bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pahs in Atmospheric Particulate in the Area of Italian Scientific Base in Antarctica
Authors: Caricchia A. M. , Chiavarini S. , Cremisini C. , Fantini M. , Morabito R. , Perini A. , Pezza M. 
Published: May 2018

Data on PAH levels in atmospheric paniculate were determined in the frame of the environment protection activities during the VI Italian Expedition in Antarctica. Samples were collected at the four cardinal points at about 200 metres from the central point of the Italian scientific base. Results are related to basic meteorological parameters, operating parameters and fuel consumption of the waste incinerator, power generators and other engines.
Data show low levels of the individual PAH (95% in the range 1-50 pg/m3) confirming the absence, up to now, of relevant contamination from Italian base.
On the basis of these preliminary results, monitor program will continue in the future expeditions in order to keep undercontrol the potential PAHs sources.
Cleaning Contaminated Sediments by Separation on the Basis of Particle Size
Authors: van Rijt C. 
Published: May 2018

In the Netherlands large quantities of contaminated sediment have to be dredged. Because it cannot be relocated directly in the marine environment, the dredged material must be placed in special contained depots which are expensive to construct. In 1989 a programme to reduce the volume of storage space required was started. This paper includes the results of research into the physical aspects of sediment cleaning.
Heavy metals are often found in the silt fraction, while organic micro pollutants occur in the silt fraction and sometimes also as tar particles in the sand fraction. The sediment can be cleaned by physical means or by the selective separation of some of the contaminants by froth flotation.
Research into the efficiency of using separation on the basis of particle size to clean contaminated sediments from five different sites and also the experience gained during three sediment clean-up operations, indicated that positive effects could only be achieved in sandy sediments. In some cases, owing to the presence of tar particles in the sediment, the quality of the sand fraction was not improved after separation in hydrocyclones. They can be removed from the sand fraction by flotation. Recent developments in selective separation by means of froth flotation, using equipment specially designed for the fine fraction, are promising.
The use of duo-flocculants has a favourable influence on the consolidation behaviour of the fine fraction after separation.
An Overview of the Trunk Scheduling System for the London Ring Main
Authors: Burnell David , Race Julia , Evans Phil 
Published: May 2018

The London Water Ring Main is one of UK's largest water investments. It will eventually carry half of London's water and greatly increase the flexibility of London's trunk distribution network. The Trunk Scheduling System is a core part of decision-support for the enhanced network. It has been written to help Operational Controllers make best use of that extra flexibility.
Cost-effective operation makes best use of the cheapest treatment works, lowenergy-loss routes and off-peak tariffs. These need to be combined to meet projected diurnal demands in over 50 zones and leave each of some 20 service reservoirs at a target end volume, whilst taking no more than the declared “reliable output” from each of 10 works. The schedule proposed must be hydraulically viable as well as cheap. Most route constraints arise from pressure limits (so as not to burst mains or leave customers without water). Hydraulic constraints are non-linear and require on-line hydraulic intelligence as the schedule is developed.
The key idea is to regard a schedule as a series of “operating regimes”, each of which is applied for a specified duration. Each regime applies within a particular timeslice. It comprises settings for each pump in the network, together with its implications: a unit cost and the effect of those settings on each source and each reservoir under hydraulic equilibrium. Trunk Scheduling provides a series of modules to answer the questions:which regimes (of the billions possible) should make up the schedule?how long should each selected regime be applied for?in which sequence should the chosen regimes be applied?
An Operational Information Database Based on the Automated Processing of Time Series Data Available from Telemetry Control Systems
Authors: Casey R. J. , Grinney S. A. 
Published: May 2018

