Source characterisation of atmospheric platinum group element deposition into an ombrotrophic peat bog

Platinum, palladium, rhodium, iridium and osmium were found to be enriched relative to their expected natural concentrations in peat samples from Thoreau's Bog, an ombrotrophic peat bog in Concord, Massachusetts. The source of osmium into the bog was determined from its isotopic composition (187Os/188Os). Osmium is composed of 4% lithogenic osmium from atmospheric soil dust, 41% of anthropogenic osmium and 55% of osmium from a non-lithogenic, non anthropogenic source, with rain being a likely candidate for the latter. Significant anthropogenic and rain contributions are also expected for iridium. In contrast, platinum, palladium and rhodium are almost exclusively anthropogenic. The larger enrichments of platinum, palladium and rhodium indicate that automobile catalysts are the source of platinum group elements to Thoreau's bog. The bog is located approximately 300 m from a major road and, therefore, the occurrence of platinum elements is evidence for regional dispersion of these metals. The absence of a clear trend following the introduction of catalysts indicates that platinum group elements are not quantitatively conserved in peat with downward leaching and plants playing an important role in the accumulation of platinum group elements.     

Exposure to anti-cancer drugs during preparation and administration. Investigations of an open and a closed system

Systems for the preparation and administration of drugs are designed to ensure that the drug is not contaminated. They do not necessarily consider the work environment for the medical staff and new techniques are therefore desirable. The aim of this work is to compare a new closed system for the preparation and administration of drugs with the traditional technique with regard to airborne emission and surface spillage of drugs. Platinum, determined using adsorptive voltammetry, was used as the tracer for airborne emission. Air samples were collected during the preparation and administration, and the collected platinum on the filters was determined by adsorptive voltammetry. For determination of spills and leakage onto surfaces the radioisotope 99m-technetium was used as a tracer. The radiation from the isotope was determined on protective gloves and bench covers after preparation and administration. The mean airborne emission was 6 ng m(-3) with the closed system and 15 ng m(-3) with the traditional pump technique. The average surface spillage using the closed technique was 0.005 microL. This is significantly smaller than with the traditional technique, which resulted in an average spillage of 64 microL. Our results also show that the dominant part of the leakage is surface spillage. Inexperienced nurses could also adequately handle the closed system.     

Collaborative evaluation of the analytical state-of-the-art of platinum, palladium and rhodium determinations in road dust

In order to control the quality of platinum, palladium and rhodium determinations in road dust, the Standards, Measurements and Testing Programme (formerly BCR) of the European Commission has started a project, the final aim of which is to certify a road dust reference material for its contents of platinum group elements. The first part of this project consisted of an interlaboratory study, which aimed to test the feasibility of the preparation of a candidate road dust reference material and to detect and remove most of the pitfalls observed in platinum, palladium and rhodium determinations. This paper presents the main results of this interlaboratory study carried out prior to the certification campaign. The concordance of the data obtained by the participating laboratories for the three elements was considered to reflect the state-of-the-art and was encouraging enough to decide on the organization of a certification campaign to be conducted during the year 2000. The progress made with respect to the analytical state-of-the-art for these elements will be of great benefit to the quality of measurements carried out in environmental monitoring in this particular field.     

Platinum concentrations in Danish air samples determined by instrumental neutron activation analysis

Platinum, gold and calcium concentrations of 20 samples of airborne dust collected at two sampling sites between 1995 and 1997 in the city of Copenhagen, which suffers from heavy traffic, were determined by instrumental neutron activation analysis (INAA). INAA of platinum using the 199Au daughter of 199Pt was performed. Two interferences on the INAA of platinum were removed by calculations. The spectral interference on 199Au from the 47Sc daughter of 47Ca was removed by separating the 157-161 keV doublet peak into its components by calculating the counts due to 47Sc from the counts of the parent 47Ca. The contribution of 197Au to 199Au by two neutron absorption was corrected for using the ratio 198Au/199Au in a pure Au standard. From the INAA results, high platinum concentrations are present in air in the range 0.25-2.74 ng m-3 and gold concentrations in the range 0.10-1.96 ng m-3.     

