贵阳市民居室内外空气污染物分布及来源研究

对贵阳市部分家庭室内外空气污染物进行了监测,并对其来源进行了分析.结果表明,除了CO浓度未超标外,SO2、NO2、PM10、CO2、甲醛和氨均出现不同程度的超标,超标率在0.5%～38%,最大超标倍数1.1～2.7,其中PM10的超标率和甲醛的超标倍数最明显.室内空气污染物中,PM10、CO、CO2和甲醛主要来自室内源的贡献,SO2则受室外源的影响大.污染物在室内不同房间之间具有较高的相关关系.     

环境空气质量综合指数计算方法比选研究

环境空气质量综合指数是进行逐月城市环境空气质量比较和排序的重要方法,提出了4种涵盖SO2、NO2、PM10、PM2.5、CO、O3等6项污染物的综合指数计算方法,基于2013年74个城市逐月污染物浓度数据使用主成分分析方法进行了对比分析。结果表明,综合指数计算方法中污染物统计指标和标准化方法不同对于主要污染物的判定有重要影响,各种计算方法中PM2.5、PM10、O3是出现频率最多的主要污染物;除O3外其他5项污染物逐月统计指标间均有极显著的正相关性,冬季O3统计指标与SO2、NO2、PM10、PM2.5呈显著负相关,夏季则呈显著正相关;主成分分析结果表明,在去除冗余信息后,PM2.5、PM10的权重被相对削弱,SO2、NO2、CO的权重得到相对强化,O3的权重夏季得到强化、冬季被削弱;综合考虑不同方案下主要污染物频率分布情况和PM2.5、PM10、O3权重变化特征,建议计算逐月环境空气质量综合指数时,SO2、NO2、PM10、PM2.5宜以月均值除以年均值标准进行标准化,CO、O3宜以特定百分位数浓度除以日均值标准(或8 h均值标准)进行标准化;该方法可延伸到季、半年和年度的环境空气质量综合指数计算。     

2014年北京市CO浓度水平和时空分布

对北京市地面监测站点的CO浓度进行分析，探讨其浓度水平、变化趋势和时空分布特征。2014年春、夏、秋、冬四季北京市CO平均浓度分别为1.06、0.87、1.34、2.17 mg/m³。CO浓度均呈双峰型变化，第一个峰值出现在07：00-09：00，主要由交通早高峰的排放引起；第二个峰值出现在23：00左右，主要受交通晚高峰排放和夜间边界层高度降低的挤压效应的共同影响。从空间分布来看，全年整体呈现南高北低的分布特征，尤其是秋、冬季较为明显，体现了工业布局和区域传输对CO的影响。从全年来看，湿度对CO浓度的影响最大。对2014年冬季北京市的一次高CO浓度分析结果表明，此次过程是由本地排放和区域传输共同造成的，气象要素中地面气压对CO浓度影响最大。     

北京地区PM_(2.5)与空气污染物的关系模型

为了研究北京地区PM2.5与空气污染物的质量浓度关系。从PM2.5监测网收集2013-04-01~2014-05-15期间PM2.5、PM10、SO2、NO2、CO、O3等主要空气污染物数据,用多元线性回归模型建立PM2.5与空气污染物的质量浓度关系。结果表明:北京地区PM2.5与空气污染物PM10、SO2、NO2、CO、O3的质量浓度相关系数分别为0.9172、0.6332、0.7683、0.8166和-0.1797,优化的拟合方程为:[PM2.5]=-22.5925+0.569109×[PM10]+23.94913×[CO]+0.113025×[BPM2.5],模型的估算值与观测值相关系数为0.9426,此方程能较好地模拟北京地区的PM2.5质量浓度。     

