北京市家具制造业涂料应用过程挥发性有机物排放现状及未来趋势

在调研北京市家具制造业涂料使用现状的基础上,采用排放因子法,分别自上而下计算北京市家具制造业挥发性有机物(VOCs)排放量,自下而上计算重点家具制造企业VOCs排放量,并采用情景分析法对未来北京市家具制造业VOCs排放情况进行预测。结果表明,2015年北京市家具制造业VOCs排放量约为1.37×10~4 t;重点企业VOCs排放量占比约29.4%。通过优化涂料品质使其达到欧美发达国家20世纪末期平均水平,且要求新建企业安装废气末端治理设施,该行业VOCs排放量可控制在1.15×10~4 t;进一步将涂料改进到欧美发达国家先进水平,且规模企业安装废气末端治理设施,该行业VOCs排放量可控制在8.80×10~3 t。对比分析两种控制措施的减排效果,提升涂料品质是控制VOCs排放的最有效措施。     

污水处理厂的挥发性有机物排放特征及健康风险评价

挥发性有机物(VOCs)种类繁多、来源广泛,污水处理厂是其中不容忽视的排放源之一。研究了某污水处理厂的VOCs组成特征、工艺特征和时间特征,并对美国环境保护署(USEPA)的综合风险信息系统中有相应毒理学数据的化合物进行了健康风险评价。结果表明,共检出了烷烃、烯烃、卤代烃、芳香烃以及含氧VOCs 5类54种化合物。筛选出10种特征化合物为乙醇、环己烷、丙酮、乙酸乙酯、二氯甲烷、苯、甲苯、丙烯、1,4-二氧己环和正己烷。污水处理厂各处理单元中检出的VOCs总浓度由高到低依次为初沉池B、缺氧池、初沉池A、厌氧池、好氧池和储泥池。在采样的4个时间段中,5类VOCs的变化趋势一致,中午(11:00—12:00)时浓度最高,下午(14:00—15:00)时最低。参与评价的9种化合物致癌危害指数均小于1.00×10~(-6),25种化合物非致癌危害指数均小于1,致癌风险和非致癌风险均在USEPA的可接受范围内。     

广州市工业挥发性有机物排放特征研究

伴随着工业经济的高速发展,广州市大气环境面临的压力日益增大,尤其是挥发性有机物( VOCs),可经过复杂的大气化学反应,引起一系列严重的空气质量问题.以源头追溯的方法,将该区域工业相关的33个VOCs排放源按照物质流动过程分为4个环节,分析了其排放特征.结果表明,2008年VOCs排放总量为182 362.7 t,各环节的贡献率分别为:VOCs的生产环节34.5％、储存和运输环节18.4％、以VOCs为原料的工艺环节9.9％、VOCs产品的使用和排放环节37.2％;污染主要来自石油炼制与石油化工、油品储运、交通运输设备制造与维修等,前12大污染源的VOCs排放量共占2008年排放总量的87.3％.2006-2008年的VOCs排放总量均超过15万t,且呈逐年增长的趋势.该研究可为“十二五”期间珠三角VOCs污染物联防联治工作提供借鉴.     

天津市典型溶剂使用行业挥发性有机物排放特征

基于天津市挥发性有机物(VOCs)的管控需要,针对天津市汽车喷涂、家具喷涂、人造板生产、包装印刷4类典型溶剂使用行业排放的VOCs进行采样监测,测定了其排放组分,评估不同处理设施对VOCs组分的影响,并对其臭氧生成潜势(OFP)进行分析.结果表明:汽车喷涂行业VOCs组分主要为烯烃和含氧VOCs(OVOCs);家具喷涂...     

浙江省船舶修造行业挥发性有机物组分特征及排放系数

基于浙江省29家船舶修造企业的调查数据,研究分析了船舶修造行业挥发性有机物(VOCs)治理情况和VOCs组分特征,并核算了VOCs产生系数和排放系数.结果表明,船舶修造行业VOCs治理设施总体覆盖率为55％,VOCs主要组分为苯系物(BETX)与含氧挥发性有机物(OVOCs).分别以船舶载重量、船舶数量为活动水平时,远...     

