bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical Controls on the Fate of Mercury and Lead Codisposed with Municipal Solid Waste
Authors: Gould J. P. , Pohland F. G. , Cross W. H.
Published: May 2018

Mercury and lead were among several toxic metals codisposed in test lysimeters with municipal solid waste. Results of analysis of leachates from these landfills during the acid phase of landfill operation have indicated that control of mercury in these systems is a consequence of reduction of divalent mercury to neutral mercury metal. This process was found to occur whether sulfide was present or not. Dissolved mercury in these leachates will exist virtually entirely as chloride complexes. Control of lead solubility was dependent on the presence or absence of sulfide. In the presence of sulfide lead would precipitate as the sulfide while in its absence, the controlling solid was the sulfate. Soluble lead speciation involved significant fractions of both chloride and sulfate complexes. While sulfide has not been detected directly in these systems, levels necessary to control lead solubility were so low as to be indetectable by available methodology and thus its involvement cannot be precluded. Since some circumstantial evidence supportive of sulfate control has been obtained, the complete elucidation of chemical control mechanisms in these systems is not possible.
The Degradation of Polyelectrolytes in the Environment: Insights Provided by Size Exclusion Chromatography Measurements
Authors: Soponkanaporn Teerapon , Gehr Ronald
Published: May 2018

Using a recently developed method for analysing high molecular weight polyelectrolytes by size exclusion chromatography (SEC), the degradation due to ageing, ozone, chlorine, and biological processes, of a commercially available cationic polyelectrolyte, was investigated. These polyelectrolytes are widely used in water and wastewater treatment, and residuals discharged into drinking water or into natural water bodies could be subjected to one or more of the above-mentioned degradation processes.

In general, degradation rate increased with decreasing concentration, increasing pH, and increasing temperature. SEC measurements showed that complete degradation (ie to CO2 and other inorganic monomers) occurred only during biodegradation. Ozonation and chlorination increased degradation rates, but also produced refractory compounds. Acrylamide, one of the starting monomers of the copolymer used, was not produced during degradation, and in fact decreased in concentration during all the degradation mechanisms studied. On the other hand, chloroform was produced as a result of interaction with chlorine. At pH 9, the mass produced, 58 µg/mg polyelectrolyte, could result in substandard drinking waters if significant residual concentrations of this polyelectrolyte were chlorinated.
Application of Expert Systems Technology in Water Quality Modeling
Authors: Barnwell Thomas O. , Brown Linfield C. , Marek Wiktor
Published: May 2018

Computerized modeling is becoming an integral part of decision making in water pollution control. Expert systems is an innovative methodology that can assist in building, using, and interpreting the output of these models. This paper reviews the use and evaluates the potential of expert systems technology in environmental modeling and describes elements of an expert advisor for the stream water quality model QUAL2E. Some general conclusions are presented about the tools available to develop this system, the level of available technology in knowledge-based engineering, and the value of approaching problems from a knowledge engineering perspective.
Practical Odour Nuisance Gauging: Two Case Studies of Objective Odour Quantification in Agriculture and Industry
Authors: du Toit A. J.
Published: May 2018

The quantification of odour problems associated with liquid and solid agricultural and industrial wastes has long been a controversial subject because of the generally subjective nature of the methods used in evaluating odour related complaints. To overcome this problem, a scheme was devised which included three separate quantification techniques, researched both locally and abroad. The collective scheme was introduced as the “Practical Odour Nuisance Gauging” method. This technique has been applied in a number of local odour related investigations and updated throughout so as to render it more practical and acceptable. Two case studies are included to serve as examples of the application of this scheme. It is shown that odour nuisances were indeed present or were likely to occur at the sites investigated.
Dissolved Oxygen Control and Oxygen Utilization Rate Estimation: Extension of the Holmberg/Olsson Method
Authors: Bocken S. M. , Braae M. , Dold P. L.
Published: May 2018

The Holmberg/Olsson method for simultaneous adaptive dissolved oxygen control and oxygen utilisation rate estimation in the diffused air activated sludge process is evaluated (Holmberg and Olsson. 1985; Holmberg, 1986). Small offsets in the parameter estimates occur because the Q/V term is not included in the estimator model. Significant offsets may occur as a result of assumptions regarding the KLa/air flow rate relationship. Extensions are proposed to overcome the offset problems.
The Application of ICA in Sewage Treatment – Witney Evaluation and Demonstration Facility (EDF)
Authors: Butwell A. J. , Burns J. M. , Fielden R. S. , Berry M. J.
Published: May 2018

