bluuebunny/crossref_metadata_2025 huggingface dataset:
Acid Rain, Catchment Characteristics and Fishery Status
Authors: Chester P F
Published: May 2018

In this paper data on lake chemistry and fishery status in the Sorlandet area of South Norway are examined for relationships between acid inputs, water composition and fishery status. The concept of the “effective reactivity” of a catchment is introduced to enable comparisons to be made between like lakes. It is found that the effective catchment reactivity is a much better predictor of fishery status than is acid input to these catchments. The factors underlying these relationships are discussed as is the possibility that acid deposition has changed the reactivity of these catchments in recent decades. Proposals are made for resolving some of the questions raised.
Fishery Status and Water Quality in Areas Affected by Acid Deposition
Authors: Howells Gwyneth D
Published: May 2018

While the relationship of SO2 and NOx emissions to ambient air quality and deposition, and to surface water quality, are still matters for debate and clarification, it is generally recognised that fisheries do not thrive in acid waters. An international advisory commission (EIFAC) has reviewed much of the literature and concluded that below pH 5 progressively more severe effects on fish can be expected. Records of acid lakes in Scandinavia and America show that about 50% of lakes below pH 5 are fishless, compared with only one in seven of similar oligotrophic lakes with pH greater than 5.

However, it is clear that the status of a fishery is not a simple function of the reported pH of a lake or river. Both field and laboratory studies provide evidence that other water quality factors (such as the levels of aluminium and calcium), biological factors (such as food supply, genetically determined tolerance, adaptation), and ecological factors (such as lake morphology, patterns of hydrological events) are also important. How else can we explain the continued presence of fish in some waters well below pH 5?

The paper will present a review of current information from both field and laboratory investigations concerning the responses of fish and fish populations to natural acid conditions in Scandinavian and N. American lakes and rivers, identifying the factors which determine survival and mortality.

The conclusions have some significance for remedial actions that may be proposed to alleviate acid conditions in Scandinavian and N. American waters.
Investigation of an Iodine-Like Taste in Herring from the Baltic Sea
Authors: Bemelmans J M H , den Braber H J A
Published: May 2018

Marinated herring from the Baltic Sea was found to have an offensive odour and taste described as iodine-like and phenolic. This taint appeared similar to the ‘Jodgeschmack' reported previously in herring. Fat isolated from herring was found to contain this taint. The volatiles were isolated from the fat, using a molecular distillation and were subsequently fractionated by gas chromatography. A fraction containing the taint was obtained and submitted to mass spectrometric analysis to identify compound(s) of interest. By this procedure, the tainted herring was found to be contaminated with o-bromophenol. This compound was not found in good quality herring or only at a concentration level below its odour and flavour threshold values.

The odour and taste thresholds of this compound and its isomers were determined. The thresholds of o-bromophenol were very low, while the character of the taste was in agreement with that of the taint observed in the herring. o-Bromophenol is thus believed to be responsible for the taint. Finally a discussion is given of the various possible sources, which might give rise to the contamination with o-bromophenol. Various bromophenols have been reported in algae, but no monobromophenols. Also, the harvest period of the herring does not correspond to the period that algae are their major food supply. Likely, the iodine-like taint is not associated with the consumption of algae, as has been suggested elsewhere. o-Bromophenol may be an industrial pollutant but is not reported to be used to any extent in industry. However, a trace amount of this compound in the sea can be bioaccumulated to produce this taint. On the other hand, a chemical reaction between bromide and phenol might occur during marination, but no evidence was found to support this.
A Standard Method for Quantification of Earthy-Musty Odorants in Water, Sediments, and Algal Cultures
Authors: Krasner S W , Hwang C J , McGuire M J
Published: May 2018

The closed-loop stripping analysis (CLSA) method of Grob, in combination with gas chromatography/mass spectrometry (GC/MS), has been used in the determination of five earthy-musty-smelling compounds (including geosmin and 2-methylisoborneol). One-liter water samples are analyzed within 3 hours, with detection limits as low as 2 ng/l each. Precision and accuracy levels of 20 percent or better are obtainable with this method. This technique has been modified to include the CLSA of sediments and laboratory-grown microbiological cultures in order to investigate the sources of the odorous compounds. CLSA-GC/MS provides a valuable tool for extended surveys and regular monitoring of water supplies, and it is indispensable in the understanding and management of earthy-musty taste and odor problems.
Case Studies on Off-Flavours in Some Norwegian Lakes
Authors: Berglind L , Holtan H , Skulberg O M
Published: May 2018

During the last twenty years, studies on freshwater algae in Norway have documen recent alterations in the trophic nature of several inland waters. Blooms and changes in type of algae were observed. Mass development of algae, e.g., cyano-phytes, upset normal lake metabolism. Objectionable effects on taste and odour in water supplies were reported. The bloom of Oscillatoria bornetii f. tenuis in the Lake Mjøsa - River Glåma system caused several problems in the waterworks Limnological, biological and chemical data from case studies in Norway were summarized, and some practical implications discussed.
Treatment Methods for the Removal of Off-Flavours from Heavily Polluted River Water in the Netherlands – A Review
Authors: Hrubec J , de Kruijf H A M
Published: May 2018

