bluuebunny/crossref_metadata_2025_split huggingface dataset:
Policy and Legislation Relevant to the Conservation of Freshwater SSSIs Subject to Eutrophication
Authors: Wilson H. , Payne S. , O'Sullivan P. , Gibson M. 
Published: July 2007

AbstractAlthough no legislation in England and Wales directly addresses the causes and effects of eutrophication of surface freshwaters, a wide range of laws may be applied to the reduction of nutrient inputs. Nature conservation laws are applicable, in that rivers, lakes, reservoirs and canals designated as ‘sites of special scientific interest’(SSSIs) are theoretically safeguarded from degradation. However, the SSSI system is not designed to protect water quality at the catchment level. Since intensive agricultural practices are responsible for significant nutrient losses, legislation aimed at extensification is also relevant. Increasingly, laws related to extensification of agriculture include environmental imperatives ‐ a trend which will inevitably extend to nutrient conservation. Basically, enrichment is a water‐quality issue, but policy and legislation in this area are not yet sufficiently developed to address the problem comprehensively. Existing regulatory systems for water quality carry the potential to work comparatively well for point sources, but appear ineffective in dealing with diffuse losses.
An Optimization Model for the Selection of Wastewater and Sludge Treatment Alternatives
Authors: Tang S. L. , Wong C. L. , Ellis K. V. 
Published: July 2007

AbstractA systems analysis technique, called the ‘analytic hierarchy process’, has been employed to develop a wastewater treatment optimization model which enables consideration to be given to subjective factors such as socio‐cultural and environmental conditions as well as to technical and economic aspects. The model is particularly applicable to the developing world. Twenty and twenty‐two parameters were identified for the selection of wastewater and sludge‐treatment alternatives respectively. Forty‐six and ninety‐four treatment alternatives were formulated as decision variables for the selection for wastewater and sludge treatment respectively. The technique was then employed to select the optimum treatment procedures.
Environmental Modelling in the Hydrological Cycle: What the Client Needs?
Authors: Gardiner J. 
Published: July 2007

AbstractThis paper summarizes expert and user views in some of the fields which are of interest to the Environment Agency. Models have been specifically designed to fulfil the needs of particular functions such as water resources, flood defence, and water quality. There are trends towards models serving more than one function and operating to represent the ‘natural’processes in an entire catchment or the wide range of parameters influencing the habitat at one point.Model evolution is likely to be driven partly by the client's requirements (based in turn on more stringent legislation, economics, public expectation and new phenomena) and partly by advances in computational power. The recent focus on holistic treatment of catchments and their multi‐functional issues may stimulate the development of the relatively new distributed, linked models more than their single‐function counterparts.
Energy Cost Savings in Motive Power
Authors: Falkner H. 
Published: July 2007

AbstractMotive power accounts for over 65% of the average UK industrial electricity bill; however, in the water industry this percentage is nearer to 90%. During 1994, UK industry spent almost £3000 million on the energy used by motors – mainly attributable to AC induction motors, with pumps and fans being the most common motor applications.Many techniques can be used to reduce the cost of running motors, from simple good‐housekeeping measures to sophisticated electronic controls. This technical note reviews a selection of these techniques using independent case studies from the Department of the Environment's ‘best practice programme’to illustrate the cost savings; the use of software to predict energy savings is also discussed.
Peak Demands from Spray Irrigation
Authors: Weatherhead E. K. , Knox J. W. 
Published: July 2007

AbstractAlthough irrigation accounts for less than 2% of water use in the UK, direct abstraction for spray irrigation can be a significant user in certain catchments in dry summers. Peak demand is expected to grow nationally by 1–2% per annum on average, but this growth varies locally. Water resource planners need to know the peak demands and how they are likely to grow within each catchment or aquifer, and the likely local annual variation and timing of demand. This paper discusses how recent developments in irrigation modelling combined with the application of a ‘geographic information system’can produce such forecasts, taking into account spatial variation in soils, climate, cropping and irrigation practice.
The Use of a Mobile Sludge Dewatering Unit at Small Sewage‐Treatment Plants in Japan
Authors: Takahashi H. 
Published: July 2007