四川省加油站挥发性有机物排放及控制现状

四川省汽车保有量2017年位列全国第7位,油品储运销过程中挥发性有机物(VOCs)排放压力巨大。利用排放因子法,结合四川省4 492座加油站的油品销售量,编制了四川省2017年加油站VOCs排放清单。另一方面,对四川省不同片区的VOCs排放特征及油气回收关键参数进行了现场实测。结果表明:四川省加油站VOCs排放量共12 294.54t,排放区域主要集中在成都市、绵阳市和宜宾市等地区;四川省四大片区VOCs排放浓度,加油环节攀西片区最高,达到7 076.86μg/m~3,卸油环节川东北片区最高,达到9 638.53μg/m~3,均是其他片区的2～3倍,加油和卸油环节排放的异戊烷最高占比(质量分数)可分别达到70.1%和67.4%;四川省油气回收系统达标情况仍然比较严峻,不达标率高达47%,密闭性和气液比不达标率尤为显著,集中式油气回收系统不达标率高于分散式。     

印刷环节挥发性有机物无组织排放特征测定研究

对使用溶剂型油墨的凹版印刷设备和使用水性油墨的柔版印刷设备无组织排放的挥发性有机物(VOCs)浓度进行了实际监测,并采用计算流体动力学模拟无组织排放VOCs的收集效率。结果表明：(1)使用溶剂型油墨的凹版连续印刷过程非甲烷总烃(NMHC)最高均值达到5 975.67 mg/m³,约为使用水性油墨的柔版印刷(191.67 mg/m³)的31.2倍。虽然使用水性油墨可明显降低NMHC的排放,但其操作空间的浓度依然存在超过《工作场所有害因素职业接触限值第1部分：化学有害因素》(GBZ 2.1—2019)的现象。(2)印刷车间应该设置专门的调墨室,能缓解印刷车间内挥发性污染气体浓度的波动。(3)计算流体动力学模拟显示,设置合理的集气罩可有效降低VOCs的无组织排放,收集效率为70%～75%。     

典型石化企业挥发性有机物排放测算及本地化排放系数研究

石化行业是中国大气挥发性有机物(VOCs)的重要来源。以中国某新建典型石化企业为例,综合采用不同核算方法估算并比较了石化企业典型排放环节VOCs的排放结果;并在此基础上计算了石化企业典型排放环节本地化排放系数。结果表明,典型石化企业各环节VOCs排放量贡献分别为:储罐50.4%、废水收集与处理29.0%、火炬8.3%、装卸5.2%、设备密封点3.4%、循环冷却水2.4%、燃烧烟气0.8%、工艺废气0.5%;在装卸、设备密封点、废水收集与处理、循环冷却水环节,不同核算方法造成核算结果差异较大,排放系数法核算结果为本研究方法核算结果的数倍,其中装卸过程为4.2倍(无回收设施)和16.4倍(含回收设施),设备密封点为4.4倍(泄漏筛分法)和55.4倍(相关方程法),废水收集与处理为2.1倍,循环冷却水为2.1倍;《大气挥发性有机物源排放清单编制技术指南》中石油炼制企业的VOCs排放系数为本研究1.8倍,因此石化企业在建立排放清单时应开展本地化研究,建立本地化系数;研究结果对于中国建立石化企业VOCs排放清单提供了一定支撑。     

Characteristics and health risk assessment of volatile organic compounds emitted from interior materials in vehicles: a case study from Nanjing,China

Environmental Science and Pollution Research - It has become a great habit for driving to work in people’s daily life in China. In order to understand the concentration of volatile organic...     

Use of biochar for the sorption of volatile organic compounds (VOCs) emitted from cattle manure

Environmental Science and Pollution Research - The ability of biochar to be used as filter or as additive for the adsorption of volatile organic compounds (VOCs) emitted from cattle manure is...     

Speciation of volatile organic compounds from poultry production

Volatile organic compounds (VOCs) emitted from poultry production are leading source of air quality problems. However, little is known about the speciation and levels of VOCs from poultry production. The objective of this study was the speciation of VOCs from a poultry facility using evacuated canisters and sorbent tubes. Samples were taken during active poultry production cycle and between production cycles. Levels of VOCs were highest in areas with birds and the compounds in those areas had a higher percentage of polar compounds (89%) compared to aliphatic hydrocarbons (2.2%). In areas without birds, levels of VOCs were 1/3 those with birds present and compounds had a higher total percentage of aliphatic hydrocarbons (25%). Of the VOCs quantified in this study, no single sampling method was capable of quantifying more than 55% of compounds and in several sections of the building each sampling method quantified less than 50% of the quantifiable VOCs. Key classes of chemicals quantified using evacuated canisters included both alcohols and ketones, while sorbent tube samples included volatile fatty acids and ketones. The top five compounds made up close to 70% of VOCs and included: 1) acetic acid (830.1 μg m^?3); 2) 2,3-butanedione (680.6 μg m^?3); 3) methanol (195.8 μg m^?3); 4) acetone (104.6 μg m^?3); and 5) ethanol (101.9 μg m^?3). Location variations for top five compounds averaged 49.5% in each section of the building and averaged 87% for the entire building.     

