江苏省沿海地区耕地系统能值分析及高效持续利用评价

采用能值分析法,在对耕地资源高效持续利用内涵及评价指标界定的基础上,对江苏省沿海区域2000-2008年耕地生态经济系统的高效持续性水平进行了评价。研究结果表明:①2000-2008年江苏沿海地区耕地生态经济系统资源环境负载指数(A₁)呈上升趋势,由2000年的0.9上升至2008年的1.573。在时间序列上,系统生产要素投入能值具有较强的稳定性,而初级生产力稳定性较弱。②研究区域耕地生态经济系统具有经济效益,集约化水平不断提高。但生产要素投入结构不合理,存在集约不经济现象,且生产要素投入结构差异性呈上升趋势。2008年土地集约度(B₁)为1.85×10¹⁶sej/hm²,不可更新资源与不可更新工业辅助能值投入比例达61.13%,比2000年均有明显增长。而产出投入能效指数(B₂)则呈现下降趋势,2008年为1.036 4,比2000年降低了15.90%。③2000-2008年农民人均能值占有量保持逐年增长,2008年已达1.08×10¹⁶ sej/人,比2000年增长了92.81%,这说明农民生活水平(C₁)越来越高。但从历年环比增长率分析,存在一定的不稳定性。2000-2008年间,研究区域耕地生态经济系统能值产出密度较不稳定,总体呈现倒V字型,2005年以来研究区域耕地生态经济系统能值产出密度呈缓慢下降趋势并趋稳发展,粮食安全压力较大。     

Wintertime measurements of aerosol acidity and trace elements in Wuhan,a city in central China

A 2-week intensive ambient aerosol study was conducted in December 1988 in Wuhan (Hubei Province), a city of nearly 2 million located on the Yangtze River in central China (P.R.C.). This is an industrial region where soft coal burning is widespread, and emission controls for vehicles and industrial facilities are minimal. The sampling site was located in one of the civic centers where residential and commercial density is highest. An Andersen dichotomous sampler was operated with Teflon membrane filters to collect fine (d_p < 2.5 μmad) and coarse (2.5 ⩽ d_p < 10 μmad) particles for total mass and element determinations. An annular denuder system (ADS) was used to collect fine fraction aerosols for analyses of ionic species including strong acidity (H⁺).The study was conducted between 18 and 30 December, which was rainless, consistently cool (3–10°C) and overcast, but without fog or acute stagnation. Fine particulate mass (PM, as μ m⁻³) averaged 139 (range 54–207); coarse PM averaged 86 (range 29–179). Trace element concentrations were also high. Crustal elements (Si, Al, Ca and Fe) were found primarily in the coarse fraction, while elements associated with combustion (S, K, Cl, Zn and Se) were enriched in the fine fraction. The concentrations of arsenic and selenium were evidence of a large source of coal burning, while vanadium levels (associated with fuel oil use) were not especially enriched.Despite the seemingly high PM loadings, ionic concentrations were not especially high. The average composition of soluble fine aerosol species (in neq m⁻³) were SO₄²⁻: 520 (range 180–980), NO₃⁻: 225 (range 50–470), Cl⁻: 215 (range 20–640), and NH₄⁺: 760 (range 280–1660). A deficit in accountable FP components (total mass compared to the total of ionic plus element masses) as well as the black appearance of collected materials indicate an abundance of carbonaceous aerosol, as high as 100 μ m⁻³. (total mass compared to the total of ionic plus element masses) as well as the black appearance of collected materials indicate an abundance of carbonaceous aerosol, as high as 100 μ m⁻³Aerosol acidity was negligible during most monitoring periods, H⁺: 14 (range 0–50 neq m⁻³, equivalent to 0–2.5 μm m⁻³ as H₂SO₄). Sulfur dioxide, measured by the West-Gaeke method for part of the study, concentrations were low. Although not directly measured, the aerosol measurments suggested that gaseous HCl (from refuse incineration) and NH₃ (animal wastes) concentrations might have been high. Higher aerosol acidity might be expected if HCl sources were more prominent and not neutralized by local ammonia or other base components.     

