais region along the English Channel in 1982–1983 (²⁰⁶Pb/²⁰⁷Pb=1.108±0.005) and 1994 (²⁰⁶Pb/²⁰⁷Pb=1.148±0.003) are paralleled by similar variations in urban aerosols within France during the same period (e.g., ²⁰⁶Pb/²⁰⁷Pb=1.115±0.008 from 1981–1989 and 1.143±0.006 from 1992–1995). These results correlate well with recent findings in the Mediterranean basin (Alleman, 1997) where this radiogenicity increase is clearly associated with industrial sources other than leaded gasoline that has remained relatively constant during its phasing out (²⁰⁶Pb/²⁰⁷Pb=1.08–1.11). Here we used archived data, air mass trajectories and aerosol diameters combined with isotopic signatures to confirm this trend at a regional scale. Indeed, the main industrial signatures from lead smelting (²⁰⁶Pb/²⁰⁷Pb=1.133±0.001) and steel metallurgy (²⁰⁶Pb/²⁰⁷Pb=1.196±0.015) in northwestern France appear more radiogenic than that of leaded gasoline. The shift in isotopic compositions also conform with the systematic change in the mean size (diameter) of aerosols at Wimereux, which ranged from 0.30 to 0.61 μm in 1982–1984 and from 0.70 to 0.89 μm in 1994.     

Quantification of emission factor uncertainty

Emissions factors are important for estimating and characterizing emissions from sources of air pollution. There is no quantitative indication of uncertainty for these emission factors, most factors do not have an adequate data set to compute uncertainty, and it is very difficult to locate the data for those that do. The objectives are to compare the current emission factors of Electric Generating Unit NOx sources with currently available continuous emission monitoring data, develop quantitative uncertainty indicators for the Environmental Protection Agency (EPA) data quality rated emission factors, and determine the possible ranges of uncertainty associated with EPA's data quality rating of emission factors. EPA's data letter rating represents a general indication of the robustness of the emission factor and is assigned based on the estimated reliability of the tests used to develop the factor and on the quantity and representativeness of the data. Different sources and pollutants that have the same robustness in the measured emission factor and in the representativeness of the measured values are assumed to have a similar quantifiable uncertainty. For the purposes of comparison, we assume that the emission factor estimates from source categories with the same letter rating have enough robustness and consistency that we can quantify the uncertainty of these common emission factors based on the qualitative indication of data quality which is known for almost all factors. The results showed that EPA's current emission factor values for NOx emissions from combustion sources were found to be reasonably representative for some sources; however AP-42 values should be updated for over half of the sources to reflect current data. The quantified uncertainty ranges were found to be 25-62% for A rated emission factors, 45-75% for B rated emission factors, 60-82% for C rated emission factors, and 69-86% for D rated emission factors, and 82-92% for E rated emission factors.     

Plume dispersion from ground level sources in simulated atmospheric boundary layers

Measurements of plume dispersion in urban and rural simulated boundary layers are compared with full scale data and theoretical treatments of plume behaviour. The experiments were conducted in the Marchwood Engineering Laboratories (MEL)9.1 × 2.7 m wind tunnel using sources of negligible buoyancy and momentum in 1/1000 and 1/300 scale neutrally stable, simulated atmospheric boundary layers. The theoretical considerations include gradient-transfer theory (analytic and numerical), similarity and statistical theory. The results of the comparisons are then used to demonstrate that the plume behaviour observed in the wind tunnel was a reasonable simulation of the Pasquill class D-C atmospheric behaviour.