Odors and volatile organic compounds released from ventilation filters

Used supply air filters were studied by sensory and chemical methods. In addition, filter dust was examined by thermodesorption/cold trap (TCT) and headspace (HS) devices connected to a GC–MS. The prefilter was the main odor source in the ventilation unit, but when humidifier was turned on odor was released mainly from the fine filter. However, the effect of the relative humidity (RH) was only temporary. At the same time, there was an increase in the concentration of aldehydes after the filters. Aldehydes, carboxylic acids, and nitrogen-containing organic compounds were the main emission products in the thermodesorption analyses of the filter dust. Many of these compounds have low odor threshold values and, therefore, contribute to the odor released from the filters. Especially, the role of aldehydes seems to be important in the odor formation.     

Head-space, small-chamber and in-vehicle tests for volatile organic compounds (VOCs) emitted from air fresheners for the Korean market

The present study investigated the emission characteristics of gel-type air fresheners (AFs), using head-space, small-chamber, and in-vehicle tests. Five toxic or hazardous analytes were found in the headspace phase of AFs (toluene, benzene, ethyl benzene, and m,p-xylene) at a frequency of more than 50%. Limonene and linalool, which are known to be unsaturated ozone-reactive VOCs, were detected at a frequency of 58 and 35%, respectively. The empirical model fitted well with the time-series concentrations in the chamber, thereby suggesting that the empirical model was suitable for testing emissions. Limonene exhibited the highest emission rate, followed by m,p-xylene, toluene, ethyl benzene, and benzene. For most target VOCs, higher air change per hour (ACH) levels exhibited increased emission rates. In contrast, higher ACH levels resulted in lower chamber concentrations. The mean concentration of limonene was significantly higher in passenger cars with an AF than without. For other target compounds, there were no significant differences between the two conditions tested. Consequently, it was suggested that unlike limonene, the emission strength for aromatic compounds identified in the chamber tests was not strong enough to elevate in-vehicle levels.     

Emission characteristics of volatile organic compounds from semiconductor manufacturing

A huge amount of volatile organic compounds (VOCs) is produced and emitted with waste gases from semiconductor manufacturing processes, such as cleaning, etching, and developing. VOC emissions from semiconductor factories located at Science-Based Industrial Park, Hsin-chu, Taiwan, were measured and characterized in this study. A total of nine typical semiconductor fabricators (fabs) were monitored over a 12-month period (October 2000-September 2001). A flame ionization analyzer was employed to measure the VOC emission rate continuously in a real-time fashion. The amount of chemical use was adopted from the data that were reported to the Environmental Protection Bureau in Hsin-chu County as per the regulation of the Taiwan Environmental Protection Administration. The VOC emission factor, defined as the emission rate (kg/month) divided by the amount of chemical use (L/month), was determined to be 0.038 +/- 0.016 kg/L. A linear regression equation is proposed to fit the data with the correlation coefficient (R2)=0.863. The emission profiles of VOCs, which were drawn using the gas chromatograph/mass spectrometer analysis method, show that isopropyl alcohol is the dominant compound in most of the fabs.     

Emissions of volatile organic compounds from building materials and consumer products

EPA's TEAM Study of personal exposure to volatile organic compounds (VOC) in air and drinking water of 650 residents of seven U.S. cities resulted in the identification of a number of possible sources encountered in peoples' normal daily activities and in their homes. A follow-up EPA study of publicaccess buildings implicated other potential sources of exposure. To learn more about these potential sources, 15 building materials and common consumer products were analyzed using a headspace technique to detect organic emissions and to compare relative amounts. About 10–100 organic compounds were detected offgassing from each material. Four mixtures of materials were then chosen for detailed study: paint on sheetrock; carpet and carpet glue; wallpaper and adhesives; cleansers and a spray pesticide. The materials were applied as normally used, allowed to age 1 week (except for the cleansers and pesticides, which were used normally during the monitoring period), and placed in an environmentally controlled chamber. Organic vapors were collected on Tenax-GC over a 4-h period and analyzed by GC-MS techniques. Emission rates and chamber concentrations were calculated for 17 target chemicals chosen for their toxic, carcinogenic or mutagenic properties. Thirteen of the 17 chemicals were emitted by one or more of the materials. Elevated concentrations of chloroform, carbon tetrachloride, 1,1,1-trichloroethane, n-decane, n-undecane, p-dichlorobenzene, 1,2-dichloroethane and styrene were produced by the four mixtures of materials tested. For some chemicals, these amounts were sufficient to account for a significant fraction of the elevated concentrations observed in previous indoor air studies. We conclude that common materials found in nearly every home and place of business may cause elevated exposures to toxic chemicals.     