The paper describes the development and subsequent management of a central database of operational information based largely on the automated processing of time series data retrieved from the Company's telemetry control systems.
Following the implementation of the system, both the quality and quantity of processed statistics available to operational managers has been greatly enhanced above the level of information originally recorded by manual methods. Also significant process modelling systems have been introduced utilising this information to improve operational efficiency.
Key to the success of the system has been the comprehensive provision of facilities to quickly and effectively validate the data, together with the facilities provided to ensure that the configuration of the database accurately matches and tracks configuration changes to the field network. The paper examines these functions in some detail.
The Usefulness of On-Line Monitoring in Effecting Savings in Combined Biological and Chemical Removal of Phosphorus in Activated Sludge Plants
Authors: Lotter L. H. , Pitman A. R. 
Published: May 2018

On-line analyzers to monitor the effluent levels of ammonia and phosphate have been installed at all four nutrient removal activated sludge plants in Johannesburg. The data from these instruments is transferred to a SCADA system for control purposes. The on-line system is supplemented by laboratory data, which is stored on a separate computer system. A combination of this data is used for routine operational control.
Dissolved oxygen probes are installed in the aerobic reactors of all plants and are used for aeration control. Automatic aeration control has recently been installed at one of the plants. In this paper some experience with on-line monitoring is discussed in terms of its usefulness and cost savings achieved. Savings of 1 million US $ in the purchase of phosphate precipitation chemicals have been achieved in the current financial year as a result of more efficient operational control.
PROCESS DESIGN OF ADVANCED STORAGE-TREATMENT FACILITIES FOR CSO CONTROL
Authors: Zukovs George , Pisano William 
Published: May 2018

Increasing focus on the abatement of combined sewer overflow has produced considerable interest in new and innovative control approaches. Particular attention has fallen upon the application of high rate physical-chemical processes as part of integrated CSO storage treatment schemes.
The extensive experience gained during a recent study in Metropolitan Toronto, Canada is used to describe and illustrate a systematic planning and preliminary design procedure for high rate CSO treatment facilities. The procedures includes five basic steps starting with catchment characterization and process flow sheet development and including process evaluation studies, comprehensive modelling and estimation of costs and performance.
JOINT CONSIDERATION OF SEWERAGE SYSTEM AND W ASTEW ATER TREATMENT PLANT
Authors: Otterpohl Ralf , Freund Martin , Sanz Juan Pablo , Durchschlag Andreas 
Published: May 2018

The total efficiency of combined sewerage systems and wastewater treatment plants (WTP) sbould be considered. By an overall planning procedure the benefits of the whole system can be optimized. For the estimation of the system behaviour with different rain events, computer simulations of the sewerage system including storage tanks and the treatment plant have to be carried out. The two systems are not coupled mathematically allowing separate simulation. Hydrographs of different scenarios computed for the sewerage system can be used for simulations of the WTP.
For comparing the effects of different throttle flows on the treatment plant an example bas been simulated. In this example the BOD5 and phosphorus loads could be reduced with a higher throttle flow. The large difference in total discharges from combined sewerage without storage tanks and with well-dimensioned tanks could also be demonstrated.
MODELLING OF FULL-SCALE WASTEWATER TREATMENT PLANTS: HOW DETAILED SHOULD IT BE?
Authors: Watson Bruce , Rupke Mark , Takács Imre , Patry Gilles 
Published: May 2018

Dynamic mathematical modelling of full-scale wastewater treatment plants requires an optimal level of detail to be accurate, effective, but still manageable. Single process models tend to oversimplify the complexities of a large-scale plant and result in erroneous calibrated parameter values or limited predictive power for the model – on the other hand, modelling of every process and process unit is usually impractical, since it cannot be supported by reliable plant data, and requires prohibitive sampling costs and effort.
Level of aggregation, settler dimensionality and reactivity, and plug-flow hydraulics were investigated with the help of a sophisticated dynamic modelling package. The results show that there is no general rule or global ‘optimal level’ of modelling – the required modelling detail is a function of influent flow and loading levels, and processes to be simulated (BOD removal, nitrification-denitrification, biological phosphorus removal, settling). In the case of real-life plants, supportable modelling level is often constrained by data availability and reliability.
APPLIED OFF-LINE EXPERT SYSTEM FOR EFFLUENT, OPERATIONAL AND TECHNICAL PROBLEMS OF WASTE WATER TREATMENT PLANTS
Authors: Ladiges Gösta , Kayser Rolf 
Published: May 2018

