bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Modular Approach for Modelling of the North Sea Ecosystem
Authors: Malmgren-Hansen A. , Baretta J. W. , Ruardij P. 
Published: May 2018

A modular approach for generating an ecosystem model for the North Sea is presented. The model structure consists of modules describing physical, chemical and biological processes. The modular approach is selected to facilitate stepwise improvements in the total ecosystem model by replacing existing modules with improved modules being developed.
The modules constituting the pelagic ecosystem describe the biological and chemical dynamics of particle production and dissolution simulating the flux of carbon and nutrients (N, P, Si) through the food web. This might be done as a suite of submodules based on functional groups of organisms or as modules describing the different trophic levels based on size distributions.
Algal growth is dependent on cellular content of the limiting nutrient, or on net photosynthesis, whichever is the most restricting, allowing for “luxury uptake” of nutrients which may be stored for subsequent periods of shortage. The role of bacteria and other microorganisms is emphasized in recognition of the importance of the “microbial loop”. The Zooplankton module describes prey ingestion in terms of feeding behaviour and the partitioning of ingested carbon, nitrogen and phosphorus into growth and reproduction and the losses through respiration, excretion and defecation.
The benthic modules concentrate on describing the small food web, since benthic biological activity in terms of carbon flow, as well as mineralization, are often dominated by micro- and meiofauna in the generally soft sediments of the North Sea. Macrobenthos are described as being a major link between the benthic small food web and higher trophic levels in the ecosystem.
Higher trophic levels are described in separate modules taking into account in principle the role of fish, mammals and seabirds.
Nutrient cycling is described, focusing on the identification and conceptual modelling of the chemical processes and mechanisms in order to describe the relationships between the biology of the North Sea and the nutrient chemistry. This represents a first step towards forecasting the response of the system to long-term changes due to e.g. eutrophication. The modelling of the nutrient sediment-water interaction emphasizes the role of sedimentation of particulates and the regeneration of inorganic components to the water column.
This totally modular concept of the North Sea ecosystem model reflects the authors' view on the present state of the North Sea, the basic knowledge about ecosystem behaviour and a way of creating models as a tool for better understanding of the ecosystem and how man affects the North Sea environment.
Distribution of Organochlorine Pollutants in North Sea Sediments
Authors: Lohse Joachim 
Published: May 2018

Sediment samples from the North Sea and the Skagerrak were analyzed for organochlorine pollutants. Standardisation for organic carbon content of sediments proved to be a suitable tool for comparison of pollution of different sea regions. Relatively high contaminant concentrations were found in coastal regions of the southern North Sea, while standardised organochlorine concentrations in the Skagerrak were almost at baseline level.
In addition to the major inputs via rivers and the atmosphere, ocean incineration of hazardous wastes was identified as a probable source of organohalogen pollution. Although the production and use of certain organochlorines have been restricted in most North Sea states, depth profiles from the Skagerrak indicate that deposition of these contaminants has increased until recently. This trend will possibly continue since only a very small proportion of all persistent organochlorines produced in Western Europe in the past has already reached the sea.
As a consequence, no persistent and bioaccumulable organics, like most organohalogens, should be allowed to enter the sea in the future. This, in many cases, will necessitate not only better filter techniques, but a dramatic reduction of organic chemical production itself.
Concentrations of Alpha- and Gamma-Hexachlorocyclohexane (Lindane) in the Coastal Waters of England and Wales
Authors: Allchin C. R. 
Published: May 2018

Concentrations of alpha- and gamma- hexachlorocyclohexane (Lindane) have been determined in the surface waters of the Humber, Thames, and Mersey estuaries, an area of the Dogger Bank, the English Channel, around the Channel Islands, from the last known positions of the lost container from the M.V. Perintis off the Cherbourg peninsula, the Baie de Seine and an area of the south-western approaches, which was used as a ‘control area'. Samples were extracted, cleaned-up and analysed at sea using high resolution capillary gas chromatography with electron capture detection. Two capillary columns of different polarity were used to aid in confirmation of residues.
Levels of Lindane in inshore waters were generally low (&lt;2ng dm−3) and declined rapidly, on moving offshore, to back-ground levels.
Techniques for and Experience with Biological Nutrient Removal – Danish Long-Term Operating and Optimization Experience
Authors: Bundgaard Erik , Pedersen Jan 
Published: May 2018

