bluuebunny/crossref_metadata_2025_split huggingface dataset:
A stochastic approach to modelling solid transport in settling tanks
Authors: Chebbo Ghassan , Forgues Nicolas , Lucas-Aiguier Emmanuelle , Berthebaud Stéphane 
Published: May 2018

Dispersion and settling models for suspended solids (SS) in turbulent flow are in the majority of cases Eulerian and deterministic. They simulate SS transport using a convection-diffusion equation. When the diffusion term is supposed not to be zero at the boundary of a settling tank, we show that an alternative (or equivalent) description of the basic convection-diffusion equation for the concentration of suspended solids consists in modelling the particles trajectories as a stochastic diffusion process.
This paper has two aims, firstly to present the proposed stochastic approach and secondly to apply this new method to the calculation of a settling tank's efficiency.
Generation of halogenated organic compounds in municipal waste water
Authors: Schulz Stefanie , Hahn Hermann H. 
Published: May 2018

Cleaning agents and disinfectants from housekeeping, hospitals and canteen kitchens are important sources of adsorbable halogenated organic compounds (AOX) in municipal waste water. They often contain inorganic compounds which are able to release activated chlorine. Together with organic waste water compounds the activated chlorine can generate halogenated organic compounds. Within the scope of this research project the generation of AOX through these active agents is compared. The effects of concentration, pH, time, temperature, presence of other oxidizing or reducing agents and synergetic effects are investigated and discussed.
According to the results the potential of these active agents forming AOX is obvious. The AOX concentration of a municipal waste water increased by the factor of 13 after adding hypochlorite containing disinfectant in common concentration. Most AOX can be formed within 30 minutes. In sewage with high amount of solid compounds the AOX generation can take a long time (several days). The amount of AOX generated strongly depends on the nature and concentration of dissolved and solid organic compounds, the concentration of active substances, temperature, pH and the reaction time.
Real time control of the sewer system of boulogne billancourt - a contribution to improving the water quality of the seine
Authors: Entem Stéphane , Lahoud Antoine , Yde Lars , Bendsen Bo 
Published: May 2018

Confronted with the problem of overflows from its combined sewer system into the River Seine during rainfall, the Department of the Hauts de Seine (which covers some thirty urban districts on the west side of Paris) has decided to implement the real time control of its sewer system. To initiate this plan, as the town of Boulogne Billancourt seemed to be a particularly favourable site for the use of such techniques, a project to control its sewer system in real time has been implemented within the scope of the SPRINT 226 programme financed by the European Community.
The preliminary studies, based on a MOUSE computer model of the sewer system, showed that the real time control of the sewer network under study had a high potential benefit, since it would allow an 80% reduction of the volumes of waste water discharged into the Seine annually in the study zone. Following on from these encouraging results, the installation of a complete real time control system was set in hand. The system, at present undergoing testing and evaluation, consists principally of a MOUSE ON LINE real time model and a system for forecasting rainfall by means of radar images.
Aerobic stabilisation criteria for BNR biosolids
Authors: Tonkovic Zlatko 
Published: May 2018

A research program was undertaken to establish the stability of waste activated sludge generated from seven activated sludge treatment plants, both nutrient removal and conventional, and determine what further treatment is required to produce a substantially stabilised (ie. non-odorous) sludge.
It has been previously thought that waste activated sludge from extended aeration plants (sludge age of approximately 25 days) was sufficiently stabilised to permit dewatering and stockpiling without odour generation. However, experience at a number of treatment plants with large unaerated mass fractions for biological removal of nitrogen and phosphorus has demonstrated that these sludges are generally odorous. With the increasing requirement for on-site storage of sludge to remove pathogens prior to sludge re-use, odour generation from secondary sludges has the potential to pose significant environmental problems for many treatment plants.
The objective of the research program was to quantify the degree of stabilisation achieved in various activated sludge treatment plants, what additional aerobic treatment is required to achieve a stabilised sludge and what are the readily identified characteristics of a stabilised sludge, including volatile solids content, specific oxygen uptake rate and pathogen destruction. The phosphorus leaching characteristics were also compared between various sludges and between continuous and intermittent aerobic digestion process.
Phosphorus uptake and active growth of Elodea canadensis Michx. and Elodea nuttallii (Planch.) St. John
Authors: Eugelink A. H. 
Published: May 2018