An off-line expel1 system has been developed and implemented at a nutrient removing waste water treatment plant to provide the operators with knowledge required to run their plant. The system can be started at occurring problems, and for the choice of setpoints for the operation of the plant. It contains knowledge bases for various effluent waste water and technical problems, combining facts and relationships for different chemical, biological and technical processes with models and algorithms. This enables the system to assess situations and give proper advice as well based on facts, experience and calculations.
The system is built on a personal computer, and works with a Windows user interface that has been developed in intense co-operation with the plant operators.
NUMERICAL MODELLING AND MEASUREMENT IN A TEST SECONDARY SETTLING TANK
Authors: Dahl C. , Larsen T. , Petersen O. 
Published: May 2018

A numerical model and measurements of flow and settling in activated sludge suspension is presented. The numerical model is an attempt to describe the complex and interrelated hydraulic and sedimentation phenomena by describing the turbulent flow field and the transport/dispersion of suspended sludge. Phenomena such as free and hindered settling and the Bingham plastic characteristic of activated sludge suspensions are included in the numerical model.
Further characterisation and test tank experiments are described. The characterisation experiments were designed to measure calibration parameters for model description of settling and density differences. In the test tank experiments, flow velocities and suspended sludge concentrations were measured with different tank inlet geometry and hydraulic and sludge loads. The test tank experiments provided results for the calibration of the numerical model and for comparing measured and calculated results.
The numerical model could, fairly accurately, predict the measured results and both the measured and calculated results showed a flow field pattern identical to the flow fields in full-scale secondary settling tanks. A specific calibration of the Bingham plastic characteristic was needed and further knowledge of activated sludge suspension rheology will be necessary to improve the numerical model.
Prediction of Sediment Quality in Catchment Areas of the River Rhine: Operation and Use of the Horizon Model
Authors: Mol G. A. J. , Benoist A. P. 
Published: May 2018

Suspended matter and sediments in the catchment areas of European rivers are often highly polluted. A forecast of sediment quality in relation to discharges is of importance in formulating policy pertaining to emission reduction and sediment sanitation. The model Horizon has been developed to predict the sediment quality in the long term under various emission reducing scenarios. The model schematics consist of a description of the Rhine, the Meuse and the large lakes and basins in The Netherlands.
The model calculates the concentration of eight inorganic and five organic micro pollutants in surface water, suspended matter and the sediment under the influence of processes such as sorption, evaporation, degradation, sedimentation, resuspension and burial. The principles underlying the model, the modelled pollutants, the schematics and the modelled physical/chemical processes are briefly discussed. The model input, calibration, validation and model errors follow. The predictions show that emission reductions more far reaching than the Rhine Action Programme (RAP) are needed to meet the Quality Objective 2000,set out in the Dutch National Policy Document on Water Management.
Submerged Macrophyte Control Using Plastic Blankets
Authors: Carter D. R. , Carter S. , Allen J. L. 
Published: May 2018

Penrith Lakes Scheme is concerned with the rehabilitation of gravel pits to create a system of large recreational lakes. A potential submerged macrophyte problem has been identified in an existing man-made lake.
The need to control the macrophytes is dependent on the proposed end use of the lakes and the potential area of invasion.
A variety of control options were assessed. Plastic blankets were tested to determine their effectiveness in controlling macrophyte growth specifically in swimming and boat access areas. Comparisons of clear, black and black woven blankets were conducted. Experiments revealed that 90% of the plants under the black and black woven blankets died within six weeks. Under clear blankets plants were reduced by between 20%-90%.
Analysis showed that significant interactions occurred between sites and treatments and times, from which it can be inferred that none are independent of each other. Success in the reduction of macrophytes appears dependent on such factors as plant species, sediment accumulation and light reduction.
Carcoar Wetland – A Wetland System for River Nutrient Removal
Authors: White G. C. , Smalls I. C. , Bek P. A. 
Published: May 2018

