Predictions of Maximum Ground-Level H2S Concentrations Resulting from Two Sour Gas Well Blowouts

Alberta has recently experienced two sour gas well blowouts: Lodgepole and Claresholm. Sulphur emissions associated with the blowouts were about 1400 and 2 tonnes per day, respectively. The Lodgepole blowout was not only of much greater magnitude but also lasted significantly longer than the Claresholm blowout (67 vs. 4 days). Special air quality monitoring with respect to H₂S was conducted to assess impacts of the blowouts. Monitoring was especially extensive for the Lodgepole incident. Maximum observed ground-level H₂S concentrations were compared to predictions obtained using a Gaussian model which makes allowance for the effects of sonic exit velocity on plume spread and the effects of wind shear on plume transport. There was appreciable agreement between predicted and observed values.     

Brominated flame retardants,a cornelian dilemma

Environmental Chemistry Letters -     

Biotransformation of phenolics with laccase containing bacterial spores

Treatment of effluents containing phenols such as textile dyes with fungal laccases is usually limited to the acid to neutral pH range and moderate temperatures. Here we demonstrate for the first time that spore-bound laccases which are stable at high temperatures and pH values can be used for phenolic dye decolorisation. Laccase containing spores from Bacillus SF were immobilized on alumina pellets. Both immobilized and free spores were able to completely decolorize the common textile dyes Mordant Black 9, Mordant Brown 96/Mordant Brown 15, and Acid Blue 74 within 90 min of incubation time and decolorized solutions were successfully used in re-dyeing.     

PRINCIPLES FOR INTERNATIONAL GROUND-WATER LAW (II)

This is the second part of a paper outlining some principles applicable to the development of international law in the sub-sector of ground-water resources. In the first part of the paper, in the previous issue of the Forum , national ground-water laws were investigated to examine their suitability for adaptation at the international level. This part of the paper is devoted to reviewing the interjurisdictional experience among federated states and among independent states. It also draws the general conclusion of the entire paper.     

Public Health,Ethics, and Functional Foods

Functional foods aim to provide a positive impact on health and well-being beyond their nutritive content. As such, they are likely candidates to enhance the public health official’s tool kit. Or are they? Although a very small number of functional foods (e.g., phytosterol-enriched margarine) show such promise in improving individual health that Dutch health insurance companies reimburse their costs to consumers, one must not draw premature conclusions about functional foods as a group. A large number of questions about individual products’ safety, efficacy, and affordability need to be answered before they might become an important part of the public health agenda. More importantly, though, the costs and benefits of functional foods relative to alternative mechanisms of public health improvement need to be ascertained. Alternative scenarios that warrant investigation are mainly the supply of nutraceutical ingredients in pill form targeting “at risk” groups and consumer education on diet and lifestyle.     

An instrumental analytical technique for vapour-phase mercury species in air

This paper describes the research and development activities culminating in a methodology for the speciation of several volatile forms of mercury in the atmosphere: elemental mercury, mercuric chloride, methylmercuric chloride, and dimethyl mercury.     

Planning and evaluating cropland reclamation after stripmining in North Dakota

Effective cropland reclamation planning must be based upon an understanding of the soil characteristics and properties that contribute to the development of productive soils. Effective use of available soil and overburden materials require the utilization of all available knowledge about processes that cause changes in soil properties. Adequate premine characterization of soil and overburden materials is a prerequisite for good planning. Proper postmine topographic design is critical for maximizing water infiltration and retention. Topsoil must be replaced on all reclaimed soils, but the depth of replacement of subsoil depends upon the texture and soluble salt and/or sodium content of the underlying spoil. Reclamation success should be evaluated by relating yields to properties of the reclaimed soils; comparison with yields from nearby reference areas of undisturbed soils is not an acceptable method.Contribution from Land Reclamation Research Center, North Dakota State University, Mandan.Superintendent and Research Associates, respectively.     

Viewer preference for spatial arrangement of park trees: An application of video-imaging technology

Research on perception of parks and recreation settings has examined several important tree attributes that influence people's visual preferences. This research, however, has usually not considered the spatial arrangement of the trees, partly because of the lack of adequate methods for representing tree arrangements with systematically manipulated geometries. In the study reported here, computer video-imaging techniques were used to construct simulated landscape scenes that varied on specific dimensions of the spatial configuration of trees. The simulations were rated for visual preference by three respondent groups: a university class, a bicycle club, and a women's civic group. Preference ratings were significantly influenced by the number of trees in the scene, by the number of clumps into which trees were grouped, and by the diameter of the clumps. The video-imaging technology implemented in this study offers important methodological advantages for the design of carefully controlled experiments to study human response to variation in landscape treatments.     

Vegetation changes along the United States east coast following the great storm of march 1962

Regional-scale vegetation changes on Assateague Island following overwash from the Ash Wednesday Storm of 1962 were investigated using historical aerial photography. Grasses and dunes were more abundant in 1974 in areas that were overwashed, whereas areas that were not overwashed have been more extensively colonized by shrubs. The increase in shrubs on Assateague Island is attributed to the absence of a subsequent storm overwash.