New Danish legislation demands that, by 1993, all wastewater treatment plants serving more than 15,000 PE must reduce total nitrogen and total phosphorus to 8 mg/l and 1.5 mg/l, respectively. On the basis of full-scale experience from more than 35 existing plants with nitrogen removal and 5 plants with biological phosphorus removal, these targets seem quite realistic.
The plants are operated in accordance with the Danish-developed methods BIO-DENITRO (N removal) and BIO-DENIPHO (N and P removal). These-methods offer most of the advantages of both the Sequencing Batch Reactor and the recirculation systems but eliminate some of the disadvantages such as intermittent operation and discharge, and internal recirculation. Further developments towards improved process performance and control are achieved through the development of new plant types utilizing hydrolyzed sludge as an additional carbon source and through the application of mathematical models for simulation of the biological processes under various operating and load conditions.
Nutrient Loading to Norwegian Coastal Waters and Its Contribution to the Pollution of the North Sea
Authors: Ibrekk Hans Olav , Molvær Jarle , Faafeng Bjørn 
Published: May 2018

The North Sea Declaration aims at reducing the load of nutrients to the North Sea by the order of 50 per cent between 1985 and 1995. This paper gives an overview of the nutrient loading to the Norwegian coastal waters, and an estimate of how much of this loading reaches the local Skagerrak coast and the North Sea.
The average annual nutrient load to coastal waters from land-based sources along the Norwegian North Sea coastline (from the Swedish border to 62°N) is approximately 3,600 tons of phosphorus and 70,000 tons of nitrogen. Municipal wastewater is the main source of phosphorus (44 per cent), while agriculture contributes with 20 per cent of the total load. Background runoff, i.e. runoff from forested areas and uplands, including effects of acid precipitation, is the main source of nitrogen inputs (40 per cent). Agriculture is the second major source (32 per cent). Our calculations indicate that deposits of airborne nitrogen via precipitation contribute approximately 15-20,000 tons of nitrogen inputs on the coastal watersheds draining to this coast. The Norwegian loading amounts to 3-4 % of the total nutrient inputs to the North Sea from the surrounding countries. Taking into consideration the dominating current systems in the North Sea and along the Norwegian coast, only a small part of this load reaches the middle and southern parts of the North Sea susceptible to eutrophication. This implies that the Norwegian nutrient input has minimal effects on the eutrophication of the North Sea.
There is a considerable need for developing standard methods for estimating nutrient inputs to the North Sea. Emphasis should be put on preparing guidelines for assessing comparable nutrient input data from all North Sea countries.
Long-Term Land Application of Activated Sludge from a Petrochemical Wastewater Treatment Plant: I - Leachate Quality
Authors: Simon Z. , Tedesco M. J. , Gianello C. 
Published: May 2018

