bluuebunny/crossref_metadata_2025_split huggingface dataset:
Algal-Bacterial Ponding Systems for Municipal Wastewater Treatment in Arid Regions
Authors: Esen I. I. , Puskas K. , Banat I. , Al-Daher R. 
Published: May 2018

A pilot plant was constructed to investigate the use of algal-bacterial systems to treat municipal wastewaters in arid regions. The pilot plant consists of sand and oil traps, weir tanks, two facultative ponds (250 m3 holding capacity each), two high-rate ponds (25 m3 holding capacity each), four sedimentation tanks, a sludge digestor, and such auxiliary facilities as a pumping station for wastewater supply, drainage systems, and a site laboratory. The main objectives of the study are to determine the design parameters needed for large-scale algal-bacterial ponds in hot climates and to determine the degree of treatment and disinfection attained in the system by operating the pilot plant. After the algae is separated from the treated water, the final effluent will be used for irrigation, and algae will be used as a soil conditioner.
Investigations during start-up, test runs and experiments completed so far focused on the growth of algae and removal of biochemical oxygen demand, chemical oxygen demand, and suspended solids. During the 20-month experimental program, various operating patterns, including series operation of facultative and high-rate ponds, will be investigated. Results obtained so far indicate significant reductions in pollution concentrations.
Sewage Stabilisation Ponds in Arabia and Kenya
Authors: Smith L. J. 
Published: May 2018

Experience of pond design and operation in Arabia and Kenya is described.
In Saudi Arabia major stabilisation pond installations were built for the Three Cities Project at Hofuf, Buraidah and Qatif. Summaries of results, comment on performance achieved and implications for future stabilisation pond design are noted.
Recently commissioned ponds in Aden for both domestic and industrial sewages are featured and points of interest indicated.
The basis of the most recent designs now ready for tender for applications in Aden and Seiyun, P.D.R. Yemen are provided.
Conclusions are drawn regarding the future potential of pond treatment for disposal of waste water for re-use in irrigation.
Steel Industry Wastes Treatment in Buffer Ponds
Authors: Bagnyuk V. M. 
Published: May 2018

The bioprocesses of steel industry wastes self-purification in buffer ponds have been studied. The representatives of 6-7 divisions of microalgae and many functional groups of bacteria have been found in the ponds. The important role of a new functional group, the “lytic” microorganisms, in the regulation of microecosystems and in bacterial self-purification has been established.
It was found that the activity of self-purification bioprocesses in the buffer ponds studied depends on a variety of ecological factors. The main limiting factor has been shown to be the high turbidity of water, and its deficit of dissolved phosphates and oxygen.
To accelerate the self-purification of steel industry wastes in buffer ponds the concentration of organic and mineral forms of the main biogenic elements (C,N,P) should be regulated. Water clarification and aeration were recommended and effectively used.
The Development of Ecological Wastewater Treatment and Utilization Systems (EWTUS) in China
Authors: Wang Baozhen 
Published: May 2018

Experience and practice of the treatment and utilization of sewage and organic wastewaters using stabilization ponds with artificial or semi-artificial ecosystems in China are described. The eco-ponds being used in China are different from those with symbiotic algae/bacteria systems in that the former consist of not only bacteria and fungi as decomposers and algae as producers, but also fish, shrimps, shellfish, ducks, geese, etc. These are consumers at different trophic levels in food chains or food webs in the pond communities where fish farming and/or duck and geese raising takes place. The eco-ponds are characterized by low capital and operation costs, energy savings, high removal efficiencies for a wide variety of pollutants, and considerable Drofits that can be gained from comprehensive utilization of wastewaters as recoverable resources.
Some typical eco-ponds for treatment and utilization of municipal and industrial wastewaters, such as fish farming ponds in Changsha, (Hunan), and in Ehcheng, (Hubei), hydrophyte ponds in Shaoxing, (Jejiang) and in Shijiazhuang, (Hebei), and treatment/storage lagoons with ecosystems are described in detail.
The concept of ecological systems for treatment and utilization of wastewaters, and the various ecological wastewater treatment and utilization systems (EWTUS) available for different regions, are also discussed in this paper.
Treatment of Wastewater in the Rhizosphere of Wetland Plants – The Root-Zone Method
Authors: Brix Hans 
Published: May 2018

