A comparison of the water management systems in France and China

This paper compares legal systems for water management in France and China, with a focus on integrated water resources management and regarding in particular the formulation of policies and their implementation. The research shows that China has committed itself to the efficient management of water resources through the development of various policy tools during the current period. This commitment, however, has often been interrupted and distorted by politics, resulting in the neglect of socioeconomic and environmental priorities. France has developed a legislative framework and practical instruments to apply integrated water resources management at the river basin level since the 1960s. This experience and the current implementation of the European Water Framework Directive brings elements that can contribute to Chinese society meeting its water challenges.     

Serum concentrations of chlorinated dibenzo-p-dioxins and dibenzofurans among former New Zealand trichlorophenol workers

This study examined serum levels of 2,3,7,8-substituted chlorinated dioxins and furans, and 15 PCBs for 346 New Zealand employees who worked at a site that manufactured 2,4,5-trichlorophenol (TCP) and 2,4,5-trichlorophenoxy acetic acid (2,4,5-T). Participants with potential TCP or 2,4,5-T exposures had mean lipid-adjusted 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) levels of 9.9 ng kg⁻¹ lipid compared to 4.9 ng kg⁻¹ for workers with no exposure at the site. Among exposed workers, we found evidence of differences in 2,3,7,8-TCDD levels by department and duties. Workers involved in an accidental release had the highest mean 2,3,7,8-TCDD levels, 37.9 ng kg⁻¹, followed by workers in the trichlorophenol plant, 23.4 ng kg⁻¹. Workers with potential intermittent exposures to 2,3,7,8-TCDD in construction, maintenance, mechanics, and transport had 2,3,7,8-TCDD levels above New Zealand background levels of 3.9 ng kg⁻¹, indicating workplace exposures. Among participants with work history indicating no 2,3,7,8-TCDD exposures, we observed some individuals with 2,3,7,8-TCDD levels above background levels. However, in most cases, these workers reported workplace exposures not recorded on their work histories or held other jobs with the potential for 2,3,7,8-TCDD exposures outside the plant. All other dioxin, furan, and PCB levels were similar among the exposed and unexposed workers.     

Humic acids as reducing agents: the involvement of quinoid moieties in arsenate reduction

Purpose  

Dissolved humic acids abiotically reduced inorganic arsenic to varying degrees, depending on solution pH, ionic strength, and type of humate used. The functionalities of dissolved organic matter responsible for these redox reactions remained in question, but quinoid moieties undoubtedly played an important role. It is not fully understood whether the quinoids are solely responsible for arsenate reduction, and what the kinetics of the relevant processes are.     

Morphology of <Emphasis Type="Italic">Penicillium funiculosum</Emphasis> During Biodegradation of Poly (β-hydroxybutyrate-co-β-hydroxyvalerate) [PHBV] with Poly (ε-Caprolactone) [PCL] Blends

Blends of poly (β-hydroxybutyrate-co-β-hydroxyvalerate) with poly (ε-caprolactone) were produced using melt mixing and solvent casting techniques. The biodegradation of blends was tested based in the ASTM G21-90 using Penicillium funiculosum fungal specie. The CO₂ production during biodegradation was measured and fitted using the Gompertz model. Biodegradation of blends varies according to the mixing technique and the proportion of bacterial polymers in the blends. Although lag phase was larger, solvent-casted blends were easier to degrade due to their porous surface and relative lower crystallinity. P. funiculosum morphology during biodegradation appeared to be related to carbon availability i.e. larger and more complex conidiophores, more phialides per conidiophore and the presence of double-phialides, were found in blends with higher PHAs proportion. P. funiculosum morphology was independent to the blending technique used. Hence, morphology of P. funiculosum could be useful as a reference for carbon bioavailability of the blends.     