AbstractThe construction of small sewage‐treatment works in Japan is increasing. In most municipalities, economical and effective treatment/maintenance systems, which match the local conditions, are needed. As one of its support strategies, the Japan Sewage Works Agency has initiated and implemented ‘co‐operation’ projects. In one of these projects, a mobile sludge dewatering unit has been shown to be the most economical method of treatment. The first unit, which was commissioned in March 1992, is being used in three municipalities, and this paper appraises its use.
Cairo Sludge Disposal Study
Authors: Hall J. E. , Smith S. R. 
Published: July 2007

AbstractThis paper describes the establishment of the Cairo sludge disposal study which is being funded within the Mediterranean Environmental Technical Assistance Programme through the European Investment Bank and promoted by the Cairo Wastewater Organization. The study is a demonstration programme to show how the problems of sludge disposal from large, rapidly developing cities, such as Cairo, can be solved through the establishment of a practical system for the safe re‐use of sewage sludge in agriculture. It is being carried out principally through a series of demonstration field trials and the development of ettensive information. This study is of relevance to Egypt and other countries with similar agricultural and environmental conditions, where (a) sludge production is increasing, (b) water protection is essential, and (c) appropriate environmentally acceptable solutions are urgently required.
The Use of Fertilizer‐Free Grass Buffer Strips to Attenuate Nitrate Input to Marshland Dykes
Authors: White S. K. , Cook H. F. , Garraway J. L. 
Published: July 2007

AbstractFertilizer‐free buffer strip establishment has proved to be effective in attenuating nitrates which are mobile in shallow water‐tables feeding watercourses of conservation potential. This paper demonstrates their effectiveness on reclaimed alluvial marshland soils.
Habitat Creation Opportunities for Landward Coastal Re‐alignment: Essex Case Studies
Authors: Dixon A. M. , Leggett D. J. , Weight R. C. 
Published: July 2007

AbstractRelative sea‐level fluctuations during the Holocene period have combined with medieval to present saline floodplain embanking to reduce the inter‐tidal saltmarsh area in Essex from 40 000 ha to 4400 ha. The present loss by erosion is estimated at 2%/annum for the country, and the reduction in these areas is not only detrimental to related habitats but has caused an increasing requirement for flood‐defence financial investment.Recent initiatives by the Ministry of Agriculture, Fisheries and Food, the Environment Agency and English Nature have created mechanisms and opportunities to develop sustainable flood‐control structures where coastal re‐alignment has been the preferred option.The Orplands frontage covers 2 km of sea wall which have been deliberately breached to allow 40 ha of rare saltmarsh to re‐establish. At Abbotts Hall, an arable field of 20 ha has been converted to its former saltmarsh by creek re‐establishment and tidal inundation by reversal of existing sluices. These two schemes have (a) regenerated habitats for halophytic and semi‐halophytic plants, marine and brackish invertebrates, and (b) provided roost, feed and breeding areas for birds and nursery areas for marine fish fry. Apart from flood control and habitat creation, particular features were incorporated to provide niche locations for targeted types of wildlife.
Variations between Continuous and Spot‐Sampling Techniques in Monitoring a Change in River‐Water Quality
Authors: Hazelton C. 
Published: July 2007

AbstractFollowing significant expenditure by Thames Water Utilities Limited at Crawley and Horley sewage‐treatment works, the quality of the final effluents being discharged to the River Mole improved considerably.The automatic quality‐monitoring station operated by the former National Rivers Authority downstream from both discharges showed a distinct improvement in water quality which was not recorded to the same degree by the NRA's formal sampling programme. The quality of data provided by the formal sampling programme can be misleading, and such data should be used cautiously in water‐quality assessment and modelling.The reasons why spot‐sample data were unreliable were investigated, and the possibility and benefits of developing a systematically biased continuous monitoring strategy to produce water‐quality data under comparative environmental conditions are explored.
Analysing and Forecasting Peak Demands on the Public Water Supply
Authors: Herrington P. R. 
Published: July 2007