Time value of emission and technology discounting rate for off-grid electricity generation in India using intermediate pyrolysis

The environmental impact assessment of a process over its entire operational lifespan is an important issue. Estimation of life cycle emission helps in predicting the contribution of a given process to abate (or to pollute) the environmental emission scenario. Considering diminishing and time-dependent effect of emission, assessment of the overall effect of emissions is very complex. The paper presents a generalized methodology for arriving at a single emission discounting number for a process option, using the concept of time value of carbon emission flow. This number incorporates the effect of the emission resulting from the process over the entire operational lifespan. The advantage of this method is its quantitative aspect as well as its flexible nature. It can be applied to any process. The method is demonstrated with the help of an Intermediate Pyrolysis process when used to generate off-grid electricity and opting biochar route for disposing straw residue. The scenarios of very high net emission to very high net carbon sequestration is generated using process by careful selection of process parameters for different scenarios. For these different scenarios, the process discounting rate was determined and its outcome is discussed. The paper also proposes a process specific eco-label that mentions the discounting rates.     

不同类型机动车尾气挥发性有机化合物排放特征研究

机动车尾气主要成分包括一氧化碳、氮氧化物、碳氢化合物、铅及苯并[a]芘等.其中,挥发性有机化合物由于其对光化学烟雾的贡献及对人体健康的影响而成为近年来大气化学研究的热点.文章首次对北京市9种车辆、5种燃料在不同工况下排放挥发性有机化合物特征进行了定量研究.结果表明,车型、燃料、净化器及工况等因素对排放量产生影响,电喷车比化油器车排放低,其中,夏利比富康与奥迪排放量高;LPG与汽油车排放量最高,柴油车与CNG车排放最低.其中,-10#柴油车比0#柴油车排放更低;使用净化器可以降低挥发性有机化合物排放量;不同工况对排放量的影响随车型、燃料类型的不同而不同.因此,使用清洁燃料、安装净化器和使用电喷装置,可减少尾气中挥发性有机化合物含量.     

城市环境中的PGEs研究进展

PGEs及其化合物是一类高发生率的致敏物,部分PGEs化合物还具有致癌效应.PGEs排放带来的环境问题已成为近年来国际环境问题研究热点之一,但尚未引起国内学术界足够重视,相关报道较少.本文从PGEs在环境中的富集特征、分布规律与来源、迁移转化及其生物有效性等方面对国内外城市环境PGEs研究现状进行了系统的阐述与总结,并...     

生活垃圾焚烧烟气中重金属排放水平及影响因素分析

通过对浙江省生活垃圾焚烧炉排放烟气中重金属的监测,分析生活垃圾焚烧烟气中重金属排放水平。结果表明,汞及其化合物的检出率最高,为95.7%,其次为铬和锰,检出率均为60%,且在不同的焚烧炉中重金属排放浓度差异较大,检出率最低的为铊和镉,且排放浓度均较低;焚烧炉排放烟气中汞及其化合物、镉+铊及其化合物、锑+砷+铅+铬+钴+铜+锰+镍及其化合物排放浓度均低于国标排放限值,最大占标率分别为76%、4%、21.9%。焚烧烟气中的重金属含量与焚烧垃圾中的重金属含量有关,烟气通过废气处理设施,可有效地减少重金属等污染物的排放。     

Fractionation of traffic-emitted Ce, La and Zr in road dusts

The introduction of catalytic converters has led to a new environmental problem since catalysts emit platinum group elements (PGEs) which are among the least distributed elements in nature. Along with PGEs the vehicle exhaust catalysts contain also a number of stabilizers, commonly oxides of rare earth elements and alkaline earth elements such as Ce, La and Zr. Since vehicular emission of these elements has received little attention so far this work attempts to offer insight into their distribution and fate in the environment by measuring their speciation in road dust samples collected along several highways in Germany and a city centre (Saarbrücken). Speciation of the elements (fractionation into associated mineralogical phases) was carried out via a conventional sequential extraction protocol and the complexing abilities of humic substances in the organic matter were investigated by selective extraction methods in combination with size segregation. For evaluation purposes soil samples spiked with catalytic converter material were analyzed, showing a much lower fraction of Ce, La and Zr mobilized in comparison to the road dust samples. It was found that the elements were effectively bound to humic substances in road dust with a preference for complexation with low molecular weight compounds (<1600 Da).     

