水电站项目生态用水工程措施设计

电站引水发电以及堤坝式电站调峰运行将使坝下河段减(脱)水,调水、引水和供水等河道以外用水水利工程也将造成下游河道减(脱)水,水文将对水生生态、生产和生活用水、河道景观等产生一系列的不利影响.为维护河流的基本生态需求,水利水电工程必须下泻一定的生态流量,将其纳入工程水资源配置统筹考虑,使河流水电动能经济规模和水资源配备向"绿色"方向发展.本文以火溪河阴坪水电站为例,简述水电工程下泄生态流量确定的主要方法和下泄生态流量的工程措施设计.     

Impact analysis of drought, water excess and salinity on grass production in The Netherlands using historical and future climate data

The coupled SWAP-WOFOST model was used to study the effects of increasing salinity of groundwater, drought and water excess on grass production in The Netherlands. WOFOST simulates crop growth and SWAP simulates transport of water, solutes and heat in the vadose zone. The model was tested using several datasets from field experiments. We applied the models at regional scale where we quantified the impact of various groundwater salinity levels on grass growth and production using historical weather data (1971-2000). The salt concentrations in the subsoil were derived from the National Hydrological Instrument. The results show that salinity effects on grass production are limited. In wet years the excess rainfall will infiltrate the soil and reduce salt water seepage. In a next step we used future weather data for the year 2050, derived from 3 Global Circulation Models. From each model we used data from two CO₂ emission scenarios. As expected higher temperatures increased drought stress, however, the production reduction as a result of salt water in the root zone is limited. Salt stress mainly occurred when irrigation was applied with saline water. The increased CO₂ concentration in combination with the limited drought stress resulted in increasing simulated actual and potential yields. Overall conclusion for grassland in The Netherlands: drought stress is stronger than stress caused by water excess which on its turn is stronger than salinity stress. Future water demand for irrigation may increase by 11-19% and result in water scarcity if water supply is insufficient.     

Review of the remediation strategies for soil water repellency

Many regions of the world are predicted to experience water scarcity due to more frequent and more severe droughts and increased water demands. Water use efficiency by plants can be negatively affected by soil water repellency (SWR). It is timely to review existing techniques to remedy SWR. Ideally remediation addresses the origins of a problem. However, the fundamental mechanisms of how and why SWR develops are still poorly understood. In this review it was hypothesized that SWR occurs where the balance of input-decomposition of organic matter is impaired, due to either increased input or decreased decomposition rates of hydrophobic substances. Direct and indirect strategies to remedy SWR were distinguished. While direct remediation aims at abolishing the causes of SWR, indirect strategies seek to manage sites with SWR by treating its symptoms. The 12 reviewed strategies include applying surfactants, clay, slow-release fertilizers, lime, and fungicides, bioremediation of SWR through stimulating earthworms, choosing adapted vegetation, irrigation, cultivation, soil aeration and compaction. Some of the techniques have been applied successfully only in laboratory experiments. Our review highlights that it is not straightforward to cure SWR based on easily measurable and site-specific soil and vegetation properties, and that long-term, large-scale field experiments are required to improve the understanding of the evolution of SWR as cornerstone to develop cost-effective and efficient remediation strategies. We also identified current research gaps around the diagnosis and prevention of SWR.     

辅料配比对污泥生物-物理联合干燥的影响

利用自主研制的污泥生物-物理联合干燥反应系统研究了脱水污泥∶树皮∶回流污泥分别为7∶3∶0.5、9∶3∶0.5和12∶3∶0.5时,污泥生物-物理联合干燥过程中温度、含水率等参数的变化规律.结果表明,污泥温度随干燥时间延长先增大后减小,含水率在0～96 h逐渐降低,继续延长反应时间,则变化不明显.当脱水污泥∶树皮∶回流...     

