bluuebunny/crossref_metadata_2025_split huggingface dataset:
Danube Field Excursion 1988: Tritium Content of River Water; Radioactivity of Danube Sediments
Authors: Rank D. , Maringer F. J. , Papesch W. , Rajner V. 
Published: May 2018

Water, sediment, and fish samples were collected during the Danube excursion 1988, within a coordinated sampling program of the Radiology Working Group of the “Internationale Arbeitsgemeinschaft Donauforschung ” (K.Hübel, Munich; I. Kurcz, Budapest; D.Rank, Vienna). The H-3 content of the river water and the radioactivity of the bottom sediments were measured at the BVFA Arsenal, Vienna.
The determined H-3 content of the Danube water corresponds with the long-term trend in the H-3 content of the hydrosphere; the values lie in the range of 3 Bq/kg downstream from Belgrade, upstream from Belgrade they are about 4 Bq/kg. It was only in the waste water plume of the nuclear power station of Kozloduj that a slightly elevated H-3 value - 6 Bq/kg - was determined. The content of the sediments of artificial radionuclides was found, at the time of the Danube field excursion, to be almost exclusively due to the radioactive material released following the reactor accident at Chernobyl in April 1986 (mainly Cs-137 and Cs-134). As a consequence of the air currents and precipitation conditions prevailing at the time of the accident, the bottom sediments in the lower course of the Danube were less contaminated than those in the upper course. The fine sediments were found to contain over 3000 Bq/kg of Cs-137 in the upper course of the Danube.
Treatability of High Strength Brewery Wastewater with Stabilized Refuse
Authors: Fan Kuo-Shuh 
Published: May 2018

A column with a surface area of 790 cm2 and effective height of 105 cm was used for the study. The column was filled with stabilized refuse (which had been studied for two consecutive years regarding leachate recycling) compacted to an average density of 500 kg/m3. High strength brewery wastewater, with a COD of 6000 mg/l, was homogeneously trickled over the top of the refuse at daily flow rates of 8, 16, 24, and 36 liters/day. Each flow rate was maintained for more than three weeks to achieve steady performance. After six months of intensive study, it was demonstrated that the stabilized refuse had a very good ability to treat the brewery wastewater. The COD was reduced to as low as 60 mg/l, which was equivalent to a removal efficiency of 99%, after the wastewater had trickled through the 90 cm refuse layer. The COD reduction achieved in the stabilized refuse layer perfectly fitted the following equation:
The variations of major parameters such as pH, alkalinity, and volatile fatty acids, strongly indicated that acidogenesis occurred quickly in the first 15 cm. As the flow rate increased, acidogenesis occurred deeper in the column and its recovery became slower. The oxidation reduction potential (ORP) dropped to as low as −290 mV in the refuse column, indicating the anaerobic conditions of the system.
Waste Water Management in a Sugar Beet Factory: A Case Study of Comparison between Anaerobic Technologies
Authors: Iza J. , Palencia J. I. , Fdz-Polanco F. 
Published: May 2018

The ACOR-l sugarbeet factory owns a waste water treatment plant which handles 2500 m3/d of medium strength wastewater (COD = 4000 mg/L). The system was designed to treat the excess wastewater from the beet transport circuit, some process streams, the sanitary waters and wastewaters from an alcohol distillery. The plant is based on two lagoons for equalization and pre-acidification of the waste, an Upflow Anaerobic Sludge Bed (UASB) reactor (efficiency &gt; 97% soluble COD) and a small lagoon used for final polishing of the effluent.
A pilot-scale Fluidized Bed (FB) reactor was run in parallel with the UASB reactor to assess the capability of the FB system. There were two runs in consecutive campaigns, where results showed very good efficiency in spite of very high loading rates and low hydraulic residence times achieved in the FB system.
Heavy Metals and Heat Value in Sewage Sludge
Authors: Reimann Dieter O. 
Published: May 2018

Of the 50 × 106 Mg of sewage sludge (5% dry solids) produced per year in the FRG, 60% is dumped, 30% used in agriculture or composted, and 10% is combusted.
For all the different types of sludge utilization, thermal sludge treatment and disposal or dumping, major problems are created by pollutants in the sludge.There may be serious levels not only of salts and organic pollutants, but also especially of heavy metals.The content of these pollutants causes environmental dangers in soil, plants, groundwater and in the air.
For the thermal treatment or disposal of sludge, knowledge of the salt and heavy metal content is important for the choice of the right flue gas cleaning system.Only by this means can hazardous emissions into the air be avoided.
The advantage of thermal sludge treatment as opposed to the dumping and utilization systems must be seen in the thermal destruction of the organic pollutants.At the same time, as a large part of the heavy metals are evaporated by the high burning temperature, they are taken up into the flue gas and can be captured by condensation on the filter-ash or in the scrubber water.
In the combustion of sludge its heat value is very important, and is dependent on the organic matter and the water content of the sludge, which can be influenced by dewatering systems. Comparative results on heavy metals and heat values for different sorts of sludges have been collected in a great number of investigations.The results of these investigations are presented and should serve as a basis for the prevention of negative environmental influences by the utilization, dumping or burning of sludge.
Enhancing Nitrogen Removal in Activated Sludge with Fixed Biomass
Authors: Bonhomme M. , Rogalla F. , Boisseau G. , Sibony J. 
Published: May 2018