The Witney Sewage Treatment Works of Thames Water has been established as the Evaluation and Demonstration Facility (EDF) for instrumentation, control and automation (ICA) in sewage treatment. The objectives of the process related EDF programme have included demonstration of the viability of computer-based process management systems, the investigation of the interactions of processes and the development of methods for their optimisation. Evaluation of process monitoring instrumentation has demonstrated that whilst severe shortcomings still exist in some areas reliable process automation can be achieved. Successful routine operation of the Witney plant has been maintained by the automatic control system and a detailed assessment of the main control functions has shown benefits which include cost savings, more accurate control and early warning of equipment failure. Progress has also been made in the modelling both of process performance and of operating costs. This work will lead to the development of software tools to aid process management and to enable process optimisation.
Changes in the Composition of the Danube River Basin Biocenosis Resulting from Anthropogenic Influences
Authors: Pujin Vlasta
Published: May 2018

In the last several decades, anthropogenic processes have brought about a number of changes in the ecosystem of the river Danube. Various hydroengineering schemes have decreased the flooded areas and flooded forests typical of the Danubian basin. Industrial and community waste waters of the centers along the river have loaded it with various organic and inorganic wastes. All this affected the composition of certain members of biocenoses. A number of plant and animal species disappeared from this ecosystem, while some new species have been introduced. Organic production in some sections multiplied, this pointing to the eutrophication process. Due to the large water body, selfpurification process has so far eliminated the load. However, the changes ocurring already provide a warning and are calling for protection measures.
Heavy Metal Contents in Invertebrates of the Danube River
Authors: Yevtushenko N. Yu , Bren N. V. , Sytnik Yu M.
Published: May 2018

The paper presents results of heavy metals content in hydrobionts and bioindication of heavy metals primary stage entrance in freshwater ecosystems, The nature investigations which were made on Danube reaches with different levels of anthropogenic influences showed the heavy metals content in invertebrates is determined by changability of heavy metals concentration in water and sediments and their species differences.
Measures to be Undertaken in Order to Preserve the Trophic State of the “New Danube” at Vienna in the Case of the Construction of the Vienna-Freudenau Hydropower Plant
Authors: Fleckseder H.
Published: May 2018

“Neue Donau” (=“New Danube”) at Vienna was erected for flood protection reasons, but turned out to be a water resort area close to the Vienna City Center (bathing, swimming, surfing along 40 km of beaches). At Vienna, a hydropower plant on River Danube (Vienna-Freudenau) is under discussion. The work presented was undertaken together with Dokulil, Herzig, Humpesch, Janauer and Kohl (Fleckseder and Humpesch, eds., 1987). This paper discusses various alternatives in order to keep the trophic state of New Danube as is at present, but takes also into account left bank water resources questions as well as the hygienic situation (bathing, swimming, surfing). A comparison of all alternatives indicates that - as eutrophication of New Danube is phosphorus driven -precipitation of P in wastewater treatment in the upstream drainage area is, in respect to the situation of New Danube as well as the overall drainage basin - including the receiving Black Sea - the most meaningful solution.
Changes in the Quality of the Danube River Water in the Section Smederevo-Kladovo in the Conditions of Backwater Effects
Authors: Peršić M. , Miloradov M. , Tutundžić V. , Čukić Z.
Published: May 2018

The paper describes specific changes in the quality of the Danube river water under the conditions of backwater effects in the Hydropower Plant Djerdap I storage. The results of longterm tests in five profiles of the investigated section, at various discharges give a global view of the intensity of changes in the composition of water mass. The analysis included changes in the contents of: organic matter, oxygen regime, reduction of turbidity and changes in the composition and abundance of plankton.

The specific changes in the domain of physico-chemical and biochemical processes and changes in the biological status of the watercourse (composition and structure of plankton) at varying retention times complete the picture of short-term changes in the investigated system. Presentation of some settling effects and processes in the sediment of the storage provides an idea of some long-term changes in the conditions of backwater effects of the Danube in the investigated section.
Water Quality of the River Sava at the Inflow of a Pulp and Paper Mill Effluent
Authors: Cibulić V. V.
Published: May 2018

The results of investigations into the effects of wastewaters from pulp and paper production on the River Sava are presented in this paper. Two situations were studied, i.e., when the treatment plant was in operation and when it was not working. The results of the investigations indicated that the wastewaters had significant effects on the Sava. Chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were increased and some toxic substances were present at high concentrations, e.g., phenols, oils and grease, dyestuff, etc. The negative influence of the wastewaters was greater during the summer, at low water levels in the Sava. The Sava is a tributary of the River Danube, into which the pollution from this river finally flows. Regardless of the water flow rates, toxic substances are constantly accumulating, and, as a result, even such large systems as the Danube and the Sava are becoming more and more polluted.
Development of Water Pollution Control in Austria–An Example of a Riparian State in the Drainage Area of the River Danube
Authors: Fleckseder H.
Published: May 2018