During December, 1991 the NSW Department of Water Resources commenced construction of an artificial wetland at the upstream end of Carcoar Dam near Blayney in central western NSW. The principal function of the wetland is to reduce nutrient inputs, especially phosphorus, from the Belubula River into Carcoar storage and consequently lower the incidence of blue-green algal blooms which occur most summers.
The wetland is a multi-faceted project involving substantial research and community involvement. Construction of the wetland weir and levees was completed during April, 1992. Stage one of the wetland planting program ran from October to December, 1992 with stage two scheduled for the same period in 1993. The wetland will not be operational until December, 1993. However, even at this early point in the project, significant experience has been gained in design, construction, planting and establishment of comprehensive community involvement programs for large constructed wetlands on the flood plain.
This paper outlines the background to the wetland, the design of the wetland system and its construction primarily as a nutrient removal mechanism in the Belubula River. The paper also outlines the direction of research undertaken and the role and nature of community involvement in various aspects of the project.
Primary fermentation of soluble and particulate organic matter for wastewater treatment
Authors: GonÇalves Ricardo Françi , Charlier Anne Catherine , Sammut François 
Published: May 2018

A new reactor based on upflow sludge blanket technology (USB) for fermentation of both the particulate and soluble fractions of domestic wastewater is presented. The process is fed with the total wastewater flow, and carries out suspended solids (SS) retention, fermentation and clarification of the fermented effluent in a single reactor. The study was carried out using pilot scale reactors, under six different operating conditions with regards to hydraulic load (hydraulic retention time, HRT, varying between 1.1 and 4.3 hours) and at a constant temperature (20 ± 1°C).
With regards to primary treatment, the process has been shown to ensure low SS residuals in the fermented effluent under all operating conditions tested. Very low residuals, with an average below 50 mg SS/l, were obtained with an upflow velocity of between 0.75 and 0.9 m/h. These trials have also highlighted the important role played by the adsorption of particulate organic matter on the biological flocs of the sludge blanket in the elimination of SS.
Fermentation efficiencies are superior to those of existing fermenters, the results clearly proving that a majority of the volatile fatty acids produced originate from the soluble fraction of the wastewater. Under the optimum conditions tested, with an HRT = 2.8 hours, 0.17 mg HAc/mg total COD are produced, over 60% of which is generated by the fermentation of the influent soluble organic matter. Under these operating conditions, maximum solubilisation of the particulate fraction has been estimated at 0.13 mg of filtered COD/mg particulate COD (total COD-filtered COD).
Interactions between biological and physico-chemical mechanisms in biological phosphate elimination
Authors: Witt P. Ch. , Grabowski F. , Hahn H. H. 
Published: May 2018

By combining a sequential P-extraction with batch experiments the presented investigations clarify the mechanisms of (enhanced) biological phosphate elimination and especially to answer the following questions: are any physicochemical mechanisms involved in the biological phosphate elimination? are there any interactions between biological and physicochemical unit operations? If so, are these of synergistic or antagonistic nature?
The following main results were found:
Results of batch experiments:
– calcium decreases under anaerobic conditions; this indicates Ca-P-precipitation.
– magnesium increases under anaerobic conditions and decreases under aerobic conditions just as phosphate does; there is a high correlation between dissolved magnesium and dissolved phosphorus. Therefore magnesium seems to participate in biological mechanisms (counter-ion of polyphosphates).
– concerning the total P elimination efficiency both unit processes seem to have a synergistic effect (biologically mediated P-precipitation).
Results of P-fractionations:
– there is a certain amount of particulate physicochemically bound phosphorus, which should not be neglected.
– although the biologically bound phosphorus dominates (as a rule), this amount depends on the concentration of the readily biodegradable COD significantly.
– during the cyclic P-release/P-uptake not only transitions from soluble phase to particulate phase but alsotransfers within the particulate phase take place.
– the total P-content of the activated sludge and the sum of the Non Reactive Phosphorus-fractions (without Phase Separation-Non Reactive Phosphorus) seem to be suitable to characterize the capacity of the biological phosphate elimination.
Conclusions:
Physicochemical mechanisms take part in the enhanced biological phosphate removal and they should be taken into consideration. Therefore they should be included into the deterministic model development.
Kinetic model for the biotransformation of tetrachloroethylene in groundwater
Authors: Ninomiya K. , Sakai M. , Ohba E. , Kashiwagi N. 
Published: May 2018

