Development of mixed conducting membranes for clean coal energy delivery

Mixed conducting membranes can be used for the separation of oxygen from air in both coal gasification and oxy-fuel power plants. In this review paper, the basic perovskite and non-perovskite structures, composition, properties and performance are addressed. Two typical perovskite materials, BSCF and LSCF, show promise in industrial applications as their oxygen fluxes are at least one order of magnitude higher than non-perovskite membranes. BSCF membranes are now delivering oxygen fluxes in excess of 5 ml min^?1 cm^?2. Latest developments in perovskite composition, effects of impurities in membrane performance and membrane geometry are discussed giving an insight into the potential utilisation in clean energy delivery processes. Strategies for improving membranes performance using unit operations with different geometries and possible future technologies are also addressed.     

OLIVERO: the project analysing the future of olive production systems on sloping land in the Mediterranean basin

From 2003 to 2006, a consortium of six European partners analysed the future of olive production systems on sloping land in the Mediterranean basin. Olive production on such land dates back to pre-Roman times, but the production systems (known by the acronym SMOPS, for "Sloping and Mountainous Olive Production Systems"), are under threat. Many are unsustainable environmentally (erosion hazard), socially (exodus of young people) or economically (high labour costs). The OLIVERO research project was possible thanks to a grant of euro1.5 million from the European Union, which gives out euro2.5 billion in subsidies annually for olive production. An extended survey conducted by the project in five sites in Portugal, Spain, Italy and Greece revealed the diversity and multifunctionality of SMOPS. Four main systems were identified as important for the future: traditional, organic, semi-intensive and intensive. The conceptual framework of OLIVERO involved six phases, ranging from the initial survey up to policy recommendations. In all phases there was intensive contact with stakeholders and institutions. End-users were identified at three levels: local, intermediate and regional, and national/international. This paper presents the highlights of the physical analysis of land and water resources, crop and land management, and economics and policies. Scenario studies gave insight into the possible future: some SMOPS will be gradually abandoned or transformed into nature conservation areas, others will exploit drip irrigation and follow the intensification patterns of agriculture in the valleys, and a third group will continue to be managed more extensively, perhaps augmenting their income with other activities (possibly off-farm) or turning to organic production systems. At the five international OLIVERO meetings held from 2003 to 2006, knowledge, experience and ideas on the future of olive production systems were intensively exchanged. A network was established for ongoing and future cooperation. Two end-user seminars were held in Matera (Italy) and Lisbon. Over 70 scientific papers have been published.     

Accumulation of perfluorinated compounds in captive Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) in China

The accumulation of perfluorinated compounds (PFCs) in the sera of captive wildlife species Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) from Harbin Wildlife Park, Heilongjiang Province, in China were analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Perfluorooctanesulfonate (PFOS) was the predominant contaminant with a mean serum concentration of 1.18 ng mL(-1) in tigers and 2.69 ng mL(-1) in lions. Perfluorononanoic acid (PFNA) was the second most prevalent contaminant in both species. The composition profiles of the tested PFCs differed between tigers and lions, and the percentages of perfluorooctanoic acid (PFOA) were greater in lions than in tigers, indicating different exposures and/or metabolic capabilities between the two species. Assessments of the risk of PFC contamination to the two species were obtained by comparing measured concentrations to points of departure or toxicity reference values (TRVs). Results suggest no risk of PFOS exposure or toxicity for the two species.     

Total fluorine, extractable organic fluorine, perfluorooctane sulfonate and other related fluorochemicals in liver of Indo-Pacific humpback dolphins (Sousa chinensis) and finless porpoises (Neophocaena phocaenoides) from South China

The concentrations of 10 PFCs (perfluorinated compounds: PFOS, PFHxS, PFOSA, N-EtFOSA, PFDoDA, PFUnDA, PFDA, PFNA, PFOA, and PFHpA) were measured in liver samples of Indo-Pacific humpback dolphins (Sousa chinensis) (n = 10) and finless porpoises (Neophocaena phocaenoides) (n = 10) stranded in Hong Kong between 2003 and 2007. PFOS was the dominant PFC in the tissues at concentrations ranging at 26-693 ng/g ww in dolphins and 51.3-262 ng/g ww in porpoises. A newly developed combustion ion chromatography for fluorine was applied to measure total fluorine (TF) and extractable organic fluorine (EOF) in these liver samples to understand PFC contamination using the concept of mass balance analysis. Comparisons between the amounts of known PFCs and EOF in the livers showed that a large proportion (∼70%) of the organic fluorine in both species is of unknown origin. These investigations are critical for a comprehensive assessment of the risks of these compounds to humans and other receptors.     

