bluuebunny/crossref_metadata_2025_split huggingface dataset:
TETrans: A User-Friendly, Functional Model of Solute Transport
Authors: Corwin D. L. , Waggoner B. L. 
Published: May 2018

A beta-test version of TETrans (acronym for Trace Element Transport) is presented which models the movement of inorganic solutes through the vadose zone under transient-state conditions. TETrans is a complete software package consisting of an interactive tutorial, user's guide and applications software. Both IBM-compatible and Macintosh versions are available to users. TETrans is specifically designed to be intuitive in its operation and require only readily available input parameters in order to enhance its utility as a real-world applications tool for transport modeling.
The transport model utilizes a mass-balance approach to determine solute concentration distributions over time and solute-loading to the groundwater. Several modeling options are available for simulating such transport-influencing factors as plant-water uptake, hydraulic bypass and adsorption. In the Macintosh version, TETrans makes full use of the Macintosh interface to enhance the user-friendliness of the model. All functions are available from pull-down menus, and simulation results are displayed in text and graphic windows.
Test data are shown which include a comparison of simulated and measured results for the movement of chloride through a soil lysimeter column over a 900-day study period. Excellent agreement is found when a single parameter for bypass is used. TETrans is distinguished from other transport models in the straightforward manner in which it handles the exacerbating problem of hydraulic bypass. The hydraulic bypass parameter, termed the mobility coefficient, is determined from simple chemical analysis of chloride in the soil solution through the soil profile following the application of a plug of chloride in the irrigation water. The mobility coefficient reflects the volume of soil water which is not subject to piston displacement
Modelling and Experiments on Fluidized-Bed Biofilm Reactors
Authors: Bignami L. , Eramo B. , Gavasci R. , Ramadori R. , Rolle E. 
Published: May 2018

Over the last few years considerable attention has been devoted to biological fluidized-bed technology which seems to be potentially more advantageous than both dispersed biomass processes and fixed bed systems. An obstacle to the spreading of this technology is the lack of rigorous criteria in designing reactors, due to the poor knowledge of interconnections of fluid-dynamic aspects with kinetic ones.
This paper reviews the rational basis for reactor design and reports on the experimental tests carried out in order to gain a better understanding in the areas of biofilm modelling and fluidization mechanics.
In particular a biofilm model, in the general case of the Michaelis and Menten equation, was developed and its validity was verified utilizing experimental data obtained in nitrifying batch tests. As to fluidization mechanics the experimental work confirms the Wen and Yu(1966) approach to correlate the bed porosity with the superficial liquid velocity.
Optimization of Nutrient Removal in Stockholm
Authors: Brattberg G. , Reinius L.-G. , Tendaj M. 
Published: May 2018

Stockholm was founded at the point where the waters of Lake Mälaren emerge into the Baltic Sea. Lake Mälaren is the water source of the water works of Stockholm. The Lake also receives water from one of the sewage treatment plants. The outlet from the two other sewage treatment plants are in the inner part of the archipelago. During 1968-73 the treatment was improved, after which the phosphorus load to the receiving water significantly decreased. The total P concentration in the surface water has decreased since 1970 and phosphorus has replaced nitrogen as the most limiting nutrient throughout the entire archipelago within 50 km from Stockholm. To further reduce the eutrophication a continued reduction of the phosphorus load is most effective. For the Baltic proper as a whole, where primary nitrogen limitation is present, it is important to reduce the supply of nitrogen to the greatest possible extent.
The treatment plants in Stockholm are located in subsurface rock-chambers. The treatment includes mechanical, biological and chemical treatment. In the mechanical stage the sewage is treated in screens, grit chambers and primary sedimentation. The biological stage is a conventional activated sludgeprocess. For the chemical precipitation ferroussulphateis added before the screens. The sludge is stabilized in anaerobic digesters and dewatered in centrifuges before disposal on farmland.
To meet more stringent requirements on nitrification and nitrogen removal several projects are going on to optimize the nutrient removal. The aim of these investigations is to improve the plants' performance within the existing plant.
Removal of Ammonia Nitrogen by the Precipitation Method, on the Example of Some Selected Waste Waters
Authors: Zdybiewska M. W. , Kula B. 
Published: May 2018

