Nickel and sulfur speciation of residual oil fly ashes from two electric utility steam-generating units

Representative duplicate fly ash samples were obtained from the stacks of 400- and 385-MW utility boilers (Unit A and Unit B, respectively) using a modified U.S. Environmental Protection Agency (EPA) Method 17 sampling train assembly as they burned 0.9 and 0.3 wt % S residual (No. 6 fuel) oils, respectively, during routine power plant operations. Residual oil fly ash (ROFA) samples were analyzed for Ni concentrations and speciation using inductively coupled plasma-atomic emission spectroscopy, X-ray absorption fine structure (XAFS) spectroscopy, and X-ray diffraction (XRD). ROFA deionized H2O extraction residues were also analyzed for Ni speciation using XAFS and XRD. Total Ni concentrations in the ROFAs were similar, ranging from 1.3-1.5 wt%; however, stack gas Ni concentrations in the Unit A were 0.990 microg/Nm3 compared with 0.620 microg/Nm3 for Unit B because of the greater residual oil feed rates employed at Unit A to attain higher 400-MW load conditions with a lower heating value oil. Ni speciation analysis results indicated that ROFAs from Unit A contain approximately 3 wt % NiSO4 x xH2O (where x is assumed to be 6 for calculation purposes) and appoximately 4.5 wt% of a Ni-containing spinel compound, similar in composition to (Mg,Ni)(Al,Fe)2O4. ROFAs from Unit B contain on average 2 wt% NiSO4 x 6 H20 and 1.1 wt% NiO. XAFS and XRD analyses did not detect any nickel sulfide compounds, including carcinogenic nickel subsulfide (Ni3S2) (XAFS detection limit is 5% of the total Ni concentration). In addition, XAFS measurements indicated that inorganic sulfate and organic thiophene species accounted for > 97% of the total S in the ROFAs. Unit A ROFAs contained much lower thiophene proportions because cyclone-separated ROFA reinjection is employed on this unit to collect and reburn the larger carbonaceous particles.     

Groundwater protection in mixed land-use aquifers

Compared with groundwater pollution episodes of a point-source nature, nonpoint-source contamination makes for particularly difficult policy design. This is especially true in the context of a mixed land-use aquifer, where the same pollutant may derive from various human land-use activities and in different concentrations. To data, the emprirical literature attempting to estimate the relative loadings of pollutants from alternative land uses is rather sparse. Yet this information is vital to a variety of numerical computer models used to predict likelihood of groundwater contamination, and the statistical results are useful in their own right for regional policy formation. Regression analysis is applied to estimate loadings of nitrate and sodium from various land uses. The model is then used to illustrate how well-intended local groundwater protection policies that fail to recognize land-use substitution and cross-pollutant effects may be misdirected.     

N-nitrosodimethylamine in drinking water using a rapid,solid-phase extraction method

A simple, rapid method for the extraction of N-nitrosodimethylamine (NDMA) from drinking and surface waters was developed using Ambersorb 572. Development of an alternative method to classical liquid-liquid extraction techniques was necessary to handle the workload presented by implementation of a provincial guideline of 9 ppt for drinking water and a regulatory level of 200 ppt for effluents. A granular adsorbent, Ambersorb 572, was used to extract the NDMA from the water in the sample bottle. The NDMA was extracted from the Ambersorb 572 with dichloromethane in the autosampler vial. Method characteristics include a precision of 4 % for replicate analyses, an accuracy of 6 % at 10 ppt and a detection limit of 1.0 ppt NDMA in water. Comparative data between the Ambersorb 572 method and liquid-liquid extraction showed excellent agreement (average difference of 12 %). With the Ambersorb 572 method, dichloromethane use has been reduced by a factor of 1,000 and productivity has been increased by a factor of 3–4. Monitoring of a drinking water supply showed rapidly changing concentrations of NDMA from day to day.     

Book reviews

Green Culture: environmental rhetoric in contemporary America. C. G. Herndl & S. C. Brown (Eds), 1996, Madison, WI, University of Wisconsin Press, 315 pp. ISBN 0 229 14990 0, £35.95 (hbk) ISBN 0 299 14994 3, £17.50 (pbk)

Earthtalk: communication empowerment for environmental action. S. A. Muir & T. L. Veenendall, 1996, Westport, CT, Praeger, Praeger Series in Political Communication, 233 pp. ISBN 0 275 953700 X, £47.95

Environmentalism and Cultural Theory. Kay Milton, 1996 London & New York, Routledge, 266 pp. ISBN 0 415 115529 9, £45.00 (hbk) ISBN 0 415 11530 2, £13.99 (pbk)

Local Environmental Struggles: citizen activism in the treadmill of production. Kenneth A. Gould, Allan Schnaiberg & Adam S. Weinberg, 1996, Cambridge University Press, 239 pp. ISBN 0 521 55519 1, £40.00 (hbk) ISBN 0 521 55521 3, £14.95 (pbk)

The Language of Environment: a new rhetoric. George Myerson & Yvonne Rydin, 1996 London, UCL Press, 264 pp. ISBN 1 85728 330 9, £35.00 (hbk) ISBN 1 85728 331 7, £11.95 (pbk)

Environmental Issues and Business: implications of a changing agenda. Sally Eden, 1996, Chichester, Wiley, ISBN 0 471 94872 1, £25.00

Green Shift: towards a green sensibility in architecture. John Farmer, edited by Kenneth Richardson, 1996, Oxford, Butterworth Architecture, with World-Wide Fund for Nature, ISBN 07506 15303