AbstractThe paper examines the magnitude of present and future peaks in the public water supply in England and Wales. Current knowledge is surveyed, including recent research undertaken for the Department of the Environment. Reference to a number of surveys permits a ‘first‐cut’estimate to be made of the micro‐components of typical domestic peaks in south and east England, and judgement is used to predict peaks for 2021. Finally, evidence concerning the effect of domestic metering on peak demands is summarized, suggesting a major role for economic instruments in the reconciliation of future demands and supplies.
Effects of Plastic Support Media on the Diffusion of Air in a Submerged Aerated Filter
Authors: Hodkinson B. J. , Williams J. B. , Ha T. N. 
Published: July 2007

AbstractThe established procedures for quantifying the aeration capacity of diffusers used in submerged aerated filter wastewater‐treatment systems do not consider the effects of support media; this may lead to ineffective design and sizing of diffused‐air systems. The study was carried out to determine the factors affecting aeration in a submerged aerated filter containing high‐voidage random‐packed plastic media. Tests were conducted in a full‐scale model reactor with and without support media.
A Biological Key to Canal Water Quality
Authors: Ruse L. P. 
Published: July 2007

AbstractSixty sites on canalized watercourses in England were sampled using the ‘Chironomid pupal exuviae technique’, and chironomid data were related directly to associated physical and chemical characteristics of each site. A scoring system is proposed for assessing canal water quality, and scores are assigned to widely distributed, frequently occurring and easily recognizable indicator taxa. A dichotomous key, based on six of these indicators, is provided for classifying canal water quality.
Arriving at the Economic Level of Leakage: Environmental Aspects
Authors: Howarth D. A. 
Published: July 2007

AbstractIn England and Wales, recent droughts and the future threat posed by climate change has intensified the debate on the suitability of either resource‐development or demand‐management approaches to ensure that supply and demand are kept in balance. The need to reduce leakage from water distribution systems has gained almost universal acceptance, and discussion now centres on what should be included in the cost‐benefit analysis in determining that economic level of leakage.This paper (a) reviews the role of the Environment Agency in leakage control and the current thinking on the economic level of leakage, (b) argues the case for the inclusion of environmental costs and benefits, and (c) explores some of the reasons why water companies appear to be reluctant to pursue the goal of further leakage reduction.
Strategies Towards Sustainable Development in Nigeria's Semi‐Arid Regions
Authors: Toro S. M. 
Published: July 2007

AbstractDuring the last three decades, there has been a steady decline in rainfall within Northern Nigeria where the total annual amount has declined below the 30‐year mean; this could be either a permanent or temporary phenomenon. Whatever the trend, the continuous deterioration in climatic conditions, combined with uncoordinated resources planning, are paving the way for a crisis of dramatic proportions in the sub‐region. In the rush to combat this threat, like most third‐world countries, Nigeria embarked upon large‐scale constructions of dams and irrigation‐infrastructure facilities without proper planning and coordination. Consequently, the schemes have now failed to achieve their forecast output.The paper attempts to establish the important role which the naturally available water‐resources potential of the sub‐region could play towards sustainable irrigated agricultural development under increasing risks of drought and desertification within the area.
Impacts of Sewers on Groundwater Quality
Authors: Bishop P. K. , Misstear B. D. , White M. , Harding N. J. 
Published: July 2007

AbstractThis paper summarizes the findings of a recent research project on groundwater contamination from leaking sewers, which was completed for the Construction Industry Research and Information Association. Fifty‐four incidents were identified in England and Wales from a combined questionnaire survey and literature review. In addition to recorded incidents, the poor quality of many urban groundwaters suggests some effects from leaking sewers. Age is considered to be the most significant characteristic governing leakage from sewers; ground conditions (predominantly aquifer vulnerability) and usage (private versus public ownership) are also important factors relating to the likelihood of groundwater pollution from leaking sewers. Recommended strategies for reducing groundwater contamination include (a) modification of existing criteria for the service performance grading of existing sewers, (b) improved construction of new sewers in appropriate areas, (c) increased groundwater monitoring, and (d) risk assessments for new groundwater sources.
An Energy‐Efficient Combustion System for High‐Moisture Organic Wastes and Biomasses
Authors: Have H. , Henriksen K. S. 
Published: July 2007

