Near-real-time measurement of trace volatile organic compounds from combustion processes using an on-line gas chromatograph

The US EPA's current regulatory approach for combustion and incineration sources considers the use of real-time continuous emission monitors (CEMs) for particulate, metals, and organic compounds to monitor source emissions. Currently, the CEM technologies to support this approach have not been thoroughly developed and/or demonstrated. The EPA's Air Pollution Prevention and Control Division has developed a near-real-time volatile organic compound (VOC) CEM, using an on-line gas chromatograph (OLGC), capable of measuring over 20 VOCs at concentrations typically present in well-operated combustion systems. The OLGC system consists of a sample delivery system, a sample concentrator, and a GC equipped with both flame ionization and electron capture detectors. Application of the OLGC system was initially demonstrated through participation in the 1995 US EPA/DOE CEM demonstration program. Additional work has improved system performance, including increased automation and improved calibration technique. During pilot-scale incineration testing, measurement performance was examined in detail through comparisons to various CEM performance criteria. Specifically, calibration error, calibration drift error, and system bias were examined as a function of full scale (absolute error) and gas concentration (relative error). Although OLGC measurement performance was not able to meet standard EPA CEM measurement performance criteria, measurement performance was encouraging. The system demonstrated the ability to perform hourly trace level VOC measurements (0–100 ppbv) for as many as 23 different VOCs with boiling points ranging from −23.7 to 180.5 °C at a known level of measurement performance. This system is a suitable alternative to VOC reference method measurements which may be performed only intermittently.     

Quantification of landfill emissions to air: a case study of the Ano Liosia landfill site in the greater Athens area.

Fugitive pollutant emissions from municipal solid waste landfills have the potential to cause annoyance and health impacts in the surrounding residential areas. The overall objective of this research was to perform an assessment of fugitive pollutant emissions and a dispersion analysis downwind of a specific landfill site. The study was performed at the closed Ano Liosia landfill site which is located in the greater Athens area. The human exposure from priority to health-risk pollutants emitted from landfill, such as vinyl chloride and benzene, was estimated by the landfill gas emission LandGEM 2.01 software combined with the atmospheric long-term dispersion model ISC3-LT. The emission and meteorological conditions under which the models were applied referred to the worst-case scenario. This scenario was used for the evaluation of the maximum human exposure assessed beyond the Ano Liosia landfill towards the residential areas. The above scenario provides the minimum downwind distance of the health-risk zone which is calculated to be equal to 1.5 km from the landfill. Within this distance the assessed air pollutant concentration for several air pollutants was significantly above the World Health Organization reference lifetime exposure health criteria. Finally, the applied methodology was used in the Ano Liosia landfill, where atmospheric concentrations of pollutants measured in the field were compared with model predictions.     

Yardsticks to Integrate Risk Assessment,Risk Management,and Groundwater Remediation

Remediation of contaminated sites has focused largely on restoration of groundwater aquifers. Often the stated remedial goal is to achieve conditions allowing unrestricted use and unrestricted exposure. Such total groundwater cleanup has occurred at some sites, but is the exception rather than the rule. At the same time, significant effort occurs to perform risk assessments for potential exposure to contaminants in groundwater at sites, both before and after remediation. The logical synergy between risk assessment and remediation is for risk management to seek opportunities for optimal use of groundwater based upon realistic expectations of cleanup technologies and the relevant acceptable residual (postremediation) levels of contaminants. This article explores an approach to improve this synergistic relationship between risk assessment, risk management, and remediation for groundwater cleanups. ©2015 Wiley Periodicals, Inc.     

Size distribution and number concentration of particles at the stack of a municipal waste incinerator