In The Netherlands the raw water, obtained from the heavily polluted river Rhine, has off-flavours which must be removed by using sophisticated and expensive treatment methods to be acceptable for drinking. One method consists of storage of river water in open bankside reservoirs with residence time of a few months followed by physical-chemical treatment involving coagulation, ozonation, rapid sand filtration, activated carbon filtration and disinfection. Another method used consists of pretreatment of river water by means of coagulation and rapid sand filtration followed by underground storage in the dune areas along the North Sea coast by means of artificial recharge. The water after the recharge is treated by using aeration, dosing of powdered activated carbon, rapid sand filtration and slow sand filtration. The most effective treatment processes for improvement of taste and odour are ozonation and activated carbon filtration.
Anaerobic Treatment of Wastewater in Fixed Film Reactors – A Literature Review
Authors: Henze Mogens , Harremoës Poul
Published: May 2018

A review of anaerobic treatment of wastewater in fixed film reactors is presented. The biochemistry and microbiology is discussed, with emphasis laid on kinetic parameters like growth constants, substrate removal rates and growth yields. The influence of temperature, toxic substances, nutrients and pH upon process performance is evaluated. The kinetics of anaerobic biofilms is discussed. The effect of diffusional limitation and methane generation within the biofilm are important factors not studied yet. The various reactor types and process configurations are commented upon. Most studies of anaerobic processes until now have been with fixed bed reactors, and with soluble substrates.

The design of reactors should be based upon biofilm area or biomass in the reactors. At present biofilm area can not be used for design due to lack of investigations on anaerobic biofilm kinetics.

Anaerobic fixed film processes can be used for almost all types of industrial wastes containing organic matter at reasonable concentrations. Treatment of municipal wastewater is at present not regarded feasible, but the development of new effective types of reactors is believed to change this in the near future.
Anaerobic Filter Treatment of Molasses Fermentation Wastewater
Authors: Carrondo M J T , Silva J M C , Figueira M I I , Ganho R M B , Oliveira J F S
Published: May 2018

Two anaerobic filters were used to assess the treatability of a high strength acidic molasses fermentation wastewater containing up to 3000 mg/l of sulphate ion. The waste had to be neutralized and buffered prior to treatment and the filters operated at ambient temperature. The inlet COD concentrations were increased from 10,000 to 50,000 mg/l, organic loads ranged from 2 to 12 Kg COD/m3 day at hydraulic retention times of 2.5 and 5 days. COD removals varied from 57 to 79% and removal rates as high as 6.8 Kg COD/m3.day were obtained. Although the gas productions were reasonable, reaching 4.8 m3/m3.day, the methane content was always lower than 40% and high concentrations of hydrogen sulphide were detected in the gas. The filters were operated for seven months without sludge removal.
Conversion Processes in Anaerobic Digestion
Authors: Gujer W , Zehnder A J B
Published: May 2018

Six different conversion processes are identified in the degradation of particulate organic material (biopolymers) to methane. Hydrolysis of particulate material is followed by the degradation of the hydrolysis and intermediary products by five independent groups of microorganisms. Process and growth kinetic data for the six processes are reviewed. The kinetic data are applied to the design of an anaerobic digester for raw domestic sludge. Variations in loading rates primarily affect acetate decarboxylation and, thereby, may cause shifts in pH which, in turn, cause the digester to operate in the acidic regime.
Anaerobic Waste Water Treatment in a Carrier Assisted Sludge Bed Reactor
Authors: Martensson L , Frostell B
Published: May 2018

A 40 1 tank reactor, filled to 3 % (v·v−1) with a small size (5-25µm) carrier material and equipped with a mechanical mixer, was used to create a sludge bed system for anaerobic waste water treatment. Solids leaving the tank with the effluent were recycled to the tank from an external settler.

Two different substrates were used, fodder molasses diluted with tap water and beet sugar factory waste water. Influent concentrations were 9.3 g COD·1−1 and 4-7 g COD·1−1 respectively, and treatment was performed at 35-37 °C. With the synthetic molasses waste water, an organic load of 5-6 kg COD·m−3·d−1 could be tolerated, with the sugar industry waste water 25 kg COD·m−3·d−1.

The difference in loading capacity was ascribed to different types of sludges formed, the molasses waste water resulting in a much more bulky sludge and a lower attainable volatile suspended solids concentration. It was concluded that much care must be exercised before designing sludge bed systems for high loads with unhydrolyzed waste waters.
Anaerobic Treatment of a Black Liquor Evaporator Condensate from a Kraft Mill in Three Types of Fixed-Film Reactors
Authors: Norrman J
Published: May 2018

A black liquor evaporator condensate from a kraft mill was anaerobically treated in a fixed bed reactor (= an anaerobic filter), an expanded bed and a fluidized bed. The condensate treated in the fixed bed reactor and the expanded bed had an average COD concentration of 1.4 kg/m3. Before treatment in the fluidized bed the condensate was diluted to 0.42 kg/m3. Efficient purification (80 % COD-reduction or better) was obtained at volumetric loads up to 2 kg COD/m3·d in the fixed bed reactor, 10 kg COD/m3·d in the expanded bed and 13 kg COD/m3·d in the fluidized bed.

