The potential for recycling municipal sewage sludge as a substrate for wetland creation

Municipal sewage sludge (MSS) is proposed as a suitable substrate for wetland creation. Sludge disposal is currently limited to terrestrial conditions due to concern for the transmission of pollutants. Wetland structure and wetland biogeochemical cycles were compared with sludge disposal practices to identify strengths and weaknesses in wetland mechanisms for pollution control. Potential pollution from sludge use is proposed to be mitigated both by wetland function and by the substrate construction method. Because MSS requires specific handling techniques to prevent undesired release into the environment, to protect workers and to be practical for construction, designs responsive to the nature of the construction material were necessary. Three designs were developed, evaluated and compared in terms of aesthetics, educational opportunities, environmental safety, nutrient cycling, waste material utilization, substrate construction requirements and wetland establishment requirements.     

Modeling toxaphene behavior in the Great Lakes

Chlorinated camphenes, toxaphene, are persistent organic pollutants of concern in the Great Lakes since elevated concentrations are found in various media throughout the system. While concentrations have decreased since their peak values in the 1970s and 80s, recent measurements have shown that the rate of this decline in Lake Superior has decreased significantly. This modeling study focused on toxaphene cycling in the Great Lakes and was performed primarily to determine if elevated water and fish concentrations in Lake Superior can be explained by physical differences among the lakes. Specifically, the coastal zone model for persistent organic pollutants (CoZMo-POP), a fugacity-based multimedia fate model, was used to calculate toxaphene concentrations in the atmosphere, water, soil, sediment, and biota. The performance of the model was evaluated by comparing calculated and reported concentrations in these compartments. In general, simulated and observed concentrations agree within one order of magnitude. Both model results and observed values indicate that toxaphene concentrations have declined in water and biota since the 1980s primarily as the result of decreased atmospheric deposition rates. Overall the model results suggest that the CoZMo-POP2 model does a reasonable job in simulating toxaphene variations in the Great Lakes basin. The results suggest that the recent findings of higher toxaphene concentrations in Lake Superior can be explained by differences in the physical properties of the lake (primarily large volume, large residence time and cold temperatures) compared to the lower lakes and increased recent inputs are not needed to explain the measured values.     

Evidence of the impact of ENSO events on temporal trends of hexachlorobenzene air concentrations over the Great Lakes

This study presents an evidence for association of the air concentrations of HCB measured in the Great Lakes region with the El Ni?o-Southern Oscillation (ENSO) during the 1990s. The measured HCB concentrations in the atmosphere collected by the Integrated Atmospheric Deposition Network (IADN) program in the Great Lakes during the 1990s show strong correlations with the Multivariate ENSO index (MEI) during winter (December-February) and spring (March-May) seasons. These correlations are stronger in the western upper Great Lakes than in the eastern portion of the Great Lakes ecosystem (lake Ontario), and correspond well to the spatial variability of the surface air temperature in North America during El Ni?o years. Departures of HCB air concentrations for each winter during 1992-1999 from that averaged over all winters of 1992-1999, i.e. the anomaly, also show the same temporal trend as that of the MEI during the same period. In the same time period, it has been reported that direct HCB emissions from application of HCB in agriculture, from industrial sources in North America and in the rest of the world have decreased substantially compared to those in the 1970s and could not by themselves account for observed HCB air concentrations around the Great Lakes since the 1990s. Interannual fluctuations of HCB concentrations are caused most likely by reemission due to volatilization of HCB from the soil contaminated from past use, followed by long-range transport associated with ENSO events. In addition to the high correlation (R(2)=0.61) between winter HCB air concentrations averaged over the Great Lakes region and the MEI the atmospheric circulation patterns associated with ENSO events are conducive to the long-range transport of HCB into the Great Lakes region.     

霍华德湿地公园

湿地是生物和水质的重要保护者。几个世纪以来,湿地就像伊利湖的肾脏,帮助其过滤杂质并清洁湖水。然而,近年来五大湖周边一半的湿地已经消失,并引发了湖水污染和有害藻类泛滥。     

近30年太湖流域湿地生态系统服务价值 对景观格局变化的响应：基于“退田还湖” 工程的实施

由于太湖流域湿地生态系统服务价值(ESV)受到"退田还湖"工程实施的影响,定量研究其发展演变规律,能够为流域湿地的保护提供参考。运用RS和GIS技术,以1990、2000、2010和2019年TM遥感影像为数据源,对4个时期太湖流域湿地景观格局动态变化进行研究,并分析"退田还湖"工程实施前后湿地ESV变化规律,探讨工程对湿地生态效益的影响。研究表明:1)1990—2000年,在"围湖造田"工程的影响下,太湖流域湿地总面积减少了3010.35km~2,其中自然湿地减少了4554.01km~2,湿地ESV降低了35.73%;2)2000—2010年,在"退田还湖"工程实施初期,自然湿地的减少趋势得到控制,湿地ESV提高了77.96%,湿地斑块数目(NP)增加了126%,香农多样性指数(SHDI)呈上升趋势;3)2010—2019年,在"退田还湖"工程的推进下,湖泊湿地呈增长趋势,坑塘与水库面积显著增加,受湿地总面积减少的影响,湿地ESV下降;4)总体来看,1990—2019年太湖流域湿地面积减少了29.40%,湿地ESV减少了50.07%。"退田还湖"工程实施前后,太湖流域湿地ESV对湿地...     

