bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modified Operational Modes at Swedish Municipal Wastewater Treatment Plants
Authors: Hultman B , Lind J E , Reinius L.-G , Eklund L , Engberg H , Lilja S , Nordström B 
Published: May 2018

During the rapid development of advanced sewage works in Sweden in the 1970's interest was primarily focused on the construction of treatment works. Practical experience from ten years of operation have shown that it may be advantageous to operate the plants in ways other than those they originally were planned for, for instance using two-stage precipitation or different techniques for recirculation of chemical and biological sludges.
In order to facilitate the introduction of more efficient operational modes a joint project was started in 1980 between the Swedish Water and Waste Water Works Association (VAV) and the National Swedish Environment Protection Board (SNV). The purpose of the project, Sewage Works Evaluation Project (SWEP), is to evaluate and optimize biological-chemical treatment of municipal wastewater. Results from this project will be reported in this paper with special emphasis on the sewage works at Boras, Eskilstuna, Hässleholm, Landskrona, and Link ö ping.
Within the SWEP, a lot of information is collected including physical and chemical data (analytical values from the laboratory), operational data (measurement values from the sewage works) and plant data. Methods of handling and evaluating these data will also be discussed in this paper.
Ten Years Experience with a Highly Loaded Activated Sludge Plant
Authors: Balmér P , Hallquist S , Hernebring M 
Published: May 2018

The Rya wastewater treatment plant in Gothenburg, Sweden serves 640 000 population equivalents. It is an extremely highly loaded activated sludge plant without presetting with a mean cell residence time of about 0.5 days. Ten years experience proves that the plant is capable of removing about 70% of the BOD load. The effluent BOD is mainly caused by non settleable suspended solids due to the partly dispersed growth of the activated sludge. The low mean cell residence time and the high suspended solids concentration in the aeration basin influent gives an activated sludge with low viability and in mass balance studies it was determined that only 12% of the influent COD and about 40% of the BOD was oxidized by the activated sludge. The activated sludge has consistently had a very low sludge volume index and the settling basins could thus be very highly loaded.
The surplus activated sludge could be thickened to solids concentrations over 6%. After dewatering the sludge was either lime treated or co-composted with bark. The plant is manned only eight hours five days a week. During unmanned time there are standby personnel. Data is presented on man power, energy and chemical use, and on costs.
Automation Aspects of Wastewater Treatment Plant Design and Operation
Authors: Briggs R 
Published: May 2018

This paper provides primarily a discussion of the instrumentation, control and automation aspects of improving the efficiency of certain wastewater treatment facilities including control and operation of sewerage systems, primary and secondary sewage treatment and sludge handling and disposal.
Relevant aspects of the activities of the recently constituted IAWPRC's Instrumentation Group receive brief mention including its activities in the areas of evaluation of existing sensors and systems, their relevance to particular needs, attributes and deficiencies, and also in the area of promotion of relevant research and development.
A brief appraisal and description of existing sensors and systems, an indication of their usefulness to date and details of alternative instrumentation configurations for use in the enhancement of their general utility is provided.
Relevant research and development is reviewed, including relevant remote sensing aspects, and developments in micro electronics and computing: finally some new horizons are explored.
The Influence of Nutrient Availability on the Ecosystem Behaviour of a Salt Water Lake
Authors: de Vries I , Veul M F 
Published: May 2018

The influence of the availability of silicon, nitrogen and phosphorus on the behaviour of the ecosystem in the salt Lake Grevelingen is evaluated. Quantification of the nutrientcycling is essentially based on a dynamic calculation of detritus formation resulting from mortality of phytoplankton and microphytobenthos, including mineralization as function of temperature and substrate concentration.
Also changes of the dissolved inorganic nutrientpools resulting from primary production, mineralization and net loading are dynamically ca1culated.
Silicon and nitrogen are reversibly fixed in bottomdetritus during the summer halfyear, which implies that primary production depends on the balance between accumulation of detritus in the bottom and mineralization. In contrast the dynamics of phosphorus depend only to a minor extent on primary production and net loading.
The net yearly load of nitrogen equals the amount of nitrogen present in the waterphase during the winterperiod. However winter concentrations do not increase and nitrogen remains a limiting factor for primary production. 3-4 g N/m2/year is apparently removed from the lake by denitrification.
The environmental factors enabling denitrification are important for consolidation of the ecosystem behaviour. From a management point of view stratification which inhibits denitrification, should be avoided.
Assessing the Environmental Impact of the Annapolis Tidal Power Project
Authors: Gordon Tidmarsh W 
Published: May 2018