Sex pheromone component ratios and mating isolation among three Lygus plant bug species of North America

The plant bugs Lygus hesperus, Lygus lineolaris, and Lygus elisus (Hemiptera: Miridae) are major pests of many agricultural crops in North America. Previous studies suggested that females release a sex pheromone attractive to males. Other studies showed that males and females contain microgram amounts of (E)-4-oxo-2-hexenal, hexyl butyrate, and (E)-2-hexenyl butyrate that are emitted as a defense against predators. Using gas chromatography–mass spectrometry, we found that female L. lineolaris and L. elisus have a 4:10 ratio of hexyl butyrate to (E)-2-hexenyl butyrate that is reversed from the 10:1 ratio in female L. hesperus (males of the three species have ~10:1 ratio). These reversed ratios among females of the species suggest a behavioral role. Because both sexes have nearly equal amounts of the major volatiles, females should release more to attract males. This expectation was supported because L. hesperus females released more hexyl butyrate (mean of 86 ng/h) during the night (1800–0700 hours) than did males (<1 ng/h). We used slow-rotating pairs of traps to test the attraction of species to blends of the volatiles with a subtractive method to detect synergism. Each species’ major butyrate ester was released at 3 μg/h, the minor butyrate according to its ratio, and (E)-4-oxo-2-hexenal at 2 μg/h. The resulting catches of only Lygus males suggest that (E)-4-oxo-2-hexenal is an essential sex pheromone component for all three species, (E)-2-hexenyl butyrate is essential for L. elisus and L. lineolaris, and hexyl butyrate is essential for L. hesperus. However, all three components are recognized by each species since ratios of the butyrate esters are critical for conspecific attraction and heterospecific avoidance by males and thus play a role in reproductive isolation among the three species. Because L. hesperus males and females are known to emit these major volatiles for repelling ant predators, our study links defensive allomones in Lygus bugs with an additional use as sex pheromones.     

Spillover of functionally important organisms between managed and natural habitats

Land-use intensification has led to a landscape mosaic that juxtaposes human-managed and natural areas. In such human-dominated and heterogeneous landscapes, spillover across habitat types, especially in systems that differ in resource availability, may be an important ecological process structuring communities. While there is much evidence for spillover from natural habitats to managed areas, little attention has been given to flow in the opposite direction. This paper synthesizes studies published to date from five functionally important trophic groups, herbivores, pathogens, pollinators, predators, and seed dispersers, and discusses evidence for spillover from managed to natural systems in all five groups. For each of the five focal groups, studies in the natural to managed direction are common, often with multiple review articles on each subject which document dozens of examples. In contrast, the number of studies which examine movement in the managed to natural direction is generally less than five studies per trophic group. These findings suggest that spillover in the managed to natural direction has been largely underestimated. As habitat modification continues, resulting in increasingly fragmented landscapes, the likelihood and size of any spillover effect will only increase.     

The variability of biogenic sulfur flux from a temperate salt marsh on short time and space scales

Three emission chambers were deployed simultaneously to measure rates of emission of dimethyl sulfide, methane thiol and carbonyl sulfide within or across vegetation zones in a New Hampshire salt marsh. Short term (a few hours) variation in fluxes of all S gases from replicate sites were small within a monospecific stand of either Spartina alterniflora or S. patens. The quantity of emergent biomass and the type of vegetation present were the primary factors regulating the rate of emission. Dimethyl sulfide fluxes from the S. alterniflora soils ranged from 800 to 18,000 nmol m⁻² h⁻¹ compared to emissions of 25–120 nmol m⁻² h⁻¹ from S. patens. This difference was probably due to the presence of the dimethyl-sulfide precursor dimethylsulfoniopropionate which is an osmoregulator in S. alterniflora but not in S. patens. Methane thiol emissions from S. alterniflora were 20–280 nmol m⁻² h⁻¹ and they displayed a similar diel trend as dimethyl sulfide, although at much lower rates, suggesting that methane thiol is produced primarily by leaves. Methane thiol emissions from S. patens were 20–70 nmol m⁻² h⁻¹. Net uptake of carbonyl sulfide of 25–40 nmol m⁻² h⁻¹ occurred in stands of S. alterniflora while net efflux of 10–36 nmol m⁻² h⁻¹ of carbonyl sulfide occurred in stands of S. patens. In general, ranges of emissions of sulfur gases were similar to most other published values.     

