冶炼烟气中砷的监测方法改进

金属冶炼烟气中的砷大都以颗粒物的形式存在,对环境造成污染.2010年,国家颁布了《铜、镍、钴工业污染物排放标准》( GB 25467-2010),对于废气中砷的监测,该标准中规定使用《空气和废气砷的测定 二乙基二硫代氨基甲酸银分光光度法(暂行)》( HJ 540-2009).然而该方法中对于烟气中砷的监测方法存在一定问题,高氯酸在高温消解过程中易爆炸,比较危险,另外采用在锥形瓶内加热至产生白烟的排酸方式不能有效地排净硝酸,会导致反应无法进行.为此,就该方法中有组织排放废气中砷的前处理部分提出了改进意见.     

大气污染排放窗口机制研究

以2种典型的污染排放源(点污染源和线污染源)为基础,提出排污窗口的概念,通过参数转换分解源强对污染扩散进行研究。首先在高斯污染扩散模型的基础上,对非持续性污染源强建模,然后以某烟囱的周期性排污分析,检验排污窗口设置的合理性。对于单双号限行的窗口性质的污染排放研究中,首先对交通流建立线污染扩散模型,然后融合元胞自动机(9元胞互影响)模拟区域多角度污染的扩散平衡,最后对"单双号限行"下北京市不同区域空气质量指标进行分析与仿真。分析结果表明,合理的排污窗口能够减轻污染程度及对人们日常生活的影响。     

Air Issues amd Ecosystem Protection, a Canadian National Parks Perspective

Several case histories illustrate national park air issues and responses in Canada. These examples include: acidification studies and establishment of a multiparticipant monitoring programme at Kejimkujik; studies of smoke at campgrounds in Jasper, La Mauricie and Forillon, its effect on health, and the management of visitors and firewood supply to mitigate these risks; and estimates of emissions from through-traffic in Yoho. From these cases and from reviews of the secondary literature, we can identify air issues that affect the maintenance of ecological integrity in national parks. These issues are: forest fires and smoke management; defining goals for ecosystem restoration; representation of natural regional conditions; visitor health and amenity; acidification; pesticides; eutrophication from airborne nitrates; permafrost melting; and UV-B. In June 1995, an International Air Issues Workshop brought together representatives from Canadian and U.S. national parks and other selected agencies. They ranked the air issues affecting national parks, producing quite an eclectic list. From the most to least serious issue, they are: acidification, toxics, visibility impairment, UV-B, smoke management, oil and gas development, fugitive dust, global warming, overflights, light pollution, noise and odour. Note that atmospheric change is only one among a group of stresses affecting national parks. Of 28 stresses recognized as significant for national parks in 1992, acid precipitation ranked 8th and climate change 23rd. Petrochemicals, 17th, pesticides, 18th and heavy metals, 21st, may be partly airborne. The 1995 workshop made several recommendations applicable to Parks Canada, from which those related to research and monitoring needs have been extracted. The air monitoring needed most by national parks is of suspended particulate and visibility. This is in response to human health and amenity concerns and international treaty obligations. The long-term protection of natural sites in national parks provides opportunities for other agencies to monitor ambient air quality and ecosystem responses, for example through the installation of under-canopy monitoring towers. The air research most needed in national parks is the modelling of natural landscapes and vegetation complexes in response to climate change. This follows from the primary purpose of each national park, to maintain the ecological integrity of an area selected to represent a natural region. The principal air research opportunities for other agencies in national parks are probably intensive instrumentation and sampling over several years to examine the air-vegetation-soil transfers of nutrients, pollutants and radiation.     

Assessment of air pollution from small scale industry

Air pollution due to small scale industries have been found tocause serious occupational health hazards and adverse effects on vegetation and heritage. The study for air pollution impactassessment for brick kiln industries was undertaken. The stackmonitoring exercise was carried out to estimate the pollution level of SPM, SO₂, and NO_x. The ambient air quality was also measured in the vicinity of brick kilns to assess the impact of stack emission on ground level concentration. Characterisation of SPM for toxic metals were studied. Modelling exercise was carried to predict the impact of emission of brick kiln on surrounding environment. To minimise the emission level and ground level concentration, airpollution mitigation measures are suggested.     

点源扩散大气预测软件

建设项目的点源扩散大气预测软件,包括了<环境影响评价技术导则-大气环境>第三级评价有风时,静风和小风扩散模式;最大地面浓度Cm及其距排气筒的距离Xm模式;烟气抬升公式以及等值线点位值的计算功能.该软件运算快速、简便、准确.     

