The potential of green roofs to manage Urban Stormwater

Green roofs have considerable potential for stormwater source control, both for new developments and as a retrofit option. In the United Kingdom the lack of local quantitative performance data and modelling tools, together with more general barriers to sustainable drainage systems (SUDS) implementation, may explain their limited uptake to date. This paper presents preliminary findings from a small-scale instrumented green roof test plot located in Sheffield, UK. During spring 2006 the average volume retention was 34% and the average peak reduction was 57%. The key hydrological determinants were the antecedent dry weather period (ADWP), mean rainfall intensity and rainfall depth. Detailed examination of rainfall–runoff relationships in summer 2007 demonstrates the dependency of performance on antecedent moisture conditions. Structural appraisal of a range of flat roof types suggests that retrofitting a green roof will be a feasible option in many cases, particularly for concrete slab roofs.     

Laboratory analysis of the outflow and detention processes from modular tray-based blue roofs

ABSTRACT

Novel laboratory experiments were carried out to investigate the outflow process and the detention effects of a tray module of a blue roof (BR) system designed for runoff control from building roofs. The experiments revealed the outflow from the tray to decline during time, due to a number of complex dynamics occurring in proximity of the outlet orifice. The tests also showed the system to provide potential for relevant attenuation of the flow peak during inflow events (i.e. precipitation) of different magnitude. Based on regression analysis, an empirical relationship was developed for the evaluation of the tray outflow as a function of time, thus providing a tool for improved design of BRs. Finally, combination of the identified relationship with a routine for the water balance simulation of the tray was shown to describe reliably the detention process in the BR tray module.     

常州城市住宅小区雨水径流水质分析

分析了导致城市水环境恶化的主要原因,通过对常州住宅小区不同下垫面类型径流水质的测定,探讨了径流水质指标及其随降雨历时的响应关系,为雨水调蓄规模的确定、初期雨水污染控制措施的制定提供参考依据。     

Chlorination and Drinking Water Quality - an Operational Overview

A vailable national guidelines for disinfection practice, and for the examination of bacteriological quality, are reviewed, together with the legislative requirements of the EC 'Drinking Water'Directive. Problems of impracticability, vagueness, and ambiguity are identified.
Experience of the maintenance of bacteriological quality in large, lowland, surface water and ground-water supply areas is given with reference to the behaviour of disinfectant residuals, trihalomethanes, nitrite, and aesthetic parameters. The way forward in terms of the management of distribution systems and water treatment is discussed.     

城区雨水水质特性分析及利用

分析了某公寓的屋面和路面径流水质变化规律及其主要影响因素，并且评价了雨水的质量，通过分析和研究，讨论了屋面和路面的雨水资源利用情况，为开发利用非常规资源、解决水资源危机等方面提供了途径。     

Characteristics of wet and dry weather heavy metal discharges in the Yeongsan Watershed, Korea

A comprehensive water quality monitoring program was conducted in the Yeongsan (YS) River, Korea from 2005 to present to investigate wet and dry weather pollutant discharge in an attempt to establish point and non-point pollution management strategies. As part of this monitoring program, 11 heavy metal species were measured during dry and wet weather conditions in the YS River, where Gwangju City (GJ), a subcatchment of the YS River, was further monitored to clarify the responsibility of different metal species discharged into the mainstream. Monthly grab water samples showed that greater amounts of metals along the YS River were discharged during the wet summer months due largely to storm runoff. In addition, further monitoring results revealed that GJ, a highly urbanized area, was a significant contributor of the heavy metals being discharged into the YS River during both wet and dry weather. The most abundant metal species discharged from GJ were manganese, aluminum and iron with different contributions of wet and dry weather flows to the total discharge load. Wet weather flow was a significant contributor to the annual dissolved metal loads, accounting for 44-93% of the annual load depending on the metal species, with the exception of chromium and cadmium (9% and 27%, respectively). Mostly, metal loads during wet weather were shown to be proportional to the rainfall depth and antecedent dry period. A substantial fraction of metals were also associated with solids, suggesting that sedimentation might be an appropriate management practice for reducing the metal load generated in GJ. Overall, although dissolved metal concentrations in YS River were at an acceptable level for aquatic community protection, continual metal discharge throughout the year was considered to be a potential problem in the long-term due to gradual water quality degradation as well as continuous metal accumulation in the system.     

分质供水住宅建筑给水设计秒流量计算

对同一分质供水住宅小区的给水设计秒流量用不同的两种方法进行了计算并做了比较，阐明了分质供水住宅建筑给水设计秒流量计算应以不同给水管道对应的卫生器具给水当量为准，才能得出正确、合理的结果。     

西朗污水处理厂BOT项目的水质、水量在线监管经验

广州市首家采用BOT方式建设和运营的西朗污水处理厂，应用在线监测技术监测进出水水质、水量的变化情况。探讨了如何使这一监测手段能够更加有效地应用于市政污水处理行业，以及在应用中存在的一些问题和经验，为我国城市污水处理行业应用在线监测的监管手段提供了重要的借鉴经验。     

Water Quality Implications of an Observed Trend of Rainfall and Runoff

The catchment of the upper Clyde estuary has experienced a significant and steady increase of rainfall over the past twenty years. The corresponding increase of runoff has had a positive impact on the water quality both of the individual rivers and of the estuary. Examples are provided to show that approximately one third of some observed improvements are attributable to the additional dilution. It is emphasized that comparisons of water quality data, either by region or by period, should allow for climate variability.     

