bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Fate of Heavy Metals in Pilot‐Plant Scale Upflow Sludge‐Blanket Clarifiers
Authors: HUNTER M. , STEPHENSON T. , LESTER J. N. 
Published: July 2007

SYNOPSISThe Removal of heavy metals and aluminium residuals during upflow sludge‐blanket clarification was investigated using a pilot‐plant system. Pilot units treating predosed raw water on site were assessed for sludge‐blanket formation and stabilization, and were found to produce clarified water of a comparable quality to the main works units after the start‐up and stabilization periods were complete. The heavy metals Cr, Fe, Mn, and Ni were the only heavy metals detectable at the investigation site and these occurred at concentrations well below guidelines values for potable abstraction and supply.Mean removals of Fe, Mn, Cr, and Ni were about 98, 89, 51, and 30 per cent respectively, during steady‐state operation, and Fe, Mn, and Cr all displayed reduced removals during transient changes in surface load, whereas Ni removal appeared to be relatively independent. Aluminium residuals derived from the dosed alum coagulant also showed decreases in removal from about 83 per cent during steady‐state operation to between 40 and 50 per cent during transient experiments.
The Water Supplies of Bahrain Island – 21 Years On
Authors: WALTON N. R. G. 
Published: July 2007

SYNOPSISThe Paper describes the dramatic changes which have occurred in the provision of public water supplies in Bahrain over the past 21 years since an earlier paper' outlined the original situation in 1965. It shows how the serious and irreversible ramifications of the continuously declining piezometry and increasing salinity of the natural, brackish, artesian groundwaters were tackled by the Government. A massive and imaginative programme was introduced to convert almost the whole island population from groundwater to mainly desalinated water by 1986. The relative success of this expensive programme and its novel use of reverse osmosis for desalinating the deeper saline water to relieve the piezometric pressure invasions of the upper fresh water aquifers is discussed. Finally, the outlook for the future stability and management of the island's total water resources is mentioned.
Mathematical Model Study of Plug Flow in a Chlorine Contact Tank
Authors: FALCONER R. A. , LIU S. Q. 
Published: July 2007

SYNOPSISThe paper describes the refinement and application of a mathematical model to investigate the hydraulic design features of a chlorine contact tank. The mathematical model study is an extension of a previous theoretical and laboratory model study, where the main objectives were to modify the flow through features of an existing chlorine contact tank, in order to reduce the effect of short circuiting and the existence of dead space zones. Flow through curves for a plug source input were obtained from the two‐dimensional depth averaged mathematical model simulations, with the predicted outflow tracer time variations being compared with the corresponding laboratory model results and field data.These comparisons were undertaken for several contact tank configurations, with encouraging agreement being obtained between the predicted and measured results for the original tank configuration. However, the agreement between both sets of results for the final tank configuration was not as good, due to the inability of the mathematical model to reproduce adequately complex three‐dimensional flow features.
Computer‐aided Load Smoothing with Energy Management (CALSEM) for Activated‐sludge Sewage Treatment Plants
Authors: NAGHDY G. , HELLIWELL P. 
Published: July 2007

SYNOPSISResearch over a ten‐year period leading up to a set of ten experiments lasting two years on a large two‐stream pilot sewage‐treatment plant has demonstrated process improvements and potential for considerable energy‐saving.A reliable, low‐cost, user‐friendly computer system is used to control the outflow from balancing storage, using available sensors. The automation system can also control de‐sludging and activatedsludge surplusing as well as monitoring and storing data on plant performance. A strategy for forecasting flow and load is effective in minimizing balancing volume.The system shows clear process improvements in reducing the risk of bulking sludge, in nitrification, and in reducing air requirement.Control of storage within the sewerage system, using forecasting, may provide some or all of the storage required. Existing tankage will, in many cases, provide the remainder of storage needed.
Colour Removal in a Reservoir and the Dredging and Dewatering of the Deposited Waterworks Sludge
Authors: KENT A. , WILSON D. , PICKLES D. M. 
Published: July 2007

