The European Water Framework Directive: Water Quality Classification and Implications to Engineering Planning

The European Water framework directive (WFD) is probably the most important environmental management directive that has been enacted over the last decade in the European Union. The directive aims at achieving an overall good ecological status in all European water bodies. In this article, we discuss the implementation steps of the WFD and their implications for environmental engineering practice while focusing on rivers as the main receiving waters. Arising challenges for engineers and scientists are seen in the quantitative assessment of water quality, where standardized systems are needed to estimate the biological status. This is equally of concern in engineering planning, where the prediction of ecological impacts is required. Studies dealing with both classification and prediction of the ecological water quality are reviewed. Further, the combined emission–water quality approach is discussed. Common understanding of this combined approach is to apply the most stringent of either water quality or emission standard to a certain case. In contrast, for example, the Austrian water act enables the application of only the water quality based approach - at least on a temporary basis.     

试论城市水环境的建设

本文通过对城市水环境的形成以及加强水环境建设对整个城市建设舒适度的影响和作用的剖析,试着引用了一种国际上较为流行的对河流综合整治的方法,对秦皇岛城市水环境建设提出了一点建议。     

我国城市污水回用现状及前景

通过对我国水资源状况和不处理状况的论述，说明了我国城市污水回用的紧迫性、必要性，分析了我国城市污水利用的现状和回用水利用的模式，提出了下一步应解决的问题的思路，展望了我国城市污水回用的前景，以实现水资源开发利用的可持续性发展。     

Multivariate Analysis of the Ecoregion Delineation for Aquatic Systems

The ecoregion concept is a popular method of understanding the spatial distribution of the environment', however, it has yet to be adequately demonstrated that the environment is distributed in accordance with these bounded units. In this paper, we generated a testable hypothesis based on the current usage of ecoregions: the ecoregion classification will allow for discrimination between lakes of different water quality. The ecoregion classification should also be more effective better than a comparably scaled classification based on political boundaries, land-use class, or random grouping. To test this hypothesis we used the Environmental Monitoring and Assessment Program (EMAP) lake water chemistry data from the northeast United States. The water chemistry data were reduced to four components using principal component analysis. For comparison to an optimal grouping of these data we used K-means cluster analysis to define the extent at which these lakes could be segregated into distinct classes. Jackknifed discriminant analysis was used to determine the classification rate of ecoregions, the three alternative spatial classification methods, and the clustering algorithm. The classification based on ecoregions was successful for 35% of the lakes included in this study, in comparison to the clustered groups accuracy of 98%. These results suggest that the large scale spatial distribution of ecosystem types is more complicated than that suggested by the present ecoregion boundaries. Further tests of ecoregion delineations are needed and alternative large-scale management strategies should be investigated.     

Securing water for people, crops, and ecosystems: New mindset and new priorities

A fundamentally new approach to water and human development will be needed during this new century if we are to secure sufficient freshwater to meet the needs of some 9 billion people while at the same time protecting the critical ecosystem services upon which the human economy depends. Signs of unsustainable water use — including falling water tables, shrinking lakes, and the drying up of rivers and streams — are widespread and spreading. In many regions, greater modification and appropriation of freshwater systems for human purposes will yield greater costs than benefits and create the risk of irreversible losses of species and ecosystem services. A new mindset is needed to guide water use and management in this new century, one that views the human water economy as a subset of nature's water economy. Living within nature's limits will require that societies satisfy the basic needs of people and ecosystems before non-essential water demands are met. It will require on the order of a doubling of water productivity. And it will require stronger institutions to encourage equitable sharing of water to alleviate tensions within and between countries.     

关于创建节水型城市的探讨

为了有效的缓解目前我国城市水资源严重短缺的现状，国家提出了大力创建节水型城市口号。为了对实践工作有一定的指导作用，本文重点对节水及节水型城市的内涵进行了剖析，特别对节水型城市内涵提出了自己的见解。以此同时，运用上述的理论，分析了目前我国在创建节水型城市工作中存在的主要问题，并结合国外节水的经验，提出了有建设性的几点建议。     

Roofing as a source of nonpoint water pollution

Sixteen wooden structures with two roofs each were installed to study runoff quality for four commonly used roofing materials (wood shingle, composition shingle, painted aluminum, and galvanized iron) at Nacogdoches, Texas. Each roof, either facing NW or SE, was 1.22 m wide x 3.66 m long with a 25.8% roof slope. Thus, there were 32 alternatively arranged roofs, consisting of four roof types x two aspects x four replicates, in the study. Runoff from the roofs was collected through galvanized gutters, downspouts, and splitters. The roof runoff was compared to rainwater collected by a wet/dry acid rain collector for the concentrations of eight water quality variables, i.e. Cu(2+), Mn(2+), Pb(2+), Zn(2+), Mg(2+), Al(3+), EC and pH. Based on 31 storms collected between October 1997 and December 1998, the results showed: (1) concentrations of pH, Cu, and Zn in rainwater already exceed the EPA freshwater quality standards even without pollutant inputs from roofs, (2) Zn and Cu, the two most serious pollutants in roof runoff, exceeded the EPA national freshwater water quality standards in virtually 100% and more than 60% of the samples, respectively, (3) pH, EC, and Zn were the only three variables significantly affected by roofing materials, (4) differences in Zn concentrations were significant among all roof types and between all roof runoff and rainwater samples, (5) although there were no differences in Cu concentrations among all roof types and between roof runoff and rainwater, all means and medians of runoff and rainwater exceeded the national water quality standards, (6) water quality from wood shingles was the worst among the roof types studied, and (7) although SE is the most frequent and NW the least frequent direction for incoming storms, only EC, Mg, Mn, and Zn in wood shingle runoff from the SE were significantly higher than those from the NW; the two aspects affected no other elements in runoff from the other three roof types. Also, Zn concentrations from new wood-shingle roofs were significantly higher than those from aged roofs of a previous study. The study demonstrated that roofs could be a serious source of nonpoint water pollution. Since Zn is the most serious water pollutant and wood shingle is the worst of the four roof types, using less compounds and materials associated with Zn along with good care and maintenance of roofs are critical in reducing Zn pollution in roof runoff.     

Eco-environmental benefit assessment of China's South-North Water Transfer Scheme--the middle route project

This paper assess the eco-environmental benefits that may come from the middle route project of China‘s South-North Water Transfer Scheme(SNWT) with principles and methods of eco-economics and planning reports of SNWT‘s middle route project. Some benefits were calculated in monetary units. To make sure that the results can be comparable with normal monetary indices, concrete assessment objects and the parameters are prudently selected according to the major characteristics of the project and its water import region. Primary assessment revealed that in different project construction stages, the benefit could be more than 13.07 billion RMB Yuan in 2010 and 19.79 billion RMB Yuan in 2030, respectively. The monetary value tends to increase with social-economic development. To realize these potential benefits, however, calls for more endeavors.     

水中Mg 2+ 的测试管快速测定

研制了一种测定水中Mg^2 的测试管，测定范围为0.5mg/L-2.0mg/L，该测试管适用于现场应急监测，具有快速、简便、抗干扰能力强和价格低廉等特点。     

城镇生活污水深度处理实验研究

采用SBR—化学混凝处理城镇生活污水,结果表明:经SBR处理后,废水中的COD、氮、磷得到很好的去除,最佳的混凝工艺条件为:废水pH7.30左右,聚合氯化铝钙用量20mg/L废水,搅拌强度120r/min,搅拌时间15min,加入PAM用量0.15mg/L废水。