郑州市不同季节空气中醛酮类化合物污染特征及来源

选择郑州市6个特征区域进行布点,在冬季和夏季,每季连续3 d采集样品,并采用2,4-二硝基苯肼吸附管吸附大气样品-高效液相色谱法测定大气中醛酮类化合物浓度水平。结果表明,郑州市大气中主要的醛酮类化合物是甲醛、乙醛、丙酮和2-丁酮,它们的小时平均质量浓度冬季分别为8.23、7.67、13.9、1.56μg/m3,夏季分别为15.4、10.3、17.1、3.30μg/m3,夏季浓度明显高于冬季;无论冬季或夏季昼间浓度均普遍高于夜间,甲醛、乙醛和丙酮的日变化最高质量浓度多出现在08:00~09:00或12:00~13:00或18:00~20:00等时段;甲醛、乙醛和丙酮在冬季相关性较好,具有相同的源和汇,甲醛和乙醛在夏季相关性较好,而甲醛、乙醛和丙酮在夏季的相关性较差。大气醛酮类化合物变化趋势表明,机动车尾气排放和光化学反应是郑州大气醛酮类化合物的重要来源。     

金汞齐富集—冷原子吸收法测定大气中的微量汞

本文介绍了大气中微量汞的一种监测方法,利用汞富集解析器富集大气中的微量汞.解析后用冷原子吸收法测定.研究了FJ-1型汞富集解析器与WYX-405原子吸收分光光度计联用的工作条件,相对标准偏差为1.7％.     

临汾市大气污染物的时间分布特征与源区分析

多年来,临汾市多次名列我国生态环境部公布的空气质量最差的重点城市之列,对其大气污染的时间分布特征和潜在源区进行分析对其环境管理与污染防治具有重要意义。利用2015—2019年临汾市5个国控空气环境质量监测站点的6种空气污染物(SO₂、NO₂、CO、O₃、PM_2.5和PM₁₀)浓度数据和气象观测数据,使用HYSPLIT模型研究了该市空气污染物的时间变化特征、轨迹输送特征和可能的来源。结果表明,PM_2.5和PM₁₀的年均浓度均超过了《环境空气质量标准》(GB 3095—2012)Ⅱ级标准,SO₂仅在2016—2017年超过该标准,其余3种污染物的年均浓度均低于该标准。6种污染物2015—2019年的月均浓度的变化特征表现为O₃浓度呈以6、7月为中心的近似正态分布,SO₂、NO₂和CO以及PM_2.5和PM₁₀浓...     

Industrial pollution transport. Part 2. Control of industrial emissions

Solutions of the pollution transport problem and its adjoint are used to monitor mean pollution concentration in an ecologically important zone. Four strategies of control over pollutants released into the atmosphere by industrial plants are suggested. They differ by the restrictions imposed on the emission rate of each plant. All the strategies use solutions of the adjoint transport problem and assure the fulfillment of the sanitary norm in the zone. A linear interpolation of these strategies also brings pollution level in the zone down to the sanitary norm. A method of detecting the plants violating the prescribed emission rates is also given. A simple example is given to illustrate the strategies suggested.     

制定污水中控制项目地方排放标准的几点考虑

以新疆石河子市为例,阐述了实行水污染物排放许可证制度,制定污水中控制项目的地方排放标准时应考虑的几点原则和确定标准值的思路.     

试论建设项目环评中总量控制目标的确定及验证

就环评报告书如何根据环境管理的要求和项目的特点,对所确定污染物总量控制目标的合理性,从多方面进行了验证。     

集合数值预报系统在上海市空气质量预测预报中的应用研究

介绍了上海市世博环境空气质量集合数值预报系统的框架,分析了各模式在上海市空气质量预报及排放源污染贡献测算中的应用情况,提出开发多种预报手段、实施集合预报是提高城市空气质量预报准确率的发展方向。     