Two related submerged freshwater macrophyte (Elodea nuttallii (Planch.) St. John and Elodea canadensis Michx.) were used in a combination of in- and outdoor experiments to compare growth rates and routes of phosphorus uptake, translocation and possible excretion. Elodea nuttalli had a higher growth rate than Elodea canadensis both in the field and under laboratory conditions.
The uptake and translocation of phosphorus was studied using 32P in a partitioned container. Roots and leaves were supplied with 32P separately and simultaneously. Both macrophyte species were able to take up phosphorus both with leaves and roots. The uptake rate of 32P by roots was higher in Elodea nuttallii when tracer was supplied to the root compartment only. Leaf uptake was stimulated by the supply of phosphate to both compartments, and the uptake was faster and reached a higher level than when the tracer was injected to the leaf compartment only. The 32P uptake by either roots or leaves was translocated. Shoot-to-root translocation predominated over the reverse. There was no significant difference between both species in root uptake rates, but leaf uptake was significantly higher in Elodea canadensis. The two studied Elodea species do not have a strong preferential source of phosphorus.
Use of on-line data to evaluate the activity in the biological stage at a wastewater treatment plant
Authors: Björlenius B. , Reinius L.-G. 
Published: May 2018

Today many WWTPs are equipped with different on-line instruments for automatic and manual control of the process. The use of computerised systems for data acquisition gives us new possibilities to evaluate collected data. This study shows the possibilities and potentials in using standard equipment, simple calculations and the biological stage as a measuring cell for activity determinations.
Evaluation of data from Henriksdal and Bromma WWTP give some examples from the biological stage where activity can be calculated on-line. The calculation of Oxygen Uptake Rates, OUR, can be used in several ways: a) Estimation of the overall activity in the aerated part of biological stage. b) Calculations of the load of oxygen consuming substanses on the aerated basin. c) Calculation of nitrification rate. d) Estimation of necessary aerated volume. e) Rapid detection of inhibition of the nitrification (and other oxygen consuming reactions). One advantage with these calculations is the fast response to changes.
Upgrading an anaerobic/aerobic wastewater treatment plant
Authors: Austermann-Haun U. , Lange R. , Seyfried C.-F. , Rosenwinkel K.-H. 
Published: May 2018

The given example of an anaerobic/aerobic wastewater treatment plant ((WWTP) for a big German brewery shows that it is possible to reduce the discharged values to a very low level, much lower than the minimum requirements of Appendix 11 of the German General Wastewater Administration Rule, which applies to breweries. This means that the present state of technology has been updated.
Tests on a semi-technical scale were carried out and found to be necessary to find the most suitable design for the wastewater treatment plant. Running the tests in the brewery, it became obvious that disinfectants had to be substituted until a stable COD elimination was achieved. Full-scale tests in the plant would not have been feasible. Numerous modifications were carried out in the brewery to reduce the amount of cleaning and disinfectant agents as well as the amount of AOX, EDTA, NTA and aluminium used.
The following article presents the findings of the investigations about the ammonification of organic nitrogen, bulking sludge and substrates for denitrification. Furthermore it demonstrates the low operating costs of anaerobic pre-treatment, even in combination with an aerobic stage and filtration unit.
Municipal waste discharge policies in Washington State and recent discharge issues between the State and British Columbia
Authors: Loehr Lincoln 
Published: May 2018

Federal and state laws mandated secondary sewage treatment for all municipal dischargers in the state of Washington regardless of need. Evidence supported the suitability of lesser amounts of treatment and the use of industrial source controls as protective of water quality, but could not be considered. The full implementation to secondary treatment is now complete.
In the 1990's, the media, environmental activists and various local, state and federal politicians from Washington State became upset with Victoria, British Columbia when they realized that most of the sewage from the greater Victoria area was only screened prior to discharge to the Strait of Juan de Fuca. The perception was tainted by a lack of understanding of the benefits and power of rapid dilution, and also the mistaken impression that the excessive treatment requirements in Washington were actually needed for water quality reasons.
A British Columbia/Washington State Marine Science Panel was established by the political leaders of the province and state to examine issues of the shared marine waters. The Panel concluded Victoria's discharges were not a problem. The media in Washington State did not report this, and the director of the state's environmental agency expressed disappointment rather than relief with the finding.
On-line monitoring of micropollutants in the river trent (UK) with respect to drinking water abstraction
Authors: Drage B. E. , Upton J. E. , Purvis M. 
Published: May 2018

Severn Trent Water (STW) have been investigating the potential of using the River Trent as a drinking water supply resource. Supply and demand assessment during recent semi-drought conditions in the United Kingdom over the last few years indicates that there is a need to utilise Trent water to safeguard supplies for the East Midlands area of England when stocks derived from the River Derwent catchment are limited.
The River Trent contains the treated sewage effluent from four million people plus industry in the Midlands and along with diffuse drainage sources means that the river quality can be highly variable. In conjunction with various treatment studies on River Trent water, the pollution risks and water quality variations have been examined. The results have been used to develop an on-line monitoring station to give effective river intake protection in line with the risks found. This monitoring includes continuous low level detection (to less than 1μg/l) of multiple pesticide groups including acid herbicides, acheived by a unique development of solid phase extraction and liquid chromatography techniques.
Service water quality monitor including hue and coloration grade
Authors: Hiraoka Mutsuhisa , Noda Naohiro , Hayakawa Chiyoji , Gotoh Keiji , Shirozu Tohru , Hosoda Saburoh , Ichinohe Masanori 
Published: May 2018

