bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Wastewater Reclamation and Reuse in the USA
Authors: Asano Takashi , Tchobanoglous George
Published: May 2018

IAWPRC's Specialist Group on Wastewater Reclamation, Recycling and Reuse (Water Reuse Group) is conducting a day-long Water Reuse Seminar on August 1, 1990 at the 15th Biennial Conference in Kyoto, Japan. This paper is prepared to review the role of wastewater reclamation and reuse in water resources management in the U.S.A., and to serve as an introduction to the theme for the Seminar.

Following a brief summary of available water resources in the United States, the role of wastewater reclamation and reuse is discussed in terms of planning and implementation. Major wastewater reuse categories are identified and discussed. The emphasis of this paper is on wastewater reuse in the context of the water supply benefits to water resources management rather than on water pollution control measures. The overriding importance in wastewater reclamation and reuse is to protect public health and to mitigate health risks. Accordingly, wastewater reclamation criteria for health protection are also presented.
Assessing Potential Health Risks from Viruses and Parasites in Reclaimed Water in Arizona and Florida, USA
Authors: Rose Joan B. , Gerba Charles P.
Published: May 2018

Wastewater reuse has been mandated in both the states of Arizona and Florida, U.S.A. In Arizona, standards have been set for enteric virus and Giardia levels to maintain a specified effluent quality depending on the reuse, while in Florida, specified treatment control has been implemented. Data on virus levels in treated wastewaters have been generated in both states. Average virus levels ranged from 13-130 pfu/100L after secondary treatment while with the addition of filtration, levels were reduced to averages between 0.13 to 1.25 pfu/100L. Giardia cyst levels also dropped by 100 fold after filtration averaging 0.32/40L. Using a probability of infection model, risk of infection from 100 ml accidental ingestion ranged from approximately 2 × 10−3 to 2 × 10−4 for the levels of viruses and protozoa foundin chlorinated secondary effluent and the risk was reduced to 2 × 10−4 to 2 × 10−6 with filtration and disinfection following activated sludge.
Effluents Quality along a Multiple-Stage Wastewater Reclamation System for Agricultural Reuse
Authors: Azov Y. , Shelef G.
Published: May 2018

A multiple stage wastewater reclamation system in northern Israel is described and analyzed for effluents quality along its components. The reclamation system uses Haifa's treated wastewater to irrigate cotton fields and other crops in the Valley of Jezreel. During five years of operation it was found that each stage of the reclamation system, after the treatment plant, has some impact over effluents quality. Degradation of organic matter and bacterial regrowth take place at the effluents conduit which connects the treatment plant and the irrigated area along 30 km. This is mainly due to relatively long retention time of the effluents within the conduit because of operational restrictions. The stabilization reservoir that stores effluents during winter time, improves their quality to a great extent. The effluents that enter the operational reservoir at the irrigation season, are mixed with fresh water from the Sea of Galilee, and may cause rapid growth of phytoplankton and Zooplankton populations. The reclamation system successfully replaces large amounts of fresh water otherwise used for cotton irrigation.
Water Quality for Potable Reuse
Authors: Lauer William C.
Published: May 2018

Denver's Potable Water Reuse Demonstration Project is designed to examine the feasibility of converting secondary treated wastewater to potable water quality. A 1.0 mgd (44L/s) treatment plant began operation in 1985 and during the first three years many processes were evaluated. Data from the evaluation period was used to select the optimum treatment sequence which is now being used to produce samples for the two-year animal feeding health effects study now underway. Operation in this configuration will continue until early 1991 during which time comprehensive analytical studies will further define the water quality in relation to existing standards and Denver's current potable supply. A decision concerning the full-scale implementation of direct potable reuse will follow extensive analysis of the test results and in-depth economic evaluation.
Trends and Problems of Wastewater Reuse Systems in Buildings
Authors: Kiya Fumitoshi , Aya Hidenori
Published: May 2018