A combined tool for environmental scientists and decision makers: ternary diagrams and emergy accounting

Ternary diagrams are presented as graphic tools to assist environmental accounting and environmental decision-making based on emergy analysis [Odum HT. Environmental accounting – emergy environmental decision making. John Wiley & Sons; 1996. 370 pp. [1]]. Beyond the unquestionable advantages of graphic interpretation over table analysis, the use of ternary diagrams or phase diagrams, widely used for physical chemistry evaluation of three component systems, permits the use of phase diagram properties to assess the dependence of the system upon renewable and non-renewable inputs, the environmental support for dilution and abatement of process emissions and the system efficiency. The prompt visualization of the emergy accounting data makes possible to compare processes and systems with and without ecosystem services, to evaluate improvements and to follow the system performance over time. With the aim of ternary diagrams, aspects such as the interaction between systems and the interactions between systems and the environment can be readily recognized and evaluated.     

Adsorption of lead on multi-walled carbon nanotubes with different outer diameters and oxygen contents: Kinetics, isotherms and thermodynamics

The effects of different outer diameters and surface oxygen contents on the adsorption of heavy metals onto six types of multi-walled carbon nanotubes (MWCNTs) were investigated in an aqueous solution and lead was chosen as a model metal ion. The results indicated that the percentage removal and adsorption capacity of lead remarkably increased with decreasing outer diameter due to larger specific surface area (SSA). The SSA-normalized maximum adsorption capacity (qm /SSA) and SSA-normalized adsorption coefficient (Kd /SSA) were strongly positively correlated with surface oxygen content, implying that lead adsorption onto MWCNTs significantly increases with the rise of oxygen content and decreases with decreasing SSA. The calculated thermodynamic parameters indicated that adsorption of lead on MWCNTs was endothermic and spontaneous. When the oxygen content of MWCNTs increased from 2.0% to 5.9%, the standard free energy (△ G0 ) became more negative, which implied that the oxygenated functional groups increased the adsorption affinity of MWCNTs for lead. Through calculation of enthalpy (△ H0 ), G0 and free energy of adsorption (Ea ), lead adsorption onto MWCNTs was recognized as a chemisorption process. The chemical interaction between lead and the phenolic groups of MWCNTs could be one of the main adsorption mechanisms due to highly positive correlations between the phenolic groups and K d /SSA or q m /SSA.     

内源呼吸过程溶解性代谢产物的光谱特性分析

微生物内源呼吸期对污水处理过程具有重要意义.为了更清晰地了解微生物内源呼吸过程,采用三维荧光光谱、紫外光谱结合呼吸图谱对微生物内源呼吸过程进行解析.结果表明,三维荧光光谱和紫外光谱在内源呼吸各个阶段有明显的不同:1内源呼吸快速下降期(第1 d):腐殖酸峰的激发波长(Ex)和发射波长(Em)分别出现5 nm、6 nm的蓝移,荧光指数f450/500和HIX(humification index)分别减小了9.3%、0.2%,UV253/203和UV254分别增加了37.5%、200%,预示着混合液中可生物降解有机物的存在;2内源呼吸慢速下降期(第2 d):f450/500增加了0.5%,HIX减小0.2%,UV253/203减小了20%,UV254增加了16.7%,预示着细胞可能出现了水解或自溶;3内源呼吸稳定期(第3~5 d):腐殖酸峰基本保持不变预示了微生物适应了饥饿环境.本研究从代谢产物的角度解析了内源呼吸过程,为污水处理过程控制提供了新的思路.     