In 1988, some 70% of the Austrian population had sewerage and some percentage-points less biological wastewater treatment. Industry - except pulp and paper - had in 1988 biological treatment for 80% of its load, and pulp and paper for 20% of its load. The paper deals with the development of Austrian Water Law, with water pollution control and its advancement in the period 1968 to 1988, with foreseeable problem areas in water pollution control in the coming years, and finally presents a table with data relating to the main riparian states in the River Danube Basin. From these data and the development in Austria over time, it is to be concluded that the actual application of activities in water pollution control seem to be determined primarily by public or political awareness of this specific task and not so much by resources available.
Evaluation of Waste Water Pollution
Authors: Dular M. , Zagorc-Končan J.
Published: May 2018

Noxiousness of waste water is directly proportional to the level of its pollution. Different methods for the evaluation of waste water pollution are used throughout the world, the most common being the experimental evaluation method. The method of establishing the charge of pollution or harmfulness of waste water differs from one country to another depending on economic and political factors.

This paper provides an overview of the evaluation of waste water pollution in individual Yugoslav republics and autonomous regions. Due to fundamental differences in methodology, the regulations do not assure an equivalent assessment of polluters throughout the country.

Based on our experimental work and experience from other authors, a methodology for the evaluation of waste water pollution for Slovenia is suggested.
Pilot-Scale Experiences on Anaerobic Fluidized-Bed Treatment of Brewery Wastes
Authors: Anderson G. K. , Ozturk I. , Saw C. B.
Published: May 2018

This paper covers the results of a pilot-plant study on the Anaerobic Fluidized-Bed Reactor (AFBR) treatment of brewery wastes. The AFBR was operated over a wide range of organic and hydraulic loading rates for a study period of more than eight months. The reactor consisted of a clear PVC column with a diameter of 165 mm and 3 m in height. Sand having a median diameter of 0.5 mm was used as the medium. The AFBR was fed with wastewaters collected from a local brewery. A COD removal efficiency of greater than 75% was observed at an organic loading rate (OLR) of 8.9 kg COD/m3 of expended bed/day for 82 days from start-up. The OLR was increased to greater than 14 kg COD/m3.d and a COD to methane conversion of 87% was achieved. Effects of OLR and COD removal efficiency on gas flowrate and on gas composition as well as concentrations of suspended solids (SS) and volatile acids (VA) were investigated. It was observed that biomass distribution along the height of the AFBR was not uniform and a strong stratification of biomass exists between the upper and lower parts of the system. The ecological structure of biomass was examined by SEM and clumps of methanogenic bacteria were identified. The Monod kinetic parameters were determined using steady-state operating data and compared to similar results given in the literature for the same waste.
Sludge-Amended Brick Production: Applicability for Metal-Laden Residues
Authors: Alleman J. E. , Bryan E. H. , Stumm T. A. , Marlow W. W. , Hocevar R. C.
Published: May 2018

This paper will examine the general concept of using sludge during brick manufacture, and will specifically address the fate of metals contained within the employed sludge relative to the vitrification process. Overall, it appears that most metals will be trapped within sludge-adulterated brick, both during firing and weathering. This behavior appears related to a silicate-based physico-chemical containment mechanism. Volatilization of metal during firing was observed in the case of selenium, and in this instance only for specimens spiked with elevated metals levels (i.e. 1000 ppm Se). Simulated weathering in pH=2.5 and pH=5.0 acetic acid resulted in nominal leachate losses beyond the U.S. EPA extraction procedure limits for arsenic, selenium, and cadmium. Here again, though, these marginally elevated losses were only observed for those bricksspiked with extremely high metals levels (i.e. 1000 ppm, or higher). Overall, the research findings presented by this paper suggest that standard municipal sludges laden with “normal” metal levels could be satisfactorily incorporated within a brick manufacturing process with little concern regarding metal release. As for hazardous metal-laden sludges, brick manufacture may comprise a similarly acceptable sludge management option; however, this latter strategy would likely warrant additional site-specific investigation prior to implementation (i.e. relative to the given metal species, concentrations, metal release characteristics, etc).
Tertiary Rotating Biological Contactors for Nitrification
Authors: Boller M. , Gujer W. , Nyhuis G.
Published: May 2018

The addition of rotating biological contactors (RBC) to existing treatment plants for tertiary nitrification showed many advantages over conventional one-stage RBC's. Compared to tertiary trickling filters, the nitrification rates could be doubled. In extended pilot experiments, it was demonstrated that nitrification can additionally be enhanced by a periodic change of the flow direction in a series of RBC's, by filtration of the wastewater between the first and the second biological stage (pre-filtration) and by the control of the rotational speed. The experimental findings were confirmed in a full scale two-stage RBC-plant with intermediate filtration.
New Trickling Filter Applications in the U.S.A.
Authors: Parker D. S. , Lutz M. P. , Pratt A. M.
Published: May 2018