湿式消解法对冷原子吸收测定生物样品中汞产生的干扰

用不同的湿式消解法对多种生物样品的进行消解测定,分析了实验的干扰因素,并推荐了比较适宜的消解方法。     

贵州东部某燃煤电厂汞排放对周边环境空气及土壤的影响

结合当地气象条件,测定贵州省东部某燃煤电厂下风向环境空气汞浓度分布情况,同时测定该燃煤电厂周边表层土壤中汞含量,并对其污染程度进行评价,探讨了土壤汞与理化性质间的相关性。结果表明,该燃煤电厂下风向环境空气汞浓度远高于北半球大气气态总汞背景值,空气汞浓度在2.7 km范围内随距离的增大而增大,在2.7~5.0 km范围内汞浓度随距离的增大而减小。电厂周边表层土壤汞含量是贵州省A层土壤Hg背景值的8.5倍,存在中度到重度程度的污染,土壤Hg与土壤pH呈正相关性,但与土壤有机质未表现出相关性。     

The Impact of Road Traffic in Madrid Community by Using a Nested Gaussian-Mesoscale Air Quality Model (GAMA)

In this contribution we show the integration of a mesoscale air quality model OPANA with the ISCST3 Gaussian model (EPA) in order to analyze the impact of different emission sources and particularly the traffic emission into the different gridboxes which define the OPANA Eulerian structure. The application is done over the Madrid (Spain) regional area with 80 × 100 km and gridboxes of about 5 km. Thousands of Gaussian runs over interested gridboxes are executed in order to simulate the traffic emissions from each gridbox. Each mobile unit is represented by a Gaussian point emitter. Input meteorological variables for the ISCST3 are taken from the OPANA mesoscale air quality model. Results shows that it is possible to model the impact of traffic emissions over each gridbox. A short comparison with air quality monitoring in each gridbox is also shown.     

Organochlorines and Mercury in Waterfowl Harvested in Canada

Samples of breast muscle from 32 species of waterfowl collected from 123 sites across Canada were analyzed for chlorobenzenes (CBz), chlordane-related compounds (CHL), hexachlorocyclohexanes (HCH), DDT, mirex, dieldrin, PCBs and mercury. ΣDDT, ΣCBz and ΣPCB were the compounds most frequently found above trace levels. ΣHCH and ΣMirex were detected the least often. Mercury was detected in all of the mergansers, over 50% of dabbling, bay and sea ducks, and in less than 2% of the geese analysed. The highest levels of contaminants were generally found in birds feeding at higher trophic levels such as sea ducks and mergansers. With the exception of a few samples of mergansers and long-tailed ducks from eastern Canada, which contained ΣPCB concentrations of 1.0–2.4 mg kg⁻¹, ΣPCB levels were less than 1 mg kg⁻¹ wet weight. Only one merganser from eastern Canada had a ΣDDT concentration (2.6 mg kg⁻¹ ww) which was greater than 1 mg kg⁻¹ ww. The highest ΣCHL (0.10 mg kg⁻¹ ww) was also found in mergansers from eastern Canada. Levels of total mercury in breast muscle were either low (< 1 mg kg⁻¹ ww) or below detection limits with the exception of a few samples of mergansers from eastern Canada which contained mercury concentrations of 1.0–1.5 mg kg⁻¹ ww. Health Canada determined that the organochlorine and mercury levels found in samples of breast muscle of ducks and geese analysed in this study did not pose a health hazard to human consumers and therefore these waterfowl were safe to eat.     

三亚市臭氧污染特征、输送路径及潜在源区分析

基于2015-2019年三亚市空气质量自动监测数据和气象观测资料,结合后向轨迹聚类与潜在源区分析等方法,分析了三亚市O₃污染特征。结果表明:2015-2019年三亚市O₃浓度总体优良,优良天数比例为97.9%(标准状态),超标天均为轻度污染,多发生在秋冬季。O₃浓度与平均相对湿度、气温和降水量呈负相关关系,与平均风速呈正相关关系,同时与风向密切相关。6-8月气温较高,主导风向为偏南风,O₃及其前体物以本地排放为主,O₃浓度较低;秋冬季盛行东北风,易受到来自内陆的污染传输影响,O₃浓度相对较高。当日最高气温为20~30℃、日均相对湿度为65%~85%、日均风速为3~8 m/s、主导风向为东北风时,三亚市发生O₃超标的概率较高。台风外围和冷高压南下是导致三亚市O₃超标的2种典型天气形势。经聚类分析得到,2019年2个污染过程气团输送路径均来自东北方向,潜在源区分析WPSCF与WCWT的高值区一致性较好,均表明珠三角地区是三亚市重要的O₃污染潜在源区,需要加强与珠三角地区O₃污染的联防联控。     

Assessment of New Vehicles Emissions Certification Standards in the Metropolitan Area of Mexico City