AbstractA special combustion system comprising a drier, combustion unit and heat‐recovery unit, designed to produce low‐grade heat from high‐moisture fuels, was investigated using sewage sludge, animal manure and energy crops as the feed material. Part of the investigation dealt with the development of a new method of combined wet pelletizing and surface drying of sludges to facilitate simple and efficient combustion as well as easy handling of the dried product. The investigation showed that (a) drying at temperatures up to at least 950° is feasible, and (b) low‐temperature heat may be produced for space and water‐heating purposes at high thermal efficiency.
High‐Pressure Water Jetting: Avoiding Damage to Sewers
Authors: Cant J. , Trew J. 
Published: July 2007

AbstractHigh‐pressure water jetting of sewers and drains is being undertaken in the UK using equipment which, under certain circumstances, can damage the pipes. Research was therefore carried out to provide information which would accurately identify the potential for causing damage and enable preventative measures to be undertaken.This paper explains the key factors which control the potential to damage sewers and drains by pressure jetting, and provides details of a new jetting test for pipes.
A Review of the 1995–96 Drought in the North West
Authors: Walker S. , Smithers H. A. 
Published: July 2007

AbstractAs environmental regulator, the Environment Agency seeks the best balance between essential needs of water supply and the environment, whilst taking into account costs and benefits; nowhere is this balance more focused than in the management of droughts. The drought of 1995–96 was the most severe on record in the North West, and presented a major challenge to both the water company and the Environment Agency in safeguarding essential water supplies and minimizing the risks to the environment.This paper describes the management of the drought from the Agency's perspective.
The Development and Use of Hybrid Aeration Processes
Authors: Chambers B. , Upton J. , Greenhalgh S. H. 
Published: July 2007

AbstractRequirements to improve effluent quality have led to the establishment of better design procedures for activated‐sludge plants. The recognition that activated‐sludge aeration is responsible for a large proportion of the energy used in sewage treatment has resulted in the specification of energy‐efficient aeration systems as part of such design procedures. Fine‐bubble diffused‐air techniques are potentially more efficient than mechanical surface‐aeration systems, but low oxygen‐transfer efficiency is often observed in practice under conditions of high aeration tank solids loading. Surface‐aeration systems appear to be able to operate at reasonable aeration efficiencies under conditions of high loading, but they are not as effective as diffused‐air systems in low‐rate processes.There is evidence that a properly designed combination of the two types of aeration system in the same process (hybrid aeration) can result in optimum energy use and good effluent quality. The paper describes the development of this concept, showing the long‐term performance of three full‐scale plants utilizing hybrid aeration.
Nutrient Removal: Experiences in Johannesburg (Abridged)
Authors: Pitman A. R. 
Published: July 2007

AbstractThe ability to remove nitrogen and phosphorus by biological means in the activated‐sludge process represents the most significant refinement of the process since its discovery. This paper reviews the development of the activated‐sludge process in Johannesburg. Emphasis is placed on the last twenty years’research into biological nutrient removal and the successful incorporation of research findings into the design and operation of full‐scale plants of up to 200 Ml/d capacity.
Activated Sludge: Latest Developments and a Look Into the Future (Abridged)
Authors: Randall C. W. 
Published: July 2007

AbstractThis paper examines and discusses (a) the innovations of the activated‐sludge process which have been developed in recent years ‐ particularly biological nutrient‐removal processes, (b) modifications to minimize the construction costs of activated‐sludge systems while simultaneously incorporating biological nutrient‐removal techniques, (c) innovative computer‐interfaced control methodologies, and (d) proposed methods of improving the biochemical versatility of activated sludge. The paper also presents potential methods of utilizing activated‐sludge processes to produce valuable by‐products from wastewaters.
An Assessment of Drainage Best Management Practices in Scotland
Authors: McKissock G. , Jefferies C. , D'Arcy B. J. 
Published: July 2007