The specific methane production was 0.10-0.30 m3/kg COD added in the fixed bed reactor, 0.07-0.15 m3/kg COD added in the expanded bed and 0.07-0.20 m3/kg COD added in the fluidized bed.
Transport Models in Ecotoxicology
Authors: Miller D R
Published: May 2018

The analogy between pharmacology and dynamics of a pollutant in an ecosystem is emphasized in a survey of the state of exposure pathway modelling in the environment It is concluded that, except for the modelling of long-term transport, we are quite able to make quantitative predictions and to specify the errors and uncertainties therein.
Permafrost's Impact on Utility Design
Authors: Ryan W L
Published: May 2018

Utility designs and construction proceedures must consider permafrost and the results of its thawing in Arctic areas. Utilities, especially those that are heated, can have an extremely detrimental effect on frozen ground which, in turn, will have a serious impact on other surface or buried facilities. Critical soil properties and soil temperature profiles must be measured or estimated. The decision must be made on whether to go above or below ground with lines and whether to go active or passive construction.
Polyelectrolyte Conditioning of Sheffield Sewage Sludge
Authors: Paine R E , Thompson K C
Published: May 2018

The paper describes detailed pressing trials of polyelectrolyte conditioned raw sludge with three different polyelectrolytes using a Mono sludge pump. Also described are full-scale trials with a Feluwa (peristaltic) sludge pump and a novel high pressure polyelectrolyte dosing system. The results of tests to determine the effectiveness of a variety of odour control chemicals to prevent the formation of malodours during the pressing and subsequent incineration of polyelectrolyte conditioned sludge are also discussed.
Analysis of the Heat Requirement for Sewage Sludge Incineration
Authors: Quirk Thomas P , Eckenfelder Wesley
Published: May 2018

The process design and evaluation of sludge incinerator performance is generally conducted using either generalized average parameters or, alternatively, complex and detailed calculations which require computer programming for their use. In the first instance the generalized parameters are found to be applicable only to an “average” incinerator which is not encountered in actual practice. In the second instance, the calculations are so numerous that a clear and general picture of what is occurring cannot be readily obtained. This paper presents a new analytical approach to incineration performance evaluation which has been developed in an attempt to redress this situation.

A three-term linear equation is developed for the combustion heat balance using net heat value of the fuels. Net heat value is defined as that heat value, per pound of fuel, which is available to perform useful thermal work other than the discharge of its own combustion products.

The well-established procedure of using ultimate chemical analyses of fuels together with an element by element accounting for combustion components has been simplified by defining three combustion ratios for a given fuel. These ratios are then used to determine the net available heat values for use in the heat balance equation.

Operating data are used to illustrate the application of the analysis technique and to demonstrate the practical application of the procedure.
Water Quality Management in the Chemical Industry – BASF's Ludwigshafen Complex as an Example – Investigations, Design, Operation
Authors: Engelhardt H , Haltrich W G , Weisbrodt W
Published: May 2018

The BASF works Ludwigshafen - the largest integrated chemical complex in Europe - via re-organization of its waste water management (installation of a separate sewerage system, intra-plant measures, central chemical-mechanical-biological treatment plant) has achieved a reduction of the substance load discharged to the Rhine by ca. 98% in terms of BOD5 and by ca. 94% for COD and TOC.

During many years (1961 - 1974) investigations have been carried out with pilot plants on laboratory scale (50l) as well as on semi-industrial scale (20 000 population equivalents) for selecting the suitable treatment procedure and dimensioning of the central treatment plant. The treatment procedure developed according to tests in the pilot plant (high-rate primary sedimentation to avoid activated sludge with poor settling properties, followed by an aeration stage in form of a circular basin according to the carrousel system, including a denitrification zone of variable volume) has proven successful in practice. The sludge volume index is 50 ml/g. In spite of varying nitrate concentrations the denitrification is working without problems. In the central treatment plant (dimensioning data 375 000 kg/d BOD5, ca. 100 000 kg/d NO3−, DWF 660 000 m3/d) BOD5 is degraded by 96%, COD as well as TOC by ca. 80 - 85%, while nitrate is eliminated by 95 %. It will be reported mainly on the operation experience.