The topic of the paper was finding a possibility of ammonie nitrogen removal by the precipitation method, on the example of municipal wastes and two kinds of liquid industrial wastes, from a coking plant and Nitrogen Works. The concentrations of this component were of such a kind that they could inhibit both the processes of biological purification and the processes of self-purification, and cause far-reaching eutrophication. The initial concentration was:70 mg/dm3 NH4+ in municipal wastes, 3600 mg/dm3 NH4+ in coking plant wastes, and 16.142 mg/dm3 NH4+ in the liquid wastes from Nitrogen Works. The industrial wastes were diluted to about 156 mg/dm3 NH4+ in the case of coking plant wsates, and to about 170 mg/dm3 NH4+ in the case of wastes from Nitrogen Works.
The precipitants for the municipal wastes were magnesium chloride and 85% phosphoric aoid, and for the remaining wastes also magnesium oxide and phosphoric acid. The reaction time used was 5-30 minutes, the reaction -pH 8.0 : 9.5 and 10.5. The quantities of the precipitants - from 0-200% of the stoichiometric dose. The precipitation of ammonia nitrogen in municipal wastes was most effective with wastes reaction pH about 9.5 and precipitants doses 0.80 g/dm3 MgCl2 and 0.47 g/dm3 H3PO4, and the reaction time of 25 minutes.The effect of ammonia nitrogen removal was 36.0% which corresponded to 100% stoichiometric doses, Whereas an increase of the doses to 200% increased the effects by only 1%. The effects of ammonia nitrogen removal from the coke plant wastes were 470% with the precipitants doses of 4.54 g/dm3 MgCl2 and 1.28 g/dm3 H3PO4 which is 100% of the stoichimetric dose, and after increasing the dose to 200% they were increased by 35%. The degree of ammonia nitrogen removal from the liquid wastes from Nitrogen Works was 62.9% with 100% dose and increased to 81.2% at 200%. The use or magnesium oxide and phosphoric acid for the removal of ammonia nitrogen from industrial wastes in analogical conditions gave much worse results.
Discussion Report on Reactor Design of Anaerobic Filters and Sludge Bed Reactors
Authors: Tilche A. , Vieira S. M. M. 
Published: May 2018

The discussion report of the session dedicated to reactor design is focused on sludge bed reactors and on upflow and downflow anaerobic filters.
The reactor hydrodynamics and their relationship with process efficiency and stability are particularly discussed.
The discussion ends with the formulation of some suggestions of design parameters for project engineers.
Winning Support for Reclamation Projects through Pro-Active Communication Programs
Authors: Wegner-Gwidt Joyce 
Published: May 2018

The importance of public attitudes in the adoption of reclamation projects has been recognized for some time. We know that people's perceptions and opinions are forces that can mean the difference between survival or extinction…success or failure. This is a reality that must be recognized in the way we plan and implement a reuse program.
While there is no “fool-proof” guarantee of success, a sound pro-active communication and education program is essential. This paper will give some guidelines that you can use to develop a planned communication program that can help you reach technical objectives, obtain public support, and win acceptance for your program.
Alternative Strategies for the Disposal of UK Estuarine Dredgings
Authors: de Silva M. S. , Fleming G. , Smith P. G. 
Published: May 2018

