The Role of Industry

A series of partitioning agents were studied to determine their ability to separate organic sulfur compounds by gas chromatography. Several columns showed promise, but did not separate organic sulfur compounds from normally occurring atmospheric hydrocarbons. Higher concentrations of organic sulfur compounds in stack gases are separated as metallic salts in a series of impingers. The nature of the precipitated sulfur compound can be determined by gas chromatography after regeneration of the compound by addition of acid to the metallic precipitate.     

The Beginning of Survival

The majority of coal ash generated by electric utilities and power plants of industrial manufacturers is disposed of in landfills; the remainder is used primarily as admixtures in construction materials. Predictive computer models used to assess the environmental impact of disposal or utilization need quantitative information on ash composition and mineralogy. Typically, compositions are reported as elemental concentrations, but this data does not indicate the mineral or glass (amorphous) phases in which the elements are contained. Such phases affect the leaching mechanisms and rates. X-ray diffraction and scanning electron microscopy combined with energy dispersive X-ray spectrometry, common methods for qualitative mineral identification and particle characterization, were used to quantify coal ash mineral compositions. Samples of industrial coal ash from a stoker boiler and a fluidized bed combustion (FBC) system were analyzed and the results were compared to those for a standard sample of coal ash from the National Institute of Standards and Testing (NIST1633a). The results show that the stoker-boiler ash is similar in composition to the NIST sample. Mullite (AI₆Si₂O₁₃) dominates the composition of the crystalline fraction and silica (SiO₂,) dominates the composition of the amorphous fraction. The FBC ash contains the same minerals, but with large proportions of calcium-based phases: anhydrite (CaSO₄), lime (CaO), calcite (CaCO₃), and portlandite (Ga(OH)₂).     

The Dynamics of Urban Ecosystem Governance in Rotterdam,The Netherlands

We explore whether Rotterdam city has the governance capacity in terms of processes at place, and the attention in terms of vision and strategy to take up an integrated approach toward urban resilience. We adopt an interpretative policy analysis approach to assess the dynamics of urban ecosystem governance considering interviews, gray literature, and facilitated dialogues with policy practitioners. We show the inner workings of local government across strategic, operational, tactical, and reflective governance processes about the way urban ecosystems are regulated. Despite the existing capacity to steer such processes, a number of underlying challenges exist: need for coordination between planning departments; need to ease the integration of new policy objectives into established adaptive policy cycles; and need to assess the lessons learnt from pilots and emerging green initiatives. Regulating and provisioning ecosystem services receive heightened policy attention. Focus on regulating services is maintained by a policy renewal cycle that limits and delays consideration of other ecosystem services in policy and planning.     

The Behavior of Buoyant Merging Plumes in The Rocky Mountain Foothills

Natural gas often contains high concentrations of hydrogen sulfide which must be removed before the gas can be transmitted by pipeline. Sour gas plants extract the sulfur, by converting it to elemental sulfur through a modified Claus process. The sulfur recovery is 93% for small plants (10–100 tonnes of sulfur per day) to 99% for large plants (1000–4000 tonnes of sulfur per day). The unrecovered sulfur is Incinerated giving rise to relatively small emissions of SO₂ characterized by high buoyancy and low momentum.

Using a unique aerial probing methodology, plume dispersion studies were conducted on two plants located fn the foothills of southwestern Alberta, Canada. These studies were generally conducted under neutral conditions and with westerly air flows typical of Chinook conditions. Notable variations of the plume dispersion parameters from accepted predictive values were found, indicating that such values cannot be used with confidence to estimate plume rise and dispersion in the mountain foothills.     

The Water Table: The Shifting Foundation of Life on Land

Hyperarid, arid, and semi-arid lands represent over a third of the Earth’s land surface, and are home to over 38 % of the increasing world population. Freshwater is a limiting resource on these lands, and withdrawal of groundwater substantially exceeds recharge. Withdrawals of groundwater for expanding agricultural and domestic use severely limit water availability for groundwater dependent ecosystems. We examine here, with emphasis on quantitative data, case histories of groundwater withdrawals at widely differing scales, on three continents, that range from the impact of a few wells, to the outcomes of total appropriation of flow in a major river system. The case histories provide a glimpse of the immense challenge of replacing groundwater resources once they are severely depleted, and put into sharp focus the question whether the magnitude of the current and future human, economic, and environmental consequences and costs of present practices of groundwater exploitation are adequately recognized.     

The Significance of Particulate Emissions

Fine participates are the subject of increasing concern as one of the major air pollutants. They contribute to smog formation. They are a health hazard because they bypass the respiratory filters and penetrate deep into the lungs, and because they may act synergistically with other pollutants. The sources of submicron particle size pollutants are discussed.     

The foundations of environmental decision-making

An account of judgement is developed, which is used to show that deliberative procedures can provide a substantially different input to environmental decision-making from that afforded by cost-benefit analysis and, specifically, by the method of contingent valuation. It is argued that environmental concern typically invokes values, which are in turn formed and expressed through the exercise of judgement – itself the outcome of a deliberative rather than a calculative process. It is concluded that environmental concern is more effectively articulated through deliberative procedures than through the method of cost-benefit analysis.     