In addition to the central treatment facilities there are numerous decentralized measures in regard to the treatment of concentrated waste waters or waters containing poorly degradable substances like halogenated hydrocarbons and heavy metal-compounds.
Tidal Power from the Severn Estuary
Authors: Corlett John
Published: May 2018

The British government set up a committee in 1978 to advise on whether to proceed with a scheme to build a barrage across the Severn estuary for the generation of electricity. Besides engineering and economic considerations the committee considered the ecological consequences of a barrage.
Appropriate Methods for Tropical Coastal Resource Inventory and Monitoring
Authors: Watson R M
Published: May 2018

Most investments in research, development and management for coastal engineering projects have taken place in temperate zones, usually in areas of highly developed infrastructures. There is a need for more coastal engineering in poor tropical regions, and many contend that the economic status of this part of the world is a consequence of poorly developed infrastructures. The provision of appropriate information on resources and ecology in the tropics, against which coastal engineering projects can be evaluated, requires special techniques for inventory and monitoring. Methods are influenced by the particular biologies of tropical coastal ecosystems, and by the undeveloped state of economies and infrastructures. A selection of methods found suitable for tropical coastal studies in Eastern Africa is described, including remote sensing, multi-stage sampling, non-biased quantification techniques, fixed point monitoring, low-level aerial surveillance and reconnaissance, an aerial collecting drogue, and a matrix analysis for evaluating environmental consequences in valid economic terms.
Ecological Problems Related to the Loire Estuary Development
Authors: Bellessort B , Caillat J M , Brossard C , Bourgouin J
Published: May 2018

Within the framework of the Loire estuary development, the Nantes-Saint-Nazaire Port Authority initiated a set of studies to define compatibility between the possible estuary developments and conservation of living natural environment. The main points of this program were as follows:−studies of hydraulic and sedimentary phenomena (desk, field and model studies)−studies of water quality−benthos, ichtyological and wet zones studies.
Modelling the Eutrophication Process of Lake Ijssel
Authors: Klomp R , Los F J , van Pagee J A , de Rooy N M , Smits J G C , Stans J C
Published: May 2018

Eutrophication can be considered as the most urgent problem in water quality management in The Netherlands. The main freshwater source for The Netherlands is the border crossing river Rhine, which is highly polluted by more or less treated industrial and domestic waste water, and therefore contains high concentration of nutrients. A branch of the river Rhine flows into the largest freshwater lake in The Netherlands, the Lake IJssel. Since this lake has to fulfil many functions, inhibited by severe (blue green) phytoplankton blooms the Dutch government initiated in 1979 a project in which a eutrophication model for the delta region of the river Rhine basin (Lake IJssel e.g. the estuary closed in 1928), consisting of two models e.g. BLOOM II, a phytoplankton model and CHARON, a model which describes the chemistry of the lake was applied.

The models have been calibrated, verified and applied to the system of the river Rhine and the Lake IJssel in the framework of a eutrophication study. The models involved in this study are shortly explained. Special attention is paid to the calibration and verification step.

The models are used to analyse the eutrophication process in the lake and to quantify the influence of policy and management scenarios including waste water treatment and measure with respect to nutrient reduction.

The results of application of the models are discussed and evaluated against the background of the decision making process of the water manager.
Development and Ecodisaster: A Lesson from Cochin Backwater System
Authors: Balakrishnan K P , Lalithambika Devi C B
Published: May 2018

Kerala, with a unique climate, has rich and varied ecosystems with luxuriant and diverse plant and animal communities. This has led to a high density of human population. The State has resorted to modern technological methods for its economic development which include industrialization and improvement of agricultural production.

The establishment of a modern port at Cochin has transformed the region into the industrial capital of the State. Simultaneous with economic progress, the environmental conditions have become deranged due to large scale shipping operations. Of late the environmental problems are increasing in the highly productive backwater system, due to industrial effluents. How developmental programs can undermine the ecological balance and cause deleterious effects as well as unforseen consequences are well illustrated by the deltaic region of Kuttanad - “the rice bowl of Kerala”. Dams, at the upper reaches of the rivers, provide power for industry and water for irrigation. But inadvertent denudation of the forests due to continuous human settlement and related activities will not only damage the dams, the industry and agriculture but also the climate of the region. The high density of population exerts undue pressure on the ecosystem whether it be terrestrial, aerial or aquatic and causes serious imbalances.
River Quality Assessment and Monitoring of the Danube – An Example of International Cooperation
Authors: Ottendorfer L J
Published: May 2018

The main characteristics of the Danube which passes through the following eight European countries (Fed. Rep. of Germany, Austria, CSSR, Hungary, Yugoslavia, Romania, Bulgaria and Russia) are described. International cooperation and activities include the work of: a) “Internationale Arbeitsgemeinschaft Donauforschung” b) ECE (Declaration of Policy on the Rational Use of Water; Long Term Perspectives for Water Use and Supply in the ECE Region) c) cooperation within the “International Hydrological Program” resulting in the preparation of a Hydrological Monography (part I: Precipitation and Discharge; part II: Water Quality Assessment of the Danube). Some of the specific problems encountered in the Danube Countries are discussed.
Objectives of a Water Quality Monitoring Programme for the International River Basins in a Developing Country in Southern Africa – Mozambique
Authors: Hugman S J
Published: May 2018

Mozambique lies on the south-east coast of Africa. Its Independence, in 1975, was particularly difficult and severely disrupted the economy. All its major rivers rise in neighbouring countries and several, in particular those from South Africa and Swaziland, are already heavily used before crossing the border.