Lewis Mumford and the Ecological Region: the politics of planning. Mark Luccarelli, 1995, New York, Guilford Press, ISBN 1572300019, £19.95

The Ecology of Hope: communities collaborate for sustainability. Ted Bernard & Jora Young, 1997, East Haven, CT, New Society Publishers, 233 pp. ISBN 0 86571 355 33 (pbk)

Turning the Tide: integrated local area management for Australia's coastal zone. Valerie A. Brown, 1995, Canberra, Australia, Department of the Environment, Sport and Territories

Involving Communities in Forestry through Community Participation. Forestry Practice Guide 10, Forestry Commission

The Scope for Community Participation in Forest Management. A Report for the Forestry Commission and Scottish Office by Bill Slee, Gill Clark & Patrick Snowdon, £10 (£15 non UK)

The Role of Woodlands in Meeting Planning Objectives in Great Britain. A Report for the Forestry Commission by Professor Paul Selman     

Photolysis of diclobutrazol in methanol

The fungicide diclobutrazol (2RS,3RS)-1-(2,4-dichlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pentan-3-ol was irradiated by ultra-violet light in methanol solution using (1) borosilicate glass apparatus and (2) quartz apparatus. The major differences observed were that photodegradation occurred more rapidly in (2) than (1) and more breakdown products were found in the former. Using g.c.-m.s. ten compounds were detected in (1) of which five were identified. In (2) twelve of the eighteen compounds observed were identified and the major component was 1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pentan-3-one. The compounds reported were formed by oxidation, loss of chlorine or by cyclisation. This previously unreported cyclisation gave the s-triazolo-(5,1a)isoquinoline ring system.     

Material Flow Analysis: A tool to support environmental policy decision making. Case-studies on the city of Vienna and the Swiss lowlands

This paper discusses the use of Material Flow Analysis (MFA) as a tool to support policy decision making in the field of resource and environmental management. In terms of policy, MFA can be used for early recognition, priority setting, to analyse and improve the effectiveness of measures and to design efficient material management strategies in view of sustainability. MFA has a high potential to be implemented as a guiding tool at the regional level, for example as part of a regional environmental management and audit system or as a part of the Local Agenda 21 process. Material management based on MFA is complementary to traditional environmental and resource management strategies, which have tended to focus heavily on specific environmental compartments, and measure the concentration of substances in various media. MFA, in contrast, provides an overview of the total system by linking the anthroposphere (that part of the biosphere in which humans' activities take place) with the environment. This system approach shifts the focus away from the back-end so-called 'filter strategies' to more pro-active front-end measures. MFA examines short- and long-term loadings rather than concentrations and highlights current and potential material accumulations, called material stocks. These stocks represent either potential environmental problems (e.g. large stocks of hazardous materials) or a potential source of future resources (e.g. urban mining). In this way, MFA can assist precautionary policy making by highlighting future environmental or resource issue problems without relying on signals of environmental stress. The objective of materials management is: firstly, to analyse material flows and stocks; secondly, to evaluate these results; and thirdly, to control material flows in view of certain goals such as sustainable development. MFA is an excellent tool for the first objective and is well suited to generate a base for the other two objectives. MFA results can be compared against environmental standards or can be interpreted using assessment or indicator methodologies (such as environmental impact assessment or ecological footprints). Selected results from two studies, carried out for the city of Vienna (substance management) and the Swiss lowlands (timber management), illustrate the use of MFA as a tool for early recognition (resource depletion and environmental quality), for priority setting and for effective policy making.     

A tale from the Island of Laputa: The UNCHS (Habitat) crowding and health project from the perspective of two reluctant Laputans

Abstract

This paper seeks to explore Canada's response to the global dialogue over sustainable development on two dimensions: policy articulation at the federal and provincial levels and policy implementation at the municipal level. In order to accomplish these goals, this analysis begins by outlining a critical framework for understanding and assessing local sustainable development. Next, it examines the evolution of Canadian federal and provincial policies supportive of sustainable development, including the role played by non‐governmental organisations (NGOs) in enhancing this process. It then contrasts the Canadian promise and experience with that of the USA. In analysing local responses to the call for sustainable communities, it offers a case study of the Hamilton‐Wentworth Vision 2020 sustainable community programme—a North American showcase of sustainable community initiatives.     

Characterizing Runoff and Water Yield for Headwater Catchments in the Southern Sierra Nevada

In a Mediterranean climate where much of the precipitation falls during winter, snowpacks serve as the primary source of dry season runoff. Increased warming has led to significant changes in hydrology of the western United States. An important question in this context is how to best manage forested catchments for water and other ecosystem services? Answering this basic question requires detailed understanding of hydrologic functioning of these catchments. Here, we depict the differences in hydrologic response of 10 catchments. Size of the study catchments ranges from 50 to 475 ha, and they span between 1,782 and 2,373 m elevation in the rain‐snow transitional zone. Mean annual streamflow ranged from 281 to 408 mm in the low elevation Providence and 436 to 656 mm in the high elevation Bull catchments, resulting in a 49 mm streamflow increase per 100 m (R² = 0.79) elevation gain, despite similar precipitation across the 10 catchments. Although high elevation Bull catchments received significantly more precipitation as snow and thus experienced a delayed melt, this increase in streamflow with elevation was mainly due to a reduction in evapotranspiration (ET) with elevation (45 mm/100 m, R² = 0.65). The reduction in ET was attributed to decline in vegetation density, growing season, and atmospheric demand with increasing elevation. These findings suggest changes in streamflow in response to climate warming may likely depend on how vegetation responds to those changes in climate.