A large number of particles and gaseous products are generated by waste combustion processes. Of particular importance are the ultrafine particles (less than 0.1 microm in aerodynamic diameter) that are emitted in large quantities from all the combustion sources. Recent findings of toxicological and epidemiological studies indicate that fine and ultrafine particles could represent health and environmental risks. Quantifying particulate emissions from combustion sources is important: (i) to examine the source status in compliance with regulations; (ii) to create inventories of such emissions at local, regional and national levels, for developing appropriate management and control strategies in relation to air quality; (iii) to predict ambient air quality in the areas involved at the source and (iv) to perform source apportionment and exposure assessment for the human populations and/or ecological systems involved. In order to control and mitigate the particles in the view of health and environmental risk reduction, a good understanding of the relative and absolute contribution from the emission sources to the airborne concentrations is necessary. For these purposes, the concentration and size distribution of particles in terms of mass and number in a waste gas of a municipal waste incineration plant were measured in the stack gas. The mass concentrations obtained are well below the imposed daily threshold value for both incineration lines and the mass size distribution is on average very stable. The total number concentrations are between 1 x 10(5) and 2 x 10(5)particles/cm(3) and are on average relatively stable from one test to another. The measured values and the comparison with other point sources show a very low total number concentration of particles at the stack gas, revealing the importance of the flue gas treatment also for ultrafine particles. Also in respect to linear sources (high and light duty vehicles), the comparison shows a negligible emission in terms of the total number of particles.     

油品储运行业挥发性有机物排放控制技术评估

分析了我国油品储运行业的VOCs排放环节和特点。选取燃烧法、吸收法、吸附法、冷凝法、膜分离法等VOCs排放末端控制技术作为研究对象,介绍了各方法的原理和适用条件。建立了包括环境性能、技术性能、经济性能3方面共10项指标的综合评价指标体系。采用模糊评价方法分析了油品储运行业VOCs排放末端控制备选技术的综合性能。结果表明,冷凝法和膜分离法具有良好的综合性能,是油品储运行业VOCs排放的最佳末端控制技术。     

Smoldering Combustion (STAR) for the Treatment of Contaminated Soils: Examining Limitations and Defining Success

Smoldering combustion, commercially available as the Self‐sustaining Treatment for Active Remediation (STAR) technology, is an innovative technique that has shown promise for the remediation of contaminant source zones. Smoldering combustion is an exothermic reaction (net energy producing) converting carbon compounds and an oxidant (e.g., oxygen in air) to carbon dioxide, water, and energy. Thus, following ignition, the smoldering combustion reaction can continue in a self‐sustaining manner (i.e., no external energy or added fuel input following ignition) as the heat generated by the reacting contaminants is used to preheat and initiate combustion of contaminants in adjacent areas, propagating a combustion front through the contaminated zone provided a sufficient flux of air is supplied. The STAR technology has applicability across a wide‐range of hydrocarbons in a variety of hydrogeologic settings; however, there are limitations to its use. Impacted soils must be permeable enough to allow a sufficient flux of air to the combustion front and there exists a minimum required concentration of contaminants such that the soils contain sufficient fuel for the reaction to proceed in a self‐sustaining manner. Further limitations, as well as lessons learned and methods to mitigate these limitations, are presented through a series of case studies. In summary, the successful implementation of STAR will result in >99 percent reduction in contaminant concentrations in treated areas, limited residual contaminant mass, reduced groundwater contaminant mass flux which can be addressed through monitored natural attenuation; and an enhanced site exit strategy, reduced lifecycle costs, and reduced risk. ©2016 Wiley Periodicals, Inc.     

A new approach to estimation of methane emission rates from landfills

Methane emission monitoring has become increasingly essential for diffusive area sources, especially for landfills, which contribute to a significant fraction of the total anthropogenic methane emission globally. Statutorily, methane emission rate from landfills in Germany shall be examined on a semiannual basis; however, an appropriate approach has yet to be developed and adopted for general use. In this study, a new method is proposed based on experimental results, which utilizes a TDLAS (Tunable Diode Laser Absorption Spectroscopy) instrument – GasFinder2.0® system and a dispersion model LASAT (Lagrangian Simulation of Aerosol Transport) as the measurement device and calculation model, respectively. Between April 2010 and December 2011, a research project was conducted at a pilot scale landfill in the south of Germany. Drawing on the extensive research into this pilot project, an effective strategy of measurement setup was determined. Methane concentration was measured with GasFinder2.0® system in the upstream and downstream sections of the project site, while wind and turbulence data were measured simultaneously by an ultrasonic anemometer. The average methane emission rate from the source can be calculated by using the results as input data in the dispersion model. With this method, site-specific measurement approaches can be designed for not only landfills, but also different diffusive area sources with less workload and lower cost compared to conventional FID (Flame Ionization Detector) method.     