An 18 MW pilot tidal power project is being developed in an existing tidal barrage on the Annapolis River Estuary in southwestern Nova Scotia to evaluate the performance of a prototype STRAFLO turbine. An environmental assessment to identify potential impacts on regional biophysical and socio-economic features was completed.
Construction of the barrage had already substantially altered the environment. The assessment focussed on impacts associated with construction and operation of the power plant itself, and the increased maximum operating elevation of the impounded basin. Environmental issues associated with the power plant included release of suspended sediment, scour in existing channels and at adjacent shorelines, flood flow management, and passage of anadromous fish through the barrage. Concerns with increased basin water levels included interference with existing agriculture, flooding, and accelerated rates of bank erosion.
Environment in the World Bank1 – Policies and Practices
Authors: Lee J A 
Published: May 2018

Environmental criteria (including conservation, pollution control and human ecology) are systematically integrated into World Bank projects in the belief that sustainable economic development depends on sound environmental management. Procedures are outlined by which the Bank incorporates necessary environmental safeguards into each stage of the project cycle, from initial identification, planning and design through construction operation and final evaluation. The Bank's other environmental functions (including technical assistance liaision work) are also outlined.
Specific Bank projects with significant coastal implications are noted.
1The views presented in this paper are solely those of the author and do not necessarily fully reflect the policies and procedures of the World Bank.
Integrated Approach to Coastal Zone Management in Puerto Galera, Oriental Mindoro, Philippines
Authors: Iriberri O C A 
Published: May 2018

Coastal zone management requires an understanding of the complex milieu of interactions and activities taking place in an environmental system. Man is beginning to recognize that the old method of dealing with individual issues and problems as single fragment of a whole ecosystem is not enough.
This paper tries to deal with the integrated manner in carrying out effectively the management of the coastal zone in Puerto Galera, Oriental Mindoro by the Man and the Biosphere Interagency Committee on Ecological Studies. To attain the objective of the project, the different agencies monitor, identify, observe, investigate various natural and physical parameters contributing to the ecological balance and study the rational use of the resources along the coastal zone. Result of the study showed that although such factors as land use practices of shifting cultivation (kaingin), human attitude towards forest and its resources, and continuous increase in population and migration of people were observed, such pressure on lands has not greatly affected the Puerto Galera coastal zone resources.
The Effects of Constructing a Barrage across the Tawe Estuary
Authors: Broyd T W , Hooper A G , Kingsbury R S W M 
Published: May 2018

A proposed barrage across the tidal reaches of the R. Tawe, South Wales, was modelled to simulate its effect on the environment. Both computer and physical models were prepared, tested and run for a variety of tidal and fresh water flow conditions.
A comprehensive data review identified further information essential for model calibration and information. Field surveys to gather physical, chemical and biological information were performed as part of the overall study.
The numerical models predicted hydrodynamic and pollutant behaviour upstream of the barrage and sedimentation effects downstream. The physical model was used for navigational effects and for identifying problems during the construction phase.
The study revealed that conditions would change but not significantly deteriorate provided that certain remedial actions were taken.
Management of the Dutch Waddensea
Authors: Vreugdenhil D 
Published: May 2018

It was not until the late Middle Ages that the sea penetrated far into the interior of The Netherlands, thus flooding three quarters of a million hectares of land.
Since then half a million hectares have been reclaimed from the sea. The Dutch Government chose to preserve the remaining quarter of a million hectares of shallow sea with mudflats of the Waddensea as a nature reserve. The management objectives are at one hand to preserve all characteristic habitats and species with a minimal interference by human activities in geomorphological and hydrological processes, and at the other hand to guarantee the safety against the sea of the inhabitants of the adjacent mainland and islands and to facilitate certain economic and recreational uses of the Waddensea without jeopardizing the natural qualities. These objectives are being elaborated in managementplans.
Integrating Environmental Aspects into Decision Making
Authors: Bidwell Robin 
Published: May 2018

Environmental Impact Assessment (EIA) was designed to provide a procedure for integrating environmental factors into planning decision. But EIA has gained a reputation of causing delay, providing irrelevant and unusable reports.
The paper draws on a number of examples of coastal water environmental assessments carried out in Europe, United States and elsewhere both to demonstrate the reasons for the failure of EIA and to put forward ways in which the problem may be overcome. These are examined under the following headings.(1)Procedural: environmental impact procedures have been developed that are carried out separately from the central decision-making process.(2)Impact selection: the need to identify key questions to be answered in the course of the environmental study.(3)Impact quantification: the problem of providing ‘answers' that are scientifically justifiable in the absence of the resources necessary for a proper scientific investigation.(4)Presentation: the need to present results in a form that can be easily understood and handled by the decision makers.
Techniques for Reducing Contaminant Release during Dredging Operations
Authors: Palermo M R , Montgomery R L , Raymond G L 
Published: May 2018

