Urban energy generation: Influence of micro-wind turbine output on electricity consumption in buildings

Small scale wind turbines installed within the built environment is classified as microgeneration technology. Such turbines may soon become a commercial reality in the UK as a result of both advancements in technology and new financial incentives provided by the government. In addition, microgeneration technologies, especially those with appreciable resource, have the potential to reduce built environment related CO₂ emissions coupled with reductions in consumers’ electricity costs. In many cases payback on capital investment is within the lifetime of the device. Micro-wind turbines installed in certain areas in the UK will fit within such criteria. The work presented here addresses modelling of such installations around the UK and presents a methodology to assess the suitability and the economic viability of micro-wind turbines for domestic dwellings. A modelling tool “μ-Wind” has been developed specifically for studying both energy yields and the payback periods for micro-wind turbines. μ-Wind predicts wind turbine performance prior to installation according to specific power curves either defined by turbine manufacturers or the user. Numerical consideration of wind speed data at specific UK sites was used to estimate energy yields and the results are projected to real electricity demand data from monitored dwellings in the UK. The results show that it is possible to predict with a good degree of accuracy the expected financial payback period for a typical domestic dwelling. Furthermore, the paper postulates that micro-wind technology could have the potential to make a significant impact upon domestic electricity generation when located at the windiest sites in the UK. The likelihood of a proliferation of these turbines in the urban or suburban environment is low but at coastal or inland high elevation sites the technology appears to have a promising future.     

Financial appraisal of wet mesophilic AD technology as a renewable energy and waste management technology

Anaerobic digestion (AD) has the potential to support diversion of organic waste from landfill and increase renewable energy production. However, diffusion of this technology has been uneven, with countries such as Germany and Sweden taking the lead, but limited diffusion in other countries such as the UK. In this context, this study explores the financial viability of AD in the UK to offer reasons why it has not been more widely used. This paper presents a model that calculates the Internal Rate of Return (IRR) on a twenty year investment in a 30,000 tonnes per annum wet mesophilic AD plant in the UK for the treatment of source separated organic waste, which is judged to be a suitable technology for the UK climate. The model evaluates the financial significance of the different alternative energy outputs from this AD plant and the resulting economic subsidies paid for renewable energy. Results show that renewable electricity and renewable heat sales supported by renewable electricity and renewable heat tariffs generates the greatest IRR (31.26%). All other uses of biogas generate an IRR in excess of 15%, and are judged to be a financially viable investment. Sensitivity analysis highlights the financial significance of: economic incentive payments and a waste management gate fee; and demonstrates that the fate of the digestate by-product is a source of financial uncertainty for AD investors.     

The use of hospital waste as a fuel. Part one.

The total quantity of hospital waste produced in the UK has been estimated to be 430kte/yr, having a combustible content equivalent to about 190kte of coal; its average gross calorific value (GCV) depends on the type of hospital, but has been estimated to be about 14GJ/te for the teaching and general hospitals which were examined. Hospitals are obliged to incinerate some of these wastes in order to destroy any pathogens which may be present, and although several hospitals have been involved in recovering the energy from this process, a number of such projects have proved to be unsuccessful. The Glenfield General Hospital (GGH) is burning combustible hospital waste on a Corsair (Erithglen) 0.5MWt (2MBtu/h) hot water boiler, the second such installation involving a new design of plant which accepts bagged, unprepared material. Although the plant suffered inevitable commissioning and teething problems, which have led to further design improvements, it has nevertheless demonstrated its ability to dispose of hospital waste reliably, safely and efficiently; it is felt, however, that it could have performed better with improved project organisation. In the light of likely future legislation to tighten control over emissions from the combustion of hospital wastes, it is anticipated that large scale plant might prove economically and environmentally attractive under certain circumstances; such plant will, in all probability, involve power generation or combined heat and power (CHP).     