After falling in disfavor in the U.S. in the 1970s, trickling filters are now reappearing in new applications. The Trickling Filter/Solids Contact (TF/SC) process uses physical and biological flocculation features to transform the poor quality of the trickling filter effluent into an effluent equal to the best activated sludge system. Over 50 TF/SC plants have been built since the process was introduced in 1979. The recent development (1988) of the Biofilm-Controlled Nitrifying Trickling Filter (BCNTF) has permitted higher rate operation and rendered the process less costly than the activated sludge system for nitrification. Three BCNTF projects are now underway in the U.S.
Suivi du fonctionnement d'une station d'epuration associant physico-chimie et biofiltration = Metabief (France)
Authors: Pujol R.
Published: May 2018

The sewage treatment plant of Metabief (East of France) has been monitored during three weeks in winter 1988. The treatment associates a physico-chemical treatment with a biological process of biofiltration. The first step eliminates about 60 % of the organic matter (COD and BOD). The biofliters improve the treatment removing 60 % of COD influent and 65 % of TSS. The process is efficient (N excepted) under conditions of the experiment but nitrification is limited by cold temperatures (< 10°C).

Important results related to biological sludge product are presented (sludge characteristic, microscopic data, sludge production). Power consumption of biofliters represents 70 % of the total plant needs. Adequate control of washing cycles and close survey of numerous movable devices are of the utmost importance to guarantee the proper operating of biofliters.
Fluidized Bed Biological Wastewater Treatment: Effects of Scale-Up on System Performance
Authors: Sutton P. M. , Mishra P. N.
Published: May 2018

The operation of a number of small and large scale biological fluidized bed pilot plants over the past ten years has resulted in the derivation of process and component information for design of commercial facilities. The General Motors (GM) Corporation represents the single, largest industrial user of the technology in the United States. Ten fluidized bed reactors are located at GM automotive manufacturing facilities. Nine of the reactors are designed to treat wastewaters originating from metalworking operations pretreated for removal of petroleum oils. The other reactor is designed for treatment of sanitary waste-water. In 1984 and 1985, GM completed extensive pilot plant studies and on the basis of the results selected the aerobic fluidized bed (AFB) process configuration for full scale implementation at various plant sites. The fluidized bed reactors located at the sites range in reactor volume from approximately 60 to 730 m3. The pilot plant results which formed the basis for process design of the full scale reactors involved operation of 77 l fluidized bed reactors. Operating information and performance results were derived from evaluation of full scale GM fluidized bed reactors located at the New Departure Hyatt (NDH) plant in Sandusky, Ohio and the Oldsmobile engine plant in Lansing, Michigan. The full scale results were compared to the pilot plant results with the objective of understanding the effects of scale-up on system operation and performance. A comparable level of reactor attached volatile solids (VS) was measured in the pilot and full scale reactors. Biomass net yield coefficients were higher in the full scale reactors, likely due to differences in the composition of the wastewater fed to the full scale versus the pilot scale units. Oxygen utilization coefficients were comparable. The full scale performance results compared favorably with results from the pilot plant studies on the basis of the relationship between effluent quality and reactor solids retention time (SRT).
Comparison of Various Systems for On-Site Wastewater Treatment
Authors: Fastenau Frits A. , van der Graaf Jaap H. J. M. , Martijnse Gerard
Published: May 2018

Diffuse pollution, caused by direct discharges from individual houses, small built-up nuclei, farms, camp-sites, etc., for which connection to central wastewater treatment systems is unfeasible, may be significantly reduced by on-site treatment.

Based on a large scale research, including intensive field-research work on 14 systems of different types and sizes in a range equal to population equivalents (p.e) of 5 - 200 persons, 8 different types of system were compared. The comparison involved technological features, such as removal efficiency, reliability, operational and maintenance aspects, environmental impacts and land claims, together with economical features showing significant differences. Advantages and disadvantages of each system are highlighted to enable a selection of suitable systems to be made. When no limiting factors are present, it was found that - in general-infiltration systems (infiltration pits; infiltration trenches) have the best features for on-site treatment up to 100 p.e. For larger capacities, or when infiltration is not possible, the rotating biological contactor will be the best solution mainly because of the lower costs.
Design and Operation of Small Wastewater Treatment Plants by the Microbial Film Process
Authors: Iwai S. , Oshino Y. , Tsukada T.
Published: May 2018