Excess activated sludge from SITEL, the wastewater treatment plant of Polo Petroquímico do Sul (South Petrochemical Complex), Triunfo, State of Rio Grande do Sul (RS), Brazil, is disposed of by subsurface injection on pangola grass and rye grass fields at an average annual rate of 24 tons/ha (dry basis). In order to assess absorption of sludge constituents by plants, modifications of soil properties and leachate quality, a microplot growth-leaching experiment is being conducted at the Department of Soils of UFRGS since 1985. Pangola grass (Digitariadecumbens, Stent) and rye grass (Loliummultiflorum, Lam) are grown in summer and winter respectively. Some microplots have been loaded with sludge enriched with Cu, Zn, Cr, Ni, Cd, Pb and Hg since 1988.
Plant nutrients such as K, Cu, Zn and B did not increase in leachate, even at the higher application rates employed. Ammonium and pH were not affected either, whilst nitrates increased at the highest application rates. Ca and Mg increased in leachate during the third and the fourth years of the experiment, probably due to the liming of the microplots. Electrical conductivity of leachate increased with sludge application. Na, chloride and sulphate, the more soluble ions, increased slowly during the first year and more rapidly during the subsequent years.
Heavy metals Cr, Ni, Cd, Pb and Hg in leachate were not consistently affected by application of pure sludge or metals-enriched sludge. The concentrations of these constituents in leachate were found to be generally below accepted limits for potable water. Exacerbation of loading of metals, bringing about introduction of total amounts that exceed current limits of addition of metals to soil, did not produce significant alterations in leachate quality. This suggests that these limits are very safe with respect to protection of aquifers.
The determination of nitrates in leachate at different sludge application rates made possible the adoption of 40 tons/ha.year as the maximum allowable sludge loading rate (on dry basis) for the real sludge farms at SITEL. This figure is approximately double the operational sludge application rate at SITEL.
The Environmental Effects of Waste Water Emanation from Sulphur Mining on Water Resources
Authors: Al-Dabbagh R. H. , Al-Dabbagh M. A. M. S. 
Published: May 2018

Mishraq sulphur mine is situated in the northern part of Iraq about 40 km south of Mosul.
The Frasch process is adopted to produce raw sulphur by injection of hot and compressed air.Hot water is channelled through the ground layers,causing the escape of mining hot- water carrying large quantities of sulphides, BOD, and suspended solids to ground water within the area as well as to Tigris river.
Three types of wastewater are produced from the purification processes. Wastewater released from debitumenization unit after treatment of raw sulphur with sulphuric acid, wast ewat er released from filtration units after treatment with tonsil and the leachate of solid waste produced from both processes. These wastewaters are highly acidic containing large quantities of suspended and dissolved organic solids.The first two wastewaters are discharged to a large pool prior to disposal to Tigris river. However,the seepage of leachate from the disposal site carries pollutants to the ground water.
Oily Wastes Application in Ceramic Materials Manufacturing
Authors: Amaral S. P. , Domingues G. H. 
Published: May 2018

The application of oily residues produced by PETRÓLEO BRASILEIRO S.A. -PETROBRÁS in the manufacturing of ceramic bricks appears as a promising alternative of their reutilization, in comparison with the traditional method of storage in ponds or dikes and to the biodégradation process by landfarming.
The application of said residues started experimentally in 1988, in a ceramic bricks factory located in the Paraíba do Sul Valley, State of São Paulo, near the Henrique Lage Refinery (REVAP). In mid-1989, the Presidente Bernardes Refinery (RPBC), the Capuava Refinery (RECAP) and the Petroleum Products Terminals of São Paulo (TEDEP) started sending oily residues to factories participating in the Red Ceramics Association of Itu and its Region (ACERVIR).
As an advantage of this process, almost all the costs with disposal of said residues are eliminated for PETROBRÁS; on the other hand, the reduction in maintenance costs, lower energy consumption, and a significant increase in production are advantages for the ceramics factories.
A New Methodology to Evaluate the Behaviour of Anaerobic Sludge Exposed to Potentially Inhibitory Compounds
Authors: Chernicharo C. A. L. , Campos C. M. M. 
Published: May 2018

The success of the newly developed “Specific Methanogenic Activity Test” (SMA-test) in measuring the potential of anaerobic sludge to convert soluble substrate into CH4 and CO2 (James et al., 1990) made this test potentially useful for a variety of investigations. The SMA-test was originally developed for assessment of specific methanogenic activity of anaerobic sludge, but the reliability of the method in detecting even very small changes of sludge activity has drawn attention to its use for many different purposes, especially to evaluate the behaviour of anaerobic sludge when subjected to potentially inhibitory compounds.
Recent investigations into the potentially inhibitory effects of the Lithium ion on anaerobic sludge were successfully carried out employing the SMA-test. The test proved to be very sensitive for this type of experiment and the results clearly showed a relationship between the degree of inhibition and the concentration of Lithium (Anderson et al., 1991).
This paper describes the methodology for measuring the specific methanogenic activity of anaerobic sludges and discusses how the SMA-test can be used for different purposes.
Historical and Present Day Management of the River Rhine
Authors: Broseliske G. H. , de Jong J. , Smit H. 
Published: May 2018