SYNOPSISThe Albert Reservoir of the Yorkshire Water Authority was built in the 1850s as the final raw water storage in the chain of impounding and storage reservoirs which feed Halifax, Brighouse, and Elland in West Yorkshire (Fig. 1).This paper describes the problems encountered with increasing raw water colour since the mid1970s, the action taken to pretreat the water at the Albert reservoir prior to pressure filtration at the Thrum Hall Water Treatment Works (WTW), and the resulting problems with the deposited alum sludge in Albert reservoir.
Water and Environmental Management in the Third World
Authors: BANKS P. A. 
Published: July 2007

SYNOPSISEuropean efforts in water and environmental management are primarily concerned with the refinement and re‐moulding of well‐established institutional structures. In the Third World such structures either exist in a state of insecure infancy or have to be created. This paper contends that whilst consulting engineers have contributed significantly to technical developments in the Third World, their influence upon related management structures has been largely stifled. The reasons for this are drawn into focus by an examination of practice in other countries and suggestions are made for new approaches. The influence of International Funding Agencies is highlighted and questioned.
Managing and Engineering Rivers for the Benefit of Man
Authors: HOCKIN D. L. , WHITTLE I. R. , BAILEY R. A. 
Published: July 2007

SYNOPSISFrom earliest times flood, famine and drought have been scourges of mankind. River engineers alleviate floods, drain the land for agriculture, and conserve water resources. They construct engineering works, guide planners and developers, and provide warnings to minimize damage caused by storms over catchments and coasts. As the country becomes more developed, problems of reconciling conflicting interests require a flexible approach. This paper examines ways of providing the basic services in a climate of increasing public clamour for wildlife and landscape protection, and recreation.
Water Quality Changes in a Septic Tank Effluent Discharged to the Chalk
Authors: MONTGOMERY H. A. C. , SHAW P. J. , CHEESEMAN R. V. 
Published: July 2007

ABSTRACTBucket‐type samplers were installed in the unsaturated zone to intercept septic tank effluent descending through the Chalf at Snowdown, Kent. Better than 90 per cent removal of BOD and COD, and of the order of 99 per cent removal of coiform bacteria, were observed after downward percolation through 2.1 m of Chalk. Nitrification of ammonia had begun at that depth, but not at intermediate depth. The results, though limited, suggest that septic tank effluent is purified in the Chalk in a similar way to settled sewage.
The Application of a Newly Developed Tubular Filter Press to the Dewatering of a Waterworks Sludge
Authors: TREFFFRY‐GOATLEY K. , BUCHAN M. I. , RENCKEN E. G. , BUCKLEY C. A. 
Published: July 2007

SYNOPSISTHE PROTOTYPE OF a tubular configured filter press has been installed at a local water treatment plant. The prototype unit dewaters the polyelectrolyte/Bentonite slurry resulting from the treatment of 30 Ml/d of surface water to a spadable cake. In this process a slurry is fed under pressure into a self‐supporting array of porous fabric tubes; the liquid in the slurry filters through the tube walls while the slurry solids are deposited as a thin layer on the internal walls of the tubes. After a relatively thin cake has been formed, it is dislodged from the tube walls by means of a roller cleaning device. The cake is transported out of the tubes and deposited on a perforated conveyor belt where it is drained and conveyed to a collection hopper. The plant is fully automated and has been operating successfully since January 1987.
Incineration of Sewage Sludge ‐ A Reappraisal
Authors: Lowe P. 
Published: July 2007

ABSTRACTThe paper briefly reviews the history of incineration in the UK. The need for an integrated flow sheet concept in the design and operation of modern incinerators is stressed. Each element of the flow sheet (dewatering, predrying, the incinerator, waste heat recovery, flue gas cleaning, ash disposal) is reviewed. The economics of the process are discussed and the importance of autogenous combustion and need to avoid the inclusion of spare capacity is emphasised.
The Quality of Private Water Supplies in Calderdale ‐ the Implications of the EC Directive on Drinking Water Quality
Authors: BARRACLOUGH J. F. , HORAN N. J. 
Published: July 2007