上海市机动车污染实时排放预警系统设计与应用

研究上海市机动车污染的动态排放测算和网格化动态排放清单构建,在实时的交通数据和交通环境监测数据的基础上,结合交通模型、机动车排放清单模型等业务模型和算法,依托大数据存储、可视化和GIS等技术,开发了上海市机动车污染物实时排放预警系统,实现了上海市全市道路的机动车动态排放测算、交通环境政策实施情景模拟和网格化排放清单,更新频率为每30 min一次,包含PM、NOx、CO、SO2、VOCs等污染物和9种车型。系统建成后直接服务于首届中国国际进口博览会,为大气污染排放实时总量跟踪评估、污染源管控措施分析及监测成因分析等提供了有力的实时数据和技术支撑。     

Diurnal variation of methane emissions from an alpine wetland on the eastern edge of Qinghai-Tibetan Plateau

Alpine wetland is a source for CH₄, but little is known about methane emission from such wetland, especially about its diurnal pattern. In this study we tried to probe the diurnal variation in methane emission from alpine wetland vegetation. The average methane emission rate was 9.6 ± 3.4 mg CH₄ m^???2 h^???1. There was an apparent diurnal variation pattern in methane emission with one minor peak at 06:00 and a major one at 15:00. The sunrise peak was consistent with a two-way transport mechanism for plants (convective at daytime and diffusive at night-time). CH₄ emission was found significantly correlated with redox potentials. The afternoon peak could not be explained by diurnal variation in soil temperature, but could be attributable to changes in CH₄ oxidation and production driven by plant gas transport mechanism. The results have important implications for sampling and scaling strategies for estimating methane emission from alpine wetlands.     

An Evaluation of Microscopic Emission Models for Traffic Pollution Simulation Using On-board Measurement

As a result of the continuously increasing numbers of motor vehicles in metropolitan areas worldwide, road traffic emission levels have been recognized as a challenge during the planning and management of transportation. Experiments were conducted to collect on-road emission data using portable emission measurement systems in two Chinese cities in order to estimate real traffic emissions and energy consumption levels and to build computational models for operational transport environment projects. In total, dynamic pollutant emissions and fuel consumption levels from dozens of light duty vehicles, primarily from four different vehicle classes, were measured at a second-by-second level. Using the collected data, several microscopic emission models including CMEM, VT-Micro, EMIT, and POLY were evaluated and compared through calibration and validation procedures. Non-linear optimization methods are applied for the calibration of the CMEM and EMIT models. Numerical results show that the models can realize performance levels close to the CMEM model in most cases. The VT-Micro model shows advantages in its unanimous performance and ability to describe low emission profiles while the EMIT model has a clear physics basis and a simple model structure. Both of them can be applied when extensive emission computation is required in estimating environmental impacts resulting from dynamic road traffic.     

汽车排气污染问题的探讨

本文主要研究了汽车排气对城市造成的污染危害，在对本市汽车保有量发展趋势现状调查的基础上，探讨了汽车排气污染问题的主要污染源和主要污染成分，以及汽车污染控制各个阶段的控制技术     

Spectrophotometric determination of platinum(IV) in alloys, complexes, environmental, and pharmaceutical samples using 4-[N,N-(diethyl)amino] benzaldehyde thiosemicarbazone

4-[N,N-(Diethyl)amino] benzaldehyde thiosemicarbazone (DEABT) is proposed as an analytical reagent for the spectrophotometric determination of platinum(IV). The DEABT forms 1:2 yellow complex with Pt(IV), which is sparingly soluble in water and completely soluble in water–ethanol–DMF medium. The Pt(IV)–DEABT complex shows maximum absorbance at 405 nm. Beer’s law is valid up to 7.80 μg cm^???3, and optimum concentration range for the determination of platinum(IV) is 0.48–7.02 μg cm^???3. The molar absorptivity and Sandell’s sensitivity of the method are found to be 1.755 × 10⁴ dm³ mol^???1 cm^???1 and 0.0012 μg cm^???2, respectively. The relative error and coefficient of variation (n?=?6) for the method does not exceed ±0.43% and 0.35%, respectively. Since the method tolerates a number of metal ions commonly associated with platinum, it can be employed for the determination of platinum in environmental samples, pharmaceutical samples, alloys, catalysts, and complexes. The method is rapid as the Pt(IV)–DEABT complex is soluble in water–ethanol–DMF medium and not requiring any time consuming extraction method for the complex.     