Although the ratio of sewer systems to population in Japan has been improving in recent years, the construction of sewer systems in small communities such as farming or fishing villages, etc. had lagged behind that of urban areas. However, construction of small-scale sewer systems in farming and fishing villages has been actively carried out in recent years. This report explains the history of the promotion of small-scale sewer systems, why submerged filter beds are being employed in many cases, and introduces the design, operation and maintenance of representative waste-water treatment plants in farming and fishing villages which incorporate de-nitrogen and dephosphorization.
Performance of a New Equipment for Treating Domestic Wastewater
Authors: Kuroda M. , Sakakibara Y. , Arai T. , Arai A. , Shibayama D.
Published: May 2018

A fixed-bed aeration reactor system was developed for on-site and small-scale wastewater treatment. The reactor was packed with horizontal plates as support materials. There was no clarifier in the system. Three operational regimes were tested, which were a 6 hours total cycle, 8 hours total cycle and 12 hours total cycle. Experimental results showed the reactor can treat household wastewater efficiently. Removal efficiencies of BOD and SS were 88% for the BOD loading rate of 0.12 kg-BOD/m3·d or 5.2 g-BOD/m2·d. Effluent BOD and SS concentrations were means of 18 mg/l and 6 mg/l during the whole time operation. Suspended solids efficiently sedimented on the horizontal support plates in a short settling time. Equations were developed to predict BOD consumption and sludge production as a function of influent soluble BOD and suspended solids. Useful design and operating parameters are identified for future evaluations of the fixed bed aeration reactor.
Conversion of Existing Primary Clarifiers According to the EASC Process for Biological Phosphorus Removal
Authors: Schönberger R.
Published: May 2018

At the end of 1988 a 22,000 p.e. municipal wastewater treatment plant in Northern Germany was converted to the EASC-biological phosphorus removal process. By simple modifications of the flow scheme of the plant, one of two existing primary clarifiers was converted to an anaerobic basin, into which both sewage and recycle sludge are fed. The supernatant as well as the sludge withdrawn from the bottom are discharged into the aeration basin. This operation mode achieves very good phosphorus uptake in the aeration basin. Since start up in November '88, the uptake-capacity increased continually, since April '89 phosphorus is removed down to concentrations of less than 1 mg/l PO4-P in the aeration basin. Due to an inadequate design and size of the existing final clarifier, phosphorus bleedback occurs and reduces removal efficiency. This bleedback could be minimized by either intensifying denitrification or reducing sludge detention time in the final clarifier.
Rehabilitation and Upgrading of the Beni Suef City Wastewater Treatment Plant
Authors: Fadel Ahmed
Published: May 2018

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively.

The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper.

Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units.

The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality.

The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed.

From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.
Improvement of Wastewater Treatment Plant Projects
Authors: Kempa Edward S.
Published: May 2018

It comes about that the construction of a wastewater treatment plant has already started and a new, more modern idea of treatment or plant construction - lower in costs - arises. The investor has the choice to be for or against the proposed changes. The following examples will show the kind of improvements which have been made at three Polish wastewater treatment plants. The first two plants have worked very well for years; the erection of the third will start soon. The construction costs of the plants in question were 50–60% of the previously calculated, separate from the simpler construction.
Subsoil Percolation of Sewage – Purification Efficiency of Unsaturated Zone and Mass Balance of Organic Load
Authors: Rettinger S. , Bischofsberger W.
Published: May 2018

The unsaturated zone is recently getting special attention because of its purification efficiency on discharges of septic tanks, leaking sewers, and seepage of agricultural lands. Since knowledge of quantitative effects and removal processes is poor, investigations are conducted by the use of lysime-ters and a full-scale soil disposal system. Results on variation of seepage water ingredients and mass balances are shown. These and further results give the possibility of upgrading soil disposal systems, in order to minimize pollution of soil and groundwater.
Further Research Needs for Impact Estimates of Urban Storm Water Pollution
Authors: Desbordes M. , Hémain J. C.
Published: May 2018

First described are the French actions which have been developed over the last 20 years in order to prevent various pollution impacts upon receiving waters. However, the remaining high levels of pollution partly explain the recent attention that has been paid to urban storm water pollution. The main elements that are encountered today in the study of urban pollution include: burden of existing sewer systems, reliability of urban pollution impact estimates, gaps between field demands and researchers' actual knowledge. Consequently it is proposed that a methodological approach needs to be developed to deal with two levels of investigation: the practical level and the research level.
Estimation of Storm Water Quality Characteristics and Overflow Loads from Treatment Plant Influent Data
Authors: Aalderink Roelof H.
Published: May 2018