To upgrade existing activated sludge treatment plants, different techniques that would remove an important flux of nitrogen rapidly on a great number of units were investigated. Nitrification with conventional activated sludge systems requires considerable multiplication of tankage volume. The necessary investment and space is not always available, especially since many older plants are now in urbanized areas. To lower the nitrogen load in receiving water, the first priority should be to obtain partial nitrogen removal with existing plants, using methods that are simple to adapt.Three techniques were tested on large scale: submerged elements in aeration basin to add fixed biomass, contact stabilisation that allows a higher sludge age in the same tankage volume, and adding submerged biotower packings as a tertiary aeration stage.
In a full scale unit (4000 m3/d), one complete section of the plant fitted with biofilter packing was operated in parallel with a similar unmodified section as reference. The volume occupied by the fixed beds was varied between 20 and 40 % of the tank. The submerged elements improved removal efficiency, to maintain effluent quality at higher loadings or obtain lower residual pollution values in existing plants. The biofilm evolution and the hydraulic behaviour of the packing was followed. No significant change in sludge settleability was observed, but fixed biomass addition reduced sludge production because of a lower overall mass loading. The resulting higher sludge age allowed the ammonia oxidizers to remain in the mixed population beyond usual F/M limits, but no installation of nitrifiers on the support media could be observed.
To verify the limits of immersed plastic surfaces for nitrification, an aerated column was fed with effluent of a highly loaded activated sludge plant. In opposition to carriers submerged in mixed liquor, nitrifier attachment was obtained, and COD and SS removal for effluent polishing was achieved. With a carbon loading exceeding 1,5 kg COD/m3 d, a maximum oxidation rate of 0,4 kg N-NH4/m3 d could be obtained.
A pilot unit was tested to assess the potential volume reduction for nitrogen elimination by contact stabilisation. This configuration stores the highly concentrated return sludge in a reaeration basin, and keeping only the minimum detention time in the contact basin to obtain nitrification. Also, an increased carbon load in the contact basin enhances denitrification. For urban wastewaters with a COD/N ratio of about 10, complete oxidation and partial removal of nitrogen were obtained with a volume loading of 1,5 kg COD/m3 d. Nitrogen removal rates of 0,15 kg N/m3 d were measured both in the anoxic and the aerobic part of the contact basin. The contact stabilisation mode was then tested on full scale combined with submerged biomass carriers. A consistant nitrogen elimination of 50 % was obtained with aeration detention times of about 4 hours.
Denitrification by Fluidized Biofilm Reactor
Authors: MacDonald David V. 
Published: May 2018

The Rancho California Wastewater Reclamation Plant, which has a design capacity of 23.6 Ml/d, is located in Southern California approximately 64 km northeast of the City of San Diego. The effluent from this plant is used for irrigation and groundwater recharge. In order to protect the local groundwater from nitrate contamination, the plant must nitrify and subsequently denitrify to a nitrate-nitrogen concentration of 2.5 mg/l. The influent nitrate-nitrogen concentration, to the denitrification facility, is normally in the range of 15 to 20 mg/l. Denitrification is achieved by three upflow, fluidized bed biofilm reactors.
The reactor is designed for a loading of 3.0 kg of N03−N per day per m3 of expanded bed volume. The upflow velocity is 0.4 cm/s and the reactor has an empty bed contact time of 10 minutes at design flow. Each reactor has a design capacity of 7.5 Ml/d. The biofilm is grown on a media of sand with an effective size of 0.6mm and a uniformity coefficient of 1.2. The reactor has a concrete perforated underdrain, 0.6 meters of support gravel and 1.2 meters of sand. Following a two month start-up period, the facility has consistently removed 95 to 100 percent of the nitrate nitrogen. The objective of this paper is to present the design criteria and evaluate one year of operating performance.
Small Sewage Treatment Plants and Wastewater Reuse in Cyprus
Authors: Hadjivassilis I. 
Published: May 2018