改进的模糊层次分析法在南苕溪临安段水质评价中的应用

南苕溪是太湖的源头水系,其水质状况对杭嘉湖平原居民饮用水安全和太湖流域的污染治理有重要意义.为了了解南苕溪的水质状况,在临安段开展了2年的水质监测,分别在2009年7月、10月和2010年1月、4月采集了水样并进行水质评价.同时,为了克服以往模糊层次分析法存在的低估污染的严重性及不能评价劣Ⅴ类水质的缺点,建立了一个改进...     

国外高绩效人力资源实践：理论回顾、分析与展望

顺应组织发展要求构建有效人力资源管理模式,增强企业的持续竞争力,已经成为战略人力资源管理的热点之一。通过梳理近年来相关研究成果,剖析国外高绩效人力资源实践的概念及其构成。从员工态度和行为、组织资本、组织能力等方面指出高绩效人力资源实践的结果变量。根据实证研究相关文献,梳理高绩效人力资源实践与企业绩效的内在关联性。在此基础上,提出高绩效人力资源实践的未来研究方向,为相关理论和实证研究提供指导。     

城市工业区环境系统中的Cd污染循环及其健康风险——以杭州市半山工业区为例

为揭示重金属元素Cd在城市环境系统多种介质中的迁移途径及其潜在危害性,系统分析了杭州市半山工业区主要环境介质（土壤-尘埃-水-底泥-生物）样品中Cd的指标含量,并用连续提取法分析了土壤、尘埃、底泥中Cd的化学形态特征.结果表明,Cd的迁移途径主要有两种,一是以尘埃为媒介在地表环境中迁移,二是通过水介质进入水体环境（水和...     

闽江下游突发性水污染事故时空模拟

以闽江下游为例,基于有限元法建立闽江下游水动力模型及水质模型,通过对模型进行率定和验证,表明该模型具有较理想的模拟效果.在此基础上,利用闽江下游2004年的水文情况,模拟了突发性水污染事故中污染物的运移扩散过程.定量模拟了突发性水污染事故发生后,闽江下游不同地点处污染物到达的时间和浓度值,并对突发风险事故的影响范围、程...     

Minimizing leakage from a smelter off-gas system by enhanced control

The off-gas handling system is a vital component of a smelter and it is essential that it operates in accordance with environmental regulations. A key feature of the off-gas management system is maintaining a slightly negative system pressure to prevent gas leakage, such as SO₂, out into the work and external environments. To enhance sustainable development, there is also growing interest in capturing and reusing the significant amount of heat and CO₂ contained within off-gas. The potential incorporation of heat and CO₂ recovery systems places importance on enhancing control to minimize the risk of both gas leakage and disturbance of the smelting process. With these requirements in mind, an easily implementable feedforward control enhancement to existing control schemes is proposed to help provide improved performance.     

Carbon footprint of food - approaches from national input-output statistics and a LCA of a food portion

The aim of the study, on which this paper is based, was to provide guidance to consumers to make environmentally responsible choices in their food consumption, to assist food supply chain stakeholders to identify the key areas for environmental improvements, and to provide policy makers with a tool for monitoring the potential impacts on climate change resulting from developments within the food sector. At the macro level, the EIO-LCA model was developed specifically for the Finnish food chain; at the micro level, LCAs were performed on 30 lunch portions. The contribution of the Finnish food chain to climate change was 14%, which comprised 40% CO₂ emissions, 25% CH₄ emissions, and 34% N₂O emissions. The share of impacts from domestic agricultural processes was the highest, at 69%. The impact of a single lunch portion ranged between 0.65 and 3.80 kg of equivalent CO₂. According to the EIO-LCA model, the average impact was 7.7 kg CO₂ eq/person daily. The consumer phase accounted for between 8 and 47% of the climate change impacts for homemade portions. In ready-to-eat portions industry and retail phases were emphasized, representing 25-38% of climate change impacts. We present an approach to steer the Finnish food sector onto an environmentally sustainable path; practical tools for consumers and farmers will especially need to be developed further.