A simple model, based on tanks in series, for the estimation of mean annual loads and frequency distributions of loads from combined sewer systems is presented. The input data, dry weather flow, dry weather quality, and storm water quality are estimated from treatment plant influent data. Two similar methods for the estimation of flow-average storm water quality were tested by using treatment plant influent data generated by the model in comparison with the model input. Both methods are based on daily mass balances, but differ slightly with respect to the averaging procedures used. The performance of both methods is about the same. They show a small bias, but the variability introduced is small when compared with the variation occurring in real storm water quality data. Application of one of the methods on field data revealed no distinct relationships between the flow-averaged storm water quality concentration and the dry weather period or the total daily rain depth. By combination of continuous and Monte Carlo simulation techniques the model can be used to estimate mean annual loads and frequency distribution of loads from combined sewer overflows. For the extreme events a large 90 % confidence interval was found due to the large variations in storm water quality.
Combined Long-Term Simulation of Runoff from Urban and Rural Areas
Authors: Ostrowski M. W. , Alsenz L.
Published: May 2018

It has become evident that emission control standards for stormwater overflow design are practical, but not sufficient to guarantee ecologically balanced quantity and quality characteristics of receiving natural water bodies. The quality and quantity of both stormwater overflow and the receiving water should be considered at the same time. One objective of the investigation was to apply a continuous complex hydrological (quantity) model for simulating combined urban and rural runoff processes to a small catchment in Northrhine-Westphalia to get more information on its suitability as a modern planning tool. The study focuses on the general applicability of the method proposed, data availability, the estimation of model parameters, and the reliability of results produced. Another objective was to solve a practical engineering problem with the methodology proposed. The results show that the method can be used to produce a sample of simultaneous overflow/riverflow events, which subsequently can be evaluated statistically. Data availability and computational efforts are suitable for general application.
Fluxes of Oxygen Equivalents and Nutrients across the Sediment-Water Interface after Combined Sewer Overflows
Authors: Lijklema L. , Meuleman A. F. M. , Bosgoed H. M. M.
Published: May 2018

The fluxes of oxygen into sediments and the release rate of COD, methane and nitrogen after deposition of fresh sewage sludge were measured in an experimental laboratory apparatus. Effects of the initial surface loading revealed a progressive contribution of COD release to the flux of oxygen equivalent to increased loading. Lower oxygen concentrations had the same effect. The actual conversion rate of the organics in the sediments was lower than the potential maximal aerobic degradation rate and higher than the anaerobic rate of hydrolysis. Preferential oxidation of soluble organics at the sediment interface over particulate material limits the release of COD except for high-loaded systems or at low DO concentrations.
Pollutant Removal and Eutrophication in Urban Runoff Detention Ponds
Authors: Toet C. , Hvitved-Jacobsen T. , Yousef Y. A.
Published: May 2018

A water quality model POND for eutrophication and pollutant removal in urban stormwater runoff detention ponds has been developed. The numerical simulation model is a relatively simple, one-dimensional deterministic water quality model consisting of a set of differential equations. Included are processes describing the removal and accumulation of dissolved and particulate constituents as well as processes concerning the yearly cycle of phytoplankton growth and nutrient transformations. The input to the pond is based on runoff quality data and a historical rainfall record.

The model has been used to simulate eutrophication and removal of phosphorus and heavy metals in an urban runoff detention pond. Especially the importance of the pond volume, i.e. the residence time of the runoff water in the pond, for pollutant removal and eutrophication has been analysed. Simulations were carried out based on measured runoff quality data and a 33 years of rainfall record. Dry, normal and wet years and summers were selected for the analysis.
Characterization of Solids Transferred into Sewer Trunks during Wet Weather
Authors: Chebbo G. , Musquere P. , Milisic V. , Bachoc A.
Published: May 2018

The paper describes the choice of parameters used to characterise sewer sediments in trunk sewers. Different sampling and measurement methods are compared for a number of sites. The sampling arrangement in the BEQUIGNEAUX retention basin, situated in Bordeaux, is described as an example of the methods used.

The first results of this study are reported in terms of size, vertical settling velocity and density of suspended solids. There is also a report on the reduction in pollution obtained by settlement of solids.
Sediment in Sewers: Initiation of Transport
Authors: Kleijwegt Rob A. , Veldkamp Robin G. , Nalluri Chandra
Published: May 2018

The initiation of sediment transport in sewers was investigated in field and laboratory studies. From the field studies it was concluded that some deposits in sewers are permanent due to the insufficient capability of the flow to erode the deposits. From the laboratory studies it was concluded that the upper limit of the critical shear stresses for cohesive sewer sediments may not exceed 5-7 N/m2. Non-cohesive sediments are eroded at lower shear stresses than predicted by Shields' criterion. The shear stresses were calculated using the general equations of continuity and motion and Einstein's separation technique for channels of compound roughness. Experiments showed the validity of this method.
Impact of Overflow on Surface Water Quality in East Brabant, The Netherlands
Authors: Bijlmakers L. L. , Dierx R. A. M.
Published: May 2018