Since 1977 the National Water Directorate has been responsible for management and development of water resources. The Directorate includes a hydrology department which maintains field-teams throughout the country.

Virtually no water quality data are available from before 1972, when irregular sample collection began. Since Independence, sampling has continued but the Directorate has redefined the objectives of the programme to obtain maximum benefit from very limited resources. These objectives were chosen for economic, hydrological and political reasons. The long-term objectives are to provide the data required for agricultural and industrial development projects, to manage and maintain the quality of Mozambique's water resources, and to meet international obligations.

In practice, the capacity of the hydrological service is insufficient to meet these objectives. The targets for the existing programme were therefore chosen to satisfy the most important objectives and to be feasible with present resources. The routine programme is being completely operated by technicians who have no more than nine years schooling.
The Contribution of River Systems to the Input of Pollutants to the Marine Environment in Northern Europe
Authors: Critchley R F
Published: May 2018

Published information on the input of pollutants to the North Sea has been used to identify the major pollutant pathways. Rivers and atmospheric deposition are the main input routes for metals, with the Rhine/Meuse and the Elbe contributing over half the riverine input. The dumping of estuarine dredging spoils results in a very large input of metals, which cannot be fully accounted for as a redistribution of riverine material unless the river inputs have been grossly underestimated. Rivers provide the largest input route for nutrients, but a substantial contribution is also made by direct discharges to coastal waters and estuaries. Sewage sludge dumping contributes less than 5% to the pollutant load to the North Sea.

Similar assessments have also been made for the Baltic Sea and the major UK estuaries.
Standards for Waters and Industrial Effluents
Authors: Chalmers R K
Published: May 2018

Experience in 25 countries shows, not surprisingly, that the trend everywhere is towards tightening legislative control on waste discharges to the environment. What is comparatively recent, however, is the rate of change in the standards required under these laws. This stems partly from the elevation of environmental protection to a political issue within the last quarter century, a new awareness among environmental pressure groups enhanced by instant communications world-wide, an international knowledge of what is - or should be - technically attainable in effluents from various manufacturing processes, and technology transfer and sometimes funding encouraged by the international agencies like those of the United Nations.

After a brief consideration of the derivation of standards 21 cases are noted in which the actual application of standards has been questionable. In view of the significant effect of effluent standards upon manufacturing costs it is important that standards are both rational and necessary. Approaches to the minimizing of industrial effluent discharges benefit both the discharger and the receiving environment.
The Significance of Water Quality Parameters for Decision-Making in Water Pollution Control – A Case Study: Lake Päijänne in Finland
Authors: Nyroos H
Published: May 2018

Estimation of water quality impacts plays an important role in the planning of water pollution control. In this paper the connection of water quality aspects with the rest of the planning procedure is examined in the light of a case study area, Lake Päijänne in Finland. For this area an integrated water resource development plan was made by the Finnish water authorities. In order to diminish the adverse effects resulting from effluents of pulp and paper mills and municipalities, different pollution control alternatives were drawn up. Next, forecasts about the development of water quality in different alternatives were made. The most important parameters from the point of view of the different modes of water utilization were taken into account. These parameters were oxygen, phosphorus, COD, lignin and colour. In addition, in assessing the impacts, toxity of effluents was taken into consideration. The impacts of these parameters on the usability and utilization of water areas were analyzed. The forecasts of impacts on vacation settlement, water supply and fisheries were made. In the comparison of the alternatives, numerous intangible factors were involved. In the assessment of the alternatives the costs of water pollution control measures, the benefits and the adverse effects were taken into consideration. The impacts of intangible factors were assessed in each alternative by comparing the water use possibilities with the goals that had been set.
A Design Storm for a Tropical Location with Limited Data
Authors: Colyer P J
Published: May 2018

Design storm profiles for an investigation of urban storm drainage in Port of Spain, Trinidad, are described. The profiles were based on analysis of 100 storms recorded on two raingauges over a two year period. A clear tendency to advanced skewness in the profiles was discovered. Rainfall depths were obtained from an existing intensity-duration-frequency analysis.
Areal Reduction Factors on Short Time and Space Intervals
Authors: Desbordes M , Raous P , Trévisiol Y
Published: May 2018

Areal reduction factors on short time and space intervals have been studied from an experimental 9 raingages network, covering 400 hectares approximatively. During the three years recording period, 51 events have been analysed for time intervals ranging from 5 minutes to 4 hours. Results have shown that mean rainfall intensities should not be considered as uniformly distributed over areas ranging 100 to 400 hectares. They have also shown that rainfall areal distributions are significantly depending on time and space intervals to be considered, regarding to the network used.
The Influence of Rainfall Characteristics on the Pollution Emission
Authors: Bakker K , van Wieringen H S J
Published: May 2018

In the Netherlands, an extensive data collecting programme has been implemented in which qualities and quantities of stormwater discharges are determined.This paper discusses the first results of the study. Water balances for various storms have been made to derive run-off coefficients. A preliminary relation is established between rainfall characteristics and pollution emissions.
Application of the UASB-Reactor for Anaerobic Treatment of Paper and Board Mill Effluent
Authors: Habets L H A , Knelissen J H
Published: May 2018

Within the holding of Bührmann-Tetterode NV, 7 Dutch paper and board mills are operating, all of them using mainly waste paper as raw material.