Light duty gasoline vehicles account for most of CO hydrocarbons and NOx emissions at the Metropolitan Area of Mexico City (MAMC). In order to ameliorate air pollution from the beginning of 2001, Tier 1 emission standards became mandatory for all new model year sold in the country. Car manufacturers in Mexico do not guarantee the performance of their exhaust emissions systems for a given mileage. The purpose of this study was to assess whether the Tier 1 vehicles will stand the certification values for at least 162000 km with the regular fuel available at the MAMC. Mileage accumulation and deterioration show that certified carbon monoxide emissions will stand for the useful life of the vehicles but in the case of non-methane hydrocarbons will be shorter by 40%, and nitrogen oxides emissions above the standard will be reached at one third of the accumulated kilometers. The effect of gasoline sulfur content, on the current in use Tier 1 vehicles of the MAMC and the impact on the emissions inventory in year 2010 showed that 31000 extra tons of NOx could be added to the inventory caused by the failure of the vehicles to control this pollutant at the useful life of vehicles.     

HEAVY METALS AND SELENIUM IN GREBE EGGS FROM AGASSIZ NATIONAL WILDLIFE REFUGE IN NORTHERN MINNESOTA

Metal levels in eggs can often be used as an indicator of exposure and of potential effects. In previous work at Agassiz National Wildlife Refuge, northwestern Minnesota, the levels of several heavy metals were shown to be significantly higher in the eggs of eared grebes (Podiceps nigricollis) compared to those in the eggs of Franklin’s gulls (Larus pipixcan), black-crowned nightherons (Nycticorax nycticorax) and double-crested cormorants (Phalacrocorax auritus, except for mercury). In the present study we test the hypothesis that there are no differences in the levels of heavy metals in eggs of three species of grebes nesting at Agassiz National Wildlife Refuge (1997, 1999). There were significant differences in levels of selenium, manganese and mercury in the eggs of the grebes collected in 1997, with pied-billed grebe (Podilymbus podiceps) having significantly higher levels of manganese and mercury, and significantly lower levels of selenium, than eared or red-necked grebes (Podiceps grisegena). In 1999, pied-billed grebes had significantly higher levels of mercury, but lower levels of selenium and tin than the other species. The only pattern that was significant and consistent among yearswas selenium; in both years pied-billed grebes had lower levels than the other species. For eared grebes, there was a decline from 1997 to 1998, and again to 1999 for arsenic, cadmium, and selenium. Levels of mercury in the eggs of grebes were not as high, however, as those found in cormorants or night-herons sampled in 1994 at Agassiz National Wildlife Refuge. There were few consistent patterns in the relationships among metals in eared grebe eggs (with the largest sample sizes). The possible reasons for the high levels of some metals in eggs of grebes are unknown, but presumably egg levels represent exposure on the wintering grounds or migratory routes. In comparison to eggs of other birds: 1) the mean levels for manganese were at the high end of the range, and the mean was an order of magnitude higher than the median for the studies examined, 2) mean levels were above the median in the eggs of other birds for lead (red-necked grebe), mercury (pied-billed grebe) and selenium (eared and red-necked grebe).     

Evaluation of Three Air Dispersion Models: ISCST2, ISCLT2, and Screen2 for Mercury Emissions in an Urban Area

The goal of this paper is to compare and evaluate the performance of three air quality regulatory models for mercury releases. The models include Industrial Source Complex Short Term model (ISCST2), Industrial Source Complex Long Term model (ISCLT2), and SCREEN2. The evaluation is conducted in multiple point source urban environment using meteorological data, emission inventory and monitoring data for eight stations for the year 1990 to 1992. The performance of the models is evaluated using eight statistical parameters. The comparison of models results for both quarterly and annual averaging periods shows that ISCST2 predictions qualitatively match the observed concentrations; whereas SCREEN2 predicts highest concentrations and ISCLT2 the lowest concentrations. The summary of statistical analysis obtained by using three different methods of observed concentration (Co) and predicted concentrations (Cp) comparison show that the ISCST2 has a better overall performance than ISCLT2 and SCREEN2 models. However, none of the models met the criteria for a reasonable model. Summaries of 95% confidence limits on normalize mean square error (NMSE), geometric mean variance (VG) and geometric mean bias (MG) for each and among model indicate that of the three models, ISCST2 has the best overall performance indicators. Improved model performance may be achieved by incorporating different types of mercury forms into emission rate and air dispersion calculations.