The present paper describes the theoretical basis of wastewater treatment in the rhizosphere of wetland plants, the so-called “root-zone method”, along with the first working experiences from eight treatment plants in Denmark.
Mechanically treated wastewater is led horizontally through the rhizosphere of wetland plants. During the passage of the wastewater through the rhizosphere, the wastewater is cleaned by microbiological degradation and by physical/chemical processes. The wetland plants supply oxygen to the heterotrophic microorganisms in the rhizosphere and stabilize the hydraulic conductivity of the soil. Nitrogen is removed by denitrification and phosphorus and heavy metals are bound in the soil.
The first working experiences from Denmark show, that as far as BOD is concerned root-zone treatment plants are very nearly up to conventional secondary treatment standards already from the first growing season (removal efficiency: 51-95%). For the nutrients nitrogen and phosphorus the results vary (total-N removal: 10-88%; total-P removal: 11-94%). The removal efficiencies depended mainly on the composition of the soils and the degree of surface runoff in each treatment plant.
It is concluded that root-zone treatment plants seem to be a viable alternative to conventional wastewater treatment technology, especially suitable for single households and small to medium sized communities. There is, however, still very little information on the removal processes for nitrogen (denitrification), on the effect of soil type and on the required surface area to load ratio,
Biodegradation of Oil on Drilled Cuttings
Authors: Bilstad T. , Bosdal T. , Toerneng E. 
Published: May 2018

Drilled cuttings from offshore petroleum exploration are discarded to sea. Oil based drilling fluids leave oil on cuttings that may become environmentally toxic.
Successful biological separation of oil and cuttings was accomplished by addition of nitrogen and phosphorus to seawater in completely mixed aerobic batch reactors at 10 and 20°C. Substantial biodegradation in flow-through aquaria, however, was not accomplished.
Both retort distillation and solvent extraction using dichloromethane in a Soxhlet apparatus separated reproduceable quantities of hydrocarbons from cuttings. The oil was characterized by glass capillary gas chromatography and medium pressure liquid chromatography.
Chlorinated Hydrocarbons in Biological Sewage Purification – Fate and Difficulties in Balancing
Authors: Schröder H. Fr. 
Published: May 2018

The fate of some chosen chlorinated hydrocarbons in the biological sewage purification was determined. Fixed quantities (250 µg/l waste water) of the different volatile compounds such as chloroform, trichloroethylene, chlorobenzene, hexachloro-1, 3-butadiene, 1,2-dichlorobenzene, 1,2, 3-trichlorobenzene, hexach lorobenzene, 2,4-dichlorophenol and γ-hexachlorocyclohexane were dosed into the aeration tanks of the pilot plants. Chlorinated hydrocarbons in the inflow, waste air, effluent and excess sludge were extracted and tested for by GC/ECD. The results of these experiments were adapted with the results of recovery experiments. The balances of the low volatile and volatile compounds also had to be adapted by the means of correction factors because of condensation effects. For example more than 50 % of 250 µg/l water of chloroform or 1,2-dichlorobenzene escaped out of the open sampling bottles which were kept in a refrigerator during the sampling period of 24 hours. The balances of the non-volatile chlorinated hydrocarbons were reaching about 100%. The very hydrophilic and low volatile chloroform was found up to 16% in the waste air, 63% in the effluent and 21% adsorbed on sludge. The very lipophilic and non-volatile hexachlorobenzene was found up to 16% in the effluent and 74% adsorbed on sludge. No hexachlorobenzene was found in the waste air. Biochemical degradation was observed for some of these compounds.
The behavior of the chlorinated hydrocarbons in biological sewage purification depended on their volatility and lipophilic property, and also the intensity of aeration and sludge loading has been of great importance. Balancing of volatile chlorinated hydrocarbons should be done by spot sampling. Bottles for composite samples should be stored in the refrigerator during the sampling period and should be sealed.
Maintenance Strategies for Sewerage Systems
Authors: Câmara A. S. , Pereira D. , Fonseca A. , Sequeira S. 
Published: May 2018