太原市2013年环境空气质量变化特征分析

为全面了解太原市的环境空气质量状况及污染物的时间变化规律,本文选取太原市8个站点2013年1月至12月六种主要污染物(SO2、NO2、PM10、CO、O3、PM2.5)为期一年的监测数据,评价该市2013年环境空气质量的总体情况,研究各污染物在不同时间尺度的变化特征及相互之间的关系。结果表明,2013年太原市环境空气质量以良和轻度污染为主,首要污染物主要为PM2.5和PM10;SO2、NO2、PM10、CO和PM2.5的小时变化规律较为一致,都呈现"双峰型"的变化特征,O3则呈显著的"单峰型"变化规律;上述六种污染物具有明显的季节变化特征,SO2的浓度峰值主要集中在供暖期,NO2和O3—8h浓度在夏季要高于其他季节,PM10的浓度峰值出现在春季(3月)和秋季(10月),CO的浓度峰值集中在11月和12月,PM2.5的浓度峰值主要集中在冬季;相关性分析结果表明,SO2、NO2、PM10、CO、PM2.5浓度日均值在全年各时段均具有很好的正相关性,化石燃料的燃烧可能是上述污染物质的共同来源。     

郑州市 PM2．5和 PM10质量浓度变化特征分析

根据郑州市2013年PM2．5和PM10颗粒物连续自动监测数据，对郑州市各国控站点的PM2．5和PM10的达标情况、变化趋势等进行探讨分析。结果表明：2013年郑州市PM10和PM2．5的年均质量浓度均超过了新标准规定的年均值二级标准限值。 PM10和PM2．5月均值峰值出现在1月和10月，谷值出现在8月，各月PM2．5的超标天数都大于PM10。PM10和PM2．5冬季的日均值浓度明显高于其他季节，呈双峰型，夜晚浓度整体高于白天；PM2．5春、夏、秋三季日变化呈单峰型，PM10夏季和秋季呈单峰型，春季呈双峰型。 PM2．5和PM10日均值有着非常显著的线性相关关系，PM2．5和PM10浓度的比值（p）10月最高。     

CALRoads模式在上海市典型道路CO扩散预测中的应用

根据上海市市区、郊区典型主干道的气象条件、车流量、车型比例,以及CO小时质量浓度的监测资料,采用CALRoads模式中CALINE4和CAL3QHC模块,对郊区主干道和市区典型路口的适用条件分别进行了验证.结果表明,在稳定的气象条件下,CALINE4模式在模拟周围相对空旷主干道附近的CO质量浓度时,具有较好的结果,将CAL3QHC模式应用于市区典型交叉口,可以得到同监测值相对吻合的模拟结果,但准确性低于郊区.应用CALRoads模型对未来城郊典型道路附近CO高峰小时质量浓度的发展趋势进行了预测,并基于情景分析给出了减少交通污染的对策建议.     

贵州农村地区室内空气质量及细颗粒物污染特征

对贵州农村地区燃煤和燃柴典型村进行了室内外空气质量的监测,并对其中细颗粒物PM2.5的特征进行了研究。结果表明:燃煤家庭厨房和卧室PM2.5分别超过《环境空气质量标准》GB 3095—2012中标准限值(75μg/m3)的1.97、1.41倍,燃柴家庭分别超标0.74、0.06倍,而SO2、CO、NOx均低于标准限值。PAHs以燃煤村厨房最高,为53.92 ng/m3,燃柴村厨房为10.34 ng/m3,2种燃料所致PAHs均以中高环组分为主,对人体健康产生较大风险。PM2.5中氟和砷含量较低,低于参考浓度限值。燃煤村和燃柴村厨房内氟均值分别为0.14、0.11μg/m3,砷平均值分别为0.020、0.014μg/m3。需采取炉灶/燃料改良干预措施来降低农村室内空气污染物浓度,保障居民身体健康。     

CO对定电位电解法测定SO2的影响及对策探讨

采用定电位电解法测定固定污染源废气中SO2,根据CO标准气体干扰SO2 测定的规律建立数学模型,并在实验室用CO标气对数学模型进行验证.用该数学模型对5家企业固定污染源废气中SO2 监测,将测定结果与碘量法的测定结果比对,绝对误差与相对误差在允许范围内.     

北京大气CH4、CO2、TOC日变化规律及垂直分布的自动连续观测

提出了一种能自动连续监测CH4、CO2、TOC日变化及垂直分布的系统,利用该系统监测了2002年冬季CH4、CO2、TOC垂直分布的日变化的变化趋势.结果发现,距地面高度增加,受湍流扩散的影响,CH4、CO2、TOC浓度降低.冬季CH4浓度的日变化呈现明显的单峰周期变化,CO2日变化呈双峰形分布,TOC日变化没有明显的特征,其日变化受机动车尾气排放的影响很大.根据2002年冬季CO2浓度与2000年以前的对比结果发现,北京市冬季燃煤排放的污染物已处于一个相对稳定期,而随着北京市机动车保有量迅速增加,尾气排放成为影响某些大气微量气体日变化的主要因素.     

