Applications of time-resolved laser fluorescence spectroscopy to the environmental biogeochemistry of actinides

Time-resolved laser fluorescence spectroscopy (TRLFS) is a useful means of identifying certain actinide species resulting from various biogeochemical processes. In general, TRLFS differentiates chemical species of a fluorescent metal ion through analysis of different excitation and emission spectra and decay lifetimes. Although this spectroscopic technique has largely been applied to the analysis of actinide and lanthanide ions having fluorescence decay lifetimes on the order of microseconds, such as UO , Cm, and Eu, continuing development of ultra-fast and cryogenic TRLFS systems offers the possibility to obtain speciation information on metal ions having room-temperature fluorescence decay lifetimes on the order of nanoseconds to picoseconds. The main advantage of TRLFS over other advanced spectroscopic techniques is the ability to determine in situ metal speciation at environmentally relevant micromolar to picomolar concentrations. In the context of environmental biogeochemistry, TRLFS has principally been applied to studies of (i) metal speciation in aqueous and solid phases and (ii) the coordination environment of metal ions sorbed to mineral and bacterial surfaces. In this review, the principles of TRLFS are described, and the literature reporting the application of this methodology to the speciation of actinides in systems of biogeochemical interest is assessed. Significant developments in TRLFS methodology and advanced data analysis are highlighted, and we outline how these developments have the potential to further our mechanistic understanding of actinide biogeochemistry.     

An ecological perspective on theory, methods, and analysis in environmental psychology: Advances and challenges

Over the course of environmental psychology's brief history, there has been an interest in ecologically oriented approaches to theory and research. Based on this work, this paper identifies a set of six principles of ecological analysis that present theoretical, methodological, and analytic challenges to future research in environmental psychology. These challenges include the theoretical treatment of the multiple contexts within which human experience and behavior occurs, the need for sampling both persons and environments, the modeling of moderating and mediating processes, the issue of self-selection into and out of different settings, the necessity of considering temporal factors in environmental research, reliance on single methods (e.g., verbal report) in data generation, cross-sectional and longitudinal research designs, and the need for greater use of statistical techniques developed for contextual (multi-level) research. These issues are discussed and illustrated using recent developments in environmentally oriented research. The paper concludes with a set of 11 recommendations for the future.     

Environmental occurrences, behavior, fate, and ecological effects of nanomaterials: an introduction to the special series

The release of engineered nanomaterials (ENMs) into the biosphere will increase as industries find new and useful ways to utilize these materials. Scientists and engineers are beginning to assess the material properties that determine the fate, transport, and effects of ENMs; however, the potential impacts of released ENMs on organisms, ecosystems, and human health remain largely unknown. This special collection of four review papers and four technical papers identifies many key and emerging knowledge gaps regarding the interactions between nanomaterials and ecosystems. These critical knowledge gaps include the form, route, and mass of nanomaterials entering the environment; the transformations and ultimate fate of nanomaterials in the environment; the transport, distribution, and bioavailability of nanomaterials in environmental media; and the organismal responses to nanomaterial exposure and effects of nanomaterial inputs, on ecological communities and biogeochemical processes at relevant environmental concentrations and forms. This introductory section summarizes the state of knowledge and emerging areas of research needs identified within the special collection. Despite recent progress in understanding the transport, transformations, and fate of ENMs in model environments and organisms, there remains a large need for fundamental information regarding releases, distribution, transformations and persistence, and bioavailability of nanomaterials. Moreover, fate, transport, bioaccumulation, and ecological impacts research is needed using environmentally relevant concentrations and forms of ENMs in real field materials and with a broader range of organisms.     