Trace-level measurement of complex combustion effluents and residues using multidimensional gas chromatography-mass spectrometry (MDGC-MS)

The identification and quantitation of non-method-specific target analytes have greater importance with respect to EPA's current combustion strategy. The risk associated with combustion process emissions must now be characterized. EPA has recently released draft guidance on procedures for the collection of emissions data to support and augment site-specific risk assessments (SSRAs) as part of the hazardous waste incineration permitting process. This guidance includes methodology for quantifying total organic (TO) emissions as a function of compound volatility. The ultimate intent is to compare the amount of organic material identified and quantified by target analyte-specific methodologies to organic emissions quantified by the TO methodology. The greater the amount accounted for by the target analyte-specific methodologies, the less uncertainty may be associated with the SSRAs. A limitation of this approach is that the target analyte-specific methodologies do not routinely quantify compounds of low toxicological interest; nor do they target products of incomplete combustion (PICs). Thus, the analysis can miss both toxic and non-toxic compounds. As a result, it is unknown whether the uncharacterized fraction of the TO emission possesses toxic properties. The hypothesis that we propose to test is that organic emissions and organics extracted from particulate matter (PM) are more complex than standard GC-MS-based instrumentation can currently measure. This complexity can affect quantitation for toxic compounds, thereby potentially affecting risk assessments. There is a pressing need to better characterize these organic emissions from hazardous waste incinerators and PM extracts from various other combustion sources. We will demonstrate that multidimensional gas chromatography-mass spectrometry (MDGC-MS) procedures significantly improve chromatographic separation for complex environmental samples. Sequential repetitive heart-cutting MDGC, with coupled mass spectrometry will be shown to be a complete analysis technique. The ability of this technique to disengage components from complex mixtures taken from hazardous and municipal waste incinerators will be shown.     

Copper Emissions from Fuel Combustion Consumption and Industry in Two Urban Areas 1900–1980

The type of energy system andindustrial structure of urban areas is veryimportant for the total amounts of Cu emitted.The total per capita emission for the New Yorkarea is estimated to be approximately 4 timeslarger than Stockholm municipality between 1900–1980. The latter was mainly the result of largedifferences in energy systems and industrialstructure. Hydro-electric power and non fossilfuels were important energy sources for Stockholmwhile coal was a much more significant fuel forthe New York area. Metal processing hascharacterised the industries of Stockholm whilethe New York area was a national centre forcopper and petroleum refining as well as thechemical industry. In both cases the estimated Cuemissions from fuel combustion and industrydecreased from 1900–1980. But in the case ofconsumption related emissions the time trendsdiffer between the two urban areas. In Stockholmend use was the largest category of Cu emissionsduring the whole time period studied. In the NewYork area consumption related emissions becamethe largest source of Cu emission in the 1950s.     

Statistical modelling for the prediction and control of PCDDs and PCDFs emissions from municipal solid waste incinerators

The emissions of a full range of polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs) have become one of the most controversial issues in siting and building new municipal incinerators. The lack of comprehensive evaluation of the PCDDs/PCDFs formation and emission control technologies in earlier times resulted in ambiguity in the decision-making of incineration projects. Until the last decade, several emission tests of municipal solid waste incineration regarding to new combustion criteria, public regulations, and risk assessments were conducted and reported in the literature. However, only a few analyses of statistical prediction and control have been established. This paper presents a series of multiple linear regression models for PCDDs/PCDFs emission prediction and control corresponding to different types of incinerators. The data used in the regression analysis were integrated from several testing programmes held in North America. By applying these regression results, evaluation of various combustion criteria, public regulations, and environmental and health risk assessment can then be achieved. Such evaluation is valuable for some developing countries which do not have sufficient finance or engineering experience to pursue large scale emission tests, but need rapid promulgation of emissions control for municipal solid waste incinerators.     

Chlorinated Hydrocarbon–Contaminated Site Investigation With Optimized 3D‐CSIA Approach