基于改进可拓物元的湿地公园PPP项目绩效评价研究

绩效评价是政府对PPP项目按效付费的依据。基于项目过程思维,从项目投入、过程、产出和效果四个方面构建湿地公园PPP项目绩效评价指标体系,引入改进的可拓物元模型,对贵安新区海绵城市试点两湖一河PPP项目绩效进行评价。评价结果显示该项目绩效水平达到优秀,但仍有提升空间。     

改扩建工程的设计思考——以拱北口岸为例

本文从总体规划、景观设计、功能布局、交通组织、建筑造型、空间形态等方面阐述了珠海拱北口岸改扩建工程的难点与特点和设计的目标与对策，尝试了特殊地域环境下的建筑创作及设计思考。     

新加坡·南京生态科技岛滨江风光带（大江侧）示范区景观设计

新加坡·南京生态科技岛滨江风光带（大江侧）示范区景观设计旨在通过广泛的生态种植、森林保护、湿地恢复和栖息地创造等措施,提升自然环境的韧性,同时顺应当地的气候变化。项目组在确保生态不受干扰的前提下,结合现状对部分开放空间节点进行了细致的规划和设计,并在视野开阔的场地设置滨江观景平台。该项目的建成,为场地生态基础设施的建立奠定良好的基础,全面保护、保育长江滨水沿线12km的野生动植物栖息地,提高生态多样性并改善城市生态     

浅谈人工湿地

结合南水北调污水处理工程,通过现场试验的方法,探讨了芦苇湿地对COD、氮、磷等污染物的降解作用,得出了温度在人工湿地系统中对去除污染物有重要影响的结论,指出采用人工湿地既能带来社会效益、经济效益,还能带来环境效益。     

襄阳护城河清淤底泥资源化制备种植土工艺设计

针对清淤工程产生的大量脱水泥饼的消纳难题,襄阳护城河清淤项目经调研比选设计了一套利用清淤底泥制备绿化种植土的工艺系统。该工程设计处理规模为100 t/d,以秸秆粉为主要添加材料,采用强化搅拌+快速堆肥工艺制备绿化种植土。结果表明,淤泥基绿化种植土主要性能指标达到《绿化种植土壤》(CJ/T 340—2016)规范要求,栽植试验效果良好,可满足鱼梁洲中心公园绿化建设种植土需求。该工程总投资为304. 40万元,单位直接处理成本为25. 7元/t,实现了脱水泥饼的资源化再利用,具有较好的经济效益和环境效益,可为类似工程脱水泥饼消纳问题提供借鉴。     

Too Big To Fail

Sarah Dunn and Martin Felsen of UrbanLab tackle the timidity of current practice: ‘Why, as a discipline, do we think that we can counter big crises with small ideas?’ They call for a contemporary revival and redefinition of the megastructure. This is exemplified by their project for the Free Water District (FWD) in the Great Lakes, which enables the infrastructural reconstruction and urban renewal of a post-industrial landscape.     

Mapping and monitoring contaminated-sediment geometry and stability

Environment Canada's National Water Research Institute (NWRI) conducts research on freshwater contaminated sediments, much of which is focused on designated areas of concern in the Great Lakes and their connecting channels. This paper reviews new acoustic and video equipment and procedures developed to map the geometry and stability of the sediments, and describes their applications. A RoxAnn acoustic seabed-classification system is used for mapping bottom-sediment types and locating the deposits of fine-grained sediments with which contaminants are associated. The system uses the acoustic properties of sediments to distinguish textural types ranging from mud to boulders, and displays the data as they are collected. The sediment thickness is measured with a weighted video-acoustic tripod which is lowered into the sediments to refusal, and which recorded penetration with a video camera or an echosounder transducer. The stability of the contaminated sediments was monitored with a bottom-mounted, high-precision echo sounder-digitizer, which logs changes in the position of the sediment-water interface produced by erosion or deposition. The same procedure can be used in capping or dredging projects to track bottom changes as they occur, or they can be measured by pre- and post-project mapping of bathymetry and morphology with sweep-sonar or side-scan sonar equipment. The new equipment and procedures have been successfully applied to a number of areas of concern in the Great Lakes basin. They provide a faster and more detailed characterization of sediment properties and geometry than was previously available, and have been particularly effective in optimizing sampling surveys and monitoring remediation projects.     

Structure,regulation, and pricing of water in the United States: A study of the Great Lakes region

The structure and regulation of the U.S. water industry is more complex than is often apparent and pricing practices vary substantially. While not representative of the region or nation, a survey of the largest water systems in the wider Great Lakes region is illustrative as well as revealing of salient considerations within the sector. Data from Wisconsin provide additional perspective with regard to trends in costs and prices for water. The context of rising costs and prices, and growing concerns about accountability and sustainability, suggests consideration of pricing practices as well as the role of economic regulation in the water sector.     