The rapid touristic development in the coastal areas of Cyprus resulting in higher water consumption, the protection of environment and water resources and the needs of reuse of wastewater, contributed to the improvement of local technology for sewage treatment and wastewater reuse for irrigation. In the last ten years, due to the lack of central sewerage systems, approx. two hundred small wastewater treatment plants have been installed, mainly in coastal areas of the island.
The method applied for the biological treatment is the activated sludge extended aeration process. The tertiary treatment based on high-speed depth filtration consists of two vertical pressure multilayer filters, working in series. Additionally, chemicals are injected for disinfection, coagulation/flocculation allowing the production of high quality of water.
Plants regularly maintained are operating with very good results, so that the treated water has the following characteristics:BOD5: &lt; 5mg/lS.S.: &lt; 5 mg/lTurbidity: &lt; 3 NTUResidual chlorine: 1.0-1.5 mg/l
The water can be used for unrestricted irrigation. It has been proved that the installation of small sewage treatment plants and the wastewater reuse for irrigation in Cyprus is a profitable investment, preventing at the same time the pollution of the environment.
Small Wastewater Treatment Plants in Norway
Authors: Ødegaard H. , Storhaug R. 
Published: May 2018

About 70 % of the total number of advanced (biological, chemical or biological/chemical) wastewater treatment plants in Norway are small (100 - 2000 PE). More than half of the small plants (55 %) are based on biological/chemical treatment. Simultaneous precipitation and post precipitation based on the activated sludge process is dominating even if systems based on biofilm processes are gaining more and more popularity.
The State Pollution Control Authority has made recommendations on design of small wastewater treatment plants. Two systems are recommended; one based on a low loaded activated sludge process with querning of particulate matter as pretreatment and with a separate waste sludge holding tank, and one based on a low loaded biofilm system (biofilter, RBC, etc.) with a large septic tank serving both as pretreatment and waste sludge holding tank.
Biofiltration as a Compact Technique for Small Waste Water Treatment Plants
Authors: Desbos Gilbert , Rogalla Frank , Sibony Jacques , Bourbigot Marie-Marguerite 
Published: May 2018

Biological aerated filters combine bacterial degradation of pollution by fixed biomass with physical filtration in a single reactor. Removal rates become independent of clarification and sludge setueability limits, and concentration of biomass is increased. Nitrifiers attach to the media, allowing nitrogen removal without sludge age constraints.
Several fullsize plants with the BIOCARBONE process for industrial and municipal wastewater treatment have established the compacity, ease of operation and high removal rates achievable with this advanced treatment system. A new biofilter design offering simplified operation and increased performance is presented, which allows implementation of biofiltration for small wastewater treatment plants.
Design data for carbon and nutrient removal were collected during extensive pilot tests. Hydraulic conditions and pollution loadings were varied in order to optimize the biological and operational parameters of the filter. The combination of an anaerobic and an aerobic zone eliminates the need for primary sedimentation.
Pollution removal rates up to 20 kg COD/m3 d could be achieved, and a widely fluctuating load of up to twice that average loading can be treated without major effluent deterioration. If lower carbon loadings are used, nitrification is achieved in the upper aerated zone. By recirculating the effluent into the non-aerated lower zone, carbon and ammonia oxidation as well as denitrification and suspended solids retention could be achieved with an overall hydraulic retention time of four hours in one reactor.
Sludge Removal from Some Wastewater Stabilization Ponds
Authors: Carré J. , Laigre M. P. , Legeas M. 
Published: May 2018

The study of sludge accumulation in the first ponds of 12 treatment plants under oceanic climate showed a mean rate of accumulation of 2.8 cm per year corresponding to 0.12 m3 of sludge per inhabitant per year.
Desludging was required about operation periods of 6 or 7 years. Sludge removal by pumping after or without emptying water is the most convenient and with a mean cost of 40FF per m3 the cheapest method. Mean desludging cost is eight times lower than mean investment cost. With regard to their agronomic characteristics stabilization pond sludges have a low fertilizer value because of their long maturation time.
Bottlenecks in the Implementation of On-Site Wastewater Treatment Plants on a Large Scale in The Netherlands
Authors: Fastenau Frits A. , van der Graaf Jaap H. J. M. , Martijnse Gerard 
Published: May 2018

More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties.
At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal.
Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.
Leachate Treatment: Design Recommendations for Small but Extremely Fluctuating, Highly Polluted Quantities of Water
Authors: Heinz Hartmann Karl , Hoffmann Erhard 
Published: May 2018