Persistent toxic substances in remote lake and coastal sediments from Svalbard, Norwegian Arctic: Levels, sources and fluxes

Surface sediments from remote lakes and coastal areas from Ny-Ålesund, Svalbard, Norwegian Arctic were analyzed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Relatively high levels of PAHs were encountered from several lakes from Ny-Ålesund, which were within the range of levels reported for European high mountain lakes and some urban/industrialized areas in the world, pointing to the role of remote Arctic lakes as potential reservoir of semi-volatile organic compounds. Specific patterns of PBDEs were observed, showing higher concentrations of lower brominated compounds such as BDE-7, 17 and 28. Estimated surface sediment fluxes of PAHs in Ny-Ålesund remote lakes were similar to those observed for some European high mountain lakes. The current PAH levels in sediments from three lakes exceeded Canadian sediment quality guidelines, suggesting the presence of possible risks for aquatic organisms and the need for further studies.     

土壤中全氟和多氟烷基化合物的污染现状及环境行为

全氟和多氟烷基化合物（perfluoroalkyl and polyfluoroalkyl substances,PFASs）是一类新兴持久性有机污染物.土壤中PFASs可以通过淋溶作用进入地下水影响水质安全,或者通过陆生食物链的传递和生物放大作用危害生态系统和人类健康,有关土壤中PFASs的赋存状况、浓度水平与行为机制的研究已经成为环境化学领域的热点之一.目前土壤中可以准确测定的PFASs在含氟化合物总量中的占比不到1%,含量为ng/g水平.我国相关研究主要集中在东部及氟化工厂周边地区,其组分以全氟辛烷磺酸（Perfluorooctane sulfonic acid,PFOS）和全氟辛酸（Perfluorooctanoic acid,PFOA）等长链PFASs为主.不同类型土壤中PFASs的赋存特征主要受到物质种类与土壤理化性质及周边人类活动的影响.除了含氟化学品生产和使用过程中的直接释放和大气传输以外,PFASs前体物在土壤环境中的转化也是其重要来源.吸附-解吸是PFASs在土壤中的主要归趋方式,化合物碳链长度及官能团种类、土壤理化性质和生物种类等因素都会影响其在土壤中的迁移转化和富集能力.鉴于目前的研究现状,需要进一步优化土壤中PFASs的提取和分析方法,关注新型PFASs在土壤中的变化趋势及行为机制,开展土壤中PFASs的生物可给性和生物可利用性研究,进一步评估PFASs的生态与人体健康风险.      

Trace contamination with dioxin-like chemicals: evaluation of bioassay-based TEQ determination for hazard assessment and regulatory responses

Many recent dioxin contamination events have been traced back to poisoned animal feed or feed ingredients. Therefore, enforcement authorities placed limits on the levels of dioxins in food and feed or implemented strict monitoring and control programs. The levels in force are generally expressed as TEQ values, which inherently accepts the underlying hypothesis that the effects of dioxin-like chemicals are additive. TEQ determination involves either chemo-analysis, with high-resolution gas chromatography in combination with high-resolution mass spectroscopy, or bio-analysis. Bio-analytical methods, more particularly the reporter gene expression method CALUX, are advantageous due to their high throughput rate and low cost. Moreover, the CALUX methodology detects the overall dioxin-like toxicity, rather than the limited number of compounds investigated by chemo-analysis. Bioanalytical methods such as CALUX also differ from chemo-analysis in that the contribution of antagonistic as well as synergistic effects, which violate the additivity principle, can be detected. The application of bio-analytical methods can facilitate a broader assessment of public health risks by intensifying the current monitoring programs in terms of both sample numbers and types. Bio-analysis provides information on the total dioxin-like activity of the samples under study (hazard assessment); however, chemo-analysis is still needed to identify the predominant contaminants (congener identification) for risk management.     

