bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eutrophication: Assessment, Research and Management with Special Reference to Scotland's Freshwaters
Authors: BAILEY‐WATTS A. E. 
Published: July 2007

ABSTRACTIn response to the extraordinarily high profile currently maintained by algae, this paper discusses aspects of pure and applied research on eutrophication. In addition to restating a number of issues which were raised decades ago when the importance of this environmental problem was first recognized, the following aspects are explored using data collected mainly over the last 20 years and referring primarily to Scottish studies: (i) algal‐nutrient relations and the contrasting manner in which nitrogen and phosphorus enter freshwaters and are sequestered by planktonic organisms; (ii) estimates of the loadings of phosphorus to freshwaters from various sources; (iii) the effects on our perception of algal problems and the use to which the waters are intended; (iv) the extent and limitations of existing scientific knowledge about eutrophication, and its application to the formulation and execution of eutrophication control strategies; and (v) the arguments for maintaining in‐depth limnological surveillance programmes.
Leaching of Pesticides from Treated Timbers ‐ a Source of Pollution
Authors: McNElLL A. 
Published: July 2007

ABSTRACTObservations at a sawmill where two major spillages of preservative had led to pollution of the River Lossie indicated that bad timber treatment practices. together with minor spillages when preservative was delivered to the premises, were contributing to the overall unsatisfactory state of the watercourse. Also, soil sampling at the sawmill, and laboratory trials, revealed that the storagc of freshly‐treated timbers can be a significant source of pollution. In order to prevent contamination of water from these sources, recommendations were issued to the sawmill, and the company relocated the timber treatment plant on a specially prepared self‐contained site to avoid pollution should further spillages occur.
The Self‐Protection of Escherichia Coli in Seawater
Authors: FINDLAY J. S. , CURRAN J. C. , MILNE D. P. , CROWTHER J. M. , WALLIS S. G. , WOOD B. J. B. 
Published: July 2007

ABSTRACTMany environmental variables are known to be involved in the inactivation processes affecting enteric bacteria in seawater. It is commonly believed that bacteria may attempt to reduce adverse effects by adhering together, thereby decreasing the surface area exposed to the hostile environment. This mechanism may be described as self‐protection and should enhance the survival of the bacterial population.Controlled laboratory experiments, epifluorescence microscopy, and Coulter counter analysis were used to examine and elucidate the inactivation mechanisms for the enteric bacterium E. coli. In general, the survival of E. coli was found to be enhanced with increasing initial cell concentration in the absence of any suspended solids.
Drinking Water Directive and Proposed Water Supply (Water Quality) Regulations for Scotland
Authors: CHAMBERS E. G. W. , GREENE L. A. 
Published: July 2007

ABSTRACTTaken in conjunction with the clauses added to the Water (Scotland) Act 1980 by the Water Act 1989 in respect of quality, as opposed to organizational terms, the introduction of the EC drinking water Directive1 and the proposed water quality Regulations2 represents the most fundamental change to Scottish water supply legislation since the Water (Scotland) Act 1946.The drinking water Directive1 was passed by the European Council on 15 July 1980, with the requirement for full compliance by Member States by 18 July 1985.Water Supply (Water Quality) Regulations for Scotland were circulated in draft form by the Scottish Development Department for informal consultation during September 1989. This had been preceded by informal consultation through the Convention of Scottish local authorities during the discussion stage of the UK Advisory Group on Drinking Water Regulations.This paper attempts to provide a simplified interpretation of the proposed Scottish Regulations on drinking water quality. It comments briefly on those requirements likely to have a significant impact on Scottish water authorities, including public communications, laboratory facilities, water treatment operational practices, and capital funding.
The Flood‐Prevention Scheme of Venice: Experimental Module
Authors: FICE J. LEWIN , SCOTTI A. 
Published: July 2007

