bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flood‐Plain Mapping of the River Leam and River Itchen
Authors: Harris E. , Archer D. 
Published: July 2007

ABSTRACTAs part of the requirements of s. 105 of the Water Resources Act 1991, the Environment Agency is producing flood‐plain maps of all major rivers. Where no historic data are available for a large flood event, mathematical models are used to simulate 100‐year design flood flow events, which allows the definition of flood‐prone areas. These maps, together with a database of the water levels and flows, will form part of a national Flood Plain Information System.This paper describes the development and generation of flood‐plain maps for the Rivers Leam and Itchen in Warwickshire. The data collection and review of topographic and hydrometric data are outlined. Procedures for combining information from gauged data, historical flood data and methods based on catchment characteristics form the basis for estimating design input flows to hydraulic models. Modelling principles and data requirements of two different hydraulic models, used to estimate peak water levels of design return period, are described.
On‐Line Toxicity Monitoring Using Amtox
Authors: Hayes E. , Upton J. 
Published: July 2007

ABSTRACTAs environmental legislation around the world becomes more stringent, it is vital that biological systems are able to treat the effluents which are discharged from wastewater‐treatment plants. Conventional treatment such as BOD removal has been achieved successfully for many years, but the requirements for toxicity removal are more onerous. The Amtox system, which was designed to give operators of wastewater‐treatment plants a tool for assessing the toxicity/treatability, uses an immobilized culture of nitrifying bacteria, maintained in a heated aerobic reactor, to determine whether or not a waste is degradable. The system has a broad range of applications from treatability tests to process monitoring and toxicity tracing and, by changing the culture, effluent toxicity monitoring.This paper details two case studies: (i) in an abattoir where an Amtox monitor was used to diagnose the source of toxicity, and (ii) on the River Trent.
Floating Filters for Particle Removal in Sewage Treatment
Authors: Ødegaard H. , Helness H. 
Published: July 2007

ABSTRACTThis paper describes experiments which were carried out on a high‐rate secondary‐treatment plant which incorporate a moving‐bed biofilm and floating filter. The same cylindrically shaped plastic elements were used both as a biofilm carrier and as a filter medium in the floating filter.
Customer Service and Operational Efficiency as Drivers for Distribution Capital Investment
Authors: Armstrong R. 
Published: July 2007

ABSTRACTIn order to realize the maximum improvement in customer service and operational efficiency from infrastructure improvement, a rational, integrated and structured approach to capital investment planning is required. This involves undertaking an operational review and predictive study based upon a full understanding of the hydraulic behaviour of the water supply and distribution system, and considers wider issues such as consequences of (a) long‐term future demands, (b) environmental issues, and (c) external regulatory pressures.The methodology has been demonstrated in work carried out for East of Scotland Water as part of their ‘integrated network management strategy’.
Contaminated‐Land Information and Guidance: User Evaluation
Authors: Petts J. , Butler B. 
Published: July 2007

ABSTRACTThis paper discusses a survey of users of contaminated‐land information and guidance. The survey was designed to assist in the understanding of user needs in the context of the developing risk‐based approach to decision‐making. Environment Agency staff, local authority officers, consultants and specialists within major industrial companies contributed. The results suggest that, whilst highly qualified in their specific environmental and scientific disciplines, people are faced with many issues (in relation to contaminated land) with insufficient technical background and assistance. The potential impact of such deficiencies is discussed, together with possible solutions.
The Two‐Stage Moving‐Bed/Activated‐Sludge Process: An Effective Solution for High‐Strength Wastes
Authors: Sunner N. , Evans C. , Siviter C. , Bower T. 
Published: July 2007