A comparison of measurements of atmospheric ammonia by filter packs,transition-flow reactors,simple and annular denuders and fourier transform infrared spectroscopy

Using data obtained during the 1985 Nitrogen Species Methods Comparison Study (1988,Atmospheric Environment22, 1517), several measurement methods for sampling ambient NH₃ are compared. Eight days of continuous measurements at Pomona College, a smog receptor site in Los Angeles, provided an extensive data base for comparing the following methods: Fourier transform i.r. spectroscopy (FTIR), three filter pack configurations, a simple and an annular denuder, and the transition flow reactor. FTIR was defined as the reference method and it reported hourly NH₃ concentrations ranging from > 60 to 2280 nmol m⁻³ (1.5−57ppb) during the course of the study, the highest values coming from the influence of nearby livestock operations.Although only limited quality assurance procedures were carried out, the following conclusions can, nevertheless, be drawn: most of the methods correlated highly with the FTIR method (correlation coefficientr > 0.96); generally, the linear regression slopes were close to unity and the intercepts were insignificantly different from zero at the 95% confidence level); relative to the FTIR average values, (1) for 4–6 h sampling periods, the averages of the three filter packs from three research groups were 83–130% and the annular denuder average was 87%, and (2) for 10–12 h sampling periods, the simple denuder averaged 90% and the two transition flow reactors were 77–98%. Possible reasons for the reported systematic biases are presented, but these are not able to fully explain the large range of differences reported by the various methods.     

Measured components in total suspended particulate matter in a Kenyan urban area

Nairobi city has a population of over 1.5 million and is growing at a rate of about 70 persons per day. Various activities in the city such as construction work, industrial processes, use of unroadworthy cars, and dust blown off unpaved roads contribute enormously to suspended particulate matter in the air. In this paper, analysis by gravimetric and energy dispersive X-ray fluorescence (EDXRF) of the suspended particulate matter in the air in the city centre, an industrial area and one residential area was carried out. The total suspended particulate matter (TSP) mean levels ranged from 69.983 to 397.903 μg m⁻³. The following components were measured from the TSP, mean values in μg m⁻³: iron 6.014–7.547, potassium 1.252–6.432, titanium 0.286–1.698, manganese 0.158–1.683, lead 0.395–1.321, bromine 0.122–0.707, zinc 0.159–0.678 and zirconium 0.017–0.245. The values of lead obtained (0.395–1.321 μg m⁻³) fall within the WHO recommendations, but compared to the values reported in some European countries, they are high. Most of the elements had low enrichment factors except for lead (104–353), bromine (429–1533) and zinc (14–79). Bromine and lead were highly correlated to the number of light vehicles (p=0.874 and 0.942, respectively). In addition the ratio of Br:Pb by weight was in the range 0.309–0.535, while the correlation factor for Br:Pb was 0.951, leading to the conclusion that both elements came from leaded gasoline.     

Fading of artists' colorants by a mixture of photochemical oxidants

Thirty-five artists' colorants were exposed for 12 weeks, in the dark, to a mixture of photochemical oxidants including ozone (200 ppb), nitrogen dioxide (75 ppb) and peroxyacetyl nitrate (PAN, 15 ppb) at ambient temperature and humidity. Color changes were measured weekly using a reflectance color analyser and were also calculated from the 380–700 nm reflectance spectra of unexposed and oxidant-exposed colorant samples. Exposure to the oxidant mixture resulted in substantial fading for nine colorants (10–60 ΔE units) and moderate fading for three colorants (2–5 ΔE units). Increasing the air humidity from 46 to 83% resulted in a substantial increase in fading. The results are discussed in terms of oxidant-fugitiveness vs colorant chemical functionality and for their implications with respect to oxidant damage to colorants in museums.     