UK research into the beneficial uses of dredged material is being undertaken at Strathclyde University, and includes initiatives in research in the use of dredgings for soil in land restoration projects, and for brick manufacture.
Extensive research in the historically industrial River Clyde in Scotland has shown that pollutant levels do not preclude the use of selected materials for land restoration work. However, limitations are imposed on the use of the material for agricultural or grazing purposes at this time.
Brick manufacture from clay sediments has proved that an attractive, quality product can be provided to the industry although some further testing is required; particularly in the area of atmospheric emissions during firing.
The use of dredged clay for landfill capping and lining also remains a viable possibility.
Economic considerations for each application vary, and require further investigation, however, the options are technically feasible and if employed on a larger scale, can account for a significant proportion of dredged sediments which are currently disposed of at sea.
Towards Integrated Chemical and Biological Monitoring
Authors: Akkerman Ida , Cofino Wim , Colijn Franciscus 
Published: May 2018

The monitoring programme of the Public Works Department of the Netherlands has recently been updated and now comprises measurements in water, suspended particulate matter, biota and sediments. Recently, a programme including biological parameters has been developed and implemented. Some examples of results of long-time monitoring series are given. The ‘amoeba' concept has been developed for presentation of biological monitoring results. In addition, biological effects techniques can be used.
Chemical monitoring in different compartments and biological monitoring should be complementary to make a proper assessment of the environmental quality possible. This integrated monitoring is reflected in the ecoplot concept. In the international monitoring programmes this approach of integrated chemical and biological monitoring is also incorporated. To achieve integrated monitoring on a large scale optimization of efforts is necessary, with special attention to quality assurance. Quality management covers the whole process from definition of the objectives for monitoring, optimization of the validity of the data to the reporting of the results.
Review of Offshore Chemical Selection, Use and Operating Procedure to Minimize Environmental Impact
Authors: Vik Eilen Arctander , Berg James D. , Bakke Siri , Lundh Tore 
Published: May 2018

The only feasible strategy to minimize pollution from offshore installations is to control the chemicals used. Chemicals are normally only used in response to observed operational problems. They are used in a large number of application areas, and an extensive list of application areas exists. Only a small fraction of chemicals used will eventually reach the marine environment, mainly depending on the water solubility of the chemicals. Since the chemicals discharged are diluted in large quantities of water before and immediately after discharge, the acute toxic effects are considered as not very severe. However, chronic ecotoxicological effects and long-term problems may arise due to accumulation within the marine food chain. Unfortunately, very little information is available on environmental effects of offshore chemicals. However, the harmonizing work which has started within the EEC, requires that new environmental regulations include ecotoxicological data in the classification of chemicals. This important information can be a valuable tool so that operating companies can select alternative chemicals suitable to their operational needs.
There is, however, still a need to continue research to develop a suitable methodology to determine possible long-term environmental effects of low solubility chemicals. This paper introduces a research project initiated by Conoco Norway Inc. late 1989.
The Design and Construction of the “Houtrust” Waste Water Treatment Plant in the Hague
Authors: Sinke M. D. 
Published: May 2018

Until a century ago, The Hague's waste water was discharged directly into the city's canals. However, the obnoxious smell and resultant pollution of local waters and beaches then necessitated the implementation of a policy of collecting and transferring waste water by means of a system of sewers. By 1937, it was being discharged, via a 400 metre-long sea outfall, directly into the North Sea. By 1967, however, the increasing volume of waste water being generated by The Hague and the surrounding conurbations called for the construction of a primary sedimentation plant. This had two sea outfalls, one 2.5 km long and the other 10 km long, the former for discharging pre-settled waste water and the latter for discharging sludge directly into the North Sea. This “separation plant” was enlarged during the period 1986-1990.
On account of the little available area - only 4.1 ha - the plant had to be enlarged in two stages by constructing a biological treatment section and a sludge treatment section with a capacity of 1,700,000 p.e. (at 136 gr O2/p.e./day). In order to gain additional space, a number of special measures were introduced, including aerating gas containing 90% oxygen and stacked final clarifiers. Following completion of the sludge treatment section, it has become possible, since 1st May 1990, to dump digested sludge into a large reservoir (“The Slufter”), specially constructed to accommodate polluted mud dredged from the Rotterdam harbours and waterways.
As a result of these measures, there has been a reduction of between 70% and 95% in North Sea pollution arising from the “Houtrust” waste water treatment plant. Related investment totalled Dfl. 200 million and annual operating and maintenance costs (including investment charges) will amount to Dfl. 30 million. Further measures will have to be taken in the future to reduce the discharge of phosphorus and nitrogen. So this enlargement is not the end. There will be continued extension of the purification operations of the “Houtrust” waste water treatment plant.
Exceptional Algal Blooms in Dutch North Sea Waters
Authors: Zevenboom W. , Rademaker M. , Colijn F. 
Published: May 2018