While three of them completely closed their watercircuits, two other mills put into practice biological waste water treatment namely anaerobic and anaerobic/aerobic. Number 6 is realising an anaerobic plant this year and for number 7 research is still being carried out, dealing with several unfavourable aspects. In September 1981 research for anaerobic treatment (UASB reactors) was started. After good results had been achieved on laboratory scale (301), further investigations were started on semitechnical scale (50 m3).

In both cases the anaerobic seed sludge granulated after a while and loadings up to 20 kg COD/m3.d could be handled. COD-removal was 70 per cent, even when the hydraulic retention time was only 2.5 hours.

In April 1983 a 70 m3 practical scale UASB reactor was started up at the solid board mill of Ceres.

In October 1983 a full scale plant was started up at Papierfabriek Roermond. This plant consists of a 1,000 m3 UASB reactor and a 70 m3 gasholder. It has been designed and constructed by Paques BV and is used for pretreatment of effluent, in order to reduce the loading of the activated sludge plant. Besides energy savings on the oxygen input, about 1 million m3/year of biogas is being generated and is used for steamproduction.

Both plants are working satisfactorily. Investment costs appeared to be relatively low. At Ceres, pay-out time is 1.5 year, while at Papierfabriek Roermond waste water treatment is cheaper than before, although capacity is doubled.
Anaerobic Downflow Stationary Fixed Film Reactors: Performance Under Steady-State and Non-Steady State Conditions
Authors: van den Berg L , Kennedy K J , Samson R
Published: May 2018

Performance of downflow stationary fixed film reactors depended on factors such as type of film support, film surface-to-volume ratio, height, temperature and fluid flow pattern. The downflow operation ensured the dilution of the waste as soon as it entered the reactor. Loading rates and organic removal efficiencies depended on the total amount of active biomass retained as well as on type of waste. For a wide variety of industrial wastes, including some of the forest industry, loading rates of 5 to 15 kg Chemical Oxygen Demand per m3 per day were readily obtained with removals of Chemical Oxygen Demand of 70-95%, depending on loading rate and type of waste. Severe hydraulic and organic overloadings were tolerated with operation back to normal, usually in 24 hours following cessation of adverse treatment. Reactors were operated with dilute and concentrated wastes (4000-130000 mg COD/1) and changed readily over from one waste to another. Intermittent loadings at high loading rates were also possible. Loading rates decreased linearly with temperatures between 35 and 10°C; at 10°C they were about 20% of those at 35°C. At thermophilic temperatures, loading rates and performance were similar to those at mesophilic temperatures. Results of a detailed study of mixing characteristics showed that mixing patterns, which depended on number of channels, their configuration and recirculation, affected performance noticeably.
Anaerobic Treatment of Sulfite Evaporator Condensate in a Fixed Bed Loop Reactor
Authors: Aivasidis A
Published: May 2018

There are a large number of advantages in using microbial anaerobic degradation processes in waste water pretreatment. A disadvantage of this method lies in the relatively long doubling times of anaerobic microorganisms which cause long residence times in a continuous stirred tank reactor. Because of the autocatalytic behaviour of the microbial processes and the low carbon incorporation rate which results in low biomass concentrations, decoupling of residence times for substrate and biomass in continuously operated systems is necessary. In this way high space time yields can be achieved under anaerobic conditions as well. From the well known variants for biomass retention, immobilisation by an inert support is thought to be an effective alternative. Experiments on anaerobic treatment of sulfite evaporator condensate by means of immobilized microorganisms were carried out in a 121-fixed bed loop reactor. Porous sinter glass from SCHOTT Mainz with a porosity of about 60 % and a mean pore diameter of 60-100 μm served as carrier. The reactor was operated for several months under steady state conditions at different residence times using an iterative approach. At a residence time of 11 h 84 % of the chemical oxygen demand (COD) was eliminated at loading rates up to 100 kg COD/m3 and day. Online data acquisition and process control are recommended and easily realized by means of a digital computer, in order to increase selection stress on microorganism population and optimize space time yield.
Anaerobic Treatment of Viscose Wastewater
Authors: Kroiss H , Plahl-Wabnegg F , Svardal K
Published: May 2018

The waste water from the viscose production process can be characterized as follows: low to medium strength of biodegradable carbonaceous matter, high concentrations of sulfate, high concentrations of zinc.