FLOOD MANAGEMENT, COMMUNITIES AND THE ENVIRONMENT: A STRATEGY FOR THE SOMERSET LEVELS AND MOORS

The Somerset Levels and Moors have been designated a 'special protection area'under the EU Habitats Directive and a Ramsar wetland of international importance. Water management is important to their well being, but drainage to improve agricultural productivity has reduced habitat quality and biodiversity interest. Over the last decade, significant progress has been made towards halting and (in some areas) reversing the declining wetland flora and fauna. However, the UK Government's target of achieving favourable conservation status by 2010 is unlikely to be achieved without further change.
This paper examines the changes which are needed to achieve sustainable agricultural flood-management and conservation objectives in Somerset as a model for wetlands in England and Wales. Agricultural policy and, in particular, the lack of cross-compliance and limited discretionary modulation, is failing marginal areas such as the Somerset Levels and Moors; also, farmers and the environment are losing out. In order to ensure that objectives are clear and options and constraints are understood, increased dialogue between stakeholders is essential.     

Priority water research questions as determined by UK practitioners and policy makers

Several recent studies have emphasised the need for a more integrated process in which researchers, policy makers and practitioners interact to identify research priorities. This paper discusses such a process with respect to the UK water sector, detailing how questions were developed through inter-disciplinary collaboration using online questionnaires and a stakeholder workshop. The paper details the 94 key questions arising, and provides commentary on their scale and scope. Prioritisation voting divided the nine research themes into three categories: (1) extreme events (primarily flooding), valuing freshwater services, and water supply, treatment and distribution [each > 150/1109 votes]; (2) freshwater pollution and integrated catchment management [100-150 votes] and; (3) freshwater biodiversity, water industry governance, understanding and managing demand and communicating water research [50-100 votes]. The biggest demand was for research to improve understanding of intervention impacts in the water environment, while a need for improved understanding of basic processes was also clearly expressed, particularly with respect to impacts of pollution and aquatic ecosystems. Questions that addressed aspects of appraisal, particularly incorporation of ecological service values into decision making, were also strongly represented. The findings revealed that sustainability has entered the lexicon of the UK water sector, but much remains to be done to embed the concept operationally, with key sustainability issues such as resilience and interaction with related key sectors, such as energy and agriculture, relatively poorly addressed. However, the exercise also revealed that a necessary condition for sustainable development, effective communication between scientists, practitioners and policy makers, already appears to be relatively well established in the UK water sector.     

Preliminary Investigation into the Microbiological Quality of a Freshwater Bathing Site: A Case for Official Identification?

The quality of recreational waters has become of increasing importance and, where water-based activities are permitted, such waters should be required to comply with minimum standards to protect public health. At present, there are no freshwater sites in the UK which are identified as official bathing areas, despite a significant proportion being identified in other EU Member States and the increasing use of such waters for bathing. This paper presents a case for the official identification of three freshwater bathing sites which, traditionally, have been used for bathing for more than ninety years.     

泰国世界遗产管理的公众参与

东巴耶延山—考爱山森林保护区是泰国一处重要的世界遗产地,由5处几乎连续的国家公园或保护区组成。在该遗产地乃至泰国的其他遗产地,尽管在公众参与管理方面还存在一些问题,但总体来讲保护管理的公众参与一直受到重视。在确定公众参与的法律地位、建设示范点方面取得了一些成就。从2个方面论述了如果缺少社区参与,遗产地保护所面对的挑战,包括生物多样性保护面临的挑战,以及生活在世界遗产地中的社区所面临的挑战。未来的方向是明确以社区为基础的资源管理的可监测的协议,并更新森林和自然资源管理专业人员需要的技能。     

Constructed wetlands for stormwater management in the UK: a concise review

The use of constructed wetlands (CWs) for stormwater management is growing due to the need for sustainable water use and to prevent damage to local watercourses caused by the pollutants collected and transported by runoff. However, despite their increased use around the world, there is a lack of information regarding the use of CWs for stormwater management in the UK. This study reviews the application of CW systems for stormwater management in the UK by examining the design, treatment performance and challenges associated with their use, while drawing comparisons with the rest of the world. The review indicates that although CWs have the potential for cost-effective and efficient stormwater management in the UK, there are several challenges that must be overcome to allow their widespread implementation. These include (i) a lack of design codes and unified guidelines; (ii) ambiguities regarding drainage responsibilities and land use issues and (iii) land availability.     

