Use of Constructed Wetlands for Urban Stream Restoration: A Critical Analysis

/ Investigation of a delta marsh restoration project proposed forthe Don River in Toronto, Ontario, underlines several concerns aboutconstructed wetland projects designed for water quality improvement andaquatic habitat enhancement. The Don is a highly urbanized river that hasundergone significant physiographic modifications and continually receives acomplex mixture of conventional, metallic, and organic contaminants frommultiple point and nonpoint sources. Rather than providing permanent removalof urban contaminants, wetland processes offer a limited capacity fortemporary storage of contaminant inputs, and potential reactions may actuallyproduce more toxic and/or bioavailable forms of some chemicals. Theseprocesses tend to result in the concentration of watershed contaminants inwetland vegetation and sediments. As the restored marsh would be availablefor spawning and feeding by aquatic fauna, the potential exists for chemicalbioconcentration and biomagnification through the aquatic community.Accordingly, wetland systems are not suited to the dual purposes of waterquality improvement and aquatic habitat enhancement. Upstream controls,including source reduction of contaminant inputs, are recommended asessential components of all constructed wetland projects.KEY WORDS: Constructed wetlands; Water quality; Ecological restoration;Don River     

黄土窑洞构造防水技术的工程试验研究

介绍了利用土壤水动力学中止水势在层状土中的阻水原理，以防止黄土窑洞在50a一遇的降雨过程中，产生渗漏雨导致坍窑成灾的工程试验。讨论了双层或三层结构在3a的实验观测中防水减渗过程方面的有效性和适用性。     

再论高压水射流清洗技术应用的专业化、规模化与社会化

高压水射流技术在清洗领域的应用，因其具有一系列优势，越来越为社会所认同和欢迎。以何种模式运行才能使其发展的更快、更好，是在该领域的工作者所普遍关注的问题。在理论与实践相结合的基础上，再次讨论并提出高压水射流清洗技术应用的专业化、规模化与社会化，以期在更大的范围引起同行的参与，共同寻求发展我国高压水射流清洗技术应用的最佳战略、策略和实施的方式。实践证明，高压水射流清洗技术应用的专业化、规模化与社会化是可以实现的。坚持为国民经济建设服务，使其专业化、规模化与社会化并逐步充实、完善，定能使之有更大的发展     

我国水污染现状及防治对策

我国是一个水资料严重匮乏和水污染十分严重的国家，加强水污染管理和控制刻不容缓。为此，本文结合发达国家立法现状，从组织，民众意识、水污染排放标准，监测方法等方面论述加强水污染控制的管理。     

OPTICAL CHARACTERISTICS OF NEW ZEALAND RIVERS IN RELATION TO FLOW1

ABSTRACT: Six years (1989–1994) of data from New Zealand's National Rivers Water Quality Network were used to characterize the optical water quality regime of river waters as regards: visual clarity (black disc visibility), turbidity, and light-absorbing aquatic humic material (referred to as ‘yellow substance,’ measured as light absorption at 440 nm). Quantitative relationships between optical water quality variables and flow in rivers are well-described by power law expressions. Visual clarity usually decreases strongly with increasing flow in individual rivers. There is a strong, inverse relationship between turbidity and visibility, but, because of differences between sites, turbidity is not a good general predictor of visual clarity (the attribute of real interest) in rivers. Yellow substance tends to increase with increasing flow, probably because during rainstorms, soil water high in yellow-colored humic material, rather than rain water or ground water, dominates discharge. Therefore, rivers are typically clear and low in humic matter at low flow, and turbid and yellow-colored at high flow.     

加强水土保持 防止生态恶化

本文论述了水土水流失对生态环境的影响和对农业生产的危害，阐明增强环境意识，加强水土保持时防止生态恶化，是我国振兴农业的重要性与紧迫性的任务。     

新型滤料──短纤维性能研究

短纤维作为一种滤料应用于水过滤器中，具有密度小，孔隙率大，比表面积大的优点，它在过滤进程中，滤速高，阻力小，过滤周期长，能使悬浮物脱除率达到９６％以上，是一种应用前景很好的滤料。在本文中对短纤维滤料的过滤性能作了系统地研究。     

优选法及正交试验在选择废水处理最佳条件中的应用

从试验考核指标出发，运用“水质指数（ＷＱＩ）”，分析影响废水处理效果的诸因素，选取ｐＨ值和处理剂加入量为可控因素，利用优选法找出钻井废水处理的最佳条件；选取两个因素水平进行正交试验，选用Ｌ４（２３）正交表，合理安排试验，确定最优因素水平组合。总之，应用优选法及正文试验于钻井废水处理工作中，获得了处理的最佳条件，对钻井生产中废水处理统一操作，降低消耗，保证废水处理达标率起着很重要的作用。     

INCENTIVE-BASED NONPOINT SOURCE POLLUTION ABATEMENT IN A REAUTHORIZED CLEAN WATER ACT1

ABSTRACT: This paper summarizes key provisions of the Clinton Administration's proposals for change in the Clean Water Act. Two of the important themes for change are tougher controls for non-point source pollution and the use of market-based instruments. A detailed analysis of market-based abatement suggests limited potential for reducing costs. The keys to nonpoint source pollution control are clearer definition of property rights combined with changes in government programs that encourage polluting activities.     

我国钢铁工业废水治理及其发展趋势

我国水资源人均拥有量仅为世界人均拥有量的四分之一，而且降水在时空分布上很不均衡。这一现实，决定了节省水资源，保护水环境是我国一项长期的战略任务。文章概要地叙述了钢铁工业废水治理及其发展过程。作者认为，要从根本上解决钢铁工业废水对水环境的污染与破坏，必须采取综合防治措施，并把整套循环用水技术引入生产工艺过程，使废水与污染物都作为资源加以回收，并实现循环利用。上述过程的实质，是模拟大自然生物圈循环运行