The problem of decaying sewerage systems is a timely topic in many urban areas, due to its importance to societal needs and to the large amounts of capital expeditures needed to bring the concerned systems to an adequate level of serviceability. Thus, there is a need for better maintenance decision-making related to periodic inspection and cleaning, repair, rehabilitation or replacement of the equipment.
In this paper, an approach offering integrated solutions to upgrade such systems, taking into account existing and foreseen structural and hydraulic conditions, is presented. The methodology relies upon a heuristic algorithm scheduling maintenance events. An application to the Almada sewerage network illustrates the method. Future improvements including the use of statistical maintenance theoretic concepts and artificial intelligence approaches are also discussed.
Socio-Technological Aspects of Automation in Public Works Activities
Authors: Garber William F. 
Published: May 2018

The history of human society is replete with examples of advances in technology overrunning the ability of societal organizations to efficiently handle the resulting massive societal dislocations. The social impacts of the “Industrial Revolution of the 18th and 19th Centuries” illustrate how profound such effects can be.
The automation-computer-robotics revolution now underway also has the potential for serious societal changes. In this regard public works activities are subject to increasing amounts of automation with impacts upon current and net total employment and training needs. To evaluate the present status of automation in the USA, questionnaires were sent to public works authorities in 110 cities or agencies. The current degree of automation, the impact upon employment and the skills now needed by public works employers were queried. It was found that in most cases automation was just starting; but that as complete automation as was possible was inevitable given the increasing complexity of the tasks, the demands of the public and the long term prospects for public works funding.
In many cases the candidates now in the work force were not properly trained for automation needs. Retraining and changes in the educational system appeared necessary if the employees now needed were to be continuously available. Public works management as well as several labor organizations appeared to be aware of this need and were organizing to handle the training problem and the changes in employment qualifications now necessary. It appeared to be a consensus that the larger societal effects of automation should be handled by society as a whole.
Conditioning of Biological Sludges with Cationic Poly-Electrolytes
Authors: Eriksson L. 
Published: May 2018

Factors determining polyelectrolyte choice and dosage in conditioning of activated sludge were investigated. It was found that due to differences in particle size distribution electrophoretic mobility did not correlate with optimal dosages. Instead the polyelectrolyte consumption to a large degree could be explained by a linear model containing the variables: sludge volume index, rest turbidity, floc break up factor obtained by CST-stirring test and CST (Capillary Suction Time) of unconditioned sludge.
For the investigated sludges biopolymers and colloidal particles were the main consumers of polyelectrolyte which however also was needed to build the existing flocs to optimum properties. The model was statistically less significant in the cases of high stirring times and high sludge volume indexes.
Sludges with high amounts of dispersed particles were best conditioned by a high molecular weight and moderately charged polymer while for well flocculated sludges with high sludge volume index a high charge density polymer was most suitable.
Influence of Oxic and Anoxic Mixing Zones in Compartment Systems on Substrate Removal and Sludge Characteristics in Activated Sludge Plants
Authors: Hoffman H. 
Published: May 2018

During a research program the influence of activated sludge compartment systems with and without anoxic mixing zone on the efficiency of the system and the settleability and dewatering characteristics of the activated sludge was tested. COD-load, number and volume of the compartments and the mixing zones were varied.
Experiments were carried out with two pilot plants, a compartment system and a totally mixed system.
The tests clearly indicate that a four-stage cascade system with a BOD-load of about 1.0 kg/(m3.d) could improve settleability and dewatering characteristics, but bulking sludge could not be avoided.
Using a nonaerated upstream zone with a volume load of 4.0 kg/(m3.d)the settling properties in the compartment system(total BOD-load 1.0 kg/(m3.d)) could be improved to such an extent that the formation of bulking sludge was prevented.
Better settleability leads to the higher solids concentration in the cascade system and to a lower sludge load. Therefore lower BOD-outflow-concentrations and higher efficiency of the activated sludge system were available.
The Efficiency of a Biological Activated Sludge Effluent Treatment Plant with Extended Aeration
Authors: Skogman Rurik , Lammi Reino 
Published: May 2018