The authors introduce an index of coloration grade for evaluation of service water colour. The principle of the coloration grade measurement has been derived from authors' modification of the Tristimulus Filter Method of AWWA 1992 and JWWA 1993 Standard Method, and it has the advantage of applicability to all colours in the visible range. The characteristics of the hue and coloration grade measurement has been tested in the laboratory using various coloured samples obtained from water service pipes or an aqueduct. Compared with the “colour” measured by the platinum-cobalt method, the coloration grade is more sensitive to various water coloration and close to human senses.
Applying the above stated device, a Service Water Quality Monitor was newly developed and successfully tested at several distinctive fields. It monitors three items, colour, turbidity and residual chlorine which are obligatory in Japan to be daily examined at appropriate house taps. For the field test of about six months without any manual calibration, the accuracy of the hue and the coloration grade has shown maximum deviation of only 2.5% FS compared with the measurement by means of the standard solutions once a month.
Adaptation of the microbial adhesion to hydrocarbon test (MATH) for measuring activated sludge hydrophobicity
Authors: Guellil A. , Block J.-C. , Urbain V. 
Published: May 2018

The “microbial adhesion test to hydrocarbon” (MATH) developed by Rosenberg et al. gives a cell hydrophobicity index (A% = percentage of adhesion) and is easy to perform. However it is not applicable with any degree of accuracy to activated sludge even when dispersed by sonication, because of the presence of aggregated and free cells and of amphiphilic organic polymers from sludge which lead to the formation of a stable emulsion. The effect of emulsion formation is a decrease in bacterial number from the aqueous phase by adhesion on to, and trapping between, the droplets of octane. This induces an overestimation of the hydrophobicity of the bacterial suspension.
To solve this problem, we propose modifications of the MATH which may be used for any bacterial suspension and which expresses the bacterial adsorption equilibrium between the surface of the octane droplets and the water phase. The test starts just as for the regular MATH by mixing the bacterial suspension and octane. The resulting emulsion is sampled, and then serially washed 10 times with 5 ml of MilliQ water. By plotting the decreasing numbers of bacteria recovered in the washing solutions against the number of bacteria adhering to octane droplets, a linear relationship is obtained the slope of which equals an equilibrium constant Ke. For the 5 samples of sludge tested, Ke (values from 1.3 to 3.2) appears to be a more accurate and sensitive parameter than A% (values from 62 to 86%).
Behaviour of activated sludge from a system with anoxic phosphate uptake
Authors: Šorm R. , Bortone G. , Wanner J. , Tilche A. 
Published: May 2018

Activated sludge from a new activated sludge modification for biological phosphorus and nitrogen removal was studied. Population dynamics and the phenomenon of anoxic phosphate uptake with simultaneous denitrification were investigated.
The ability of the process to remove nutrients and to suppress filamentous bulking was studied. The course of phosphate concentrations along the tested system showed an anoxic phosphate uptake with simultaneous denitrification. The mechanism of anoxic phosphate uptake was confirmed using kinetic batch tests.
Anaerobic processes in activated sludge
Authors: de Beer Dirk , Schramm Andreas , Santegoeds Cecilia M. , Nielsen Helle K. 
Published: May 2018

We found anoxic zones in aerated activated sludge flocs, and demonstrated denitrification under normal operating conditions. Sulfate reduction was not found. Micro-environments and microbial conversions in flocs from bulking and non-bulking activated sludge were determined with microsensors for H2S, O2, NO2− and NO3−. Denitrification and sulfate reduction rates were mmeasured with 15N- and 35S-tracer techniques. We showed that under normal reactor conditions (ca. 20% air saturation) anoxic zones develop within flocs allowing denitrification. The denitrification rates amounted to 40% of the rates under anoxic conditions. At 100% air saturation no anoxic zones were found and no denitrification occurred. However, in flocs from bulking sludge (at 20% air saturation) anoxic zones were absent and denitrification did not occur. In bulking sludge only at total anoxia was denitrification found. Confocal microscopy showed that flocs from bulking sludge were much looser than those from non-bulking sludge. The absence of anoxic zones and of denitrification was attributed to the open floc structure, allowing advective oxygen transport.
Sulfate reduction was not detected in any of the sludges tested by microsensors or by tracer techniques even under anoxic conditions. this indicates that the sulfur cycle (sulfate reduction and sulfide oxidation) does not play a role in mineralization processes and bulking in activated sludge. Preliminary molecular work (in situ hybridization with the 16S-rRNA probe SRB385) indicated the presence of small amounts of sulfate reducing bacteria in all sludges. Either the probe is not specific or the sulfate reducers present are not active under reactor conditions.
Monitoring of environmental effects and process performance during biological treatment of sediment from the petroleum Harbour in Amsterdam
Authors: Stefess Guus C. 
Published: May 2018