ABSTRACTRecords exist of the flooding of Venice from the days of the Republic. During the last century flooding incidents have become more severe due to subsidence of the city and rising water levels in the Adriatic. Calamitous flooding occurred in 1966, and two devastating floods were experienced during the last decade. The ‘Special Law for Venice’, enacted by the Italian Parliament in 1973, paved the way for a competition to devise a flood‐prevention scheme.A consortium of Italian contractors, who were commissioned to submit proposals for the implementation of the scheme, designated Technital Spa of Verona to carry out the design of the flood‐prevention works and improvements within the lagoon. This resulted in the design of three movable barrages to seal off the Venice lagoon in the event of a flood. The construction of a full‐size gate and caisson (the prototype of the eighty gates forming the barrages) was subsequently authorized.This paper describes the experimental module containing the buoyant gate and its caisson, its novel features as well as some of the events leading up to its design and construction.
The Channel Tunnel and its Impact on the Folkestone and District Water Company
Authors: MONK R. B. 
Published: July 2007

AbstractFolkestone and District Water Company's statutory area covers south‐east Kent, being that part of England nearest to mainland Europe. Its principal source of water is the chalk ridge known as the North Downs.The Channel Tunnel is an £8.5 billion scheme linking France to England by rail, beneath the Straits of Dover.The English portal for the project is located in what was previously the centre of the Company's distribution network, at the Cherry Garden, Folkestone. The works include three tunnels through the Lower Chalk, dropping from a ground level of 60 m AOD at the portal to about 50 m below the sea bed at the coast. This has provided a possible risk of draining scarce fresh‐water resources from the Chalk into the sea, and allowing saline intrusion to extend into the centre of the aquifer.As a major civil‐engineering project, the tunnelling and terminal works have required a temporary, but substantial, water supply. Detail design of the works proceeded as the scheme progressed, and consequently water demand could not be estimated precisely at the beginning of the contract. In excess of 30 metered supplies, varying in size from 15 mm to 250 mm in dia., have been provided, some being several kilometres from the Company's distribution system.The paper gives a brief outline of the development of a fixed cross‐channel link, and describes the interaction between the project and the Water Company, in relation to the supply of Eurotunnel's temporary and permanent water requirements, protection of the Company's sources and changes to the trunk mains system. It will also be shown how active cooperation and constant review of proposals are leading to benefits for both parties, even through the two years of drought that have afflicted the water supplies in south‐east England.
Simazine Concentrations in a Stream Draining an Agricultural Catchment
Authors: WILLIAMS R. J. , BIRD S. C. , CLARE R. W. 
Published: July 2007

AbstractThis paper reports the concentrations of the herbicide simazine which were found in a stream draining a small agricultural catchment as a result of normal agricultural practice. The study, part of the National Rivers Authority Research and Development programme, shows that peaks in the concentration of simazine occurred very soon after rainfall events. It goes on to show that although the mass of simazine transported from the catchment during each rainfall event is small as a percentage of that applied (less than 1%), the concentrations observed are far from insignificant. It is suggested that monitoring programmes need to be designed to cover such pesticide pulses generated as the result of rainfall events occurring at times of peak application. Also, more realistic environmental‐quality standards need to be developed and applied where the EC drinking water Directive is inappropriate, and to reflect the intermittent nature of the problem.
Commissioning and Operation of Yau Kom Tau Water‐Treatment Works (Hong Kong) Using Direct Filtration
Authors: CHAN KIN MAN D. , SINCLAIR J. 
Published: July 2007

AbstractThe paper outlines the commissioning, performance trials, and operational experience of the direct‐filtration process at the Yau Kom Tau treatment works in Hong Kong.The commissioning tests established the capability of the treatment plant to produce water of the required potable quality. However, the contractual performance trials were carried out at a time when adverse raw water might be expected, in order to assess the overall attainment of guarantees on the treated water quality, filter run, and washwater percentage.Since the works became operational in November 1985, a number of incidents of raw water quality outside the design limits have been experienced. The use of polyelectrolyte was found to enhance the performance and reliability of the direct‐filtration process.The paper also reports the results of some optimization tests and comments on the overall performance of the plant compared with expectations at the time of design.
The Development of Ion Chromatography for Metals Analysis in Saline Waters
Authors: COMBER S. D. W. 
Published: July 2007