Indicators for managing biosolids in Ireland

Sustainable development indicators (SDIs) have emerged as a tool to measure progress towards sustainable development for a number of fields. However, no indicator initiative to date has been aimed at biosolids management at local authority, regional or national levels. This paper presents a study where stakeholders involved in the management of biosolids in Ireland participated in the development of SDIs for managing biosolids at the local/regional level. A significant 81% of participating stakeholders find SDIs either 'useful' or 'very useful' as a tool for managing biosolids. A suite of 22 indicators has been developed and arranged according to the driving force-pressure-state-impact-response (DPSIR) indicator framework. The indicators address all the domains of biosolids management namely, production, quality, cost, legislation/regulation, training/research and recycling/disposal. The stakeholder approach is recognition that no effective indicator set can be developed without the input of stakeholders.     

美国高校实验室废弃物安全管理浅析

实验室废弃物的收集、管理不当会造成严重的环境污染甚至人员伤害,这已经引起国内外相关部门的高度重视。美国高校在实验室废弃物安全管理方面积累了科学、规范的管理经验：通过对实验室科研人员的专业培训保证废弃物的安全分类收集;通过专业环境健康安全管理部门人员的科学管理实现对废弃物的安全收集与存放;通过专业废弃物收集处置公司来实现废弃物的安全转移运输和最终无害化处理。为加强国内高校实验室废弃物的安全管理,在对美国高等院校实验室废弃物的收集、储藏、运输和处理等方面调查研究的基础上,结合国内实验室废弃物安全管理的现状,对国内外高校实验室废弃物的安全管理进行了对比分析,以期为国内高校实验室废弃物的安全管理工作提供有益的借鉴。     

Using a model selection criterion to identify appropriate complexity in aquatic biogeochemical models

Aquatic biogeochemical models are widely used as tools for understanding aquatic ecosystems and predicting their response to various stimuli (e.g., nutrient loading, toxic substances, climate change). Due to the complexity of these systems, such models are often elaborate and include a large number of estimated parameters. However, correspondingly large data sets are rarely available for calibration purposes, leading to models that may be overfit and possess reduced predictive capabilities. We apply, for the first time, information-theoretic model-selection techniques to a set of spatially explicit (1D) algal dynamics models of varying parameter dimension. We demonstrate that increases in complexity tend to produce a better model fit to calibration data, but beyond a certain degree of complexity the benefits of adding parameters are diminished (the risk of overfitting becomes greater). The particular approach taken here is computationally expensive, but several suggestions are made as to how multimodel methods may practically be extended to more sophisticated models.     

Estimating undiscovered oil resources: An engineering approach

This paper is an evaluation of the earlier work of M.K. Hubbert with the aim of more objectively estimating total recoverable (i.e. producible) oil in the United States and Nigeria. The results, based upon an engineering model, indicate that 198 billion barrels are ultimately recoverable in the United States of which 113.8 billion barrels have been produced through 1977. For Nigeria, 19.4 billion barrels are ultimately recoverable of which 6.1 billion barrels have been produced at the end of 1977.     

The Shallow‐Water Component of the Chesapeake Bay Environmental Model Package

The shallow‐water component of the Chesapeake Bay Environmental Model Package emphasizes the regions of the system inside the 2‐m depth contour. The model of these regions is unified with the system‐wide model but places emphasis on locally significant components and processes, notably submerged aquatic vegetation (SAV), sediment resuspension, and their interaction with light attenuation (Ke). The SAV model is found to be most suited for computing the equilibrium distribution of perennial species. Addition of plant structure and propagation are recommended to improve representation of observed trends in SAV area. Two approaches are taken to examining shallow‐water Ke. The first compares observed and computed differences between deep‐ and shallow‐water Ke. No consistent difference in observations is noted. In the preponderance of regions examined, computed shallow‐water Ke exceeds computed deep‐water Ke. The second approach directly compares Ke measured in shallow water with modeled results. Model values are primarily lower than observed, in contrast to results in deep water where model values exceed observed. The shortfall in computed Ke mirrors a similar shortfall in computed suspended solids. Improved model representation of Ke requires process‐based investigations into suspended solids dynamics as well as increased model resolution in shallow‐water regions.     

Self-healing concrete for sustainable buildings. A review

Environmental Chemistry Letters - A total of 12 billion tons of concrete materials are produced annually, about 2 tons per person. More sustainable buildings are thus needed to decrease the carbon...