The treatment process to be presented consists of anaerobic pre-treatment of the neutralized waste water combining the removal of carbonaceous matter with zinc removal by sulfide precipitation. The organic pollution of the waste water is used as a substrate for sulfate reducing bacteria present in the anaerobic reactor. The hydrogen sulfide produced precipitates the zinc as insoluble zinc sulfide. Labscale experiments lasting several months resulted in stable zinc effluent concentrations below 1 mg/l combined with a COD removal of about 40 - 50 %.
Cost Comparison of Aerobic and Anaerobic Wastewater Treatment Systems
Authors: Rantala P , Väänänen P
Published: May 2018

The costs of different types of aerobic, anaerobic and combined wastewater treatment systems are compared in this study. The assumed BOD or COD-loads from typical forest industry processes form the basis of comparison. General cost curves for various waste treatment processes and some case examples are also presented.

In the calculations it is assumed that the wastewater is treated to the same effluent quality by using activated sludge, modified activated sludge and combination of anaerobic-aerobic treatment process. In anaerobic-aerobic systems different types of combinations are analyzed. Investment, running and annual costs have been evaluated for each system.

The study shows that selection of the method or combination of methods must always be made case by case. It has been found out that in some cases the anaerobic-aerobic process combination is economically competitive. Competitiveness will increase if biogas can be utilized and a moderate price could be calculated for it. In some cases activated sludge, and especially aerated lagoon processes, has a disadvantage of requiring larger treatment spaces. Poor soil conditions and long distances to lead effluent may significantly increase the cost of these aerobic treatment methods.
Mass Transfer Mechanisms in a Heterotrophic Biofilm
Authors: Siegrist H. , Gujer W.
Published: May 2018

The diffusion coefficient of three different chemical species in naturally grown, heterotrophic biofilms have been measured. The mechanical structure of the biofilm matrix reduces the molecular diffusion to about 50 to 60 % of the value in pure water. Depending on the roughness of the biofilm surface and the flow conditions eddy diffusion increased the mass transfer into the biofilm near the surface.

The influence of the diffusion potential and the donnan potential on the ions have been evaluated by comparing the diffusion coefficients of a positively and negatively charged ion and a neutral molecule in experiments with different background electrolyte concentrations. Mass transfer effects by electrostatic forces are negligible at the ionic strength of waste water and tap water.
Detection of Hepatitis a Virus (HAV) in Drinking Water
Authors: Sobsey M. D. , Oglesbee S. E. , Wait D. A. , Cuenca A. I.
Published: May 2018

Using recently developed cultivation and assay systems, currently available methods for concentrating enteric viruses from drinking water by adsorption to and subsequent elution from microporous filters followed by organic flocculation, were evaluated for their ability to recover HAV. Cell culture-adapted HAV (strain HMl75) in seeded tap water was efficiently adsorbed by both electronegative (Filterite) and electropositive (Virosorb lMDS) filters at pH and ionic conditions previously used for other enteric viruses. Adsorbed HAV was efficiently eluted from these filters by beef extract eluents at pH 9.5. Eluted HAV was further concentrated by acid precipitation (organic flocculation). Using optimum adsorption conditions for each type of filter, HAV was concentrated >100-fold from samples of seeded tap water with about 50% recovery of the initial infectious virus added to the samples. Electropositive filters were used to concentrate HAV from six samples of a fecally contaminated ground water supply implicated in an outbreak of hepatitis A in a rural community. HAV was detected and quantified in four of the six concentrate samples by radioimmunofocus assay in African green monkey kidney cell cultures. The presence of infectious HAV in water sample concentrates was further confirmed by experimental infection of chimpanzees and by virus isolation in African green monkey kidney cell cultures. The ability to recover and quantify HAV in contaminated drinking water with currently available methods should prove useful in further studies to determine the role of drinking water in HAV transmission.
Detection and Health Risk Associated with Low Virus Concentration in Drinking Water
Authors: Payment P. , Trudel M.
Published: May 2018

During the last decade, with the amelioration of the detection methods and the increasing number of studies on the subject, the isolation of viruses in treated drinking water has been reported more frequently than ever. These reports have in common the very low number of viruses isolated and these viruses are usually found only after concentration procedures involving several hundred liters of water. Our own studies have shown that during the conventional treatment of drinking water 99.998% of the indigenous viruses are removed. The residual viral fraction does not exceed 10 viruses per 1 000 liters of water. Using a probabilistic approach this viral concentration in drinking water is well below any dangerous level of enteric viruses in water and the presence of these viruses should not be considered as a health problem but more as the limit of the water treatment methodology.
Viruses and Bacteria in a Chalk Well
Authors: Slade J. S.
Published: May 2018

Human enteroviruses have been found in water from a chalk well with history of excellent bacteriological and organoleptic quality. A proportion of these viruses survived disinfection treatment which consisted of a nominal 1 mg/ℓ of free chlorine maintained for a minimum contact period of 15 minutes at a pH value of 7.2. It is concluded that viruses may occur in underground sources which have consistently proved to be satisfactory in routine monitoring tests for bacterial indicators of faecal pollution. Possible mechanisms which these circumstances may arise are discussed.
Virus Inactivating Effect of Anaerobic Mesophilic Digestion of Municipal Sludge with or without Different Preceding Types of Treatment
Authors: Wekerle J. , Leuze M. , Koch K.
Published: May 2018