AbstractPrevious attempts to utilize ion chromatography for the analysis of sea water samples have failed through chronic interference by the major ions (na, Mg, Ca) during the preconcentration stage. As part of ongoing research into ion chromatography, a technique has been developed to overcome these interferences, using a two‐stage preconcentration step, prior to separation on a cation‐exchange column. This has made it possible to detect μg/l quantities of trace metals in samples containing g/l concentrations of sodium, magnesium and calcium. A modified commercially‐available ion chromatographic system was used to analyse copper, nickel, zinc, cobalt and manganese in saline waters. Detection limits were typically less than 1 μg/l, with relative standard deviation of less than 10%. Hence this new method has the potential to provide an inexpensive multi‐elemental sea water analysis with the minimum of handling. In addition, the simplicity and sensitivity of the technique may make it suitable for unattended use as a remote monitor of metals.
A Small‐Scale Study of Wastewater Discharges from Domestic Appliances
Authors: BUTLER D. 
Published: July 2007

AbstractThe pattern and daily total production of waste‐water from domestic sanitary appliances is a subject area in which a very limited amount of research has been carried out, despite its need for rational and economic drainage design. This paper consists of an analysis of data from a small‐scale diary survey of domestic wastewater production and a comparison with previously published data.The diurnal variation of activity for each major appliance has been established to give both peak and average frequencies of use. Good correlation has been shown for average (daily) values with published water‐supply data. Peak values were difficult to compare, but were probably lower than previously‐reported data. The wash basin and kitchen sink were found to have two modes of discharge, namely: running to waste and emptying a full bowl. The former mode was the most common in both appliances, although, surprisingly, the volume of each type of discharge was found to be approximately the same. Tests on appliance discharge durations, volumes and flow rates were also carried out.
Alternative Methods of Procurement for Works of Water and Environmental Management
Authors: McGILL R. E. N. 
Published: July 2007

AbstractThe paper considers methods of procurement for the construction of water‐ and sewage‐treatment works other than the traditional use of the ICE 5th Edition Conditions of Contract and Bills of Quantities. This is as a consequence of the speed at which schemes are currently required within the water industry.The paper particularly focuses on the use of target contracts, using the Institution of Chemical Engineers’Green Book form, and considers various types of target. It also discusses the form which tender documents may take, and how targets may be calculated.Tendering procedures, including the use of two‐stage tenders and negotiated targets, are considered, as are the procedures for cost monitoring and the financial management of the contract. Finally, the role of the engineer and quantity surveyor is considered.
Bulking Sludge: A Theory and Successful Case Histories
Authors: SIMPSON J. R. , LIST E. , DUNBAR J. M. 
Published: July 2007

AbstractFilamentous bulking sludge is the most difficult problem encountered in the operation of activated‐sludge plants. A number of reasons have been cited as the cause of the problem, but none explains why slow‐growing filamentous micro‐organisms predominate over faster‐growing flocculent microbes. Competition or inhibition are suggested as possible reasons why filamentous forms predominate.The paper briefly reviews certain aspects of microbial growth and waste treatment, drawing attention to the fact that, while it is known that nitrogen and phosphorus nutrients must be present, equally other essential substances must be present, including a number of trace metals. The theory is proposed that where trace metals are limiting growth, the filamentous micro‐organisms predominate because they are more competitive in adsorbing and absorbing these scarce materials. This is so because the filaments have a higher surface to volume ratio than the flocculent forms. The roles of metals are briefly discussed, and data are presented on the composition of cells. The theory is used to explain some of the reported causes of bulking, and the results of several full‐scale field trials are presented.
The Importance of Hydrological Source Areas in Terrestrial Liming
Authors: WATERS D. , JENKINS A. , STAPLES T. , DONALD A. P. 
Published: July 2007

