An Assessment of Residues from Duct Injection Demonstration Sites

The duct injection retrofit process for flue gas cleanup of sulfur dioxide emissions has been demonstrated at several sites in the United States through a series of U.S. Department of Energy research projects. As a subcontractor on one of the projects, the University of North Dakota Energy & Environmental Research Center performed a comprehensive characterization of four residues from three demonstration sites. The characterization task objective was to facilitate understanding of materials handling and to identify potential disposal and utilization options for these high-volume coal utilization solid residues. Characterization included evaluation of the physical and engineering properties, chemical composition, mineralogy, and leaching potential. Chemical characterization results provided interesting and valuable information from the standpoint of the bulk chemistry and phase assemblages, as well as potential environmental issues associated with the use or disposal of these materials. Results of the chemical and mineralogical characterizations indicate that duct injection residues will be suitable for specific utilization applications and that disposal of these residues should be similar to many conventional coal combustion residues. Significant mineralogical phase changes were noted in long-term leaching experiments.     

Multi-decadal changes in tundra environments and ecosystems: synthesis of the International Polar Year-Back to the Future project (IPY-BTF)

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in subarctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies.     

"What Works Well; What Needs Improvement": Lessons in public consultation from British Columbia's resource planning processes

Resource planning and management in British Columbia, Canada, has been steadily moving towards more active public participation. While government agencies have long been required to consult the general public during the course of land or resource use planning, the 1990s brought in a period of more intense public involvement. In terms of resource planning, this led to the creation of several new planning processes. Given that there is now considerable experience with the Commission on Resources and Environment (CORE) and the Land and Resource Management Plan (LRMP) processes, it is time for an appraisal. In particular, the paper examines the public's perceptions of these processes with respect to 'what works well' and 'what needs improvement'. The results highlight a number of areas to which process designers and managers should direct attention. There are three key items of note. First, there are generally low levels of awareness by respondents of public consultation processes in their community. Second, there is a need for access to timely, relevant and readable information throughout the course of the process in order to keep participants and the public as up-to-date as possible. Finally, there must be greater clarity about the process itself, including mandates, participants and decision-making powers.     

The concept of the Portuguese National Ecological Reserve: constraints and impossibilities in the Azores Archipelago

The biophysical features of small islands (SI) distinguish them from other territories; isolation, small size and several anthropogenic pressures reduce the resilience of ecosystems and increase their vulnerability to global changes. Many SI have a shortage of infrastructures, institutions and technical/financial resources that hinder planning and require different integrated solutions. In Portugal, the National Ecological Reserve (NER) is legally binding for spatial planning instruments. It aims to defend natural values and areas of ecological value, or sensibility, or susceptible to natural hazards. However, the criteria for the design of NER are strictly set for mainland territory, not taking into account specific features of small islands. A case study of the Azores Archipelago is used to demonstrate that spatial planning instruments should be adapted to island contexts. Such adaptation will increase the effectiveness of their implementation in relation to the protection of natural resources, stability of biophysical structures and prevention of natural hazards. Observing the main differences between mainland and the Azores Archipelago it is possible to define a methodological transposition of the NER aims and goals into an island context. This approach is an answer to the constraints in effective adaptation of spatial planning instruments for islands.     

Indigenous community-based fisheries in Australia

The commercial sea cucumber species known as Sandfish (Holothuria scabra) occurs intertidally and subtidally in the Northern Territory of Australia, on or adjacent to Aboriginal land. A 4-yr program of community-based fisheries research with Aboriginal Australians was implemented to assess the viability of indigenous Australians' involvement in the wild-stock fishery. The research involved extensive and intensive indigenous participation, unusual in Australian biophysical sciences research, during field survey and habitat mapping, complemented by commercial catch data modelling and discussion of its implications. Field surveys produced Sandfish distribution and site-specific density, and revealed some areas that were not commercially fished. Catch data modelling results suggested that no additional effort could be sustained, however commercial fishers increased their effort, expanding their operations into the newly mapped areas. These actions effectively precluded indigenous peoples' aspirations of entry into the commercial fishery. The efficacy and outcomes of participatory program design with indigenous Australians need critique in the absence of the political will and statutory backing to provide equitable access to resources.     

Biological aspects of metal waste reclamation with biosolids

Smelter waste deposits pose an environmental threat worldwide. Biosolids are potentialy useful in reclamation of such sites. Biological aspects of revegetation of Zn and Pb smelter wastelands using biosolids are discussed in this report. The goal of the studies was to assess to what extent biosolid treatment would support ecosystem functioning as measured by biological indicators such as enzyme activities of revegetated metal waste or plant growth. Another crucial aspect was related to the assessment of metal transfer to the ecosystem which could affect the health of local fauna and also create a food chain risk. A field experiment was conducted on a smelter waste deposit in Piekary Slaskie, Silesia, Poland, with two separate fields - established on wastes from the Welz and Doerschel smelting processes. The tested methods allowed revegetation of the fields - application of municipal biosolid at the rate 300 dry t ha(-1) combined with the incorporation of commercial lime in a mixed oxide and carbonate form at the rate of 1.5 and 30 t for Welz waste or use of a 30 cm by-product lime cap followed by incorporation of biosolid at a rate of 300 t ha(-1) for the more acidic Doerschel waste. Studies on biological activities demonstrated that the reclamation methods used are an effective way to establish new, fully-functioning ecosystems that support plant growth. They also provided strong evidence that forage crops grown on Zn, Cd and Pb contaminated sites reclaimed using lime and biosolids do not pose identified risk for wildlife and food safety.     

Integration of traditional and innovative characterization techniques for flux-based assessment of Dense Non-aqueous Phase Liquid (DNAPL) sites

Key attributes of the source zone and the expanding dissolved plume at a trichloroethene (TCE) site in Australia were evaluated using trends in groundwater monitoring data along with data from on-line volatile organic compound (VOC) samplers and passive flux meters (PFMs) deployed in selected wells. These data indicate that: (1) residual TCE source mass in the saturated zone, estimated using two innovative techniques, is small ( 10 kg), which is also reflected in small source mass discharge ( 3 g/day); (2) the plume is disconnecting, based on TCE concentration contours and TCE fluxes in wells along a longitudinal transect; (3) there is minimal biodegradation, based on TCE mass discharge of  6 g/day at a plume control plane  175 m from source, which is also consistent with aerobic geochemical conditions observed in the plume; and (4) residual TCE in the vadose zone provides episodic inputs of TCE mass to the plume during infiltration/recharge events. TCE flux data also suggest that the small residual TCE source mass is present in the low-permeability zones, thus making source treatment difficult. Our analysis, based on a synthesis of the archived data and new data, suggests that source treatment is unwarranted, and that containment of the large TCE plume ( 1.2 km long,  0.3 km wide; 17 m deep;  2000–2500 kg TCE mass) or institutional controls, along with a long-term flux monitoring program, might be necessary. The flux-based site management approach outlined in this paper provides a novel way of looking beyond the complexities of groundwater contamination in heterogeneous domains, to make intelligent and informed site decisions based on strategic measurement of the appropriate metrics.