The potential for increased atmospheric CO2 emissions and accelerated consumption of deep geologic CO2 storage resources resulting from the large-scale deployment of a CCS-enabled unconventional fossil fuels industry in the U.S.

Desires to enhance the energy security of the United States have spurred renewed interest in the development of abundant domestic heavy hydrocarbon resources including oil shale and coal to produce unconventional liquid fuels to supplement conventional oil supplies. However, the production processes for these unconventional fossil fuels create large quantities of carbon dioxide (CO₂) and this remains one of the key arguments against such development. Carbon dioxide capture and storage (CCS) technologies could reduce these emissions and preliminary analysis of regional CO₂ storage capacity in locations where such facilities might be sited within the U.S. indicates that there appears to be sufficient storage capacity, primarily in deep saline formations, to accommodate the CO₂ from these industries. Nevertheless, even assuming wide-scale availability of cost-effective CO₂ capture and geologic storage resources, the emergence of a domestic U.S. oil shale or coal-to-liquids (CTL) industry would be responsible for significant increases in CO₂ emissions to the atmosphere. The authors present modeling results of two future hypothetical climate policy scenarios that indicate that the oil shale production facilities required to produce 3 MMB/d from the Eocene Green River Formation of the western U.S. using an in situ retorting process would result in net emissions to the atmosphere of between 3000 and 7000 MtCO₂, in addition to storing potentially 900–5000 MtCO₂ in regional deep geologic formations via CCS in the period up to 2050. A similarly sized, but geographically more dispersed domestic CTL industry could result in 4000–5000 MtCO₂ emitted to the atmosphere in addition to potentially 21,000–22,000 MtCO₂ stored in regional deep geologic formations over the same period. While this analysis shows that there is likely adequate CO₂ storage capacity in the regions where these technologies are likely to deploy, the reliance by these industries on large-scale CCS could result in an accelerated rate of utilization of the nation's CO₂ storage resource, leaving less high-quality storage capacity for other carbon-producing industries including electric power generation.     

Apportionment of ambient primary and secondary fine particulate matter at the Pittsburgh National Energy Laboratory particulate matter characterization site using positive matrix factorization and a potential source contributions function analysis

Fine particulate matter (PM2.5) concentrations associated with 202 24-hr samples collected at the National Energy Technology Laboratory (NETL) particulate matter (PM) characterization site in south Pittsburgh from October 1999 through September 2001 were used to apportion PM2.5 into primary and secondary contributions using Positive Matrix Factorization (PMF2). Input included the concentrations of PM2.5 mass determined with a Federal Reference Method (FRM) sampler, semi-volatile PM2.5 organic material, elemental carbon (EC), and trace element components of PM2.5. A total of 11 factors were identified. The results of potential source contributions function (PSCF) analysis using PMF2 factors and HYSPLIT-calculated back-trajectories were used to identify those factors associated with specific meteorological transport conditions. The 11 factors were identified as being associated with emissions from various specific regions and facilities including crustal material, gasoline combustion, diesel combustion, and three nearby sources high in trace metals. Three sources associated with transport from coal-fired power plants to the southeast, a combination of point sources to the northwest, and a steel mill and associated sources to the west were identified. In addition, two secondary-material-dominated sources were identified, one was associated with secondary products of local emissions and one was dominated by secondary ammonium sulfate transported to the NETL site from the west and southwest. Of these 11 factors, the four largest contributors to PM2.5 were the secondary transported material (dominated by ammonium sulfate) (47%), local secondary material (19%), diesel combustion emissions (10%), and gasoline combustion emissions (8%). The other seven factors accounted for the remaining 16% of the PM2.5 mass. The findings are consistent with the major source of PM2.5 in the Pittsburgh area being dominated by ammonium sulfate from distant transport and so decoupled from local activity emitting organic pollutants in the metropolitan area. In contrast, the major local secondary sources are dominated by organic material.     

The Importance of Maintenance for Lime Flue Gas Desulfurization Systems

The successful, reliable operation of a power plant flue gas desulfurization (FGD) system depends largely on a good program of maintenance. Identifying the FGD equipment that is most critical to an FGD system’s overall reliability or its ability to meet emission regulations plays an important role in determining the extent of a maintenance program for a particular site. FGD maintenance programs vary considerably, depending on site-specific requirements and the support of plant owners. Many owners are reluctant to spend money on FGD maintenance because an FGD system is a nonproductive part of a power plant; however, a good maintenance program can result in longer equipment life, improved equipment performance, increased system availability, better safety, and lower operating costs. This paper uses wet and dry lime FGD systems to illustrate the advantages of good maintenance and the consequences of poor maintenance. Examples of specific tasks for preventive, scheduled, planned, and emergency maintenance are described. Also, because of the importance of FGD maintenance personnel, a section on organization and training is included.     