Determination of Ni(CO)4, Fe(CO)5, Mo(CO)6, and W(CO)6 in sewage gas by using cryotrapping gas chromatography inductively coupled plasma mass spectrometry

Evidence for the occurrence of Ni(CO)4 in addition to Mo(CO)6 and W(CO)6 in fermentation gases from a municipal sewage treatment plant is presented for the first time. The gases were sampled at the top of the sewage sludge digester using Tedlar bags, and were analysed using cryotrapping followed by gas chromatography coupled with inductively coupled mass spectrometry (GC-ICP-MS). The use of an ICP-MS as an element-specific detector gives sufficiently low detection limits for metals and was coupled to a packed column gas chromatograph. This method provides information about the speciation of volatile transition metals in contrast to previously used methods for the determination of Ni(CO)4 in gas samples. The element-specific detection of three different isotopes (m/z 58, 60, 62) and the correspondence of the samples' retention times with those of the standard provided convincing evidence that Ni(CO)4 is present in the fermentation gas. The concentrations found were in the sub-ppb level, which is at least one order of magnitude lower than the threshold level of 1 ppb (v/v). In addition, Mo(CO)6 and W(CO)6 were also measured in the sub-ppb range in contrast to the absence of Fe(CO)5. The stabilities of Ni(CO)4, Fe(CO)5, and Mo(CO)6 were tested in a carbon monoxide atmosphere. In the presence of distilled water, the following order of stability was found after 11 weeks: Fe(CO)5 < Ni(CO)4 < Mo(CO)6. In the presence of an aqueous solution containing nickel, molybdenum, tungsten and iron, however, only Fe(CO)5 was significantly decomposed (< 0.3% recovery); Ni(CO)4 and Mo(CO)6 were stable after 11 weeks. No W(CO)6 was formed. The low stability of Fe(CO)5 in the presence of water could be the reason why no volatile iron compound was found in sewage gas. This study showed that GC-ICP-MS can be employed to identify species-specific traces of metal carbonyls in process gases such as sewage gas.     

Catalytic CO oxidation over manganese-containing perovskites

Mixed metal oxides are discussed as possible substitutes for noble metals in automobile catalytic converters. The catalytic activity for CO oxidation of LaMnO₃ and La_0.5Sr_0.5MnO₃ catalysts was examined.The ability of these catalysts to provide lattice oxygen and to sustain the oxidation reaction, even in the absence of molecular oxygen, has been confirmed. Measurements were performed of the reversible oxygen uptake on the two catalysts.     

CO2 Capture and Storage with Leakage in an Energy-Climate Model

Geological CO₂ capture and storage (CCS) is among the main near-term contenders for addressing the problem of global climate change. Even in a baseline scenario, with no comprehensive international climate policy, a moderate level of CCS technology is expected to be deployed, given the economic benefits associated with enhanced oil and gas recovery. With stringent climate change control, CCS technologies will probably be installed on an industrial scale. Geologically stored CO₂, however, may leak back to the atmosphere, which could render CCS ineffective as climate change reduction option. This article presents a long-term energy scenario study for Europe, in which we assess the significance for climate policy making of leakage of CO₂ artificially stored in underground geological formations. A detailed sensitivity analysis is performed for the CO₂ leakage rate with the bottom-up energy systems model MARKAL, enriched for this purpose with a large set of CO₂ capture technologies (in the power sector, industry, and for the production of hydrogen) and storage options (among which enhanced oil and gas recovery, enhanced coal bed methane recovery, depleted fossil fuel fields, and aquifers). Through a series of model runs, we confirm that a leakage rate of 0.1%/year seems acceptable for CCS to constitute a meaningful climate change mitigation option, whereas one of 1%/year is not. CCS is essentially no option to achieve CO₂ emission reductions when the leakage rate is as high as 1%/year, so more reductions need to be achieved through the use of renewables or nuclear power, or in sectors like industry and transport. We calculate that under strict climate control policy, the cumulative captured and geologically stored CO₂ by 2100 in the electricity sector, when the leakage rate is 0.1%/year, amounts to about 45,000 MtCO₂. Only a little over 10,000 MtCO₂ cumulative power-generation-related emissions are captured and stored underground by the end of the century when the leakage rate is 1%/year. Overall marginal CO₂ abatement costs increase from a few €/tCO₂ today to well over 150 €/tCO₂ in 2100, under an atmospheric CO₂ concentration constraint of 550 ppmv. Carbon costs in 2100 turn out to be about 40 €/tCO₂ higher when the annual leakage rate is 1%/year in comparison to when there is no CO₂ leakage. Irrespective of whether CCS deployment is affected by gradual CO₂ seepage, the annual welfare loss in Europe induced by the implementation of policies preventing “dangerous anthropogenic interference with the climate system” (under our assumption, implying a climate stabilisation target of 550 ppmv CO₂ concentration) remains below 0.5% of GDP during the entire century.