Distribution of particulate matter in relation to the thermal cycle in Lake Vechten (The Netherlands): The significance of transportation along the bottom

Throughout the thermal cycle of Lake Vechten (The Netherlands) the concentrations and chemical composition of particulate matter suspended in the water, deposited on the bottom near the shore and collected in sediment traps was measured. With regard to the distribution of particulate matter two significant periods during the thermal cycle could be distinguished. From May till mid-August a temperature gradient was present in the water column. During that period the average rate of increase in dry weight of bottom deposits and the sedimentation rate on that location were similar, i.e. lake wide 1.5 and 1.7 gm ²d⁻¹ respectively. This indicates a dominating role of settling particles in the building-up of the temporary shallow sediment, which resulted in the typical summer maximum of nearly 145 g m⁻². From mid-August onwards the concentration of this sediment zone decreased sharply coinciding with the disappearance of the temperature gradient. This removal was explained by the mechanism of enhanced turbulence, occurring when thermal homogeneity was reached, which initiated resuspension and subsequent transportation of the particles to greater depths. From light profiles it was inferred that the flux of particles was confined largely to the water layer of 1 m near the bottom. From comparison of the sedimentation rate in the central part of the lake with that in the shallow zone it could be estimated that compared to the particle flux in the open water towards profundal sediments, the flux along the bottom amounted during the thermal stratification period to an average of at least 42%.     

吉林西部洋沙泡底泥及周边土中氟释放研究

洋沙泡作为“引嫩入白”供水工程的设计蓄水水库,由于湖泊水体及底泥中氟的含量很高,对供水工程存在一定的环境影响。为了进一步确定引水工程实施后,洋沙泡底泥氟的释放对引入水体氟含量的影响,本文设计了氟的解吸试验。试验先将水样和底泥土样进行混合,然后连续振荡使底泥中的水溶性氟充分解吸,在不同时间段测定底泥氟的释放量。解吸试验结果表明：土样中氟含量很高,与水体接触后氟的释放作用强烈并逐渐变缓;氟的释放量与时间成对数曲线的关系,水样原始氟含量对底泥氟的解吸有一定的影响。     

North American economic integration and industrial pollution in the Great Lakes region

This paper provides an assessment of the impact of increased economic integration within North America on industrial pollution intensities within the Great Lake states of the United States. It utilizes a three-country, applied general equilibrium model of the North American economy, data from the World Bank's Industrial Pollution Projection System, and employment data from the US Bureau of Economic Analysis to simulate the industrial pollution impacts of North American trade liberalization within the Great Lakes region. The results reflect the liberalization of tariff and non-tariff barriers, their trade and production impacts, state-level shares in the production changes, and the resulting industrial effluent changes. Two trade liberalization experiments show that, in many cases, the Great Lake states account for a substantial portion of the total emission changes caused by North American economic integration. Of particular concern to the Great Lake states are the emissions of the base metals, transportation equipment, and petroleum sectors. Received: October 2001/Accepted: December 2001 This research was supported by the Office of the Great Lakes through the Michigan Great Lakes Protection Fund. We would like to thank Roger Stough and three referees for very helpful comments.     

天津梅江风景区——水的记忆

梅江风景区的规划定位为全方位开放、具有郊野风格的、注重生态的、集儿童游乐、体育功能、生态保育、市民娱乐活动于一体的综合性市民风景区。项目充分利用地热资源设置温泉养生、地热水广场、地热植物群落等。并在公园中设计潜流式、表流式、生态湿地等生态水处理系统来进行生态调节。     

滇池外海湖滨生态湿地系统的设计

昆明市滇池外海西山片区湖滨生态湿地系统的建设应融入风景之中。通过对西山片区湿地系统污染处理量的分析,确定了湿地建设中湖滨湿地、表流湿地、泥沙沉滨地(包含蓄水调节)等多种设计方案,并提出了湿地建设时对入湖水流进行拦截及处理的措施。介绍了最后选择具有耐污去污能力的以湿地本地植物为主的物种,构建湖滨生态系统。     

苏州港某件杂货码头工程PHC桩基裂缝加固设计

介绍了苏州港某件杂货码头工程PHC管桩的裂缝状况,分析了裂缝对码头承载能力和耐久性能的影响.针对工程特点和裂缝性状,结合国内外现有技术,系统提出了桩基裂缝处理与加固补强方案.工程运用表明,采用本方案对出现裂缝的PHC管桩进行加固处理是可行的,施工方便、快捷,效果良好.     

海南自贸港应急救援体系创新发展探讨

摘 要：海南自贸港面临自然灾害、城市化发展、产业升级带来的多重灾害事故风险挑战,因而始终把风险防范作为底线工程。为了更好地统筹发展与安全,海南十分注重应急救援能力建设。本文立足海南自贸港面临的灾害事故新风险和应急救援工作新挑战,借鉴国内外应急救援体系创新做法,提出了海南自贸港的应急救援体系新格局,为中国特色综合应急救援体系建设提供思路和借鉴。