SYNOPSISThe NUMBER AND nature of private water supplies in Calderdale Metropolitan Borough Council, West Yorkshire, were determined and each of these supplies sampled once or more to determine their compliance with the 1985‘EC Directive on drinking water quality’. A total of 560 private water supplies were located serving 1970 properties. Of a total of 1160 samples tested, 83 per cent failed to meet the maximum admissible concentration for one or more of the parameters specified in the EC Directive. These parameters monitored included faecal coliforms, for which 48 per cent of the samples failed, and lead, for which 25 per cent failed. Possible reasons for these failures are discussed and the implications of these results on the implementation of the Directive are considered.
Improved Sewage Treatment with Ozonated Activated Sludge
Authors: LEEUWEN J. VAN 
Published: July 2007

ABSTRACTActivated SLUDGE SEWAGE treatment processes are often inadequate to comply with effluent criteria as promulgated in anti‐pollution legislation. Ozonation was studied as a means of improving nutrient removal activated sludge processes without the salinity and other disadvantages of the often used polyvalent metal salt addition. Direct ozonation into the aeration basin of a 150 I/d Phoredox (modified Bardenpho) system led to improved removal of organic substances. Nitrification was improved while phosphate removal was not adversely affected. Beneficial biological activity in the activated sludge was enhanced. The trihalomethane formation potential was reduced. Pollutional loads could be lessened, while an effluent with increased reuse potential was produced.
The Application of Cross‐flow Microfiltration Technology to the Concentration of Sewage Works Sludge Streams
Authors: BINDOFF A. M. , TREFFRY‐GOATLEY K. , FORTMANN N. E. , HUNT J. W. , BUCKLEY C. A. 
Published: July 2007

SYNOPSISA LOCALLY DEVELOPED cross‐flow microfiltration process using woven fabric tubes was used to concentrate waste activated sludge and anaerobic digested sludge from a conventional sewage works.Results showed that waste activated sludge could be concentrated from 5 to 50 g/l total solids. The permeate quality was good (0 to 50 mg/l suspended solids), but deteriorated both with time and increasing feed solids concentration.A cross‐flow microfilter was coupled to a pilot scale anaerobic digester and the digester solids were increased from 26 to 55 g/l total solids. The organic loading to the digester was increased from 1.8 to 3.1 kg volatile solids per m3 per day. The solids retention time was held constant at 26 days, while the liquid retention time was decreased from 26 to 14 days. The permeate quality was significantly better than the supernatant liquor from a comparable digester (suspended solids 122 and 570 mg/l, respectively).Data obtained from the cross‐flow microfiltration of waste activated sludge was used to regress for the constants in a mathematical model of steady‐state flux.
A Study into the Cause of Decline in pH During Water Distribution
Authors: SMITH PAUL G. , WATKER ANNE F. 
Published: July 2007

ABSTRACTThis STUDY INVESTIGATES the decline in pH of soft waters during distribution. The fieldwork and laboratory data confirmed and quantified the pH decline in soft water that had had the pH increased by lime addition at the treatment stage. A pH of 9.0 can decline to 7.5 during distribution. The role of humic acid as a causative agent of pH decline is examined in detail by modified jar test experiments and the development of a dialysis technique. The results of these experiments show that binding or complexing occurs between the humic acid and the calcium ions. This complexing generates H+ ions with the consequential decline in pH of the water.
Upgrading Disinfection Installation in Strathclyde Region
Authors: GREENE L. A. , FADZEAN C. J. 
Published: July 2007

ABSTRACTIn 1984‐85 Strathclyrde Regional Council Water Department received 108 EC Directive (80/778/ EEC) Article 20 Delays in Respect of Microbiological Parameters 57 and 58. This paper details the strategy which was adopted by the Department to complete the programme within a limited timescale, together with the associated costs. Plant performance data based on divisional and regional assessments are discussed, together with some ancillary information on trihalomethane production. Reference is also made to some public opposition to chlorination in remote areas on the grounds of aesthetic supply acceptability.
The EC Bathing Water Directive: a Sampling Problem
Authors: CURRAN J. C. 
Published: July 2007