ABSTRACTThe paper describes a moving‐bed bioreactor which was used as the first stage of a two‐stage process to provide an effective and simple means of reducing the biochemical oxygen demand of a wastewater prior to further treatment in a conventional second‐stage activated‐sludge plant.At Corby, a scheme was required to (a) meet the requirements of a more stringent effluent consent and (b) provide capacity for further anticipated growth in industrial effluent loads. The original works comprised conventional primary sedimentation tanks, biological filters and humus tanks, followed by an activated‐sludge oxidation ditch and further settlement tanks. A pilot plant has been in operation at Corby for two years, and the results were used to design a moving‐bed bioreactor to replace the existing filters.At Pyewipe, a new coastal treatment plant was required and, following the change in status from a ‘high natural dispersion area &, a ‘normal’ programme was initiated to achieve the required completion date. A value‐management workshop was held which identified the two‐stage moving‐bed bioreactor/activated‐sludge process, and a pilot plant was operated for eighteen months. A full‐scale plant is now under construction and incorporates a number of innovative features.
A New Generation of Biological Aerated Filters
Authors: Bigot B. , Tallec X. Le , Badard M. 
Published: July 2007

ABSTRACTBiological filters with fixed submerged beds are normally used for secondary or tertiary treatment and are recognized for their good performance. These processes are designed to meet, simultaneously, strict requirements of quality and operation. The achievement of the discharge consent requires the use of fine media which features a large support surface for the growth of biomass. On the other hand, the achievement of long filter run times is intrinsically related to the use of coarse media. Nowadays, all biological filters have mono‐media, which offers a compromise between these two conflicting criteria.The B2A process is a newly developed compact filter which ensures high filtration performance and long filter run times, even when used for crude sewage. The technology has been in use since 1992 for nitrification/ denitrification using an applied load of 0.7 kg/m3. d to obtain an effluent quality of 20 mg/l total nitrogen. Further tests have proved its efficiency in the removal of carbonaceous pollution.The B2A process is the first compact filter capable of treating screened crude sewage yet producing effluent qualities which are equal to that from conventional biological filters receiving settled sewage.
The Changing Picture of Water Consumption By Power Stations
Authors: Martin P. C. , Todd I. J. 
Published: July 2007

ABSTRACTRecent advances in open‐cycle gas‐turbine technology have resulted in station thermal efficiencies which are comparable with the large fossil‐fired stations built in the 1970s. The combination of a steam cycle to the gas turbine culminating in the ‘combined cycle gas turbine’ station has led to even greater generating efficiencies. These advances in power‐station design have led to reductions in water demand per megawatt of electricity generated. However, water usage still contributes significantly to increasing fuel efficiency in (a) the electrical generating process, (b) reducing atmospheric emissions from stations burning fossil fuels, and (c) utilizing gas turbines. Considerations arising from the competitive electricity market and wider issues of sustainability and environmental improvements, in general, suggest that water will continue to be required for power generation in the foreseeable future.
Optimizing Nitrification On Biological Filters
Authors: Pearce P. A. , Foster D. M. 
Published: July 2007

ABSTRACTA recently developed nitrification model for biological filters has been applied to the design of three sites to increase nitrification. The first site was upgraded by the installation of a dedicated recirculation facility, the second by reconfiguration to double filtration, and the third by the installation of a chemical pre‐precipitation plant. All three sites responded well to the modifications and achieved compliance with ammoniacal nitrogen consents of 3–5 mg/l on a 95%oile basis. The key influence of hydraulic load on nitrification capacity and reliability was demonstrated on all three plants. The ability to upgrade existing biological filter installations to meet stringent ammoniacal nitrogen consents allows a significant reduction in environmental impact and revenue costs when compared with energy‐intensive options such as the activated‐sludge process.
Water Supply and Demand Balances: Converting Uncertainty Into Headroom
Authors: Carnell J. , Lawson J. D. , von Lany P. H. , Scarrott R. M. J. 
Published: July 2007

ABSTRACTThis paper reports on research into the development of a standard procedure for calculating headroom. Headroom is a legitimate planning allowance to account for uncertainties in the supply/demand balance in a water‐resource plan. Prior to this research, the UK water industry did not have an agreed method for calculating headroom, which resulted in inconsistencies in regulatory submissions. The research built on previous studies to define an approach that would be practical and easy to apply. A pragmatic methodology using a series of forms with clear guidelines was developed. The methodology has been applied in the 1998 supply/demand balance submissions to the regulatory authorities as part of the Asset Management Plan 3 periodic review.
Direct Use of Spent Distillery Wash Liquor on Paddy Fields in Thailand
Authors: Phanapavudhikul S. 
Published: July 2007