A full-scale (470 m3) process for biological treatment of dredging spoil from the Petroleum Harbour in Amsterdam has been monitored during a pilot project. The dredging spoil was heavily polluted with polycyclic aromatic hydrocarbons (PAH) and mineral oil. The remediation chain involved dredging, transport of dredged spoil, hydrocyclone separation, froth flotation of the coarse particles, and biological treatment of the silt fraction (&lt;20 μm) in stirred bioractors. The independent monitoring was aimed at recording the environmental effects, product quality and performance of the biological process.
Hydrocyclone separation (cut point 20 m) resulted in two bulk streams: 65% sand and 30% silt (based on total dry weight of the input). The sand was cleaned and could be reused as building material. PAH and mineral oil were successfully concentrated in the silt fraction (&lt;20 μm), which was treated biologically. Biological treatment during continuous feeding of fine fraction, at a residence time of 8-10 days for the entire bioreactor system, resulted in considerably reduced mineral oil and PAH contents. Furthermore, the leaching of organic contaminants was reduced, as well as the ecotoxicity. The obtained silt product however did not meet the demands, and had to be landfilled. Minor emissions of contaminants were measured in wastewater and offgas. The energy and chemicals consumption were acceptable.
The biological process appears to be promising for the treatment of less-severely contaminated dredged material.
Agricultural diffuse pollution in Thailand
Authors: Tonmanee N. , Kanchanakool N. 
Published: May 2018

Over the past two decades there have been a number of changes in Thailand, changes in the environment and quality of life for its people, changes in its communities and in the foundations of its economy. Before 1970, Thailand was a rural society in which local communities depended on the natural resources which surrounded them, and the national economy relied on the export of native crops. The sustainable use of resources was a fundamental aspect of rural life, people understood the interrelationships between the different components of their local environment and their activities which were defined by the need to protect their surrounding resources.
Agriculture is the major profession and source of income for the rural poor. Land degradation and soil depletion result in low crop yields and pollution of the environment; soil erosion and landslides are found in Thailand. Nutrient uptake by crops and loss by leaching is much greater than the nutrients applied. Hence soils become less productive and it results in more land requirement for food production. Forest land declines rapidly in hilly watershed areas.
Thailand is located in a tropical region and European countries are located in a temperate region. The climate is completely different, the temperature during summer in some European countries is probably almost the same as winter in Thailand. Not only is the climate in the two regions different, but land use and soil type are different also. These parameters have to be considered when studying the impact of agricultural diffuse pollution on the environment.
Research studies on agricultural diffuse pollution in water resources in Thailand show that nutrient loads and pesticide residues still do not exceed the standard level. However, there was a trend showing the increase of N-NO3 in water resources, in short-term monitoring of nutrients in the east of Thailand between 1988-1990 and 1993-1995. The result showed the increase of N-NO3 from 1.60 ppm to 2.54 ppm in the same watershed and landuse areas. If the use of fertilizers and pesticides in agriculture is increased without due consideration, Thailand will face the same problem as European countries.
Combination of a Well Functioning Constructed Wetland with a Pleasing Landscape Design in Nairobi, Kenya
Authors: Nyakang'o J. B. , van Bruggen J. J. A. 
Published: May 2018

The constructed wetland consists of a combination of a sub-surface horizontal flow system (VSB) planted with Typha, followed by a series of three pond systems planted with a variety of plants, including ornamental plants. The plant species include Typha, Cyperus latifolius, Cyperus papyrus, Hydrocotyle, Hydrocleis and Pontederia. The wetland is treating wastewater from a restaurant (The Carnivore) and a swimming pool resort with recreational facilities (Splash), both in Nairobi, Kenya.
The wetland is designed to treat wastewater as well as to provide an aesthetically pleasing and environmentally sensitive landscape with ponds and ornamental plants for recreation. The 0.5 ha wetland is designed for 1,200 population equivalents, and has a high treatment efficiencies for BOD5, SS, COD, faecal coliforms, Kj-N, NH4-N and o-PO4 of 98, 85, 96, 99, 90, 92 and 88% removal.
An attempt has been made to determine a mass balance for the system. Most of the nitrogen and phosphorus is deposited in the soil of both the subsurface horizontal flow constructed wetland and the ponds. Some nitrogen is removed by denitrification, only 6% of it is retained by the plants. The sediments play therefore, a major role in the removal of the nutrients. The constructed wetland attracts many birds (128 bird species have been reported) and amphibians. The overall impression of the wetland is that the dual function of beauty and wastewater treatment is achieved.