浅议城镇供水水质安全

针对城镇供水水质安全愈来愈受到重视的情况,分析了我国城镇供水水质安全的现状、城镇供水水质安全存在的主要问题,提出了确保城镇供水水质安全的具体措施,从而保证广大城镇居民的身体健康、生命安全和社会稳定。     

南方某市供水管网水质在线监测管理系统的建立

以南方某市为例，介绍了其供水管网水质在线监测管理系统的建立过程。首先，对系统进行总体设计，确定在线监测点的位置、数量和在线监测指标，选定在线监测仪器和在线数据传输方式。其次，基于管网水质在线监测信息建立了水质在线监测管理系统，可实现数据库连接、列表、查询、统计报表打印、实时监测数据显示等功能。最后，依据统计分析与人工智能的方法建立了三种水质预测模型，并将其与水质在线管理系统集成，实现了对供水管网主要水质指标的在线监测、管理与预测。对该系统采用管网实测数据进行考核、验证，结果令人满意。     

Transport and the Environment: Effects of Organic Pollutants on Water Quality

The eighteenth report of the Royal Commission on Environmental Pollution made no reference to any potential environmental impacts resulting from runoff pollution associated with transport activities. This paper identifies the magnitude and extent of pollution associated with discharges from various transport sources and identifies solids, metals, hydrocarbons, herbicides and de-icing agents as the principal contaminants of environmental concern. The impacts of these pollutants on the receiving water are reviewed. They are primarily associated with highways which have a high traffic density, and herbicides are considered to be the only potential and widespread hazard to groundwaters. Highway and airport runoff are shown to have both acute and chronic effects on biotic diversity and organism mortality rates, although these effects appear to be largely confined to reaches immediately downstream from the discharge outfalls.     

Long-term changes in quality of discharge water from abandoned underground coal mines in Uniontown Syncline, Fayette County, PA, USA

Changes in water quality over 25 years have been documented for discharges from an extensive network of abandoned underground coal mines in the Uniontown Syncline, Fayette County, PA, USA. A baseline study of 136 mine discharges in the syncline was conducted in 1974-1975. In 1998-2000, follow-up water flow and quality monitoring was conducted at 21 selected discharges for 2 years to assess the degree of mine water-quality improvement since 1974-1975. The data from the two periods of time were compared, with consideration of differences in measurement methods. The degree and rate of water-quality improvement was found to be highly dependent on the amount and duration of flooding in the mine voids. Water quality of discharges from the substantially flooded mine voids improved significantly, going from acidic water with high sulfate and iron concentrations in 1974-1975 to alkaline water with substantially lower sulfate and iron concentrations in 1998-2000. In contrast, the water quality in the unflooded mines showed less improvement over the 25 years between studies. The water discharging from the unflooded mines in 1974-1975 was acidic with high sulfate concentrations and in 1998-2000 was still acidic but showed somewhat lower sulfate and iron concentrations, reflecting depletion of readily available pyrite. The data obtained provide insight into the potential and rate of natural amelioration of mine water quality in different abandoned underground coal mine systems.     

城市供水系统的水质化学稳定性变化规律研究

提出了适合我国城市供水系统的水质化学稳定性评价体系,重点研究了水处理及输配过程中水质化学稳定性的变化规律。研究发现,混凝沉淀、过滤、消毒等工艺均会增加水的腐蚀倾向,而投加臭氧则可缓解其腐蚀倾向;在输配过程中,管网水的化学稳定性变化不大,因而改善管网水水质化学稳定性的关键是提高出厂水的化学稳定性。     

变流量变温差调节对对流型散热器热工性能影响的研究

随着人们节能意识的提高,以及分户计量、分室控制等节能技术的推广应用,住户可根据热舒适度要求的不同、作息时间不同,在使用中通过控制进出散热器的流量实现对室内温度的调节。按照变流量模式运行,进出散热器的流量随时在发生变化,此时散热器热工性能将随之发生变化,为明确其是否满足实验室按照GB/T13754—92《采暖散热器散热量测定方法》测试所得出的计算公式,通过对新型铜管铝串片散热器不同工况条件下热工性能进行试验,研究变流量、变温差调节对散热器热工性能的影响。     

饮用水深度处理技术现状及研究

新国标的制定对出厂水水质提出了更高的要求,而我国水源水受到有机物、氨、氮、磷及有毒污染物较低浓度污染状况又日趋严重,突发性水源水质污染事件频发,常规水处理工艺又难以生产出符合新国标水质标准的饮用水。因此强化常规水处理工艺,加大力度研究并推广饮用水的深度处理工艺就显得尤为重要。指出了我国水处理行业所面临的困难局面,并综合概述了我国饮用水处理技术的研究程度和发展状况。     

直插式水质监测仪在供水管网中的应用研究

介绍了直插式水质监测仪的工作原理及优点,指出该设备可以对水流、压力和多个水质参数进行同步实时监测,并通过采用最新的第三方通讯技术,将所有指标的数据实时传送到世界上的任何地方,这一高度集成的创新技术突破了目前管网监测的难点,值得推广。     

Enhanced Chemiluminescence as an Indicator of Water Quality

The enhanced chemiluminescence test is based upon monitoring the emission of light from an enhanced chemiluminescence reaction in the presence of an environmental sample and comparing it with a similar reaction using a de-ionized water control sample. The presence of polluting materials can be detected by changes in the intensity and the kinetics of light emission. This trial demonstrated that the effects of components within a sewage-works' effluent are detected by enhanced chemiluminescence and that this test has moderately close correlation with parallel bacterial determinations. A high correlation was achieved between the performances of two commercially available enhanced chemiluminescence reagents, and these reagents responded consistently to the effects of a sewage-works' effluent on the quality of a small river.