Comparison of annular denuder and filter pack collection of HNO3 (g), HNO2((g), SO2 (g), and particulate-phase nitrate,nitrite and sulfate in the south-west desert

During the 15 January–4 February 1986 SCENES Special Study, a comparison study was conducted to determine atmospheric HNO₃ (g), HNO₂ (g), SO₂ (g), and particle-phase nitrate, nitrite and sulfate sampled with annular diffusion denuder and filter pack sampling systems for 12-h periods. The results of the ion chromatographic analyses of the denuder and filter extracts from the annular denuder system showed that an average of 88% of the total nitrate measured was HNO₃ (g), 97% of the total nitrite was HNO₂ (g), and 91% of the total sulfur was present as SO₂ (g). Analyses of the various gas-phase species collected by replicate annular denuder systems indicated that a precision of ± 3% to ± 18% was achieved using these denuders. The good agreement in HNO₃ (g) concentrations observed between the filter pack and the denuder (r²=0.873, slope=1.06±0.03, intercept=0±3.5 nmol m⁻³) results from the fact that the majority of the atmospheric nitrate consisted of HNO₃ (g), which minimized any positive artifact in HNO₃(g) due to loss of HNO₃(g) from particles collected in the filter pack. The particulate-phase nitrate correlation between the two sampling systems was not as good (r²=0.709, slope=0.519±0.045, intercept =0±1.2 nmol m⁻³) because the lower percentage of nitrate present as the particulate species was more affected by the loss of particulate nitrate during sampling with the filter pack.     

Quantifying the electron-donating and -accepting capacities of wastewater for evaluating and optimizing biological wastewater treatment processes

Biological processes have been widely used for the treatment of both domestic and industrial wastewaters. In such biological processes, pollutants are converted into pollution-free substances by microorganisms through oxidation-reduction reactions. Thus, how to quantify the internal oxidation-reduction properties wastewaters and seek out targeted countermeasures is essential to understand, operate, and optimize biological wastewater treatment systems. So far, no such approach is available yet. In this work, a novel concept of electron neutralization-based evaluation is proposed to describe the internal oxidation-reduction properties of wastewater. Pollutants in wastewater are defined as electron donor substances (EDSs) or electron acceptor substances (EASs), which could give or accept electrons, respectively. With such an electron neutralization concept, several parameters, i.e., electron residual concentration (R), economy-related index (E and E_r), and economical evaluation index (Y and Y_r), are defined. Then, these parameters are used to evaluate the performance and economic aspects of currently applied wastewater treatment processes and even optimize systems. Three case studies demonstrate that the proposed concept could be effectively used to reduce wastewater treatment costs, assess energy recovery, and evaluate process performance. Therefore, a new, simple, and reliable methodology is established to describe the oxidation-reduction properties of wastewater and assess the biological wastewater treatment processes.     

The benefits of a Brazilian agro-industrial symbiosis system and the strategies to make it happen

Alcohol fuel is generally presented as a sustainable fuel in comparison with other fossil fuel due to lower emissions during production and combustion steps as well as due to its (assumed) closed carbon cycle. However, assessing the Brazilian traditional alcohol production cycle, many social and environmental impacts may still be indicated: burning, pesticides, biodiversity, labor exploration, high water consumption, erosion and others. Based on the strategy of an agro-industrial networking and symbiosis, a project was designed to optimize the system by means of polygeneration and total integration of production steps. The case presented in this paper is the project for a social and ecological agro-industry model, named GERIPA (Geração de Energia Renovável Integrada à Produção de Alimentos), which produces renewable fuel, electricity and organic food. Besides the technical project, an economic evaluation is also presented, resulting into a five year pay back time. In addition, environmental and social aspects were evaluated by means the Emergy Synthesis methodology (Odum, 1996), which assesses the value of all inputs through an estimate of the environmental work directly and indirectly required for their production and sustainable supply. The emergy-based comparison of GERIPA system and a traditional system in Brazil indicates better performance of GERIPA, with an eMergy Sustainability Index of 1.26, much higher than for a traditional system, 0.22. The project is presently under discussion with investors and Government and, if approved, will be carried out in marginal and presently unused land. In addition to providing an environmentally friendly process for food and energy production, the project would generate new jobs opportunities for Brazilian rural workers presently unemployed.     