Dredging practices in the United States have evolved primarily to achieve the greatest possible economic returns through maximizing production. Recently, more consideration has been given to environmental impacts because various Federal and State regulatory agencies have implemented restrictions on the dredging cleanup activities. Conventional dredges are not specifically designed or intended for use in dredging highly contaminated material. However, dredges are the logical, and perhaps only, means of removing contaminated sediments that may be found in the Nation's waterways. Some modification to equipment and/or dredging techniques could result in their use for that purpose with minimal adverse impact on the environment. In some instances special dredges may be needed for cleanup activities.
The Corps of Engineers has initiated research to develop a method for predicting resuspension and release of contaminants using various types of dredging equipment and techniques and to improve and/or develop new equipment and techniques for dredging highly contaminated sediments. The investigation includes an evaluation of the resuspension of solids and potentially toxic constituents in the immediate vicinity of operating cutterheads, dragheads, and clamshells. Because the environmental impact associated with each type of dredge and dredging technique is directly related to the dynamics of the dredging operation, in situ sampling systems are being used when possible.
A dredging demonstration on the James River, Virginia, compared the performance of a conventional cutterhead and a modified dustpan dredge operating in sediments contaminated with Kepone. Demonstrations comparing performance of conventional and watertight clamshell buckets were conducted in the Tampa, Florida area. These will be used as case studies to illustrate the advantages of various equipment types for dredging contaminated sediments.
A Two Dimensional Water Quality Model Application for Hong Kong Coastal Waters
Authors: Postma L 
Published: May 2018

Water quality modelling is presented as a means of quantification of environmental impacts of civil engineering projects in coastal areas. This is illustrated with an application concerning the operation of a replacement airport for Hong Kong in Lantau Bay.
The water movement to be expected, after the planned reclamation, is calculated separately with the two dimensional depth averaged model WAQUA on a minute to minute basis.
The mu1ti-dimensiona1 water quality model DELWAQ is implemented in a two dimensional depth averaged way too, with a time step of several minutes. It has been used to calculate concentrations of three nitrogen fractions, phosphorus, BOD, coliforms and oxygen deficit, due to wasteloads to be expected. Also tentative calculations of suspended solids were performed.
Results are presented in contour graphs, 3-dimensiona1 drawings and a movie of 3-d drawings.
Depth-Duration Models of Short Time Increment Rainfall
Authors: Ramachandra Rao A , Chenchayya B T 
Published: May 2018

The depth-duration characteristics of short time increment (10 min. and hourly) rainfall sequences are investigated in the present paper. The basic objectives of the study are to investigate the models proposed for storm depths and durations and to investigate the effect of different time scales on modelling the process. Both regression and bivariate probability distribution models are used in the study. Hourly and 10-minute rainfall measured at Lafayette, Indiana are used in the study.
The following principal results are obtained from the study. Regression models for storm depth-duration relationship are adequate when they are used with appropriately classified storms. Significant differences and some surprising similarities are found in the characteristics of short time increment rainfall processes in different climatic regions. Finally, the characteristics of the 10 minute and hourly data are quite similar to each other.
Real-Time Estimation and Forecasting of Spatially Distributed Areal Rainfall
Authors: Schilling Wolfgang 
Published: May 2018

After a short demonstration about the need for operational rainfall forecasts, a literature survey, constraints for model development and definition of criteria of model performance a simple multi-variate autoregressive model is presented that forecasts point rainfall spatially distributed, for short lead times, quantitatively and automatically. For model operation only remotely transmitted standard raingage data is necessary.
The model is expanded to forecast and estimate also areal rainfall from point measurements using the Kaiman filter technique and the theory of regionalized variables.
It is demonstrated that the Kaiman filter model is superior for areal rainfall estimation (compared to the Thiessen procedure) as well as for areal rainfall forecasting compared to trivial forecasts and the point forecasting model mentioned above.
Nitrification and Denitrification in Single-Stage Activated Sludge Plants – Operational Results of the Lüdinghausen Waste Water Treatment Plant, F.R.G.
Authors: Schlegel S 
Published: May 2018

About 15,000 Population Equivalents are connected to the Lüdinghausen Waste Water Treatment Plant of the Lippeverband. The activated sludge stages, designed for 30,000 PE and a BOD5 sludge load of 0.3 kg/(kg · d), are, thus, at present operated with a sludge load of 0.15 kg/(kg · d), i.e. in the nitrification range. In order to reduce energy costs for aeration and prevent possible sludge losses resulting from the denitrification processes, the aeration tanks are equipped with denitrification zones.
Because of the loading conditions, the only possible denitrification method was that of primary denitrification. However, contrary to usual practice, a multi-stage cascade, comprising two denitrification and two nitrification tanks, was installed.
Apart from a very high degree of nitrification, nitrate is eliminated to a farreaching degree. Better reduction of BOD5 and COD is also attained. Moreover, the settlability of the activated sludge is, compared to earlier conditions, substantially more favourable.
Biological Phosphorus and Nitrogen Removal via the A/O Process1: Recent Experience in the United States and United Kingdom
Authors: Hong S , Krichten D , Best A , Rachwal A 
Published: May 2018