Re-Imagining Psychiatric Asylum Spaces through Residential Redevelopment: Strategic Forgetting and Selective Remembrance

The closure of psychiatric asylums across the western world has brought significant amounts of ‘brown field’ land onto the market over the past few decades. Situated on the edge (or former edge) of many cities, these sites have proven attractive for residential redevelopment. Drawing on two case studies from the UK and New Zealand, we consider the implications of such recycling in the built environment for the memory of the former use, asking how redevelopment addresses the stigmatised past of the asylum. We discuss issues associated with the ‘re-imagining’ of heritage buildings and landscapes and examine the extent to which the past is strategically forgotten or selectively remembered in the repackaging of the asylum as housing. We conclude that while stigma continues to cast a shadow over reuse of former asylum spaces, in both case studies impacts seem to dissipate over time. In the UK, this dissipation appears to be enhanced by the presence of policies that cast redevelopment for housing as a source of funding for heritage conservation.     

Sewage-effluent phosphorus: a greater risk to river eutrophication than agricultural phosphorus?

Phosphorus (P) concentrations from water quality monitoring at 54 UK river sites across seven major lowland catchment systems are examined in relation to eutrophication risk and to the relative importance of point and diffuse sources. The over-riding evidence indicates that point (effluent) rather than diffuse (agricultural) sources of phosphorus provide the most significant risk for river eutrophication, even in rural areas with high agricultural phosphorus losses. Traditionally, the relative importance of point and diffuse sources has been assessed from annual P flux budgets, which are often dominated by diffuse inputs in storm runoff from intensively managed agricultural land. However, the ecological risk associated with nuisance algal growth in rivers is largely linked to soluble reactive phosphorus (SRP) concentrations during times of ecological sensitivity (spring/summer low-flow periods), when biological activity is at its highest. The relationships between SRP and total phosphorus (TP; total dissolved P+suspended particulate P) concentrations within UK rivers are evaluated in relation to flow and boron (B; a tracer of sewage effluent). SRP is the dominant P fraction (average 67% of TP) in all of the rivers monitored, with higher percentages at low flows. In most of the rivers the highest SRP concentrations occur under low-flow conditions and SRP concentrations are diluted as flows increase, which is indicative of point, rather than diffuse, sources. Strong positive correlations between SRP and B (also TP and B) across all the 54 river monitoring sites also confirm the primary importance of point source controls of phosphorus concentrations in these rivers, particularly during spring and summer low flows, which are times of greatest eutrophication risk. Particulate phosphorus (PP) may form a significant proportion of the phosphorus load to rivers, particularly during winter storm events, but this is of questionable relevance for river eutrophication. Although some of the agriculturally derived PP is retained as sediment on the river bed, in most cases this bed sediment showed potential for removal of SRP from the overlying river water during spring and summer low flows. Thus, bed sediments may well be helping to reduce SRP concentrations within the river at times of eutrophication risk. These findings have important implications for targeting environmental management controls for phosphorus more efficiently, in relation to the European Union Water Framework Directive requirements to maintain/improve the ecological quality of impacted lowland rivers. For the UK rivers examined here, our results demonstrate that an important starting point for reducing phosphorus concentrations to the levels approaching those required for ecological improvement, is to obtain better control over point source inputs, particularly small point sources discharging to ecologically sensitive rural/agricultural tributaries.     