Advancing Sustainable Bioenergy: Evolving Stakeholder Interests and the Relevance of Research

The sustainability of future bioenergy production rests on more than continual improvements in its environmental, economic, and social impacts. The emergence of new biomass feedstocks, an expanding array of conversion pathways, and expected increases in overall bioenergy production are connecting diverse technical, social, and policy communities. These stakeholder groups have different—and potentially conflicting—values and cultures, and therefore different goals and decision making processes. Our aim is to discuss the implications of this diversity for bioenergy researchers. The paper begins with a discussion of bioenergy stakeholder groups and their varied interests, and illustrates how this diversity complicates efforts to define and promote “sustainable” bioenergy production. We then discuss what this diversity means for research practice. Researchers, we note, should be aware of stakeholder values, information needs, and the factors affecting stakeholder decision making if the knowledge they generate is to reach its widest potential use. We point out how stakeholder participation in research can increase the relevance of its products, and argue that stakeholder values should inform research questions and the choice of analytical assumptions. Finally, we make the case that additional natural science and technical research alone will not advance sustainable bioenergy production, and that important research gaps relate to understanding stakeholder decision making and the need, from a broader social science perspective, to develop processes to identify and accommodate different value systems. While sustainability requires more than improved scientific and technical understanding, the need to understand stakeholder values and manage diversity presents important research opportunities.     

The organization of integrated environmental research in The Netherlands

This article presents new concepts for the organization of increasingly complex environmental research activities on the institutional, the national, or the international level. An environmental research cycle with four phases, similar to the industrial product cycle, is described, and its implications in managing the interface between research, policy making, and enforcement are depicted. Furthermore, five main themes of future environmental research are proposed, including advanced analytical methods, environmental monitoring, an environmental management information system (EMIS), and the development of ecological targets at a national and a global level. The specific tasks of universities, private organizations, and governmental institutions in the total environmental research area are defined and a structure is proposed to develop collaborative networks.     

Identifying relationships between baseflow geochemistry and land use with synoptic sampling and R-mode factor analysis

The relationship between land use and stream chemistry is often explored through synoptic sampling of rivers at baseflow conditions. However, baseflow chemistry is likely to vary temporally and spatially with land use. The purpose of our study is to examine the usefulness of the synoptic sampling approach for identifying the relationship between complex land use configurations and stream water quality. This study compares biogeochemical data from three synoptic sampling events representing the temporal variability of baseflow chemistry and land use using R-mode factor analysis. Separate R-mode factor analyses of the data from individual sampling events yielded only two consistent factors. Agricultural activity was associated with elevated levels of Ca2+, Mg2+, alkalinity, and frequently K+, SO4(2-), and NO3-. Urban areas were associated with higher concentrations of Na+, K+, and Cl-. Other retained factors were not consistent among sampling events, and some factors were difficult to interpret in the context of biogeochemical sources and processes. When all data were combined, further associations were revealed such as an inverse relationship between the proportion of wetlands and stream nitrate concentrations. We also found that barren lands were associated with elevated sulfate levels. This research suggests that an individual sampling event is unlikely to characterize adequately the complex processes controlling interactions between land use and stream chemistry. Combining data collected over two years during three synoptic sampling events appears to enhance our ability to understand processes linking stream chemistry and land use.     

Engagement with climate change and the environment: a review of the role of relationships to place

A growing body of literature examines how human bonds with place influence engagement with climate change and other environmental issues. Yet, studies in this vein derive from a number of disconnected literatures with a variety of place concepts employed. We set out to assess the current state of knowledge in this field and provide a framework for analysing dimensions of relations to place and their links with environmental engagement. We systematically analysed the characteristics of 66 studies identified for: focus of research, location, methods, and findings, particularly whether relationships to place aided in environmental engagement. We also categorised the studies according to our dimensions of place relations framework, cultural and environmental contexts, and intensity of climate impacts experienced. The answer to our guiding research question – whether place attachment was an effective way to communicate with people about climate change and get them actively engaged with it – was yes (74.2%), but with considerable variation according to these characteristics and dimensions. Based on this analysis, we identify gaps in current research and suggest critical paths for future research, especially in terms of geography and demography because of their implications for justice and equity in the processes of climate change mitigation and adaptation. Needed future research includes studies of place relations in regards to climate change specifically, studies in the Global South, of minority populations, beyond rural areas, and qualitative or mixed-method studies able to draw out the complexities of relations to place.     

Finding local answers to fuelwood problems

This paper presents an analytical approach to the identification of characteristic fuel-wood situations in developing countries. This approach recognizes the tension between achieving a level of generalization needed for policy formulaion and the need to capture the specifics of fuelwood production and use at a local level. A typology, based on environmental and socioeconomic criteria, is advanced which is intended to form the basis of a refining of policy principles to the specifics of different localities. A series of brief case studies is presented to illustrate the characteristics of different types of locality, and conclusions of the future direction of fuelwood policy are advanced.     