The effect of the conventional mesophilic anaerobic one-step digestion, and of two-phase processes with and without pre-pasteurisation and pasteurisation of the digested sludge on three non-enveloped viruses was investigated. Reovirus Type 1 and bovine Enterovirus (ECBO-LCR-4) were inactivated completely by the one-step mesophilic anaerobic digestion process with a mean hydraulic retention time (MHRT) of 20 days, as well as by the two-phase process with a MHRT of two days in the anaerobic pretreatment at 33°C or 20°C and eight days in the main digestion at 33°C, with and without prepasteurisation. None of the processes inactivated bovine Parvovirus (strain Haden) completely. Even by pasteurisation of the digested sludge this virus could not be inactivated in all cases.
Removal of Soluble Substrates in Fixed Films
Authors: la Cour Jansen Jes , Harremoës Poul
Published: May 2018

Experimental results with removal of soluble substrates in fixed films are presented. Experiments are performed with denitrification and with oxidation of methanol, acetic acid and glucose in a laboratory fixed film reactor.

The experiments confirm the predictions of the half order reaction model, taking diffusion of the substrates and zero order intrinsic reaction rate of the bacteria as the dominating processes in the film. The experiments enable calculation of the kinetic parameters: diffusion coefficients, intrinsic reaction rates and half order rate constants for nitrate, methanol, acetic acid, glucose and oxygen within fixed films.
The Role of an Anaerobic Stage on Biological Phosphorus Removal
Authors: Fukase T. , Shibata M. , Miyaji Y.
Published: May 2018

A detailed study was conducted on biological removal of phosphorus by an activated sludge process composed of an anaerobic stage followed by an aerobic stage in order to clarify the role of the anaerobic stage of the process. Two distinctive sludges, one contained approximately 10 percent phosphorus, most of which existed in the form of polyphosphates, and the other contained 1.9 percent phosphorus, were obtained by changing BOD concentration of influent and hydraulic detention time of the process. Although the polyphosphate-containing sludge released phosphorus in proportion to the absorbed BOD at anaerobic conditions, the sludge which did not contain polyphosphates also absorbed an equal amount of BOD at the identical rate without any external sources of oxygen. Both sludges accumulated identical levels of poly-β-hydroxybutyrate within the sludges as the BOD sources were absorbed. These results suggest that the polyphosphate-containing sludges have no advantage over the sludges with no polyphosphates when they uptake BOD in the anaerobic stage.
Modeling Phosphate Sludge Production
Authors: Veldkamp R. G.
Published: May 2018

Sludge mass production and volumetric sludge production were measured in a series of bench scale tests. This experiment was performed as a 3-factorial design. Variables were chemical dosing level (expressed as mole ratio cation/P), P-concentration and pH. Experimental data are statistically evaluated with analysis of variance and multiple regression. Some models for the prediction of sludge production are developed.
Phosphate Removal by Crystallization in a Fluidized Bed
Authors: van Dijk J. C. , Braakensiek H.
Published: May 2018

A new process for the removal of phosphate from effluent from sewage treatment plants is described. The process is based on the crystallization of calcium phosphate in a fluidized bed. The major advantage of the process is the fact that no sludge is produced, but a small quantity of waterfree pellets that can be reused in the phosphate industry. The results of five years of research and development are presented. In 1984 the first demonstration plant will be built. Cost calculations for a full-scale plant are also given.
Batch Anaerobic Methanogenesis of Phenolic Coal Conversion Wastewater
Authors: Fedorak Phillip M. , Hrudey Steve E.
Published: May 2018

Batch experiments using the Hungate serum bottle technique were used to determine the anaerobic treatability of phenolic (7600 mg/1 by 4-aminoantipyrine) wastewater from an H-coal conversion pilot plant. Methane production above controls was achieved at up to 6% V/V dilution. At these levels, inhibitory components in the wastewater retard but do not stop volatile organic acid (VOA) fermentation to methane.

Ether-extracted wastewater was tested at up to 50% V/V on cultures receiving 200 mg/1 phenol and was found not to be inhibitory, suggesting that inhibitory components in the wastewater are ether-extractable. Finally, a “reconstituted H-coal” which contained pure phenolic constituents added to ether-extracted H-coal exhibited batch methanogenesis above controls at H-coal dilutions up to 10% V/V. These findings indicate that the ether-extractable inhibitory substances are not one of the major phenolic compounds present in the H-coal wastewater.
The Potential use of Enzymes for Removal of Aromatic Compounds from Water
Authors: Maloney S. W. , Manem J. , Mallevialle J. , Fiessinger F.
Published: May 2018

Enzymatic methods have shown promise for removing aromatic compounds from (high strength) industrial waste water. The removal of these compounds was studied at low levels which might be encountered in surface waters which receive some industrial discharge. The results indicate that enzymatic oxidative coupling may be useful in eliminating aromatics which are not well removed in biological or physical water treatment.