AbstractTerrestrial liming experiments have been carried out in the Welsh uplands at Llyn Brianne, 30 km northwest of Brecon. Limestone has been applied to an entire moorland catchment and to the hydrological source areas of a moorland catchment. The hydrological source areas were derived from topographic data. Blanket liming and source area liming proved successful in (a) raising the pH value of the stream, (b) increasing the calcium concentration, and (c) decreasing the aluminium concentration. The response to the source area liming proved to be more successful, resulting in a higher calcium concentration. Neither site showed any signs of long‐term exhaustion, although the initial response in stream chemistry indicated the importance of the soil exchange complex in determining optimum application rates. Source area liming has economic and environmental advantages over blanket liming, and its increased effectiveness suggests that it is the most viable technique for ameliorating acidification in upland areas.
Pesticides in Surface Waters and Groundwaters
Authors: CROLL B. T. 
Published: July 2007

AbstractDiffuse pollution by pesticides, particularly herbicides, has been recognized in the UK for several years. Atrazine, Simazine, Mecoprop, Dimethoate and, more recently, Isoproturon and Chlortoluron have been found frequently in surface waters at concentrations up to 0.5 μg/l, with a maximum of 11.5 μg/l. Pesticides are detected less frequently in groundwaters, at concentrations generally lower than 0.1 μg/l. Atrazine is found most frequently. Concentrations in untreated surface and ground‐waters have generally been below the maxima recommended for drinking water by the Department of the Environment (DoE). Concentrations in treated drinking water have not exceeded the DoE recommended maximum concentrations, but measures are being taken to reduce concentrations to below 0.1 μg/l.
Energy Saving Using Jacked Aerators at Biddulph Sewage‐Treatment Works
Authors: SODIPO B. O. , GREENWOOD WENDY , CLOUGH G. F. G. 
Published: July 2007

AbstractA means of improving the energy efficiency of an existing mechanically aerated activated‐sludge system by mounting the existing aeration units on jacked platforms is described. The level of the platforms, and hence the immersion of the aerators, is automatically controlled to maintain a constant concentration of dissolved oxygen in the mixed liquor. Comparison of the controlled stream, in which there were two aerators, against an otherwise identical control stream showed energy savings of 20% and 13% respectively when the control involved both or only one aerator, without adverse effect on final effluent quality.
Durban's Newest Water Resource ‐ The Inanda Dam
Authors: TOLLOW A. J. 
Published: July 2007

AbstractThe Inanda Dam is one of a series of reservoirs constructed to utilize the water resources of the Umgeni River, which rises in the Natal midlands and reaches the Indian Ocean at Durban, South Africa. The structure exploits the local topography and geology, with mass concrete founded on the granite forming the right bank and river bed, and a clay core earth embankment on the weaker left bank. Due to high ambient temperatures, the placing temperature of the concrete had to be controlled to avoid crack formation. Mix designs were modified by the addition of blast‐furnace slag, and the mix water was cooled using liquid nitrogen to reduce the placing temperature of the concrete. Major floods also occurred, and although they caused little damage to the structure itself serious damage was sustained by the existing water‐supply infrastructure, resulting in a review of the operational strategy of the system. The reservoir is to be operated initially as a river regulator with downstream abstraction. However, in order to provide additional security, a tunnel aqueduct linking the reservoir directly to the water‐treatment works is under construction.
Paris Improves Its Drinking Water Treatment Plants
Authors: BARBIER J. M. , RICCI O. , MONTIEL A. , RICHARD Y. 
Published: July 2007