ABSTRACTSpent wash liquor (or stillage) from the Excise Department's distillery plant at Ubonratchathani Province, Thailand, has a flow‐rate of 550 m3/d. About 100 m3/d of the liquor are fed to an anaerobic digester by the ‘upflow anaerobic sludge blanket’ process ‐ the remainder being transferred directly to a large storage lagoon. The digested liquor is then diluted and pumped during the dry season (December to July) to 400 ha of paddy fields; this has resulted in a 2–3 fold increase in rice yield. Also, the liquor serves as an oxygen‐depletion aid which inhibits the growth of thrips and eradicates insect pests. In return, the farmers save 66–80 p/m3 in terms of equivalent chemical fertilizer and insecticides. This direct use of spent wash liquor is a promising trend towards sustainable development in developing countries.
Implementing a Sustainable Flood‐Defence Strategy for London's Tidal Thames
Authors: Penrose J‐P. , Fry C. M. 
Published: July 2007

AbstractThe tidal flood defences in London protect the city and its citizens from potentially catastrophic flooding. In recent years there has been increased recognition of the environmental value of the tidal Thames; however, this environmental renaissance has been matched by increased river‐side development, creating intense pressures upon the tidal Thames environment.Building on the application of environmental assessment at the project level, the Environment Agency is developing new tools to evaluate the cumulative environmental impact of‐works to individual frontages. Using current case studies, this paper describes practical examples of these approaches which aim to provide sustainable and economically justifiable flood defences and contribute to the enhancement of the tidal Thames.
Submerged Biotower Technology for Tertiary Nitrification of Poultry Abattoir Wastewater
Authors: Dale C. J. 
Published: July 2007

AbstractThe paper describes the design and operation of a submerged biotower, i.e. flooded upflow reactor which utilises a random‐packed polypropylene medium for supporting the biomass. The process can be used for carbonaceous removal or nitrification. In the application which is described, the process has been used for tertiary nitrification of a poultry abattoir wastewater as an extension to the existing effluent‐treatment plant. Details of process commissioning at low temperatures are given and results from twelve months’operation are discussed. Operating costs are compared with other processes.
Life‐Cycle Assessment of a Sewage‐Treatment Plant in South‐East Asia
Authors: Zhang Z. , Wilson F. 
Published: July 2007

AbstractThis paper analyses the environmental impacts of a large‐scale sewage‐treatment plant and identifies opportunities for environmental performance improvements over the three life‐cycle phases of construction, operation and demolition. Results show that nearly 70% of energy consumption occurred during the operation phase, which was lower than the normal energy consumption level of the conventional activated‐sludge process. The results of the life‐cycle assessment may have implications in material selection, energy management, process design, supplier and contractor management, and environmental policy making.
Thermochemical Treatment of Sewage Sludge
Authors: Furness D. T. , Hoggett L. A. , Judd S. J. 
Published: July 2007

AbstractTechnologies for the thermochemical treatment of sewage sludge are appraised with reference to their efficacy in terms of (a) operational parameters, (b) pre‐and post‐treatment requirements, and (c) the extent of their use for the application. Particular attention is given to the characteristics of the solid and gaseous products and how such characteristics affect post‐treatment, reuse or disposal – this being dictated by environmental legislation.Of specific interest is the off‐gas treatment, which can contribute significantly to operating and capital costs of incineration. On the other hand, gasification and pyrolysis generate a combustible product for use in heat and/or power generation. Available information, although limited, suggests that gasification offers significant advantages over the conventional incineration process, yielding a combustible gaseous product (which can be directly utilised on site) and a solid char product (which is less prone to leaching of toxic metals).
Ultrasonic Sludge Pretreatment for Enhanced Sludge Digestion
Authors: Clark P. B. , Nujjoo I. 
Published: July 2007