水体中氟乐灵的生物毒性和去除研究进展

作为一种在全球范围内广泛使用的二硝基苯胺类除草剂,氟乐灵对环境和人体健康的潜在危害越来越受到人们的关注.本文首次总结了水体中氟乐灵的来源、生物毒性、毒性机理以及饮用水处理中去除氟乐灵的物理、化学和生物方法.传统单独的加氯消毒、生物膜工艺等通常难以高效去除水体中的氟乐灵,而以紫外线和臭氧为基础的高级氧化技术（AOPs）由于能产生具有强氧化能力的羟基自由基而对水体中痕量氟乐灵有较好的去除效果.最后在此基础上,对今后的研究方向进行了展望,提出改进饮用水中微量氟乐灵的毒性检测和去除工艺亟待解决的问题.     

Local Dirt, Global Dreams: mining investment and land use change in Arizona

A central problematic for researchers working at the interface of economic and environmental change is the development of research designs and methodologies that can satisfactorily link economic processes of global reach (such as direct investment) to environmental change at local and regional scales. This article reviews recent efforts to couple economic and environmental change and finds that relatively little effort has been made to use the direct investment process as a means of linking industrial restructuring to land use change. The article argues that direct investment, when conceptualised as a political-economic process involving the assemblage of a package of rights (to land, water, pollution permits etc), can be an effective vehicle for tracing through the impacts of industrial restructuring on local environments. To develop this analytical approach, an empirical case of mineral investment in the Gila Valley of eastern Arizona is presented. The case study identifies the acquisition of land and water rights as central strategic issues for mineral firms seeking to make investment, and traces through the impact of these acquisition strategies on existing patterns of land ownership and land use.     

Biodegradation and bioconversion of cellulose wastes using bacterial and fungal cells immobilized in radiopolymerized hydrogels

Annually, great amounts of cellulose wastes, which could be measured in many billions of tons, are produced worldwide as residues from agricultural activities and industrial food processing. Consequently, the use of microorganisms in order to remove, reduce or ameliorate these potential polluting materials is a real environmental challenge, which could be solved by a focused research concerning efficient methods applied in biological degradation processes. In this respect, the scope of this chapter is to present the state of the art concerning the biodegradation of redundant cellulose wastes from agriculture and food processing by continuous enzymatic activities of immobilized bacterial and fungal cells as improved biotechnological tools and, also, to report on our recent research concerning cellulose wastes biocomposting to produce natural organic fertilizers and, respectively, cellulose bioconversion into useful products, such as: ‘single-cell protein’ (SCP) or ‘protein-rich feed’ (PRF). In addition, there are shown some new methods to immobilize microorganisms on polymeric hydrogels such as: poly-acrylamide (PAA), collagen-poly-acrylamide (CPAA), elastin-poly-acrylamide (EPAA), gelatin-poly-acrylamide (GPAA), and poly-hydroxy-ethyl-methacrylate (PHEMA), which were achieved by gamma polymerization techniques. Unlike many other biodegradation processes, these methods were performed to preserve the whole viability of fungal and bacterial cells during long term bioprocesses and their efficiency of metabolic activities. The immobilization methods of viable microorganisms were achieved by cellular adherence mechanisms inside hydrogels used as immobilization matrices which control cellular growth by: reticulation size, porosity degree, hydration rate in different colloidal solutions, organic and inorganic compounds, etc. The preparative procedures applied to immobilize bacterial and fungal viable cells in or on radiopolymerized hydrogels and, also, their use in cellulose wastes biodegradation are discussed in detail. In all such performed experiments were used pure cell cultures of the following cellulolytic microorganisms: Bacillus subtilis and Bacillus licheniformis from bacteria, and Pleurotus ostreatus, Pleurotus florida, and Trichoderma viride from fungi. These species of microorganisms were isolated from natural habitats, then purified by microbiological methods, and finally, tested for their cellulolytic potential. The cellulose biodegradation, induced especially by fungal cultures, used as immobilized cells in continuous systems, was investigated by enzymatic assays and the bioconversion into protein-rich biomass was determined by mycelial protein content, during such long time processes. The specific changes in cellular development of immobilized bacterial and fungal cells in PAA hydrogels emphasize the importance of physical structure and chemical properties of such polymeric matrices used for efficient preservation of their metabolic activity, especially to perform in situ environmental applications involving cellulose biodegradation by using immobilized microorganisms as long-term viable biocatalysts.     

