Pilot‐scale demonstration of in situ capping of PCB‐containing sediments in the lower Grasse River

A fish‐consumption advisory is currently in effect in a seven‐mile stretch of the Grasse River in Massena, New York, due to elevated levels of PCBs in fish tissue. One remedial approach that is being evaluated to reduce the PCB levels in fish from the river is in situ capping. An in‐river pilot study was conducted in the summer of 2001 to assess the feasibility of capping PCB‐containing sediments of the river. The study consisted of the construction of a subaqueous cap in a seven‐acre portion of the river using various combinations of capping materials and placement techniques. Optimal results were achieved with a 1:1 sand/topsoil mix released from a clamshell bucket either just above or several feet below the water surface. A longer‐term monitoring program of the capped area commenced in 2002. Results of this monitoring indicated: 1) the in‐place cap has remained intact since installation; 2) no evidence of PCB migration into and through the cap; 3) groundwater advection through the cap is not an important PCB transport mechanism; and 4) macroinvertebrate colonization of the in‐place cap is continuing. Additional follow‐up monitoring in the spring of 2003 indicated that a significant portion of the cap and, in some cases, the underlying sediments had been disturbed in the period following the conclusion of the 2002 monitoring work. An analysis of river conditions in the spring of 2003 indicated that a significant ice jam had formed in the river directly over the capping pilot study area, and that the resulting increase in river velocities and turbulence in the area resulted in the movement of both cap materials and the underlying sediments. The pilot cap was not designed to address ice jam–related forces on the cap, as the occurrence of ice jams in this section of the river had not been known prior to the observations conducted in the spring of 2003. These findings will preclude implementation of the longer‐term monitoring program that had been envisioned for the pilot study. The data collected immediately after cap construction in 2001 and through the first year of monitoring in 2002 serve as the basis for the conclusions presented in this article. It should be recognized that, based on the observation made in the spring of 2003, some of these conclusions are no longer valid for the pilot study area.The occurrence of ice jams in the lower Grasse River and their importance on sediments and PCBs within the system are currently under investigation. © 2003 Wiley Periodicals, Inc.     

Local Environmental Investments and Sustainable Development: the evaluation of environmental projects in Scotland supported by the European Agriculture Guidance and Guarantee Fund

In the UK for the period 1994-99, a broad range of environmental projects were given financial support through the European Agriculture Guidance and Guarantee Fund under the Objective 1 and Objective 5b programmes. This paper is concerned with the ex-post evaluation of these projects set within a Sustainable Development framework. The aim was to identify project types or characteristics that offered the greatest return on investment. A classification of six broad project types was adopted. The evaluation revealed that there were significant differences between individual projects with respect to the type and scale, and temporal and social distribution of the benefits they delivered. In particular, as well as delivering environmental and economic benefits, many projects made a significant contribution to the development of human and social capital. The paper concludes that it is possible to improve the basis for future project selection in order to maximise the returns on environmental investments in the context of sustainable development.     

The Water Poverty Index: Development and application at the community scale

The article details the development and uses of the water poverty index (WPI). The index was developed as a holistic tool to measure water stress at the household and community levels, designed to aid national decision makers, at community and central government level, as well as donor agencies, to determine priority needs for interventions in the water sector. The index combines into a single number a cluster of data directly and indirectly relevant to water stress. Subcomponents of the index include measures of: access to water; water quantity, quality and variability; water uses (domestic, food, productive purposes); capacity for water management; and environmental aspects.
The WPI methodology was developed through pilot projects in South Africa, Tanzania and Sri Lanka and involved intensive participation and consultation with all stakeholders, including water users, politicians, water sector professionals, aid agency personnel and others. The article discusses approaches for the further implementation of the water poverty index, including the possibilities of acquiring the necessary data through existing national surveys or by establishing interdisciplinary water modules in school curricula. The article argues that the WPI fills the need for a simple, open and transparent tool, one that will appeal to politicians and decision makers, and at the same time can empower poor people to participate in the better targeting of water sector interventions and development budgets in general.     

利用地理信息系统(GIS)开发多功能空管系统

在航空运输中 ,飞行安全最为重要 ,空管指挥是保证飞行安全的重要手段。地理信息系统 (GIS)能够将空间位置和性质属性结合在一起 ,非常适合空管指挥中直观性、安全性方面的需要。笔者在研究开发多功能空管系统的基础上 ,讨论了对地形、地物、航道、空管区、禁飞区等进行数字化的方法 ,提出了系统开发的主要技术 ,介绍了多功能空管系统的显示、控制、示警、辅助决策、智能纠错等功能 ,指出了空管系统的发展方向     

安全外部性问题

安全外部性问题是安全科学的“盲点”。对安全外部性问题进行了界定与分类，分析了它的成因，提出了解决的办法。     

瓷砖釉面TiO2薄层对甲基橙的光催化降解

采用溶胶-凝胶法，在瓷砖釉面上制备了良好光催化活性TiO2薄层材料，研究结果表明瓷砖釉面TiO2薄层材料对甲基橙的光催化反应遵循一级动力学规律，光催化降解率与液层厚度符合指数关系。在太阳光照射下，釉面瓷砖TiO2薄层材料能对甲基橙有效地降解。     

污水处理厂自动化监控系统

自动化技术在能源、电力、机械、环境等行业的应用越来越广泛，也促使了自动化水平的不断提高。由于Synall2000强大的网络化功能，为将来系统在子网级和企业级实施基于Synall2000网络化数据监控系统打下了坚实、可靠的基础。在全面实施单个站点自动化监控的基础上，可方便地实现子网级的网络化数据自动采集与监控系统。