英国份地的现状、特征和发展策略研究及其对中国的启示

中国城市自然土地资源趋紧,人们密切关注城市种植,积极开展公共健康和城市园艺相关实践。通过数据汇总和案例分析,总结英国传统份地的研究进展、供求情况、集约化管理、收支压力和公益化发展现状,解析份地的生产、环保、健康美学和精准化服务等现代特征。基于现状和特征的总结,进一步阐述份地在参与、供应、监管和维护等方面的协同发展与增效策略。借鉴英国份地发展经验,提出应普及城市种植和生态保护理念,探索城市种植地的定位和规划管理路径,缓解人地矛盾,寻求我国城市种植地差异化发展策略,并构建全龄化城市种植服务体系等建议。对规划层面的土地利用转型和保护、城市绿地系统的完善、种植地管理方式的健全、城市种植地能效提升和营造宜居城市具有一定的借鉴意义。     

Asset deterioration and discolouration in water distribution systems

Water Distribution Systems function to supply treated water safe for human consumption and complying with increasingly stringent quality regulations. Considered primarily an aesthetic issue, discolouration is the largest cause of customer dissatisfaction associated with distribution system water quality. Pro-active measures to prevent discolouration are sought yet network processes remain insufficiently understood to fully justify and optimise capital or operational strategies to manage discolouration risk.Results are presented from a comprehensive fieldwork programme in UK water distribution networks that have determined asset deterioration with respect to discolouration. This is achieved by quantification of material accumulating as cohesive layers on pipe surfaces that when mobilised are acknowledged as the primary cause of discolouration. It is shown that these material layers develop ubiquitously with defined layer strength characteristics and at a consistent and repeatable rate dependant on water quality. For UK networks iron concentration in the bulk water is shown as a potential indicator of deterioration rate. With material layer development rates determined, management decisions that balance discolouration risk and expenditure to maintain water quality integrity can be justified. In particular the balance between capital investment such as improving water treatment output or pipe renewal and operational expenditure such as the frequency of network maintenance through flushing may be judged. While the rate of development is shown to be a function of water quality, the magnitude (peak or average turbidity) of discolouration incidents is shown to be dominated by hydraulic conditions. From this it can be proposed that network hydraulic management, such as regular periodic ‘stressing’, is a potential strategy in reducing discolouration risk. The ultimate application of this is the hydraulic design of self-cleaning networks to maintain discolouration risk below acceptable levels.     

Cultivation of zebra mussels (Dreissena polymorpha) within their invaded range to improve water quality in reservoirs

Algal and cyanobacterial blooms in reservoirs are driven by nutrient enrichment and may present economic and conservation challenges for water managers. Current approaches such as suppression of algal growth with barley straw, ferric dosing or manipulation of fish stocks have not yielded long term successes. A possibility that has sparked growing interest is the encouragement and cultivation of natural filter feeders, such as mussels, which remove suspended matter from the water and reduce nutrient levels through biodeposition and assimilation.This review focusses on the zebra mussel (Dreissena polymorpha) as a tool for enhancement of water quality in reservoirs. Native to the Ponto-Caspian region, this species has invaded many lakes and reservoirs across North America and Western Europe, where it occurs in very high densities. While purposeful introduction of a non-native species into new sites is socially unacceptable, we investigate the possible benefits of encouraging increased abundance of zebra mussels in sites where the species is already established.We estimate that the annual nitrogen and phosphorus input into a large UK reservoir (Grafham Water) could be assimilated into zebra mussel biomass by encouraging settlement onto 3075 m and 1400 m of commercial mussel ropes, respectively. While zebra mussel cultivation has an incredible capacity to push eutrophic systems towards a clear water state, there are many risks associated with encouraging an invasive species, even within sites where it has already established. The zebra mussel is a prominent biofouler of native unionid mussels and raw water pipes, it changes the physical characteristics of the places it inhabits, in sites low in phosphorus it can be responsible for toxic cyanobacterial blooms, it alters nutrient cycling and community structure and it can have negative impacts on amenity value. Increased propagule pressure from elevated numbers of veliger larvae in the water column may increase the risk of spread to other locations. This may render some reservoir systems, such as dammed rivers which have outflows to downstream watercourses, unsuitable for cultivation. Such reservoirs are especially common in North America.We consider the practicalities of putting a zebra mussel cultivation system into place and identify gaps in knowledge. We conclude that zebra mussel cultivation offers an attractive tool for managing nutrient-enriched reservoirs, but that the benefits and costs must be balanced on a site-by-site basis.     