The river Rhine has undergone changes in morphology, chemistry, and ecology. They represent the results of historical management of the river.
An overview of the river management from 1815 on is given together with an analysis of the present situation and the changes necessary to meet the final objectives of the Rhine and North Sea Action Programmes.
The complexity and level of the present problems make it necessary that an integrated problem approach and a multinational decision making is used for an adequate future management of the river basin.
Unsteady Transport of Pollutants in Rivers Due to Pulse Disposal
Authors: Thabit Al-Kadi Bashir , Nuri Fattah Qais 
Published: May 2018

Mixing of pollutants in rivers is accomplished by the process of mechanical dispersion. Physically, dispersion may be considered as a hydraulic mixing process, by which the waste concentrations are attenuated while the waste pollutants are being transported downstream. Turbulent diffusion and velocity gradients are the two main mechanisms in dispersion. An exact analytical solution is developed for the two-dimensional unsteady convective-dispersion equation. The solution describes the concentration distribution for a conservative pollutant or substance injected as a pulse (not continuous) into a river by a diffuser pipe installed normal to the direction of the river bank. The river has a constant mean velocity and a relatively large discharge in comparison to the pollution discharge.
The solution is developed using Laplace and Finite Fourier Transforms. The distribution of the transporting concentration of the pollutant in the river due to such disposal is developed in terms of error functions, exponential, and trigonometric series. Variations in the location of the diffuser pipe in the river are examined. The concentration distribution is determined across and along the river as a function of time. The effects of variations in river velocity, lateral and longitudinal dispersion coefficients on the mixing patterns are presented. The solution presents variations in concentration distribution in the river with time during and after the pulsing injection period of the pollutant. Sensitivity analysis is carried out to determine significant variations in the solution due to changes in various parameters.
A Case History; Minamata Mercury Pollution in Japan – From Loss of Human Lives to Decontamination
Authors: Kudo Akira , Miyahara Shojiro 
Published: May 2018

At Minamata Bay in Japan, more than 100 people lost their lives and many thousands more were permanently paralyzed from eating mercury contaminated fish. In the long history of water pollution, this was the first known case where the natural bioaccumulation (in fish) of a toxicant from an industrial wastewater killed a large number of human beings. The mercury, discharged from a factory, was deposited on the bottom of the Bay and has remained there since the 1950's.
The fate of the mercury was traced by measuring 268 mercury concentrations in the surface sediments at Yatsushiro Sea (outside of the Bay) during the last 14 years. Twenty-four sampling stations were established to collect samples at the same location every year. Samples were analyzed for total mercury concentrations.
The concentrations of mercury in the surface sediments at the Sea were not alarming. Only 33 samples exceeded a mercury concentration of 1 ppm. The dispersion of the mercury from the Bay, however, was clearly documented with the data. On average, 3.7 tons of the mercury was transported outside from the Bay every year. A decontamination project started in 1984 dramatically decreased the flow of mercury from the Bay to the Sea. A historic rainfall in 1982 also ‘purified' the surface sediments. Organic mercury concentration in the sea water was 5.1 ng/l while total mercury was 120 ng/l at the center of the Bay in 1985.
Linear Alkylbenzenes (LABs) in Urban Riverine and Coastal Sediments and Their Usefulness as a Molecular Indicator of Domestic Wastes
Authors: Takada Hideshige , Ishiwatari Ryoshi 
Published: May 2018