The requirements imposed on the Finnish forest products industry by the water authorities have focused on the reduction of BOD and suspended solids in the wastewaters.
The industry has tried to comply with these requirements, first through internal measures such as process changes and closed systems. When these have not been sufficient, external treatment has been resorted to.
The Wilh. Schauman Company in Jakobstad has chosen activated sludge with extended aeration from among the available methods for treating effluent. The plant has operated since the beginning of 1986 with extremely good results. In addition to the reduction of BOD and suspended solids, there has been a marked decrease of chlorinated phenols. Chlorinated substances with higher molecular weight are also removed during the process.
Evaluation of the ‘Fugacity' (FEQUM) and the ‘Exams' Chemical Fate and Transport Models: A Case Study on the Pollution of the Norrsundet Bay (Sweden)
Authors: Kolset Knut , Heiberg Anders 
Published: May 2018

Two different models have been used to investigate how chemicals present in wastewater from a kraft mill are transported and spread in an aquatic environment. The models, FEQUM (Fugacity EQUilibrium Model) and EXAMS, are presented, their characteristics explained and a comparison of the models is made. In FEQUM the concept of fugacity is considered as the driving force behind chemical transport. The EXAMS dispersion model uses water and sediment flow as the basis for calculating the dispersion of chemicals. FEQUM encompasses the whole environment, water, air, soil, sediments, suspended matter in water and biota, whereas EXAMS includes the aquatic domain only.
Both models have been applied to the Norrsundet area. Norrsundet is a heavily polluted bay on the east coast of Sweden. The pollution is mainly due to a kraft mill located in the area. The models were calibrated using data on chloroform in wastewater and seawater, and then tested on four other pollutants present in the wastewater. Both models give satisfactory results for the compounds investigated, tetrachlorocatechol constituting the only exception. Correlation coefficients between calculated and measured concentrations vary from 0.86 to 0.97. The poor results obtained for tetrachlorocatechol are probably due to the especially high affinity of this compound for suspended particles.
Effects of Pulp Mill Effluents on Skeletal Parameters in Fish – A Progress Report
Authors: Bengtsson Bengt-Erik 
Published: May 2018

In the Gulf of Bothnia the fourhorn sculpin (Myoxocephalus quadricornis) demonstrated elevated levels of deformed spine and/or vertebrae in areas polluted by bleached kraft mill effluents (BKME). Laboratory tests confirmed a correlation between the observed defects and BKME, diluted about 200-1000 times. Analysis of mechanical parameters (strength, elasticity etc) and chemical composition (Ca, P, collagen, proline, hydroxyproline) of single vertebrae confirmed the effects of BKME on bone characteristics in feral and laboratory exposed fourhorn sculpin. Similar effects were recorded also for feral perch (Perca fluviatilis) caught in the vicinity of a pulp mill and bleak (Alburnus alburnus) exposed to various BKME in the laboratory.
After about 4 1/2 months of exposure to 0.1 and 0.5 mg tetrachloro-1,2-benzoquinone/L fourhorn sculpin demonstrated vertebral deformities and aberrant mechanical properties of vertebrae. The results are discussed in relation to results obtained from feral fish exposed to BKME and fish exposed to BKME in the laboratory.
The recorded effects are suggested to be the results of long-term metabolic dysfunction, leading also to other serious effects in the organism.
The Vyredox and Nitredox Methods of in situ Treatment of Groundwater
Authors: Braester Carol , Martinell Rudolf 
Published: May 2018