南京市机动车污染物减排因素分析

以南京市机动车排污监控系统的实时检测数据为基础,简述了南京市机动车减排效果,在“十二五”期间南京市机动车保有量增长71.8%的背景下,实现了污染物排放量削减18.8%,单车平均排放CO、HC、NOx较3年前分别下降了33%,31%和36%;排放标准和使用年限二因素方差分析表明,其对NOx、CO和HC排放值的影响由大到小排序均为：油品质量〉排放标准〉使用年限。提出,进一步提升油品质量至关重要。     

与我国环境管理对接的大气污染源排放清单分析

环境管理与大气污染源清单对接的基础是环境管理数据体系。选取京津冀大气污染传输通道"2+26"城市中的14个城市实施访谈与问卷调查,普遍认为大气污染源清单的主要用途为大气污染应急、预警以及污染源解析,但由于环境统计、污染源监测和排污许可三大环境管理数据体系差异较大,导致环境管理数据的行业和工艺过程针对性不强,无法满足污染源清单的需求。造成该问题的主要原因在于基层生态环境部门技术储备不足、污染源信息分散以及数据管理任务分工不明确。促进环境管理与大气污染源清单的对接,重点在于污染源数据定期更新和环境管理数据的一体化,应着重形成多部门数据共享、全面和全过程环境管理以及人才和技术保障机制。     

Biogenic Emissions by Oak Trees Common to Mediterranean Ecosystems

The experimental site was a Mediterranean type forest located in Viols-en-Laval near Montpellier (France). The principal species studied were Quercus ilex and Quercus pubescens. The determination of biogenic emissions was carried out by the enclosure method, which consists in enclosing an intact branch in a Teflon cuvet. The evolution of global terpenic emissions were recorded on June 1995.For Quercus ilex it appears that most terpenic emissions take place during the diurnal period. The evolution of terpenic emission rates versus light (PAR), internal temperature within the cuvet, CO2 exchange and transpiration (H2O) were carried out. A close relation between terpene emission and light-triggered physiological activities, was always found. It is obvious that there was no simple correlation between the leaf temperature and the terpenic emission. The temperature of the leaves does not seem to play a significant role in the regulation of the monoterpenic emission. This behaviour allows us to conclude that light with its effect on assimilation and stomatal behaviour is the most important factor for monoterpenic emission by Quercus ilex like for Quercus pubescens which is an isoprene emitter.     

深圳市汽车排气污染的管制与防治

深圳地狭人多,特区人口密度高达7310人/平方公里,是中国人口密度最大的城市之一。随着社会经济的高速发展,汽车拥有量的急剧增加,汽车排气污染已成为深圳市最主要的大气污染问题。文章分析了深圳市汽车排气污染的状况及其对城市空气质量的影响,简要介绍了近年来深圳市在控制汽车排气污染方面所做的工作。     

利用MOBILE 6.2模型预测LPG出租车排放因子

针对MOBILE6．2预测天然气汽车排放因子的功能,分析了其在预测液化石油气（LPG）轻型汽车上的可行性。并根据LPG出租车汽车排放总量分析系统（VMAS）测试结果,得到所需参数,预测了实验车队的排放因子,与实测值的误差≤10％,表明MOBILE6．2预测LPG轻型汽车排放因子具有良好的适用性。     

How to effectively guide carbon reduction behavior of building owners under emission trading scheme? An evolutionary game-based study

The building sector accounts for the largest proportion of global carbon emissions. The implementation of a market-based emission trading scheme offers a wider range of strategic choices and greater flexibility for building owners to reduce carbon emissions, but few of them are enthusiastic and actively engaged. To address the problem, this study explores how governments can effectively guide the carbon mitigation actions of building owners under an emission trading scheme (ETS) by continually adjusting and optimizing their regulation strategies. First, an extended evolutionary game model is built, considering the synergistic effect of multiple regulation policies, to theoretically depict the long-term interactive, extensive correlative, and dynamic feedback relationship between the government and building owners. Second, taking advantage of system dynamics as a policy laboratory, a scenario cultivation and simulation analysis is conducted to fully investigate the implementation effects of different regulation strategies based on the behavioral responses of building owners under different scenarios. The city of Shenzhen is a pioneer in covering the building sector in its carbon trading scheme in China, and its hotels above four stars are selected as the realistic setting for the simulation analysis. The results demonstrate that under the emission trading scheme, compared with increasing levels of carbon monitoring and non-financial incentives for building owners, intervention measures, including penalties, subsidies, and public scrutiny, are more efficient and important for the government. These findings provide important theoretical guidance and practical implications for the government to further adjust and optimize its carbon regulation strategies for the building sector.