Tritium Levels in Leachates and Condensates from Domestic Wastes in Landfill Sites

An extensive review study of leachate composition, from landfills which have received mainly domestic wastes in the UK, has been carried out by Aspinwall & Company on behalf of the Department of the Environment. This work has provided detailed information on concentrations of a wide range of determinands. One set of analyses which has produced particularly interesting results comprises the determination of tritium. Tritium is a natural isotope of hydrogen (³H), with a half-life of 12.43 years, which decays radioactively to form stable ³He atoms, releasing beta particles. Although tritium concentrations can be measured accurately as tritium units (TU), these represent extremely low levels of activity, and concentrations of tritium well in excess of 100 000 TU would be needed before acceptable levels of radio-activity in drinking water were exceeded.
Background levels of tritium in UK rainfall rarely now exceed 50 TU although, in the 1960s, values of up to 3000 TU in rainfall were associated with atmospheric testing of atomic weapons. It was somewhat surprising, therefore, to discover that relatively high concentrations of tritium (>10 000 TU) were widespread in leachates from landfills which had received primarily domestic wastes. This paper presents results from samples taken at 30 representative UK sites, and discusses potential sources of tritium.     

Long-term variability in the deposition of marine ions at west coast sites in the UK Acid Waters Monitoring Network: impacts on surface water chemistry and significance for trend determination

Eight lake sites in central and south-west Scotland, north-west England and north Wales, forming part of the UK Acid Waters Monitoring Network (UKAWMN), have been studied with regard to the influence of marine ions on surface water chemistry. Since monitoring began in 1988 these sites have exhibited large and long-term variation in Cl concentration, which are consistent between regions and can be linked to inter-annual variations in wet deposition. Through regression analysis against Cl, the response of other solutes to these fluctuations has been assessed. Sites show a highly consistent pattern of Na, and Mg retention during periods of high Cl, in accordance with the 'sea-salt' mechanism of marine cation adsorption onto soil exchange sites following large marine inputs. An associated displacement of cations with non-marine sources is also observed, with one or more of non-marine Ca, labile Al and hydrogen ions exhibiting a positive relationship with Cl at all sites. The relative extent to which these are released appears not to follow a simple relationship to site acidity, and may be linked to site/region-specific geology and soil characteristics. In addition, an inverse relationship between non-marine SO4 and Cl is observed at five of the sites, and the possibility is considered that a sea-salt related process, with soil retention and subsequent release, may also operate for SO4. A mechanism that might explain this process is suggested. The impact of marine inputs on non-marine solutes, including important indicators of acidification such as pH, labile Al and non-marine SO4, has clear implications for the detection of long-term trends in acidity status and is, therefore, of particular relevance to the UKAWMN. Due to their unpredictability, and the long timescale over which they operate, fluctuations caused by marine inputs may be difficult to separate from acid deposition related long-term trends. Evidence from a longer Cl time series from mid-Wales shows that fluctuations in concentration could be linked to the North Atlantic Oscillation and might therefore be expected to exhibit a similar, decal periodicity. Currently, the UKAWMN dataset only appears long enough to represent one climatic cycle. Consequently, and since few surface water chemistry datasets in the UK extend over more than a decade, it is important that: (a) trend analyses of current data from marine-impacted areas take account of possible marine input cycles; and (b) long-term monitoring is maintained into the future so that the impact of these cycles can be better quantified, and distinguished from anthopogenically-induced long-term changes.     