During airborne and sea-going surveys, phytoplankton composition, and dynamics as well as relevant factors involved, were studied in Dutch North Sea waters.
The aim of the study is to increase our understanding of phytoplankton dynamics, the impacts of eutrophication and the measures that are taken to reduce the risk of adverse eutrophication effects. In the coastal zone during spring (April), the relative abundance of diatoms is small when compared with the dominant scum-forming species Phaeocystis pouchetii (71-96% of total). Some potentially toxic species, like Dinophysis acuminata. were present predominantly in late summer and autumn during calm weather conditions, in the coastal zone and northern offshore waters (Oyster grounds, Dogger Bank), but in lower concentrations in 1988 and 1989 when compared with 1976, 1979 and 1981. During these three years Dinophysisacuminata blooms gave rise to mussel infection (DSP) in the Dutch Wadden Sea. The potentially toxic species Gyrodinium aureolum showed higher abundance in somewhat deeper waterlayers than at the surface. The presence of the potentially toxic species Gonyaulax(Alexandrium)tamarensis was for the first time recorded in June 1989 in concentrations of ca. 2000 cells per litre. The results further indicate an increase in occurrence of the non-toxic species Noctiluca scintillans in Dutch North Sea waters. Airborne surveys from 1979 onwards demonstrated an annual occurrence of large-scale surface algal blooms with a total annual area coverage ranging from 30 km2 (in 1982) to 1860 km2 (in 1989). Surface algal blooms are predominantly occurring during May through August, and are likely to be promoted by calm sunny weather conditions, with windforce &lt; 5 Bft over several days. Distinct “stratified” algal layers of some dominant species within an algal patch were observed, with Noctiluca in the top layer, and rather low oxygen concentrations below the large surface algal blooms.
Since nutrient availability in Dutch coastal waters has remained rather constant and high over the last 10-15 years, the risks of occurrence of nuisance algal blooms and their adverse effects have remained unchanged.
Groundwaters in Location of Chernobyl Atomic Station and Their Contamination with Radionuclides after the Accident
Authors: Ivanushkina N. I. , Ryabtseva G. P. 
Published: May 2018

An evaluation of the influence of the Chernobyl Atomic Power Station (APS) accident upon ground waters of meliorative systems was carried out in a 30 km zone around the station. At the locations where elevation exceeds 5 m, the danger of contamination is minimum in the first 5 years, which is why emphasis was placed on flood plains of river valleys. In flood plains the ground water table (GWT) before the accident varied from 0.2 to 3.3 m with fluctuation from 0.5 to 3 m. Since the accident the systems haven't been in operation, the GWT fluctuation amplitude has decreased, the period of high water table has lengthened, and locations with secondary waterlogging have appeared. The ground waters chemical composition influencing the migration and sorption processes is typical for surplus soil water regions: mineralization is up to 1.0 g/l and pH from 6 to 7.5.
Ground waters are not naturally protected here against radionuclide migration because of the small thickness of aeration zone, the sandy and loamy composition of soils, and their low adsorption.
In 1989 contamination of ground waters with caesium-137 amounted from 2.26 × 102 to 2.413x 103 Bq/m3 and with strontium-90 it was from 37 Bq/m3 to 3.66 × 104 Bq/m3. Radionuclide migration towards ground waters depends not so much on surface contamination intensity as on soil physical and chemical characteristics in the aeration zone. It appeared that there were no direct dependencies between soil surface contamination intensity and that of ground waters contamination. It was noted that the amount of radionuclides depends upon the season.
Analysis of radionuclides concentration in ground waters at different depths, considering soil surface contamination, allows us to define a relatively safe level of GWT with initial contamination; this information contributes to working out the measures on GWT lowering to optimum levels.
Fast Transmission of Nitrates into a Detritic Aquifer (Lepe, Huelva, Spain)
Authors: Gonzaléz A. , Romero E. 
Published: May 2018