AbstractDuring recent decades, the anaerobic digestion process has been extensively studied and various methods for process enhancement have been explored. These methods include heat treatment, alkali addition, phase separation and membrane enhancement. In general, whilst technically feasible, the methods have not proved to be economically competitive.The pretreatment of sludges with high‐power ultrasound has been investigated as part of a twelve‐month research project funded by six UK water utilities. Cell lysis and particle‐size reduction (caused by ultrasonic cavitation) are thought to be the key parameters through which the digestion process is enhanced. A series of laboratory‐scale anaerobic digesters has been operated and significant increases in biogas yield have been noted following ultrasonication. Experiments have been completed with a variety of ultrasonic devices (of different geometries and construction materials) and sludge types (e.g. primary, secondary and co‐settled). Current experiments are investigating methods through which the technology can be successfully scaled‐up and applied on a full‐scale plant.
Water Pollution Control Issues in an Independent Ukraine
Authors: Nazarov N. , Cook H. F. , Woodgate G. 
Published: July 2007

AbstractWater‐quality monitoring in the Ukraine is intended to control pollution and enforce water‐protection legislation. The control is both state and institutional, with institutional control being predominant. Despite the fact that the country has a good scientific and technical background for effective water‐quality monitoring, there are failures in the operation of state environmental law enforcement inspectorates. This appears to be due to the economic crisis in the country; as a result, there are serious water pollution problems. The only long‐term solution is considered to be an improved performance in the Ukranian economy, which would allow society to pay for enhanced ‘environmental goods’.
Developments in Structured‐Wall Plastics Sewer Pipes and a Method of Testing Their Resistance to Damage
Authors: Rasbash J. 
Published: July 2007

AbstractStructured‐wall plastics sewer pipes rely upon the structural configuration of their walls to enhance their stiffness, whilst saving on material. Their properties and performance vary widely with the type and material from which they are made, and opinion is divided as to the acceptability of these products for sewerage systems. The UK water industry and the Committee for European Normalisation are actively developing standards for them, but there are a number of performance‐related concerns which need to be addressed if they are to be accepted in the UK.A test, which measures a pipe's resistance to being damaged, has been developed at the University of East London, and preliminary results confirm a wide variation in performance.
A Realistic Basis for an International Comparison of Real Losses from Public Water‐Supply Systems
Authors: Lambert A. O. 
Published: July 2007

AbstractThe paper considers the subject of physical (real) losses from pressurised systems which are used for public water supply. To date, attempted comparisons of leakage management performance between water undertakings world‐wide have been severely compromised because there have been no standard methods of defining and calculating real losses. Performance indicators, which have been traditionally used for comparisons, have been too simplistic. Limitations of existing performance indicators are identified in the paper by reference to key factors which should be incorporated in objective comparisons of real losses.The paper describes an improved methodology which was developed by an International Water Association Task Force, based upon logical concepts using local key parameters, calibrated using auditable assumptions, and tested against twenty‐seven diverse sets of data from twenty countries.
Statistical Analysis of the Performance of a Biological Nutrient‐Removal Plant
Authors: Williams S. , Hardy P. , Green D. , Wilson I. 
Published: July 2007

AbstractThames Water operated a demonstration‐scale biological nutrient‐removal plant for two years to investigate the feasibility of retrofitting it into existing activated‐sludge plants. The plant was operated with and without the addition of short‐chain fatty acids to the anaerobic zone. The results from the trial showed that phosphorus removal was possible, but that performance was not consistently good. The data show that the key parameters which affect the effluent soluble phosphorus concentration are (i) the soluble phosphorus and oxidised nitrogen concentrations at the end of the aeration lane, and (ii) the sludge‐blanket depth. Further analysis of the data suggests that secondary release of phosphorus was marked when the concentration of short‐chain fatty acids in the anaerobic zone was low, even if the sludge blanket was shallow and when oxidised nitrogen was present in the return sludge. In contrast, secondary release of phosphorus was limited when the concentration of short‐chain fatty acids in the anaerobic zone was high.
Estimating Pipe Reticulation Losses in a Municipal Water‐Supply System
Authors: Stent A. F. , Harwood N. 
Published: July 2007