The biotransformation of tetrachloroethylene (PCE) to trichloroethylene (TCE) and then to cis-1,2-dichloroethylene (cis-DCE) under an anaerobic condition was studied using static soil microcosms. The kinetics of the biotransformation could be well approximated by the consecutive first-order reaction model, PCE →k1 TCE →k2 cis-DCE
This model implied that the total amount of the above three compounds was always constant and was equal to the initial amount of PCE, even if the amount of each compound changed with time. Based on this stoichiometric relationship, two indices to characterize groundwater contamination with PCE were derived. The first was the total contamination level which was defined by the total molarity of the three compounds. The second was the degradation level which was defined by the total molar percentage of the products (TCE+DCE). These indices enabled us to evaluate the initial molarity of the pollutant PCE and the degree of the degradation. The kinetic theory also provided a useful rule such that the same time-concentration profile was obtained for the same ratio of the kinetic constants k2/k1, even if the scale of time changed. This rule enabled us to estimate the ratio of the kinetic constants, which suggested environmental fate of groundwater, from observed molarities of the three compounds.
Sludge Retention Times Distribution in Clarifier: A Key Point for Population Dynamic and Nutrients Removal Control
Authors: Audic J. M. , Fayoux Ch , Lesty Y. , Brisset P. 
Published: May 2018

Experiments were carried out on full scale clarifiers. Two types of clarifiers were studied, circular scraper-type and radial suction tubes clarifiers. Sludge tracing experiments were made with radioactive gold.
For the first type of clarifier, the results obtained show a short circuit concerning 10 to 30% of the sludge and a large distribution of the remaining sludge arrivals materialized by a succession of peaks that appear with increasing delay. Depending on cases studied, 40 to 50% of the sludge remained more than 5 hours in the system.
For the suction clarifier, a perfect sludge distribution with time was observed for thin sludge bed (90% of the sludge recycled within 2 hours), but this result is rapidly affected by an increase of the sludge bed depth (60% within 5 hours).
Status and Direction of Waste Minimization in the Chemical and Petrochemical Industries
Authors: Englande A. J. 
Published: May 2018

This paper presents an evaluation of the status and direction of toxic/hazardous waste reduction in the chemical and petrochemical industries from an international perspective. Pertinent approaches, experiences and trends are described. Industrial waste management has evolved from an “end-of-pipe” treatment mentality to source reduction as the preferred option. It is generally agreed that the Chemical/Petrochemical Industries generate more hazardous and toxic waste than any other industrial sector. Also because of the large quantities of materials and energy used by these industries, significant opportunities are available for waste reduction. In almost all cases costs savings have resulted, many of which are significant. The importance of pollution prevention by “clean technologies” instead of remediation, multi-media considerations and the significance of product life-cycle assessment in pollution prevention programs is stressed. Examples are provided which demonstrate, that a proactive approach by DOW, E.I. DuPONT, AMOCO, 3M Corp., CIBA-GEIGY and others is now becoming the norm.
From an international policy perspective, important commonalities and differences in strategy and efforts for toxics/hazardous waste management exist. Much can be learned by the mistakes and solutions between cultures and countries. Much progress has been made in protection of public health and the environment - but much remains to be done. This paper is intended to provide a stimulus for discussion aimed at optimizing future waste minimization activities in the chemical and petrochemical industries.