Today's practice in leachate treatment and disposal in the FRG comprises two possibilities:a) the combined leachate domestic wastewater treatment (transportation to the treatment plant either using the sewer system or tank trucks)b) complete, decentralized treatment at the source of the leachate production.
As a result of the updating of the general water management law (WHG § 7a) the discharge of waste waters containing dangerous substances (e.g. AOX) into sewer systems is no longer permitted. As there is no possibility of a selective removal of the hazardous substances, the future consequence will be that the whole amount of leachate has to be treated at the landfill site.
Existing leachate treatment plants are often designed for average loading rates. Because of the high fluctuations of the leachate quantity such plants are often overloaded. In the past there were two solutions:a) temporary transportation to a municipal treatment plant using trucks,b) recycling of the excessive leachate volume.
As transportation is no longer accepted there is only the possibility of recycling left. The feasibility of buffering the runoff peaks has not yet been studied in detail (reservoir management). This cost-favourable option (earth basin with sealing) offers two advantages. First, the plant design can be based on mean conditions while secondly the loading of the plant will be almost constant (no variation concerning the hydraulic loading; concentration equalization effect of the storage tank).
Herewith an attractive way of adapting existing plants to the time dependent changing requirements is available.
Packed-Entrapped-Mixed Microbial Cells for Small Wastewater Treatment
Authors: Yang P. Y. , Wang M. L. 
Published: May 2018

The primary goal of the research is to develop and evaluate a biological treatment system in which mixed microbial populations are physically immobilized by entrapment. The immobilized system was evaluated initially for its ability to remove simple benzene-based compounds from a synthetic wastewater as a model for treating pesticide-containing waters.
Cellulose triacetate was used as the preparation of monocarrier and combined cellulose triacetate and calcium alginate were used for the preparation of bi-carrier. Phenol was used as substrate to test the entrapped mixed microbial cell process. Process performance including steady state, shock load and comparison of entrapped microbial cell process with and without entrapped microbial cell was investigated. It was concluded that the critical loading rate for phenol synthetic wastewater appeared to be 9 g COD/L/day. The COD removal efficiency could be maintained higher than 90%. Because of the low effluent suspended solid concentration, conventional-secondary-settling tanks could be eliminated. Also, the process could take both concentration and hydraulic shock loads of phenol synthetic wastewater successfully without the need of external sludge recycling. The equalization and external sludge recycling facilities equipped in the conventional wastewater treatment plant could be eliminated. When the process is operated only at low COD loading rate (less than 1.3 g/L/day), entrapped cells might not be required. However, when operated at higher loading rate, combined adsorbed and entrapped cells appeared to remove phenol more efficiently. For the application, mono-carrier (cellulose triacetate) is preferable to bi-carrier (cellulose triacetate and calcium alginate), since it is easier to prepare and the operational performance is better. Therefore, the application of packed-entrapped mixed microbial cell process for treatment of small-toxic-organic wastewater holds great potential.
Upgrading of the Treatment Plants in Stockholm to Meet More Stringent Requirements
Authors: Hultgren J. , Reinius L.-G. , Tendaj M. 
Published: May 2018

The purification requirements for the Stockholm sewage treatment plants will become more stringent in the future. The expected limit values for the effluent, expressed as annual mean values, are for BOD7, Tot-P, and Tot-N, 10, 0.3 and 15 mg/l respectively.
If these contents are multiplied by the design flow values for the three plants, we obtain the maximum quantities which may be released. If the relevant authorities permit the municipality to distribute these total quantities as desired between the three plants, future necessary extensions can be optimized. The following main principles apply to an extension of the three plants:
Loudden sewage treatment plant: This comparatively small treatment plant could, if the requirements are lower than in the other two plants, continue in operation with no other extensions than the inclusion of anoxic zones. It would, however, be necessary to refurbish the plant after a number of years of neglected maintenance.
Bromma sewage treatment plant: The biological stage was extended during the 1982-84 period. For this reason, the municipality suggests that no further extensions of the aeration tanks be required, before 1995 at the earliest. A nitrogen removal with outgoing contents of Tot-N of 15-17 mg/l is expected to be achieved by measures taken to reduce the load on the biological stage instead. These measures consist of centrifuging the excess sludge and pumping it directly to the digesters instead of returning it to the inlet. Furthermore, separate treatment of the reject water from the sludge centrifuges is planned. A third measure could be changing over to a more efficient precipitation chemical to permit a further reduction of the load on the biological stage with regard to, inter alia, BOD7, Tot-N etc. To meet the requirements for phosphorus removal (0.3 mg/l), the plant will be extended with a filter stage after the existing biological stage.
Henriksdal sewage treatment plant: At this plant, which is the largest of the three, the largest extensions are planned. To meet the requirements for nitrogen removal, the present volumes in the aeration tanks will be tripled and will be utilized as anoxic and aerated zones as required. Three new lines with aeration tanks and secondary sedimentation tanks will be constructed. The existing aeration tanks will also be deepened from 5 to 12 m.
The requirements for low phosphorus contents in the effluent will be met by installing a filter stage, as in the Bromma plant.