Land management as a factor controlling dissolved organic carbon release from upland peat soils 2: Changes in DOC productivity over four decades

Increasing DOC concentrations in surface waters have been observed across parts of Europe and North America over the past few decades. Most proposed explanations for these widespread trends invoke climate change or reductions in sulphate deposition. However, these factors do not seem apposite to explain either the fine-scale (within kilometres) or regional-scale spatial variation in DOC concentrations observed across the UK.We have reconstructed DOC concentrations and land use for one North Pennine and five South Pennine catchments (UK), located in three discrete areas, over the last four decades. Rainfall, temperature and sulphate deposition data, where available, were also collated and the potential influence of these factors on surface water DOC concentrations was assessed.Four of the six catchments examined showed highly significant (p < 0.001) increases (53-92%) in humic coloured DOC (hDOC) concentrations in drainage waters over the period 1990-2005. Changes in temperature and sulphate deposition may explain 20-30% of this trend in these four catchments. However, the rapid expansion of new moorland burn on blanket peat can explain a far greater degree (> 80%) of the change in hDOC. Far smaller increases in hDOC (10-18%) were identified for the two remaining catchments. These two sites experienced similar changes in sulphur deposition and temperature to those that had seen largest increases in DOC, but contained little or no moorland burn management on blanket peat.This study shows that regional-scale factors undoubtedly underlie some of the recent observed increases in drainage humic coloured DOC. However, changes in land management, in this case the extensive use of fire management on blanket peat, are a far more important driver of increased hDOC release from upland catchments in some parts of the UK. It suggests that the recent rapid increase in the use of burning on blanket peat moorland has implications for ecosystem services and carbon budgets.     

Managing knowledge: lessons from the oil and gas sector

Knowledge management (KM) is of increasing interest to a number of leading UK construction organizations. Companies are keen to find out what other organizations are doing both within the construction and other industry sectors. There are important lessons to be learned from Canadian oil and gas organizations on how they manage their knowledge. A case study is used to explore the KM activities of eight leading organizations and investigate the opportunities for construction organizations to adopt some of their ideas. Three areas are covered: KM strategy and implementation, people aspects of KM and metrics for KM performance. There are several potential lessons for UK organizations: the need for KM to be driven by senior management if it is to have any notable success; the use of people‐centred techniques for sharing tacit knowledge and IT tools for sharing explicit knowledge; the importance of selling solutions to project teams to obtain employee support for KM; peer recognition has a more sustainable impact than financial reward; and KM measurement should be considered as a way of improving its impact, rather than justifying expenditure.     

英国和中国历史建筑改造更新的比较分析：基于能源利用视角

在英国,更新改造成为节能减排的核心政策。尽管有很多实际应用的案例,但研究表明,更新改造和政策要全面实施仍然存在许多悬而未决的问题。与此同时,在中国等发展中国家,国际生态学者、开发者和决策者指明了更新理念和政策的发展方向。但是调查初步显示,在发展中国家,更新实践的全面实施也非常困难,这是因为与更新既有普通建筑和遗产地建筑相比,地方决策者和开发者对新建设项目更感兴趣。鉴于英国是较早实施更新改造的国家,而中国是近期开始更新实践的国家,本文选择它们作为核心案例进行研究。文章揭示了两个国家在更新历史建筑时面临的不同阻碍,探索了在各自的国情下,更新改造的潜在驱动力。     

Inferences over the sources and processes affecting polycyclic aromatic hydrocarbons in the atmosphere derived from measured data

Data concerning atmospheric lifetime and relative source contributions of polycyclic aromatic hydrocarbons (PAH) are fragmentary and contradictory. In this study, two datasets of measurements of atmospheric PAH (sum of particulate and gaseous phases), one from a national network, the other from a more local three-site study, were analysed and used to infer processes affecting PAH in the atmosphere, and their sources. PAH congener profiles measured at urban and rural locations were remarkably similar suggesting that atmospheric decay processes are relatively slow. This allows the use of such profiles to elucidate sources. A spatial analysis of two PAH datasets showed a clear influence of industry and road traffic upon local PAH concentrations. When Principal Component Analysis (PCA) was applied to UK national network data, it showed a clear influence of steel industry emissions and of home heating emissions from coal and oil in Northern Ireland. These sites also showed different winter/summer concentration ratios to the main group of sites. In the data from Birmingham (UK), PCA identified separate factors relating to gasoline and diesel vehicles, as well as the influence of wood combustion on “Bonfire night”, and a factor related to home heating emissions which shows up only in the cold season.