青海省西宁市与天峻县大气中得克隆与十溴联苯醚的水平与来源

十溴联苯醚(BDE-209)与得克隆(DP)是两种常见的添加型卤代阻燃剂,被广泛应用于各种电子产品中.由于其普遍存在于多种环境介质中,现已成为一种广泛存在的污染物,可能会对人体及生态系统产生潜在的危害.本研究测定了青海省西宁市与海西蒙古族藏族自治州天峻县夏、冬两季大气中BDE-209与DP的水平.结果表明,青海省西宁市夏、冬两季大气中BDE-209的平均水平分别为370 pg·m-3、470 pg·m-3,天峻县为220 pg·m-3、390 pg·m-3,与其他城市和地区相比,属于水平较高的地区.而西宁市大气中DP的平均水平为0.85 pg·m-3、0.25 pg·m-3,天峻县为0.24 pg·m-3、0.16 pg·m-3,西宁市水平高于天峻县,夏季水平高于冬季,与其他地区相比,青海省DP整体水平较低.西宁市与天峻县DP的同分异构体中,anti-DP所占比例分别是0.66±0.04与0.68±0.06,在时间与时空上的变化均不明显.青海省BDE-209与DP呈现弱的负相关性,说明两种污染物在青海省可能没有相同的本地源.     

Comparison of soil N availability and leaching potential,crop yields and weeds in organic,low-input and conventional farming systems in northern California

Increasing dependence on off-farm inputs including, fertilizers, pesticides and energy for food and fiber production in the United States and elsewhere is of questionable sustainability resulting in environmental degradation and human health risks. The organic (no synthetic fertilizer or pesticide use), and low-input (reduced amount of synthetic fertilizer and pesticide use), farming systems are considered to be an alternative to conventional farming systems, to enhance agricultural sustainability and environmental quality. Soil N availability and leaching potential, crop yields and weeds are important factors related to agricultural sustainability and environmental quality, yet information on long-term farming system effects on these factors, especially in the organic and low-input farming systems is limited. Four farming systems: organic, low-input, conventional (synthetic fertilizer and pesticides applied at recommended rates) 4-year rotation (conv-4) and a conventional 2-year rotation (conv-2) were evaluated for soil mineral N, potentially mineralizable N (PMN), crop yields and weed biomass in irrigated processing tomatoes (Lycopersicon esculentum L.) and corn (Zea mays L.) from 1994 to 1998 in California’s Sacramento Valley. Soil mineral N levels during the cropping season varied by crop, farming system, and the amount and source of N fertilization. The organic and low-input systems showed 112 and 36% greater PMN pools than the conventional systems, respectively. However, N mineralization rates of the conventional systems were 100% greater than in the organic and 28% greater than in the low-input system. Average tomato fruit yield for the 5-year period (1994–1998) was 71.0 Mg ha⁻¹ and average corn grain yield was 11.6 Mg ha⁻¹ and both were not significantly different among farming systems. The organic system had a greater aboveground weed biomass at harvest compared to other systems. The lower potential risk of N leaching from lower N mineralization rates in the organic and low-input farming systems appear to improve agricultural sustainability and environmental quality while maintaining similar crop yields.     

中国自然资源管理体制与制度：现状、问题及展望

自然资源在国家发展中扮演着重要角色。十九大以来,党和国家对自然资源管理保持高度重视,我国自然资源管理的体制、制度以及理念方法不断变革创新,逐步形成了较为符合我国国情的管理体系和模式。然而,管理实践中仍然存在诸多不足和矛盾。从我国自然资源管理体制和制度建设的现状着手,从管理对象、管理主体和管理保障三个方面,阐明自然资源管理体制和制度建设的发展困因,总结凝练当前制约管理实践发展的突出现实问题,并从构建国家安全视角下的多维自然资源管理体系和建立健全自然资源管理制度体系两个方面,为我国自然资源管理体制改革和制度建设的未来发展提供思考和建议,这将有助于我国可持续发展和生态文明建设的更进一步推进。     