Ricin as a weapon of mass terror — Separating fact from fiction

In recent years there has been an increased concern regarding the potential use of chemical and biological weapons for mass urban terror. In particular, there are concerns that ricin could be employed as such an agent. This has been reinforced by recent high profile cases involving ricin, and its use during the cold war to assassinate a high profile communist dissident. Nevertheless, despite these events, does it deserve such a reputation? Ricin is clearly toxic, though its level of risk depends on the route of entry. By ingestion, the pathology of ricin is largely restricted to the gastrointestinal tract where it may cause mucosal injuries; with appropriate treatment, most patients will make a full recovery. As an agent of terror, it could be used to contaminate an urban water supply, with the intent of causing lethality in a large urban population. However, a substantial mass of pure ricin powder would be required. Such an exercise would be impossible to achieve covertly and would not guarantee success due to variables such as reticulation management, chlorination, mixing, bacterial degradation and ultra-violet light. By injection, ricin is lethal; however, while parenteral delivery is an ideal route for assassination, it is not realistic for an urban population. Dermal absorption of ricin has not been demonstrated. Ricin is also lethal by inhalation. Low doses can lead to progressive and diffuse pulmonary oedema with associated inflammation and necrosis of the alveolar pneumocytes. However, the risk of toxicity is dependent on the aerodynamic equivalent diameter (AED) of the ricin particles. The AED, which is an indicator of the aerodynamic behaviour of a particle, must be of sufficiently low micron size as to target the human alveoli and thereby cause major toxic effects. To target a large population would also necessitate a quantity of powder in excess of several metric tons. The technical and logistical skills required to formulate such a mass of powder to the required size is beyond the ability of terrorists who typically operate out of a kitchen in a small urban dwelling or in a small ill-equipped laboratory. Ricin as a toxin is deadly but as an agent of bioterror it is unsuitable and therefore does not deserve the press attention and subsequent public alarm that has been created.     

Spatial/temporal variations of elemental carbon, organic carbon, and trace elements in PM10 and the impact of land-use patterns on community air pollution in Paterson, NJ

An urban community PM10 (particulate matter < or = 10 microm in aerodynamic diameter) air pollution study was conducted in Paterson, NJ, a mixed land-use community that is interspersed with industrial, commercial, mobile, and residential land-use types. This paper examines (1) the spatial/temporal variation of PM10, elemental carbon (EC), organic carbon (OC), and nine elements; and (2) the impact of land-use type on those variations. Air samples were collected from three community-oriented locations in Paterson that attempted to capture industrial, commercial, and mobile source-dominated emissions. Sampling was conducted for 24 hr every 6 days from November 2005 through December 2006. Samples were concurrently collected at the New Jersey Department of Environmental Protection-designated air toxics background site in Chester, NJ. PM10 mass, EC, OC, and nine elements (Ca, Cu, Fe, Pb, Mn, Ni, S, Ti, and Zn) that had more than 50% of samples above detection and known sources or are toxic were selected for spatial/temporal analysis in this study. The concentrations of PM10, EC, OC, and eight elements (except S) were significantly higher in Paterson than in Chester (P < 0.05). The concentrations of these elements measured in Paterson were also found to be higher during winter than the other three seasons (except S), and higher on weekdays than on weekends (except Pb). The concentrations of EC, Cu, Fe, and Zn at the commercial site in Paterson were significantly higher than the industrial and mobile sites; however, the other eight species were not significantly different within the city (P > 0.05). These results indicated that anthropogenic sources of air pollution were present in Paterson. The source apportionment confirmed the impact of vehicular and industrial emissions on the PM10 ambient air pollution in Paterson. The multiple linear regression analysis showed that categorical land-use type was a significant predictor for all air pollution levels, explaining up to 42% of the variability in concentration by land-use type only.