Nearly one fifth of all water used in the world is obtained from groundwater. The protection of water has become a high priority goal. During the last decades pollution of water has become more and more severe. Today groundwater is more and more used in comparison with surface water. Recently we have seen accidents, which can pollute nearly all surface water very quickly. Generally the groundwater is easier to protect, as well as cheaper to purify, and above all it is of better quality than the surface water.
During the past two decades, alternatives to the traditional method of treating the water in filters have been developed, that is in situ water treatment i.e. the VYREDOX and NITREDOX methods.
The most common problem regarding groundwater is too high content of iron and manganese, which can be reduced with the VYREDOX method. In some areas today there are severe problems with pollution by hydrocarbons and nitrate as well, and with modification of the VYREDOX treatment method it is used for hydrocarbon and nitrate treatment as well. The method to reduce the nitrate and nitrite is known as the NITREDOX method.
Migration of Soluble ASH Components from a Tip to Groundwater
Authors: Kempa E. S. , Jȩdrczak A. 
Published: May 2018

An area used for storage of ash generated in a thermal power plant is located in an old gravel mine. The effluent from the ash pond is reclaimed and reused, without any treatment, for hydraulic transport of new ash. The pond has been used for about 12 years, and specific tests and groundwater analyses have been undertaken since 1975.
The concentration of inorganic constituents in the groundwater, measured at different distances from the pond, show that:–the concentration of inorganic substances decreases with distance from the pollution source;–an increase in the concentration of pollutants is found at the same points in consecutive years.
These patterns allow us to evaluate the influence of the ash pond on the soil environment and groundwater at the present time and in the future. With the help of the research mentioned and this specific case study, we are able to verify the model of migration of contaminants in soil.
Geochemical Modelling of Water-Rock Interaction in Deep Groundwater
Authors: Pitkänen P. , Pirhonen V. , Snellman M. 
Published: May 2018

A deep borehole (1001 m deep) was drilled in a granitic intrusion in Lavia in southwestern Finland in 1984 within the framework of the site investigation programme for spent fuel disposal /1/. Groundwater samples were taken from five depths in the borehole in 1984-1985 /2/. This paper describes the attempts to evaluate the geochemical interaction between groundwater and bedrock minerals in the borehole.
The modelling of the water-rock interaction in the borehole was performed by using the geochemical codes PHREEQE and EQ 3/6. The modelling was principally performed with PHREEQE. For comparison some cases were also calculated with EQ3/6. Based on the chemical analysis of the water including also pH, Eh and temperature, the distribution of species in solution is solved by the aqueous model using mass action and mass balance equations. From the calculated distribution of species equilibrium partial pressures of gases are calculated, as well as the saturation state of the solution with respect to appropriate mineral phases. On the other hand based on the identified minerals the model was also used to calculate the dissolution of the minerals found in the borehole into water in order to test which minerals are the main sources of the elements in groundwater.
The major elements in groundwater were found to occur mainly in ionic form. The mineral saturation indexes (SI) are presented in Figure 1. Quartz is in equilibrium with water at every groundwater sampling level. The high saturation indexes found for kaolinite and muscovite are in agreement with the fracture minerals identified in the borehole. Calcite is dissolving at the depth of 94–99 m, which is in accordance with the distribution of calcite in factures. The behaviour of ores (pyrite, goethite and hematite) is analogous with mineral analyses of fractures. According to the fluid mineral stability diagram kaolinite is the stable mineral phase at the lower and upper sampling levels. At the depth 422–427 m the equilibrium is in the muscovite field.
Both SI- and fluid mineral stability diagrams indicate more stagnant groundwater conditions at the 422-427 m level than at the lower and uppermost sampling levels of the borehole.
According to the calculations based on the minerals found in the borehole the main sources for sodium and calcium are montmorillonite + albite and calcite + fluorite, respectively.
The results obtained so far are considered only tentative as they depend on several factors such as the correct thermodynamic constants, the accurate analysis of all dissolved species, the physico-chemical parameters and the composition of mineral phases, which all together control the solute content.