An optimized “Three‐Dimensional Compound Specific Isotope Analysis (3D‐CSIA)'' investigation was conducted at a chlorinated hydrocarbon–contaminated site in order to (1) determine if multiple onsite sources of groundwater contamination existed and (2) demonstrate the cost‐effectiveness of applying isotope fingerprinting at such a complex contaminated site. Previous groundwater investigations identified chlorinated hydrocarbons at levels that significantly exceed drinking‐water standards but failed to determine the source(s) of contamination due to the lack of vadose‐zone contamination and the absence of groundwater contaminants in shallow portions of the surficial aquifer. To better understand the contaminant source(s), groundwater samples were taken and tested for both the presence of chlorinated hydrocarbons and their isotopic signatures of ¹³C/¹²C, ³⁷Cl/³⁵Cl, and ²H/¹H. A site investigation with an optimized 3D‐CSIA approach revealed multiple chlorinated hydrocarbon releases from different sources, which was also cost‐effective considering the new lines of evidence of target contaminants obtained with the 3D‐CSIA approach instead of any traditional fingerprinting approaches. In addition, the 3D‐CSIA results inferred in situ bioremediation of chlorinated hydrocarbons would be feasible at the site. © 2013 Wiley Periodicals, Inc.     

Assessment and comparison of the environmental performances of a regional incinerator network

In Emilia-Romagna region (Northern Italy) the integrated waste treatment system consists of material collection and recycling, incineration with energy recovery and landfill as final disposal. In particular, at least one incineration plant is working in almost every province of the region. In this work, a screening life cycle assessment approach is applied to seven different incinerators, to compare the different plant technologies and identify the most relevant environmental impacts and processes. The characterization method used in the life cycle impact assessment step is Eco-indicator 99. The functional unit is 1 ton of waste input. As a first result, it can be noted that while the combustion systems are rather similar, the main variables are ascribable to gas cleaning options and efficiency in energy recovery, which result in quite different environmental performances. Among heavy metals, particular attention must be paid to Cd and As, due to their high toxicity, despite their low quantities. The impact due to dioxin emission is orders of magnitude lower than other contaminants (e.g., heavy metals). Furthermore, a catalytic system could be useful for a complete removal of organic contaminants and for a more effective abatement of nitrogen oxides. Finally, the environmental impact assessment sorts the various plants according to their age, i.e., the most recent plants provide the best environmental performances for the same quantity of combusted waste.     

控制挥发性有机化合物污染的技术

介绍了工业生产中排放的挥发性有机化合物的种类,主要排放源及其处理方法,并着重介绍了世界上比较先进的蓄热式燃烧法和蓄热式催化氧化法。     

炼油恶臭污染治理技术在中国石化天津分公司的应用实例

简述了炼油装置区恶臭污染源的主要分布、恶臭气体组成和排放规律,介绍了恶臭治理的基本方法。通过治理实例,重点分析了目前常用的吸收法、燃烧法、生物法和吸附法等恶臭治理技术的优势和相对不足,并对恶臭治理应用技术方案的选择提出建议。     

Air Quality Management in Izmir Region of Turkey as Required by Clean Air Plans

As a first step to work out an abatement plan against air pollution, a local emission inventory with 1 hr temporal and 1 km spatial resolution in the city of Izmir and its surroundings was prepared. The study area consisted of a 200 × 170 km² rectangle having the city of Izmir at the centre. The studied pollutants were total particulate matter (PM), sulfur oxides (SO_x), nitrogen oxides (NO_x), volatile organic compounds (VOC) and carbon monoxide (CO). Emissions of these pollutants were determined by estimation methods making use of suitable emission factors. Emission sources were evaluated in three categories; point, area and line sources. For year 2000 total emissions in the study area on an average day were estimated as 173 tons PM, 299 tons SOx, 136 tons NOx, 68 tons VOC and 320 tons CO. At the second part of the study, calculated emissions were transformed into air quality predictions in the area by using the Industrial Source Complex – Short Term (ISCST3) dispersion model. Model results were tested with monitoring data from urban air quality stations obtained during the year 2000. Results of the past, present and future air quality estimates in the region were discussed. In order to do so, future scenarios including various control technology applications were formulated and tested to see their effect on the future air quality.     

Mathematical modelling of particle mixing effect on the combustion of municipal solid wastes in a packed-bed furnace

Packed bed combustion is still the most common way to burn municipal solid wastes. In this paper, a dispersion model for particle mixing, mainly caused by the movement of the grate in a moving-burning bed, has been proposed and transport equations for the continuity, momentum, species, and energy conservation are described. Particle-mixing coefficients obtained from model tests range from 2.0x10(-6) to 3.0x10(-5)m2/s. A numerical solution is sought to simulate the combustion behaviour of a full-scale 12-tonne-per-h waste incineration furnace at different levels of bed mixing. It is found that an increase in mixing causes a slight delay in the bed ignition but greatly enhances the combustion processes during the main combustion period in the bed. A medium-level mixing produces a combustion profile that is positioned more at the central part of the combustion chamber, and any leftover combustible gases (mainly CO) enter directly into the most intensive turbulence area created by the opposing secondary-air jets and thus are consumed quickly. Generally, the specific arrangement of the impinging secondary-air jets dumps most of the non-uniformity in temperature and CO into the gas flow coming from the bed-top, while medium-level mixing results in the lowest CO emission at the furnace exit and the highest combustion efficiency in the bed.     