This paper summarizes the state of the art of the proprietary A/01 system for biological nutrient removal. The A/0 system is a modified form of the activated sludge process employing an anaerobic zone to promote biological phosphorus removal. Process options discussed include BOD oxidation, biological phosphorus removal, nitrification and denltrification. The biochemical basis for phosphorus removal is reviewed. Results of several pilot studies and a 11400 m3/day demonstration plant operated for 3 years are given.
1A/O is a registered trademark of Air Products and Chemicals, Inc., Allentown, Pennsylvania, USA.
The Use of Biofiltration for Further Wastewater Treatment
Authors: Rüffer H , Rosenwinkel K.-H 
Published: May 2018

The City of Mannheim (FRG) expanded its one stage biological treatment plant by addition of a second stage based on dry bed filtration and designed for an average wastewater flow of QTW = 8.800 m3/h and an average BOD5 of 70 mg/l. Five firms in the foreground of process selection conducted from 1980 to 1982 experiments on purification systems for the effluent from the first biological stage. Systems tested were biofiltration in dry and submerged beds and activated two sludge systems.
Filter materials used were inert material, activated carbon and Biolite. In one case a pretreatment by coagulation was employed. The influent of submerged filters without coagulation was supplied with technical oxygen whereas submerged filters with coagulation were supplied with atmospheric oxygen.
The two sludge process employed a plastic medium (Flocor E) in an aeration tank of up to 40% total bed volume; aeration was achieved with compressed air. The results of the submerged filtration tests are compared to those of the two sludge system with respect to retention of suspended solids, elimination of BOD5 and COD and soluble and total nitrogenous compounds. A procedural evaluation and cost comparison are made. In addition the problems that arise by solution of oxygen up to high concentrations are indicated and solution possibilities discussed.
Concentration of Seeded and Naturally Occurring Enteroviruses from Waters of Varying Quality by Hollow Fiber Ultrafiltration
Authors: Bicknell E. A. , Dziewulski D. M. , Sturman L. S. , Belfort G. 
Published: May 2018

A semi-automated hollow fiber ultrafiltration system was used to concentrate viruses from tap water, river water and treated and untreated wastewater. Samples were dehydrated by filtration through an asymmetric polysulfone hollow fiber module with a molecular weight cut-off of 10,000 D. Retained solute was recovered from the filter by backwashing with water, buffer and other solutions.
One hundred liters of tap water seeded with poliovirus type 2 Sabin were processed in 161 ± 22 minutes (average flux 1.2 ± 0.1 × 10−3 cm/sec). Retained virus was recovered from the filter by backwashing with 150 ml of 0.05 M glycine, pH 10.0, which was further reduced to about 10 ml by the organic flocculation technique. Average recovery of 60 plaque-forming units (PFU) of poliovirus from 100 1 of tapwater was 148 ± 10%.
Hudson River water (100 1 with an average turbidity of 3.2 NTU) was processed in 218 ± 34 minutes (average flux 0.8 ± 0.2 × 10−3 cm/sec). Recovery of 114 PFU of poliovirus seeded into 99 1 of river water was 35%. No natural virus was recovered from unseeded river water.
Naturally occurring viruses, tentatively identified as echovirus type 14, coxsackie virus type A9 and coxsackie virus types B2-B5, were isolated from concentrates qf treated and untreated wastewater (average fluxes 0.58 × 10−3 and 0.46 × 10−3 cm/sec, respectively).
Some Experimental Discussion of Accuracies in Quantitative Virus Assessment for Water Supply
Authors: Sumitomo Hisashi 
Published: May 2018

Chlorination has been believed to be the best sterilization method in water supply engineering for many years. However, the recent carcinogenic problem of trihalomethanes (THM) formed from organic compounds by chlorination requires us to assess the public health risk of THM.
The author tried an assessment of a suitable chlorination technique considering both the effects of THM and viruses on human health, using Lake Biwa as a representative example of a water resource in Japan. Statistical handling of data was revealed to be important because of the statistical nature of the data. In other words, since both concentrations are very low in tap water, we need to quantify both the effects and concentrations with probabilities.
In the first part of this paper, a statistical procedure and numerical results of the assessment of virus and THM risks are shown. In the second part some results of accuracies in virus experiments are briefly shown. These experiments concerning statistical problems are particularly important for more precise assessment of the public risk of viruses in tap water.