Using the Gasoline Additive MTBE in Forensic Environmental Investigations

A variety of additives are used in gasoline, and they can sometimes be used to help identify the source, timing, or number of gasoline spills at a site. The physicochemical characteristics of the additive MTBE, and its historical use pattern in the United States since 1979, make it a key compound to study when conducting forensic investigations of gasoline spills. MTBE's low octanol: water distribution coefficient and high solubility cause it to dissolve into groundwater more readily than other gasoline components. Thus, the initial appearance of MTBE in the groundwater is often a good indicator of a recent gasoline spill. MTBE's very low retardation and minimal biodegradation in groundwater can be used with transport rate calculations to establish relatively accurate estimates of spill timing. Because MTBE moves faster in groundwater than BTEX compounds, if a gasoline spill site has a BTEX plume that is longer than the MTBE plume, it is certain that at least two distinctly different gasoline releases have occurred. This allows for the identification of new gasoline spills, even when substantial subsurface petroleum contamination already exists. An example application is reviewed to demonstrate the use of MTBE data in forensic investigations.     

An introduction to decision science for conservation

Biodiversity conservation decisions are difficult, especially when they involve differing values, complex multidimensional objectives, scarce resources, urgency, and considerable uncertainty. Decision science embodies a theory about how to make difficult decisions and an extensive array of frameworks and tools that make that theory practical. We sought to improve conceptual clarity and practical application of decision science to help decision makers apply decision science to conservation problems. We addressed barriers to the uptake of decision science, including a lack of training and awareness of decision science; confusion over common terminology and which tools and frameworks to apply; and the mistaken impression that applying decision science must be time consuming, expensive, and complex. To aid in navigating the extensive and disparate decision science literature, we clarify meaning of common terms: decision science, decision theory, decision analysis, structured decision-making, and decision-support tools. Applying decision science does not have to be complex or time consuming; rather, it begins with knowing how to think through the components of a decision utilizing decision analysis (i.e., define the problem, elicit objectives, develop alternatives, estimate consequences, and perform trade-offs). This is best achieved by applying a rapid-prototyping approach. At each step, decision-support tools can provide additional insight and clarity, whereas decision-support frameworks (e.g., priority threat management and systematic conservation planning) can aid navigation of multiple steps of a decision analysis for particular contexts. We summarize key decision-support frameworks and tools and describe to which step of a decision analysis, and to which contexts, each is most useful to apply. Our introduction to decision science will aid in contextualizing current approaches and new developments, and help decision makers begin to apply decision science to conservation problems.     

流动注射分光光度法在线分析水中总铁

采用流动注射邻菲哕啉分光光度法在线分析水中总铁,考察了显色剂、消解液、酸度、反应盘管长度、载流流量、注样体积、采样时间等因素对试验的影响。方法在0.100mg／L-10.0mg／L范围内线性良好,检出限为0.04mg／L,实际水样平行测定的RSD≤3.7％,加标回收率为95.0％-96.0％。     

Identification of the antifungal peptide-containing symbiont of the marine sponge Theonella swinhoei as a novel δ-proteobacterium, “Candidatus Entotheonella palauensis”

 The Palauan sponge Theonella swinhoei (class Demospongiae, order Lithistida, family Theonellidae) harbors filamentous bacterial symbionts that contain theopalauamide, an antifungal, bicyclic glycopeptide. In this study, the filamentous symbionts were shown to be novel bacteria belonging to the δ-subdivision of proteobacteria. The 16S rRNA gene sequence was determined using a combination of denaturing gradient-gel electrophoresis (DGGE) and specific polymerase chain-reaction (PCR) primers, and its source was confirmed by in situ hybridization. In a series of culture experiments, the filamentous bacteria were propagated in a mixed culture on agar plates. Related 16S rRNA gene sequences were isolated from related sponges with slightly different chemistry. The taxonomic status “Candidatus Entotheonella palauensis” is proposed for the theopalauamide-containing filamentous bacteria from T. swinhoei. Received: 12 June 1999 / Accepted: 22 January 2000     

Fractionation and ecotoxicological implication of potentially toxic metals in sediments of three urban rivers and the Lagos Lagoon,Nigeria, West Africa

The potential environmental impact of sediment-bound Cd, Cr, Cu, Pb and Zn in three trans-urban rivers in Lagos state and in the Lagos Lagoon was assessed by use of the modified Community Bureau of Reference (BCR) sequential extraction. The quality of the data was checked using BCR CRM 143R and BCR CRM 701. Good agreement was obtained between found and certified/indicative values. Of the rivers, the Odo-Iyaalaro, was generally the most contaminated and the Ibeshe the least. Higher concentrations of metals were generally found in the dry season compared to the wet season. Cadmium and Zn were released mostly in the acid exchangeable step of the sequential extraction, indicating that they have the greatest potential mobility and bioavailability of the analytes studied. Chromium and Cu were associated mainly with the reducible and oxidisable fractions, and Pb predominantly with the reducible and residual fractions. Sediments with the highest pseudototal analyte concentrations also released higher proportions of analytes earlier in the sequential extraction procedure. The study suggests that, during the dry season, potentially toxic metals (PTM) may accumulate in sediments in relatively labile forms that are released and can potentially be transported or bioaccumulate in the rainy season. Application of risk assessment codes and Hankanson potential risk indices indicated that Cd was the element of greatest concern in the Lagos Lagoon system. The study indicated that there is a need to strengthen environmental management and pollution control measures to reduce risk from PTM, but that even relatively simple strategies, such as seasonal restrictions on dredging and fishing, could be beneficial.