There are more than 900 overflow locations from the combined sewerage system in East Brabant, The Netherlands. The impact of overflow on surface water composition can be considerable, especially because of the characteristics of the water courses in the area. Consequently the water quality standards in force will not be reached. Two examples are examined in detail.
Ecological Waste Treatment and Utilization Systems on Low-Cost, Energy-Saving/Generating and Resources Recoverable Technology for Water Pollution Control in China
Authors: Wang Baozhen
Published: May 2018

Various ecological waste treatment and utilization systems (EWTUS) available in urban and rural areas in China are described, among which are land treatment and utilization systems (LTUS), eco-pond systems mainly consisting of macrohydrophytes-growing ponds, fish ponds and duck/geese ponds, and comprehensive circulation eco–systems for the treatment and utilization of wastes in rural areas, such as semi–closed eco–system in fish ponds, “rice–fish” and “rice–azolla–fish” symbiotic systems, recycling eco–systems with methane-generating digesters as central link, and comprehensive recycling eco–systems with digesters and eco–ponds as central link.

In the various EWTUS, the sewage and wastewaters and other wastes are utilized and converted into various forms of recoverable resources and/or energy, while they are being purified to good quality effluents, meeting their respective discharge standards, and hence acceptable to receiving waters.
Options for the Rational Design and Operation of Oxidation Ponds
Authors: Bower Carberry Judith
Published: May 2018

Oxidation ponds can degrade wastewaters at low cost and provide a useful biomass if rational design, operation, and sludge removal practices are carried out. Here, the design of a plug flow Algal Bacterial Clay Treatment System (ABCT) is presented on the bases of both incident sunlight and incoming BOD concentration. Results of kinetic experimental studies are presented in order to determine both optimal and limiting operational parameters. From these experiments, it appeared to be critical to limit pH diurnal variations for effective operation of the treatment system. Empirical computer models were developed to predict reactor parameter variations due to diurnal effects. A computer model based on continuous oxidation reduction potential (redox) measurements appeared to be most useful for automated computer control of variations due to diurnal effects. Chemical addition of CaCl2 facilitated algal biomass flocculation in order to prepare liquid effluents for plant discharge and to prepare biomass for possible beneficial use.
Experimental Studies on the Purification of Wastewater in Water Peanut Ponds
Authors: Xu Hang , Yang Quanda , Liu Runfen , Ma Fang , He Jin
Published: May 2018

Experiments on the efficiency, mechanism and hydraulic flow pattern of wastewater purification, especially the removal of N and P, in water peanut (Alternathera Philoxeroides) ponds are introduced in this paper. The results obtained show that water peanut pond advances over the symbiotic bacteria/algae systems pond and duckweed pond in removing COD, BOD5, TN, NH3–N, TP and phosphate salts at higher efficiencies. In comparison with water hyacinths (Eichhornia crassipes) pond, water peanut pond has higher removal efficiencies in removing BOD5, COD, TN and NH3–N and lower efficiencies in removing TP and PO43–.

The mechanism of the high pollutant removal efficiencies in the water peanut pond, which is proved through the experiments, is as follows: dominant bacteria such as Bacillus, Pseecomonas and Alcaligenes adhering to the root system of the plants help to achieve the efficient degradation of C, N and P containing matters into CO2, NH4–N and PO43−–P, which are then taken up by the roots for the growth and generation of the plants; this is the main mechanism of N and P removal from the wastewater. Due to the smaller number of nitrifying bacteria and algae existing in the pond, there will be no further concern of pH increase in the pond, hence the contribution of nitrification, denitrification, NH3release and settling of hydroxylopatite caused by the reaction of phosphate and calcium in N and P removal was negligible.

It was also determined through the experiments that the flow pattern in the rectangular water peanut pond was close to plug flow.
A Study of Anaerobic Treatment for Highly Concentrated SO42− + Ca2+-Rich Organic Wastewater and Purified Water Reclamation
Authors: Zhou Ding , Chen Yanmin , Meng Xianlin
Published: May 2018

This paper reports the effects of anaerobic treatment for synthetic wastewater and SO2−+Ca2+- rich single-cell protein (SCP) wastewater in a factory. The results show that with the increase of SO2−4+Ca2+concentration, methane productivity will decrease, and that Ca2+ affects the COD removal in wastewater greatly. However, if certain compounds are added in, and acclimated, these disadvantages will be overcome satisfactorily. For SCP wastewater, the COD removal efficiency can reach 75% and methane productivity 260-320 1 CH4/kg COD under the conditions of fermentation temperature of 36±l°C and COD volume loading of 2.3-2.8 kg/m3d. Besides, the purified wastewater can basically be reclaimed.
Model and Numerical Studies on Buoyant Jets in Crossflows: Yantai Marine Outfall System
Authors: Gu Guowei , Wei Heping , Cai Bute
Published: May 2018

The main object of this model research is to study the dilution and diffusion of buoyant jets in crossflows. Combining with a prototype project of municipal sewerage discharge for Yantai, the model tests were taken. Froude's law was used to design the model, and an undistorted model has been adopted. The length scale is taken as l:100. Six integral control equations were deduced, with which we can calculate initial dilution, rise height and spreading width of buoyant jet in the near field.