ABSTRACTThe study was carried out to establish the extent to which source‐control systems are being used in Scotland. An investigation into the level of knowledge of such systems was also initiated. Over 100 questionnaires were sent to organizations which have been involved in the development of surface‐water drainage schemes, and the 43 responses were analysed.Further work was then undertaken to establish the locations of source‐control systems in use. The collated information was utilized and, with the help of the Scottish Environment Protection Agency consent files and correspondence with consultants, a database indicating the locations of sites, was compiled. Information was collected on approximately 79 examples of such systems, currently in use or proposed, in Eastern Scotland.
Estimation of Outage Allowances
Authors: Cullen N. , Fenn C. R. 
Published: July 2007

ABSTRACTA methodology is described for estimating the allowances or safety margins which can be applied to estimates of water resources to allow for outages (random or periodic interruptions to supply). The methodology follows recent published UK Government and water‐industry guidelines and provides estimates at two levels: on‐average estimates, and risk‐related estimates. Example applications are described, and advice is given on ways of improving the supply/demand balance. The final choice of any outage allowance to be used should take account of (a) patterns of demand, and (b) the consequences of failure.
The Use of Membranes for Salt Reduction in the UK
Authors: Moss P. 
Published: July 2007

ABSTRACTReverse‐osmosis membranes, which have been used for reducing the salt content of water since the late 1960s, are available for a variety of desalination applications, ranging from seawater to brackish water and specific species removal, including hardness and organics. In recent years, major advancements have been made in the salt‐rejection capabilities and in pressure requirements, which have made the use of membrane technology in water treatment an attractive proposition.The paper focuses on (i) seawater desalination, reviewing the present study which is being carried out by Anglian Water; (ii) brackish water desalination, in particular a project which is being undertaken by Essex and Suffolk Water, and (iii) well‐water desalination, describing a project which is being executed by Anglian Water.
Leachate Ammonia Flushing from Landfill Simulators
Authors: Purcell B. E. , Butler A. P. , Sollars C. J. , Buss S. E. 
Published: July 2007

ABSTRACTThe operational management of landfills is currently being reviewed in the UK and Europe. In the UK, the ‘flushing bioreactor’ approach to landfilling involves (a) enhancing microbially mediated degradation of domestic waste to promote rapid waste stabilization, (b) increased methane recovery, and (c) reduced timescales to final landfill stabilization. Flushing oeprations under bioreactive conditions could be used to optimize the removal of ammoniacal nitrogen from landfilled waste. In this study, the flushing of ammonia from pulverized domestic waste was investigated using laboratory‐scale test cells to simulate landfill conditions. A simple mathematical model, based on test‐cell water balance, was used to describe the latter stages of ammonia reduction.
Healthcare Wastes: A World Health Organization Perspective on Waste Treatment and Disposal Options (Abridged)
Authors: Rushbrook P. 
Published: July 2007

ABSTRACTDuring the last three decades, the World Health Organization has been actively involved in assisting countries and health authorities to improve their healthcare waste management. Wide disparities exist internationally on the standards of treatment and disposal of healthcare wastes which are achievable and sustainable in individual countries and localities. Three levels of practice can be identified: (i) a ‘foundation’ level in which some improvement in hospital hygiene and public health is achieved by removing wastes from wards to simple burning grounds and landfills, (ii) an ‘intermediate’ level whereby more organized collection and treatment is possible, and (iii) a more ‘sophisticated’ level involving treatment, enforcement of strict emission standards and landfilling regulations.This paper summarizes the range of practices in use and the options for (a) thermal treatment, (b) alternative technologies, and (c) engineered landfill. Details are also given on some of the activities undertaken by the World Health Organization in the areas of advice and guidance, direct assistance and research.