The Analysis of Airborne Sulfate

This report reviews the current state of analytical methodology for sulfate in airborne particles. Methods for determination of total aerosol sulfate and total soluble sulfate are assessed. A more detailed review of the relatively new techniques for quantitative speciation of airborne sulfate then follows. Size distribution methodology and filter sampling difficulties relating to the collection of airborne sulfate-containing particles are enumerated. Experiments are suggested which use new, improved, and potentially applicable sulfate speciation techniques to obtain a better understanding of the generation, transport, transformation and removal processes that, in turn, determine the identity and concentrations of sulfate species in ambient air.     

The ultraviolet photolysis of tetrachlorodibenzofurans

Several tetrachlorodibenzofuran isomers were photolyzed by ultraviolet irradiation and the relative amounts of the various trichlorodibenzofurans produced were determined. A simple set of guidelines for predicting the relative amounts of these photolysis products has been formulated.     

The bibliometrics of atmospheric environment

Bibliometric analysis is an important tool in the management of a journal. SCOPUS output is used to assess the increase in the quantity of material in Atmospheric Environment and stylistic changes in the way authors choose words and punctuation in titles and assemble their reference lists. Citation analysis is used to consider the impact factor of the journal, but perhaps more importantly the way in which it reflects the importance authors give to papers published in Atmospheric Environment. The impact factor of Atmospheric Environment (2.549 for 2007) from the Journal Citation Reports suggests it performs well within the atmospheric sciences, but it conceals the long term value authors place on papers appearing in the journal. Reference lists show that a fifth come through citing papers more than a decade old.     

The Inhibition of Photochemical Smog

Additional inhibitors for the conversion of NO to NO₂ in C3H6—NO—0₂ irradiated mixtures have been tested at 25°C. These mixtures initially contained 16 mTorr C₃H₆, 8 mTorr NO, 0.012 mTorr NO₂, additive, and enough O₂ to bring the total pressure to 100 Torr. The NO₂ pressure was monitored photometrically. In the absence of additive, the NO₂ pressure first increases with irradiation time reaching a maximum conversion at about 15 minutes. As the irradiation time increases beyond 15 min, the NO₂ pressure drops. Before adding the inhibitors, runs were done with 10 Torr of CO added, and in these runs the conversion was speeded so that the maximum in NO₂ pressure occurred at 10 min. This enhancement in conversion rate is considered to be diagnostic for the presence of HO radicals. Next 10-min irradiations were done with various amounts of hexafluorobenzene (C₆F₆), nitrobenzene (C₆H₅NO₂), or naphtha lene (C₁₀H₈) added. The NO₂ pressure was reduced to one-half its value in the absence of inhibitor with 270 mTorr C₆F₆’, 220 mTorr C₆H₅N0₂, or 4 mTorr C₁₀Hg. The C₁₀H₈ is a very efficient inhibitor, but additions of up to 1 8.5 mTorr C₁₀H₈ did not reduce the N0₂ pressure to zero. Studies of the percent conversion of NO to NO₂ vs. irradiation time were done with either 4.2 mTorr C₁₀H₈ or 40 mTorr 2,6-di-ferf-butyl-4-methylphenol (Ph) added. In the former case the peak conversion was delayed from 15 to 22 min, while in the latter case no delay occurred. However, with the Ph added, there appeared to be some reduction in the maximum value of percent conversion.     

The Odor Threshold of Phosphine

In the literature for odor threshold, values of phosphine are given which vary between 3 ppm^1,2 and 0.02 ppm.³ According to another paper phosphine is odorless even in concentrations up to 200 ppm.⁴ Since phosphine prepared from metal phosphides is used as a fumigant for foods, feeds, and processed food products, we carried out new investigations to clarify the discrepancy.     

The acute toxicity of arsenobetaine

The acute toxicity of arsenobetaine was studied in male mice. No deaths were observed with oral administration of 10 g/kg of arsenobetaine. Therefore the LD₅₀ value was higher than 10 g/kg. This compound was found in urine in the non-metabolized form. No particular toxic symptoms were observed following administration. These results suggest that arsenobetaine has low toxicity and is not metabolized in mice.     

The Sulfur Balance of Incinerators

Municipal refuse usually contains only 0.10-0.15% sulfur. During combustion a minor fraction of the sulfur is released as SO₂, while the major fraction is fixed in the ash, which contains alkaline oxides. Contrasted with coal and heavy fuel oil, municipal refuse is a minor to negligible source of SO₂ air pollution.     

The parable of the carpenter

This paper describes how the Shanxi Environmental Protection Agency and SINTEF have acted on the recommendations of a joint study by UNEP and the National Environmental Protection Agency of PR China (NEPA) to implement the following cooperation programme: to establish the Shanxi Centre for Energy and Environment; to develop a masterplan against air pollution in Shanxi province; and to initiate pilot projects with cleaner technologies. The work has so far (1997) been funded by Norwegian Agency for Development Aid (NORAD). Further action will however require contribution from a number of other sources, such as the Global Environment Facility, private companies, investment banks and governments. The results from our work have shown that such efforts, in a region like Shanxi province, give environmental cost benefits far ahead of most other places in the world.