Carbonation and CO2 uptake of concrete

This study developed a reliable procedure to assess the carbon dioxide (CO₂) uptake of concrete by carbonation during the service life of a structure and by the recycling of concrete after demolition. To generalize the amount of absorbable CO₂ per unit volume of concrete, the molar concentration of carbonatable constituents in hardened cement paste was simplified as a function of the unit content of cement, and the degree of hydration of the cement paste was formulated as a function of the water-to-cement ratio. The contribution of the relative humidity, type of finishing material for the concrete surface, and the substitution level of supplementary cementitious materials to the CO₂ diffusion coefficient in concrete was reflected using various correction factors. The following parameters varying with the recycling scenario were also considered: the carbonatable surface area of concrete crusher-runs and underground phenomena of the decreased CO₂ diffusion coefficient and increased CO₂ concentration. Based on the developed procedure, a case study was conducted for an apartment building with a principal wall system and an office building with a Rahmen system, with the aim of examining the CO₂ uptake of each structural element under different exposure environments during the service life and recycling of the building. As input data necessary for the case study, data collected from actual surveys conducted in 2012 in South Korea were used, which included data on the surrounding environments, lifecycle inventory database, life expectancy of structures, and recycling activity scenario. Ultimately, the CO₂ uptake of concrete during a 100-year lifecycle (life expectancy of 40 years and recycling span of 60 years) was estimated to be 15.5%–17% of the CO₂ emissions from concrete production, which roughly corresponds to 18%–21% of the CO₂ emissions from the production of ordinary Portland cement.     

Nine-year trend of air pollution by CO in Athens,Greece

Air quality data obtained by the Athens air pollution monitoring system from the nine-year period started in 1986 were analysed to determine time variations and the effect of various meteorological parameters on air quality by CO. From the ten monitoring stations measuring CO, the station located in a street with high traffic was selected since this site had the longest time record and presented the highest values of CO during the period examined. The time variations show that higher concentrations of CO were measured during the winter months, on working days and between 09.00 and 23.00 hours. The long-term trend shows a definite decline of CO concentrations after 1990 resulting from the substitution of gasoline-powered vehicles with vehicles equipped with three-way catalysts. Finally, it was found that during days with calm or S-SW blowing light winds the CO concentrations presented their higher values.     

低浓度二氧化碳检测管的研制

应用活性氧铝—百里香酚酞吸附ＣＯ２线性比长法研制出低浓度ＣＯ２检测管。测定范围０．０５～０．９０％;灵敏度为０．０５％;检测管变色长度与ＣＯ２浓度的相关系数γ＝０．９９８１,精密度与准确度符合国家标准８３ＧＢ７２２０～７２８０。其可靠性与经典的何氏气体分析器比较,结果基本一致。低浓度的ＳＯ２、Ｈ２Ｓ和ＮＨ３对测定无明显干扰,现场监测应用效果可靠,值得推广应用。     