#x0201c;两酸#x0201d;装置大气污染源分析及治理

石化企业的酸性水汽提装置、酸性干气脱硫装置和硫磺回收装置统称为#x0201c;两酸#x0201d;装置。对#x0201c;两酸#x0201d;装置所采用的工艺流程进行详细分析,得出#x0201c;两酸#x0201d;装置的有组织排放大气污染物主要为SO₂和NO_x,无组织排放大气污染物主要为H₂S、NH₃、有机硫化物和烃类。无组织排放源集中在各单元反应器、储罐和酸性气管线。针对无组织排放源,从防止逸散和恶臭治理两个方面提出了相应的污染防治措施,并比较了溶剂吸收法、燃烧法、湿法化学吸收法等目前常用的恶臭治理技术的优缺点。     

我国大气铅浓度水平与污染源排放特征

总结和评价了我国大气铅浓度水平、大气铅污染源的主要类型和排放特征,对今后我国大气铅污染发展趋势进行了说明.汽油无铅化以后,我国城市大气环境中的铅浓度有所下降,一般不超过国家标准的限值,但农村地区大气铅污染状况应引起高度重视.涉铅工业排放、燃煤排放和汽车尾气是大气铅污染的主要来源.我国大气铅污染源涉及行业和部门庞杂,伴随着铅产品的整个生命周期.     

A STUDY TO DEFINE A STANDARD HEALTH PROTECTION ZONE FOR SANITARY LANDFILL IN FU SHAN CITY

The concept of a Health Protection Zone for Sanitary Landfill of Urban Refuse has beeen established in Fu Shan City. It is based on a series of local air quality investigations and measurements. For determining major air pollutatns from a sanitary landfill, and area source dispersion model is used to calculate a fugitive emission rate of various air pollutatnts. According to the Ambient Air Quality Standard of China, (GB 3095-82), and by reference to Allowed Concentration in Habitable Areas of America and Japan, a Standard for a Health Protection Zone for Sanitary Landfill of Urban Refuse in Fu Shan has been developed.     

Impact on health of chlorinated dioxins and other trace organic emissions

The potential health effects of incineration of municipal solid waste (MSW) have been studied by the Swedish National Institute of Environmental Medicine.The greatest concern for health effects relates to the emission of PCDDs and PCDFs (“dioxins”). MSW incineration is presently estimated to be a large source for the emission of these compounds into ambient air. Based upon animal experiments, and by applying safety factors in the range 200–1000, a highest tolerable daily intake (TDI) has been estimated to be 1–5 pg kg⁻¹ of TCDD for humans. This TDI-value has been extended to cover all the congeners of PCDDs and PCDFs by the application of the concept of “TCDD-equivalents” (Eadon et al., 1983). The high concentrations found in human breast milk and fish indicate that the TDI value may be exceeded, especially among breast-milk fed babies. If the emission can be reduced to the proposed Swedish limit value of 0.1 ng m⁻³ n TCDD-equivalents, or less, the contribution from this source will be lowered. MSW incineration can be considered acceptable when the following aspects are taken into account: the risk estimation for TDI is conservative; there is no indication that man belongs to the most sensitive species although infants may be particularly sensitive; available studies indicate that the concept of TCDD-equivalents used overestimates the effect of mixtures of PCDDs and PCDFs; present levels in fish and human milk reflect the cumulative effect of many years of emission. Besides PCDDs and PCDFs, MSW incineration also gives rise to relatively high emissions of PAH, chlorinated PAH, phenols, benzenes and mutagenic substances under less well controlled combustion conditions. The emission of organic compounds is generally dependent on the combustion efficiency. If the combustion process is optimized and advanced flue-gas cleaning is applied so that the emission of TCDD-equivalents does not exceed 0.1 ng m⁻³, emission of other organics probably will not cause significant health hazards.