Biogenic volatile organic compound analyses by PTR-TOF-MS: Calibration,humidity effect and reduced electric field dependency

Green leaf volatiles (GLVs) emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds (BVOCs). Proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) is a high-resolution and sensitive technique for in situ GLV analyses, while its performance is dramatically influenced by humidity, electric field, etc. In this study the influence of gas humidity and the effect of reduced field (E/N) were examined in addition to measuring calibration curves for the GLVs. Calibration curves measured for seven of the GLVs in dry air were linear, with sensitivities ranging from 5 to 10 ncps/ppbv (normalized counts per second/parts per billion by volume). The sensitivities for most GLV analyses were found to increase by between 20% and 35% when the humidity of the sample gas was raised from 0% to 70% relative humidity (RH) at 21°C, with the exception of (E)-2-hexenol. Product ion branching ratios were also affected by humidity, with the relative abundance of the protonated molecular ions and higher mass fragment ions increasing with humidity. The effect of reduced field (E/N) on the fragmentation of GLVs was examined in the drift tube of the PTR-TOF-MS. The structurally similar GLVs are acutely susceptible to fragmentation following ionization and the fragmentation patterns are highly dependent on E/N. Overall the measured fragmentation patterns contain sufficient information to permit at least partial separation and identification of the isomeric GLVs by looking at differences in their fragmentation patterns at high and low E/N.     

Biogenic volatile organic compound analyses by PTR-TOF-MS: Calibration, humidity effect and reduced electric field dependency

Green leaf volatiles(GLVs) emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds(BVOCs). Proton transfer reaction time-of-flight mass spectrometry(PTR-TOF-MS) is a high-resolution and sensitive technique for in situ GLV analyses, while its performance is dramatically influenced by humidity, electric field,etc. In this study the influence of gas humidity and the effect of reduced field(E/N) were examined in addition to measuring calibration curves for the GLVs. Calibration curves measured for seven of the GLVs in dry air were linear, with sensitivities ranging from 5 to10 ncps/ppbv(normalized counts per second/parts per billion by volume). The sensitivities for most GLV analyses were found to increase by between 20% and 35% when the humidity of the sample gas was raised from 0% to 70% relative humidity(RH) at 21°C, with the exception of(E)-2-hexenol. Product ion branching ratios were also affected by humidity,with the relative abundance of the protonated molecular ions and higher mass fragment ions increasing with humidity. The effect of reduced field(E/N) on the fragmentation of GLVs was examined in the drift tube of the PTR-TOF-MS. The structurally similar GLVs are acutely susceptible to fragmentation following ionization and the fragmentation patterns are highly dependent on E/N. Overall the measured fragmentation patterns contain sufficient information to permit at least partial separation and identification of the isomeric GLVs by looking at differences in their fragmentation patterns at high and low E/N.     

Life cycle inventory for thermal treatment of waste solvent from chemical industry: a multi-input allocation model

Waste solvent incineration is an important issue in life cycle assessments (LCAs) dealing with chemical products and/or processes. Nearly all chemical products and processes involve organic solvents, and incineration is often the favoured solution to waste solvent treatment as it can deal with a large variety of solvent types and quantities. At present, there are no generic models for waste solvent incineration which allow integrating this technology as a unit process in LCA. As waste solvents as a rule are incinerated as a mixture of several solvents, an allocation problem occurs: measurements of the consumption of ancillaries and energy carriers, and of emission of pollutants and generation of co-products, always refer to the mixture of waste solvents. However, in LCAs usually waste specific data is needed. To solve this problem we developed a multi-input allocation model of the incineration process. A comprehensive case study on a waste solvent incineration plant from chemical industry provided the necessary data. The results from the multi-input allocation modelling are consumption and emission factors which facilitate the calculation of solvent specific life cycle inventory results.