AbstractDomestic water consumption in the city of Dunedin, New Zealand, is unmetered. Recently, the Council's Water Department adopted sampling methods to estimate domestic water consumption and system losses, consistent with the recent reports on managing leakage produced by the UK water industry. This paper describes the exercise (which is ongoing), including the treatment of practical issues which arise in applying the methodology. System losses were estimated to increase substantially over the initial two years of the study, leading to the investigation of an assignable cause. The data reflect the effects of the corrective action, lending considerable support to the validity of the method.
Low‐Cost Separation of Arsenic from Water: With Special Reference to Bangladesh
Authors: Mamtaz R. , Bache D. H. 
Published: July 2007

AbstractThe main objective of the study was to develop a low‐cost technique for the removal of arsenic from contaminated groundwater, as found in Bangladesh. It was shown that arsenic can be removed by co‐precipitation with the naturally occurring iron which is found in groundwater. Tests showed that the removal rate was largely controlled by the arsenic concentration, the iron/arsenic ratio, and pH. Iron precipitation was induced by aeration and mixing through manual shaking.Bench‐scale tests demonstrated that up to 88% of the arsenic (III) in water could be removed by settlement over a period of 24 h. This was better than the removal rate achieved by filtration. It was found that the removal rate was mainly independent of the mode of mixing. For solid‐liquid separation, draw‐off arrangements were studied. It was found that the sample should be drawn off with a slow flowrate (<0.5 l/min). In such conditions the treated water quality is not seriously impaired for the particular design of the container which was examined.From maps of the known distributions of arsenic, iron and pH, it was evident that 63% of the area in Bangladesh complied with the Bangladesh standard for arsenic. By interpreting the maps and applying the potential removal identified in the study, it was estimated that a further 9% of the area would comply with the Bangladesh standard, freeing 8 million people from arsenic contamination.
Development of a Methodology to Set Up Odour‐Quality Objectives for Sewage‐Treatment Plants in Flanders
Authors: Van Broeck G. , Van Langenhove H. 
Published: July 2007

AbstractOn the basis of elaborate odour studies around three sewage‐treatment plants, the relationship between modelled 10 mins average odour concentrations in combination with exceedence frequencies (percentiles) and annoyance near the sewage‐treatment plants, was investigated. Annoyance was measured by means of a telephone survey in the vicinity of the odour source. The odour concentrations were determined using sniffing measurements in combination with short‐term and long‐term dispersion model calculations – over a period of one year.
New Insights into the Appraisal of Flood‐Alleviation Benefits: (2) the Broader Context
Authors: Penning‐Rowsell E. C. , Green C. 
Published: July 2007

AbstractDuring the last twenty‐five years, new approaches to the appraisal of flood‐alleviation investment have developed. This paper (a) identifies some of the key data inputs to this process, (b) evaluates the impact of these on decision choices, and (c) explores the issues concerning the relationship between flood losses and flood probability.
Modelling the Soil Moisture Deficits Developed under Grass and Deciduous Woodland: the Implications for Water Resources
Authors: Finch J. W. 
Published: July 2007

AbstractThe area of deciduous woodland in the UK is increasing as a result of Government policy, and studies suggest that this might result in reduced streamflow and groundwater recharge. Measurements of soil water content were carried out (a) at a site on a sandy loam soil, (b) under land covers of grass, and (c) in deciduous woodland. The data show that both the field capacity and wilting point of the soils were much less under the woodland than those under grass. In 1997, soil moisture deficits were developed down to a depth of 1 m under grass and in excess of 3 m under the deciduous woodland. A simple daily water‐balance model was able to simulate the observed soil water contents and emphasised the importance of interception losses from the deciduous woodland canopy. For a 25‐year period, the model predicted that the mean annual runoff and soil drainage for the woodland was less than half those for grass.