Linear alkylbenzenes (LABs) and linear alkylbenzenesulfonates (LAS) were measured in river and coastal (bay) sediments in Tokyo metropolitan area. LABs are widely distributed in the sediments with concentrations of a few µ g/g-dry sediments. LAS contents in sediments are extremely low in Tokyo Bay (~ 0.01µg/g) as compared with those in the rivers (hundreds µg/g). This fact indicates the higher persistency of LABs in the riverine and coastal sediments.
The progressive relative depletion of external isomers (in which the phenyl group is attached near to the end of the alkyl chain) was observed on going from the source (i.e. LABs in commercial LAS-detergents) to Tokyo Bay sediments. An incubation experiment substantiated that the isomeric change of LABs is caused by selective microbial degradation. The I/E ratio (ratio of [6-C12 AB + 5-C12 AB] relative to [4-C12 AB + 3-C12 AB + 2-C12]; n-Cm : n indicates the position of substitution of phenyl group to alkyl chain and m indicates the number of carbons in the alkyl chain) was proposed as an index of LAB degradation. I/E ratio of LABs in Tokyo Bay sediments indicates the degree of degradation of LABs to be 50 % at most.
Nitrogen and Phosphorus Limits for Nutrient Deficient Industrial Wastewaters
Authors: Möbius Christian H. 
Published: May 2018

For biological treatment of nutrient deficient industrial wastewaters, such as those of the pulp and paper industry, the addition of nitrogen and phosphorus is essential. As a certain surplus is necessary, both elements will be found in the effluent in varying concentrations.
For the often used activated sludge treatment 5 parts of N and 1 part of P are said to be required for elimination of 100 parts of BOD. In-plant optimization generally leads to about 3.5 parts of N and 0.6 parts of P for 100 parts of BOD. In most plants N is added as urea and P as phosphoric acid.
Optimized nutrient dosage aimed at stable operating conditions in the treatment plant generally gives average concentrations of 1 mg/l of both ammonia N and phosphate P in the treated effluent. However, due to fluctuations in loading and efficiency, variation coefficients of more than 100 % result in maximum concentrations in 24 hours mixed samples of more than 10 mg/l for N and P. Three examples of operational results are evaluated and discussed in detail.
Water quality requirements will impose general limitations on N and P concentrations in treated effluents. Depending on the concentration limits and on the type of limited substance - i.e. ammonia N, total inorganic N or total N, phosphate P or total P - different strategies have to be developed.
Nutrient dosage depending on the wastewater amount will become state of the art in the near future. The next step would be a loading dependent dosage. No results of technical operation are known which show the effluent concentrations obtainable with this technique.
For cases in which limits cannot be met with this strategy the possibilities of nitrification, denitrification and biological P removal are discussed for nutrient deficient wastewaters. Results show that nitrification will work at low ammonia concentrations, however no steady nitrification will be obtained. Denitrification, on the other hand, seems to be difficult with low nitrate concentrations. At the present stage, no technical process meeting stringent total N or total inorganic N limits is known to exist for this type of effluent.
Low P concentrations in the effluent can only be achieved by tertiary treatment, preferably final flocculation filtration processes. However, these will give rise to special problems in the treatment of pulp mill wastewaters, which are discussed in the paper.
Conductivity for Nutrient Control in CTMP Wastewater Treatment
Authors: Rosén B. , Modell R. , Bruneau L. , Gunnarsson L. 
Published: May 2018

The control and monitoring of nutrients is imperative for the efficient biological removal of organic matter. Adding too much chemicals will not only affect operating costs, but will introduce a significant secondary pollution to the receiving waters.
If the influent organic load from a mill is relatively constant, nutrients can be dosed in proportion to the flow, which is the most common control method for nutrient addition. If, on the other hand, the organic load on the treatment is varying, a more sophisticated control is necessary for optimal operation.
At the 60 000 t/a CTMP-mill at Vaggeryd in southern Sweden, being taken into operation in May 1989, a two-stage activated sludge plant with pre- and post-precipitation, has been installed for reducing the incoming BOD from 12 tons per day to less than 500 kilo per day. The results normally show a BOD- and COD- reduction of 96-98% and 75-85 % respectively, or less than 250 or 1800 kg/d in the effluent.
The possible use of conductivity as the measurement of the incoming organic content has been studied. For the actual wastewater, the correlation between conductivity and the COD-content in the influent has been good. As the COD in the influent can be predicted with less than 20% deviation by the use of conductivity measurement, the dosage of nutrient can be easily and reliably controlled.