Particulate organic compounds emitted from motor vehicle exhaust and in the urban atmosphere

The emission rate of particle-phase petroleum biomarkers in vehicular exhaust compared to the concentrations of these biomarkers in ambient air is used to determine the particulate organic compound concentration due to primary particle emissions from motor vehicles in the southern California atmosphere. A material balance on the organic particulate matter emitted from motor vehicle traffic in a Los Angeles highway tunnel first is constructed to show the proportion which is solvent-extractable and which will elute from a GC column, the ratio of resolved to unresolved compound mass, the portion of the resolved material that can be identified as single organic compounds, and the contribution of different classes of organic compounds to the overall identified fraction. It is shown that the outdoor ambient concentrations of the petroleum biomarkers track primary emissions measured in the highway tunnel, confirming that direct emissions of these compounds from vehicles govern the observed ambient petroleum biomarker concentrations. Using organic chemical tracer techniques, the portion of fine organic particulate matter in the Los Angeles atmosphere which is attributable to direct particle emissions from vehicle exhaust is calculated to vary from 7.5 to 18.3% at different sites throughout the air basin during a summertime severe photochemical smog episode. A similar level of variation in the contribution of primary motor vehicle exhaust to fine particulate organic matter concentrations during different times of day is seen. While peak atmospheric concentrations of fine particulate organic carbon are observed during the 1200–1600 PDT afternoon sampling period, only 6.3% of that material is apportioned to the directly emitted particles from vehicle exhaust. During the morning traffic peak between 0600–1000 PDT, 19.1% of the fine particulate organic material is traced to primary emissions from motor vehicles.     

Particulate organic compounds emitted from experimental wildland fires in a Mediterranean ecosystem

Fine (PM_2.5) and coarse (PM_2.5–10) smoke particles from controlled biomass burnings of a shrub-dominated forest in Lousã Mountain, Portugal, enabled the quantification by chromatographic techniques of several molecular tracers for the combustion of Mediterranean forest ecosystems, which could be conducive to source apportionment studies. The major organic components in the smoke samples were pyrolysates of vegetation cuticles, mainly comprising steradienes and sterol derivatives, carbohydrates from the breakdown of cellulose, aliphatic lipids from vegetation waxes and methoxyphenols from the lignin thermal degradation. Most of these compounds are chiefly found in fine particles. Polycyclic aromatic hydrocarbons (PAH) were also present as minor constituents. Anhydrosugar and PAH molecular diagnostic ratios were applied as source assignment tools. Some biomarkers are reported for the first time in biomass burning smoke.     

A study on dynamic volatile organic compound emission characterization of water-based paints

Volatile organic compounds (VOCs) emitted from surface coatings have caused growing public concern for air quality. Even the low-emitted VOC impact from water-based paints on indoor air quality in urban areas has caused concern. This paper presents experimental data using a mathematical model to simulate dynamic VOC emissions from water-based paints that is based on mass transfer and molecular diffusion theories. A series of field-analogous experiments were carried out to continuously measure the VOCs emitted from two typical water-based paints using a gas chromatography-flame-ionization detector monitor in an artificial wind tunnel system. In the study cases, the mass flux of VOCs emitted from the water-based paints was up to 50 microg/m2sec. It was found that the time needed to completely emit VOCs from water-based paints is just hundreds of seconds. However, the order of magnitude of the VOC emission rate from water-based paints is not lower than that from some dry building materials and solvent-based paints. The experimental data were used to produce a useful semiempirical correlation to estimate the VOC emission rates for water-based paints. This correlation is valid under appropriate conditions as suggested by this work with a statistical deviation of +/- 7.6%. With this correlation, it seems feasible to predict the dynamic emission rates for VOCs during a painting process. This correlation is applicable for assessing the hazardous air pollutant impact on indoor air quality or for environmental risk assessment. Associated with the dynamic VOC emission characterization, the air-exchange rate effect on the VOC emission rates is also discussed.