Environmentally adjusted productivity measurement: an Australian case study

This paper critically examines various methods for estimating productivity incorporating environmental effects for the Australian agricultural sector. The agricultural sector has been selected because of its strategic position in the economy of Australia. The findings of this study indicate that the application of environmentally adjusted productivity methods is a credible approach to measure productivity, in the context of sustainable development. Although the empirical findings of this research are case study specific, the results provide evidence supporting the adoption of these techniques to other sectors of the economy when measuring productivity and needing to be cognisant of sustainable development. The findings suggest that adjusting for the environmental impacts of soil erosion can result in higher or lower agricultural productivity depending on the assumptions we make regarding damage costs of erosion. It is argued in this paper that, for soil erosion in Australia, assumptions yielding higher productivity (i.e., upwardly adjusted) are justified. Finally, the findings of this study and the use of the methods presented point to important gaps in data availability. This gap needs to be addressed by policy makers if sustainable development objectives are to be credibly assessed using these techniques.     

How planners and stakeholders learn with visualization tools: using learning sciences methods to examine planning processes

Planning researchers traditionally conceptualize learning as cognitive changes in individuals. In this tradition, scholars assess learning with pre- and post-measures of understandings or beliefs. While valuable for documenting individual change, such methods leave unexamined the social processes in which planners think, act, and learn in groups, which often involve the use of technical tools. The present interdisciplinary research program used Learning Sciences research methods, including conversation analysis, interaction analysis, and visualization of discourse codes, to understand how tools like agent-based models and geographic information systems mediate learning in planning groups. The objective was to understand how the use of these tools in participatory planning can help stakeholders learn about complex environmental problems, to make more informed judgments about the future. The paper provides three cases that illustrate the capacity of such research methods to provide insights into planning groups’ learning processes, and the mediating roles of planning tools.     

Local Dirt,Global Dreams: Mining investment and land use change in Arizona

A central problematic for researchers working at the interface of economic and environmental change is the development of research designs and methodologies that can satisfactorily link economic processes of global reach (such as direct investment) to environmental change at local and regional scales. This article reviews recent efforts to couple economic and environmental change and finds that relatively little effort has been made to use the direct investment process as a means of linking industrial restructuring to land use change. The article argues that direct investment, when conceptualised as a political-economic process involving the assemblage of a package of rights (to land, water, pollution permits etc), can be an effective vehicle for tracing through the impacts of industrial restructuring on local environments. To develop this analytical approach, an empirical case of mineral investment in the Gila Valley of eastern Arizona is presented. The case study identifies the acquisition of land and water rights as central strategic issues for mineral firms seeking to make investment, and traces through the impact of these acquisition strategies on existing patterns of land ownership and land use.     

Life-cycle assessment: A survey of current implementation

Life-Cycle Assessment (LCA) is an analytical tool that evaluates the environmental consequences of a product, process, or activity across its entire life cycle. LCA is used internationally by government and industry to obtain a comprehensive perspective of the interactions between an activity and the environment and provides a method to systematically identify opportunities for improvement. The framework is integrated into environmental management programs motivated by market awareness, public perception, and cost savings. The use of LCA is driven by external forces such as eco-labels and the recent development of the ISO 14000 standards. However, LCA has many shortcomings that need to be addressed. The concerns of poor data quality, data availability, high implementation costs, subjectivity, and lack of standardization have sent LCA into a state of flux. In light of the recent surge of interest in LCA, the authors of this article have conducted a corporate survey that targets the implementation of LCA. Their goal is to determine the level of activity of LCA among known practitioners and to elucidate common themes. This article presents their findings from responses by 34 companies that were known to be actively involved in LCA or contemplating its future use.     