The nitrate ion has become in recent years extremely prevalent, particularly in the uncarbonated coastal aquifers. This is due to its almost exclusive origin in contamination from agricultural activities, which are especially intense in these aquifers.
This article describes a study of the causes of fast mobilization of nitrates and their almost instant (though very localized) transmission to a detritic coastal aquifer, increasing sharply their percentage in the groundwater and making it undrinkable.
The nitrates originate from solid and liquid nitrogenous fertilizers which are used as manure in the growing of strawberries and citrus fruits by the farmers of the region.
The high amount of fertilizers used, the proximity of many crops to the groundwater wells for urban supply the unsuitable construction of certain wells, and a period of very intense precipitation during November and December in 1989 can be considered among the principal causes of the high content of nitrates in the groundwater in some locations which has obliged the Town Hall of Lepe to declare the water undrinkable for 3½ months.
Chlorinated Hydrocarbons Liquid Wastes: Steam Extraction in Place of Incineration
Authors: Victorelli J. C. , de Andrade P. S. , Elkaim J.-C. 
Published: May 2018

A process was devised to extract high levels (2000 ppm) of chlorinated and aromatic solvents from liquid wastes generated by our synthesis processes. It consists basically in introducing the wastes at the top of a column, appropriately filled, and injecting steam at the bottom. The resulting “cleaned” wastes get out of the system with less tham 0.5 ppm. The extracted solvents are absorbed on charcoal filters that can be regenerated.
The system consists in collecting liquid wastes in 3 m3 vessels. After the pH is adjusted, the incoming wastes are heated in two heat exchangers (12 m2 each), then they are injected at the top of a steel column (heights 4.8 m, diameter: 0.6 m ), with a flow of 1.5 m3/h. Steam is injected at the bottom of the column with a flow of 200 kg/h and a pressure of 4 kgf/cm2. The outcoming “cleaned” wastes get out at 100°C and are cooled on the two heat exchangers already mentioned. As can be seen the outcoming wastes are used to heat the incoming ones. Then this solution is collected in a 15 m3 vessel where it is neutralised and cooled to 40/50°C. The vapors of the extracted solvents that get out at 85°C are condensed in a heat exchanger of 12 m2 and the resulting mixture goes into a “F1orentino” vessel to separate the water phase from the solvents. The water phase goes back to the 3 m3 vessel to be mixed with the incoming wastes. The separated organic phase is put in drums. The heat exchangers and the “Florentino” vents are connected to a charcoal filter (0.1 m3 ) where the chlorinated vapors are trapped. This filter is reactivated every three days, and the solvents are again separated in the “Florentino” vessel.
Sanitation of Polluted Soil Areas and Hazardous Waste Management at DSM
Authors: Dijkstra F. 
Published: May 2018

Hazardous waste management at DSM, a large chemical company in the Netherlands, relates to two types of activities:sanitation of areas polluted by waste or by operations in the past,management and control of waste, including hazardous waste, from existing operations.
Uncontrolled landfill and operations between 1925 and 1980 at the DSM site led to the creation of several polluted soil areas. In the period from 1987 to 1990 a large controlled landfill was constructed in order to sanitate a number of these places. The costs are about $ 25 million.
In order to deal in a proper way with all solid and liquid waste (except waste water) a central waste management department was established. Measures are being taken to prevent new cases of soil pollution. In accordance with the policy of the Dutch government DSM started a program to minimize waste production.