According to model tests and calculated results of integral control equations, we suggest the essential parameters to be used in the diffuser project at Yantai.
Treatment, Reuse and Disposal of Drainage Waters
Authors: Lee Edwin W.
Published: May 2018

Treatment, reuse and disposal of agricultural drainage water present formidable technical problems. Various treatment technology and disposal methods have been studied. Reuse of drainage is possible with salt tolerant crops but has not been proven in large scale operations. Brine recovery for solar gradient pond and salt harvesting are promising technologies, but the economics of these reclamation processes have not been proven. Promising alternatives must be proven by further research and development before they can be applied to drainage problems.
Removal of Organochlorine Compounds in an Upflow Flocculated Algae Photobioreactor
Authors: Fei Wu Xu , Kosaric N.
Published: May 2018

An upflow alum-flocculated algae photobioreactor was investigated for removal of toxic chlorinated organic compounds, chlorobenzene and 2,4-dichlorophenol. Biodegradation was evaluated by monitoring substrate disappearance and concurrent generation of artifacts. Chlorobenzene disappeared faster than 2,4-dichlorophenol. Relative rates of removal were greater by the live than by the dead algae biomass. In this study, gravity-concentrated, suspension-centrifuged, and alum-flocculated algae biomass cultures of Chlorella and Scenedesmus were used. In batch and continuous upflow photobioreactor experiments to treat wastewaters containing 50, 100, 200 (batch), and 1,000 mg/l (continuous) each of chlorobenzene and 2,4-dichlorophenol were applied to the bioreactors individually and also as a mixture. The continuous upflow photobioreactor system was found to be efficient, versatile, adaptable and easy to operate for removal and biodegradation of these organochlorine compounds.
The Development of Best Optimum Solutions to Drainage Problems
Authors: Ashley R. M. , Goodison M. J.
Published: May 2018

New computer-based approaches to the management of wastewater systems have been developed in response to increasingly stringent legislation. Technical models are now available for the simulation of the quantity and quality performance of sewerage systems, treatment works and receiving waters. In order to formulate the best optimum solutions to accord with the requirements of legislation and minimise costs, cost models now need to be combined with the technical models. This will give an integrated suite of software as the basis for a holistic appraisal of wastewater system performance. Studies are described for the UK in which detailed research studies in one catchment have provided the basis for the formulation of a planned holistic approach to a second catchment using systems analysis techniques.
Comparison of Aeration Equipment under Operating Conditions
Authors: Frey W.
Published: May 2018

In the course of investigations in order to control the efficiency of aeration equipment or to judge the loading of technical activated sludge plants the oxygenation capacity under operating conditions has been evaluated. Plants for industrial as well as for domestic waste water have been investigated.

The investigations were conducted on the oxygenation characteristics - the connection between oxygenation efficiency and specific power consumption, the flexibility of aeration control and adaptability of the aeration equipment to varying demands. Besides these parameters that can be classified quantitatively, practical experiences from the operational point of view as well as the aging properties will be dealt with. Moreover criteria for the selection of compressors and pumps as well as problems of air distribution at compressed air aeration systems, with the related problems for measurements and control of air flow, will be discussed.
Optimization of the Cascade System of Activated Sludge by Means of the Metabolic Activity Measurements of Microorganisms
Authors: Miksch Korneliusz
Published: May 2018

A system composed of four sections of the same size and a final clarifier has been investigated. Wastewater from the production of fodder yeast of average COD of 10220 mg/l has been purified. The investigations have shown that the processes which occurred in the first section of the cascade played a dominant role in the removal of the organic impurities. An analysis of the dynamics of the processes in the particular sections of the cascade has shown, however, that the substrate removed in the first section was metabolized only in the next ones, in the oxygen processes, whereas the measurements of dehydrogenase activity have proved that after the termination of the intensive biological oxygen processes, the microorganisms still metabolize the adsorbed substrate in a process which does not consume large quantities of oxygen. The metabolic activity measurements permitted the readjustment of the sewage detention time in the particular sections of the cascade to the observed phasing of the biochemical transformations. In the cascade system studied the optimum aeration time was 96 hours, and the substrate loading - about 0.84 gCOD/g MLSS.d. Such parameters made possible a complete metabolizing of the substrate by microorganisms while preserving favourable biochemical and physical features.