Development of environmental thresholds for streams in agricultural watersheds

Global increases in consumption of chemical nutrients, application of pesticides, and water withdrawal to enhance agricultural yield have resulted in degraded water quality and reduced water availability. Efforts to safeguard or improve environmental conditions of agroecosystems have usually focused on managing on-farm activities to reduce materials loss and conserve habitat. Another management measure for improving environmental quality is adoption of environmental performance standards (also called outcome-based standards). This special collection of six papers presents the results of four years of research to devise scientifically credible approaches for setting environmental performance standards to protect water quantity and quality in Canadian agriculturally dominated watersheds. The research, conducted as part of Canada's National Agri-Environmental Standards Initiative, aimed to identify Ideal Performance Standards (the desired environmental state needed to maintain ecosystem health) and Achievable Performance Standards (the environmental conditions achievable using currently available and recommended best available processes and technologies). Overviews of the papers, gaps in knowledge, and future research directions are presented. As humans, livestock, and wildlife (both terrestrial and aquatic) experience greater pressures to share the same limited water resources, innovative research is needed that incorporates a landscape perspective, economics, farm practices, and ecology to advance the development and application of tools for protecting water resources in agricultural watersheds.     

Spectroscopic approaches for phosphorus speciation in soils and other environmental systems

In the past decades, environmental scientists have become increasingly involved in developing novel approaches for applying emerging spectroscopic techniques to complex environmental matrices. The objective of this review is to convey the most common chemical species of phosphorus reported for soils, sediments, model systems, and waste materials based on analyses by four spectroscopic techniques: X-ray absorption near-edge structure, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and Raman spectroscopy. Unique information is provided by each technique at a level of specificity that depends in part on matrix complexity. The X-ray absorption near-edge structure and nuclear magnetic resonance techniques reveal inorganic and organic P species in intact environmental matrices or in chemical extracts, whereas the Fourier transform infrared and Raman techniques can provide more specific bonding information about mineral or adsorbed P species in model analogs of matrix components. The most common P species in soils and sediments as indicated by spectroscopy are hydroxyapatite and octacalcium phosphate minerals, phosphate adsorbed on Fe- and Al-oxides, pyrophosphates and polyphosphates, phosphate mono- and di-esters, and phosphonates. Continued advancements in spectroscopic methods should improve speciation-based models of P mobilization and transformations in the environment.     

Agroforestry systems and environmental quality: introduction

Investments in agroforestry research during the past three decades-albeit modest-have yielded significant gains in understanding the role of trees on farmlands, and the ecological and economic advantages of integrated farming systems. While early research focused mostly on farm or local levels, broader-level ecosystem services of agroforestry systems (AFS) have raised high expectations in recent years. The nine papers included in this special collection deal with three of such environmental benefits of AFS: water-quality enhancement, carbon sequestration, and soil improvement. These benefits are based on the perceived ability of (i) vegetative buffer strips (VBS) to reduce surface transport of agrochemical pollutants, (ii) large volumes of aboveground and belowground biomass of trees to store high amounts of C deeper in the soil profile, and (iii) trees to enhance soil productivity through biological nitrogen fixation, efficient nutrient cycling, and deep capture of nutrients. The papers included have, in general, substantiated these premises and provided new insights. For example, the riparian VBS are reported to increase the reservoir life, in addition to reducing transport of agrochemicals; the variations in C storage in different soil-fraction sizes suggest that microaggregate (250-53 μm) dynamics in the soil could be a good indicator of its C-storage potential; and the use of vector analysis technique is recommended in AFS to avoid consequences of inaccurate and overuse of fertilizers. The papers also identified significant knowledge gaps in these areas. A common theme across all three environmental quality issues covered is that more and varied research datasets across a broad spectrum of conditions need to be generated and integrated with powerful statistical tools to ensure wide applicability of the results. Furthermore, appropriate management practices that are acceptable to the targeted land users and agroforestry practitioners need to be designed to exploit these environmental benefits. The relative newness of research in environmental quality of AFS will pose some additional challenges as well. These include the lack of allometric equations for tree-biomass determination, absence of standardized norms on soil sampling depth, and limitations of fixed-effect models arising from issues such as pseudo-replication and repeated measures that are common in studies on preexisting field plots. Overall, this special collection is a timely effort in highlighting the promise of AFS in addressing some of the environmental quality issues, and the challenges in realizing that potential.