AbstractThe relatively frequent observation, during periods of onshore drift, of a surface line of convergence in nearshore coastal waters may have significant implications for the sampling procedure used for monitoring compliance with the EC Bathing Water Directive. A simple theory is developed for predicting the formation of the convergence line, and a possible alternative sampling method is suggested.
Water Source Protection and Protection Zones
Authors: HARRYMAN M. B. M. 
Published: July 2007

AbstractThis paper discusses Government policy to August 1989 on the use of protection zones to protect UK water sources from pollution by nitrate. It outlines the use of the powers in the Water Act 1989 to declare Nitrate Sensitive Areas, and the procedures that would be followed in declaring such zones. The circumstances are outlined in which compensation would be paid in Nitrate Sensitive Areas and the reasons for departing from the ‘polluter pays’ principle. UK policy is related to the proposed European Community Directive on the control of nitrate, and the similarities between the two approaches are illustrated.
The Elimination of Pentachlorophenol Pollution from the Forth Catchment
Authors: CAMPBELL D. , RIDGWAY I. M. 
Published: July 2007

AbstractFollowing adoption of the EC Directive 86/280/EEC, three major point sources of pentachlorophenol (PCP) were identified in the River Forth catchment. At least one of these was known to be causing serious water pollution. While methods to determine low concentrations of PCP in the environment were being developed, discussions were held with the dischargers on ways to eliminate PCP from their effluent. Despite the additional costs involved, agreement was reached on the substitution of alternative, biodegradable fungicides. Although these major polluting discharges of PCP have now been eliminated, background levels of PCP found in rivers in the Forth River Purification Board's area show that other minor sources of PCP remain, indicative of the widespread use of this powerful and persistent fungicide.
The Seaford Sea Defence Scheme
Authors: HOLMES A. E. 
Published: July 2007

ABSTRACTDuring THE LaST 100 years the shingle beach levels at Seaford have gradually declined, with the result that the 10‐m high sea wall, protecting low‐lying areas of the town against flooding, came under serious threat of collapse.Southern Water Authority assumed responsibility for the frontage in 1981, and the paper briefly describes the history of events leading into the problem, model studies, and the solution which was adopted. Details of behaviour of the beach during the months following completion, including the great storm of October 1987, are also given.
Application of Granular Activated Carbon in the Water Industry
Authors: HYDE R. A. 
Published: July 2007

ABSTRACTUntil the mid 1980s granular activated carbon (GAC) was used in only a small number of water‐treatment plants in the UK. Since then the material has been installed in over 30 plants, either as a result of an operational decision to treat the water by GAC or for the purpose of full‐scale experiments. GAC is used for a variety of reasons including taste and odour control, removal of a wide range of synthetic organic compounds (for example volatile chlorinated solvents, pesticides, oils) of molecular weight 100–500, and adsorption of trihalomethane precursors (molecular weight 103‐105). The performance of different GACs for a particular duty may vary by a factor of 10, and the best GAC for one application may be the worst for another. Thus, to minimize the cost of GAC treatment, it is essential to identify the purpose for which GAC is being used and then to select, by pilot trials or by more rapid laboratory procedures and mathematical modelling, the most appropriate GAC for that particular application.
Improvements to Activated‐Sludge Plant Aeration Systems at Hawick and Jedburgh Sewage‐Treatment Works
Authors: Wallis B. F. J. 
Published: July 2007

ABSTRACTIn response to the requirement of the Tweed River Purification Board for a higher standard of effluent, improvements have been carried out to the activated‐sludge aeration systems at Hawick and Jed‐burgh sewage‐treatment works.This paper describes the electrical and mechanical refurbishment involved, and the performance of the completed systems. Process control was considered to be of particular importance in these projects as the plant receives a high proportion of industrial effluent.
Experimental Assessment of Rates of Nitrate Removal by River Bed Sediments
Authors: WYER M. , KAY D. 
Published: July 2007