ABSTRACTThe upgrading of the Ivry‐sur‐Seine water‐treatment plant, which produces potable water for consumption in Paris, is described. This upgrading is based on the slow biological filtration stage. The pretreatment comprises a primary filtration stage through biolite, and a secondary filtration stage through sand, with the possibility of coagulation. The polishing treatment includes ozonation and biological filtration through granular activated carbon. Ozone is produced from pure oxygen, with two ozone generators operating at medium frequency and producing a total of 52 kg/h. A description of pilot tests of the upgraded plant is given, together with the first results.
Waste Stabilization Ponds in Europe
Authors: MONTE M. H. DO MARECOS 
Published: July 2007

ABSTRACTThe European countries where sewage treatment in waste stabilization ponds is largely developed and commonly used are West Germany (more than 2000 operational systems) and France (about 2500 plants). Portugal has over 50 systems at present and will have about 100 by the year 1993. Spain has more than 10 operational plants and in Denmark there are 50 ponds for tertiary treatment. A survey on the present practice in the countries where the process is largely applied, including size of plants, type of ponds, type of influent and design criteria, is presented. It is found that waste stabilization ponds are particularly appropriate for full treatment of effluents from small communities (less than 5000 population equivalent) and for tertiary treatment following conventional larger plants.
Septicity in Sewers: Causes, Consequences and Containment
Authors: BOON A. G. 
Published: July 2007

ABSTRACTThis paper reviews research and development on the causes, consequences and methods of controlling septicity in sewers. It draws on information given in 55 published papers on the subject. Explanations are given on the deviation of equations used to predict critical conditions in sewers and rising mains. The consequences of septicity, including toxicity, corrosion and odour nuisance, are described and discussed. Prevention is always recommended over cure, but where this cannot be achieved the methods of controlling septicity generally rely on maintaining an adequate supply of oxygen (dissolved or chemically available) to oxidize previously‐formed sulphide. Other options to cure the effects of septicity include minimizing the emission of hydrogen sulphide into the atmosphere, deodorizing vented air, and the use of protective coatings or corrosion‐resistant pipes.
UK Developments in Sewage Sludge Processing
Authors: BRUCE A. M. 
Published: July 2007

ABSTRACTA considerable amount of research and development has been undertaken in the UK during the last 25–30 years in the field of sewage sludge processing. The research has been sponsored mainly by the water utilities with the objective of improving process efficiency and reliability and reducing costs. Government‐funded research has focused mainly on the environmental aspects of sludge disposal to land and to the sea.Finding ways of reducing sludge production has proved difficult, but one new method of sewage treatment has some advantages in this respect.Arising from the research on sludge processing, (a) new methods of characterization of sludge have been developed, (b) an improved method for the design and operation of gravity thickeners has been successfully implemented, (c) advances have been made in the process of heated anaerobic digestion, and (d) an effective system for aerobic thermophilic digestion of sludge at small works has been established. A new method for measuring sludge filtrability – the PFT meter – has been developed, and the economics of flocculation have been improved by the introduction of a new type of mixer. An improved method for controlling the operation of filter presses is now available.The problems of odour nuisance from sludge operations may now be controlled using biological systems to treat odorous air.
Parallel Processes in Hydrology and Water Quality: A Unified Time‐Series Approach
Authors: YOUNG P. C. 
Published: July 2007

ABSTRACTMost well‐known time‐series methods treat the system as a univariate, bivariate or multivariate ‘black box’whose parameters provide a convenient and concise description of the data. This is in contrast to physically based, mechanistic models, whose parameters normally have an identifiable physical interpretation. The present paper describes a unified ‘data‐based mechanistic’approach to the modelling of dynamic systems from time‐series data using continuous or discrete‐time transfer function models in the time derivative, backward shift or delta operator. This approach, which exploits recursive methods of parameter estimation, represents a useful compromise between the physically based methods of mechanistic modelling and the ‘black box’methods of time‐series analysis. It provides a powerful tool for the objective investigation of environmental dynamic systems when time‐series data are available for analysis. Its practical potential is illustrated by several real examples concerned with the objective investigation of parallel processes in hydrology and water quality.