Increased levels of bacterial markers and CO2 in occupied school rooms

Our group previously demonstrated that carbon dioxide (CO2) levels in heavily occupied schools correlate with the levels of airborne bacterial markers. Since CO2 is derived from the room occupants, it was hypothesized that in schools, bacterial markers may be primarily increased in indoor air because of the presence of children; directly from skin microflora or indirectly, by stirring up dust from carpets and other sources. The purpose of this project was to test the hypothesis. Muramic acid (Mur) is found in almost all bacteria whereas 3-hydroxy fatty acids (3-OH FAs) are found only in Gram-negative bacteria. Thus Mur and 3-OH FA serve as markers to assess bacterial levels in indoor air (pmol m(-3)). In our previous school studies, airborne dust was collected only from occupied rooms. However, in the present study, additional dust samples were collected from the same rooms each weekend when unoccupied. Samples were also collected from outside air. The levels of dust, Mur and C10:0, C12:0, C14:0, and C16:0 3-OH FAs were each much higher (range 5-50 fold) in occupied rooms than in unoccupied school rooms. Levels in outdoor air were much lower than that of indoor air from occupied classrooms and higher than the levels in the same rooms when unoccupied. The mean CO2 concentrations were around 420 parts per million (ppm) in unoccupied rooms and outside air; and they ranged from 1017 to 1736 ppm in occupied rooms, regularly exceeding 800-1000 ppm, which are the maximum levels indicative of adequate indoor ventilation. This indicates that the children were responsible for the increased levels of bacterial markers. However, the concentration of Mur in dust was also 6 fold higher in occupied rooms (115.5 versus 18.2 pmole mg(-1)). This further suggests that airborne dust present in occupied and unoccupied rooms is quite distinct. In conclusion in unoccupied rooms, the dust was of environmental origin but the children were the primary source in occupied rooms.     

Metabolic regulation in methanogenic archaea during growth on hydrogen and CO2

Methanogenic Archaea represent a unique group of micro-organisms in their ability to derive their energy for growth from the conversion of their substrates to methane. The common substrates are hydrogen and CO₂. The energy obtained in the latter conversion is highly dependent on the hydrogen concentration which may dramatically vary in their natural habitats and under laboratory conditions. In this review the bio-energetic consequences of the variations in hydrogen supply will be investigated. It will be described how the organisms seem to be equipped as to their methanogenic apparatus to cope with extremes in hydrogen availability and how they could respond to hydrogen changes by the regulation of their metabolism.Abbreviations Coenzyme F₄₂₀ 5-dezaflavin derivative - F₄₂₀H₂ 1,5-dihydro-F₄₂₀ - F₃₉₀ 8-adenylylated-(F₃₉₀-A) or 8-OH-guanylylated-(F₃₉₀-G)-F₄₂₀ - H₄MPT 5,6,7,8-tetrahydromethanopterin - HS-CoM coenzyme M, 2-mercaptoethanesulfonate - methyl-S-CoM 2-methylthioethanesulfonate - HS-HTP 7-mercaptoheptanoylthreonine phosphate - CoM-S-S-HTP heterodisulfide of HS-CoM and HS-HTP - FDH formylmethanofuran dehydrogenase - FRH coenzyme F₄₂₀-reducing hydrogenase - HDR heterodisulfide reductase - MCR methylcoenzyme M reductase - MDH 5,10-methylene-H₄MPT dehydrogenase - MVH non-coenzyme F₄₂₀, Viologen-reducing hydrogenase     

佛山市交通CO2排放及低碳出行对策

以佛山市2012年数据为基础,结合COPERT模型,分析了车型种类、排气量、燃油类型、排放水平等对CO2排放因子的影响规律,探讨了不同车型组成与排放水平下的CO2排放分担率,讨论并评估了佛山市的低碳交通出行对策。结果表明:排放水平对CO2排放因子的影响不明显,除重型客车与公交车,燃油类型对CO2排放因子的影响亦不明显,各车型的CO2排放因子随着排气量的增加而增加;当佛山市机动车平均行驶速度提高至55 km/h时,每辆车CO2综合排放因子可达最小值125.73 g/km;轻型客车和摩托车的CO2排放量最大,分别为1469 493 t/a和394 174.3 t/a,分担率分别为52.1%和14.0%;不同排放水平的载客车CO2排放分担率从大到小排序依次为:国I国0国Ⅱ国Ⅲ国Ⅳ,分别为34.7%、22.0%、21.2%、17.5%及4.6%。