ABSTRACTConcentrations OF Chloride, nitrate‐N, sulphate, sodium, ammoniacal‐N and potassium were monitored for six days in 20 riverine sediment‐water flow tank experiments. Only nitrate‐N and ammonical‐N showed consistent patterns over a period of time. Nitrate‐removal rates ranged from −15 mg N/m2.d (coarse material) to +49 mg N/m2.d (fine sediment) when the initial concentration of nitrate‐N was 2 mg/1. An increase in initial concentration to 11 mg/1 produced corresponding removal rates of 67–241 mg N/m2.d. Likely removal mechanisms are discussed. The results suggest management possibilities for stream bed ecosystems and raw water impoundments with respect to nitrogen cycling.
The Ecology and Survival of Legionella Pneumophila
Authors: COLBOURNE J. S. , DENNIS P. J. 
Published: July 2007

ABSTRACT L. pneumophila serogroup 1 was detected in 12% of water sources used for the supply of drinking water in England in a survey carried out between September 1985 and June 1987. The bacterium, the causative agent of legionnaires' disease, was found more often in underground supplies in late summer–early autumn; the time of year when indigenous community‐acquired infections also increase in number. Using an immunofluorescent assay it was observed that L.pneumophila could survive conventional water treatment including disinfection with chlorine and, whilst being non‐culturable, retained its ability to colonize pipe surfaces and grow in the warmer water systems of buildings. Viability of non‐culturable legionella was demonstrated by heat shock. These findings confirm the importance of preserving water quality within buildings by good design, thorough maintenance, and careful operation of water systems, following the guidance issued by the Department of Health and the Health & Safety Executive.
Leakage Control in a Universally Metered Distribution System: Pinetown Water's Experience
Authors: MILLS R. E. 
Published: July 2007

ABSTRACTAs a result of water losses reaching a high point of 16% in 1973, combined with a relatively high and increasing retail tariff, the Pinetown Regional Water Services Corporation embarked upon a programme to reduce losses to an acceptable level of about 10%. The programme involved: (i) the establishment of district metering throughout the distribution system; (ii) the replacement of certain retail meters; and (iii) the metering of new fire connections (other than those serving sprinkler installations). Further steps were taken to improve the situation and included: (a) the monitoring of minimum night flows, (b) regular sounding of distribution mains; (c) the establishment of a full‐time waste detection gang; and (d) with improved control valves becoming available, more effective pressure control of the system. The Corporation's computer was called upon to determine: (i) the monthly losses from each of the hundred or so districts; (ii) the life history, in graphical form, of retail meters under review; and (iii) a record of expenditure on leakage control. The paper describes the development of the methods used in leakage control, costing less than half a cent per cubic metre of water purchased, and outlines the practical experience gained in reducing losses from 16% to less than 5% over a period of 14 years.
New Technology in a Water Company
Authors: CARTER J. 
Published: July 2007

ABSTRACTThe South Staffordshire Water Company serves a population of 1.25 million within an area of 1502 km2. This paper describes how the Company employs new technology across a broad spectrum of its activities, operational, scientific and administrative, and how it has benefited from these applications. It demonstrates how available technologies have been investigated, adapted and developed to meet the Company's particular requirements for improved efficiency, new regulations and standards, and cost savings. The Company is a leading innovator in the use of new technology, and the paper illustrates how this success has been achieved through the encouragement and development of new ideas and the careful control and monitoring of new projects.
Gravel Bed Hydroponic Systems Used for Secondary and Tertiary Treatment of Sewage Effluent
Authors: BUTLER J. E. , LOVERIDGE R. F. , FORD M. G. , BONE D. A. , ASHWORTH R. F. 
Published: July 2007

ABSTRACTGravel bed hydroponic (GBH) systems planted withemergent hydrophytes, such as Phragmites australis (the common reed), treat domestic sewage effluents to acceptable environmental standards in an economic and efficient manner. Biochemical oxygen demand (BOD), ammonia, and coliform bacteria can be reduced by over 90% and dissolved oxygen (DO) substantially increased. In temperate zones, such as Europe, GBH systems can be used to replace conventional small rural treatment works, and for tertiary treatment of final effluents. In tropical and arid zones, GBH systems can provide locally‐managed, cost‐effective alternatives to hightechnology systems which are inappropriate for use in developing countries. Portsmouth Polytechnic reed‐bed sewage treatment GBH projects in the UK and Egypt are discussed and current progress is assessed.