To solve the shortage of available water source, the national government and local authorities have introduced the policy to make use of alternative water sources such as reuse of wastewater and utilization of rainwater in big buildings. This paper deals with the background, the details of the practice of wastewater reuse systems in buildings, and survey results on the performance of recycling systems installed in big buildings. The investigation suggests that most of reclamation plants perform very good in quality but not good in quantity. There has never been any serious claim from users nor any hygiene trouble in these several years. But the full capacity of plants was not usually utilized as designed. The very small demand at weekends and holidays creates operational problems of biological treatment plants and raises cost of reclaimed water. Individual building wastewater reuse is not efficient enough as expected to solve the shortage of water resources. However, it still remains to be a very important means to deal with urban problems. It will lessen excess loading on existing sanitary sewers and interceptors, and will reduce pollutants discharged from a sewage treatment plant.
Anaerobic Digestion of Piggery Wastes
Authors: Andreadakis A. D.
Published: May 2018

Anaerobic digestion can be an attractive and economically feasible method for the treatment of piggery wastes, provided that maximization of gas production and efficient subsequent utilization can be attained. Expedience from anaerobic digestion of domestic sludges can not be directly transferred to the design of digestion treating piggery wastes, due to the particular characteristics of the latter. The sequential anaerobic degradation of these wastes favours the adoption of short retention times for maximum gas production while at the same time satisfactory stabilization can be obtained.
Anaerobic-Aerobic Pretreatment of Waste Paper Mill Effluent
Authors: Kroiss H. , Svardal K. , Nowak O.
Published: May 2018

The discharge of the mechanically treated waste water of a waste paper mill to the regional sewer system caused several environmental problems. Investigations have been carried out to find the optimal solution for these problems. Convenient solutions turned out to be the pretreatment of this waste water by either the high-rate activated sludge process or a high-rate anaerobic process combined with an activated sludge posttreatment. Mainly because of lower total costs, an anaerobic-aerobic pretreatment plant with an UASB reactor has been erected. The plant has in been in operation for three months and the operational results are satisfying.
Soft Drinks Industry Wastewater Treatment
Authors: Tebai Larbi , Hadjivassilis Ioannis
Published: May 2018

Soft drinks industry wastewater from various production lines is discharged into the Industrial Effluent Treatment Plant.

The traditional coagulation/flocculation method as first step, followed by biological treatment as second step, has been adopted for treating the soft drinks industry wastewaters.

The performance of the plant has been evaluated. It has been found that the effluent characteristics are in most cases in correspondence with the requested standards for discharging the effluent into the Nicosia central sewerage system.
Integrated Computer Aided Process Design of Wastewater Treatment Plants on a PC System
Authors: Spinos M. , Marinos-Kouris D.
Published: May 2018

This paper presents the development of an integrated computerized procedure for the process design of wastewater treatment plants, regarding not only the calculations of the basic equipment size but also the production of all documents related with the process design stage. The core of the system is a database containing all the information (numeric or alphanumeric data, and graphical objects) necessary for the selection and design of wastewater and sludge treatment processes. Three subsystems access the database. The CAD system and the database manager provide the required project data, while the simulator executes the calculations and produces the desired output.
Aerobic Thermophilic Waste Sludge Treatment
Authors: Mason C. A. , Häner A. , Hamer G.
Published: May 2018

The expansion in both industrial and municipal wastewater treatment in recent years has resulted in a major increase in the quantities of by-product sludge produced and has exacerbated problems of waste sludge treatment and/or disposal. The traditional method for waste sewage sludge treatment is anaerobic mesophilic digestion for sludges that are to be disposed of on agricultural land. Other disposal methods for untreated sludges include incineration, an option receiving increased interest, and ocean dumping, an option that is environmentally incompatable and used much less frequently today compared with 10 years ago. Sewage sludge can be considered to be a resource as far as its mineral nutrient composition is concerned. However, this resource cannot be exploited in agriculture because sludges are inevitably contaminated with noxious chemicals that partition into the sludge during either primary or secondary wastewater treatment. In the case sewage sludge, pathogenic and potentially pathogenic organisms are also present unless such contaminants are removed during treatment. Traditional mesophilic treatment under anaerobic conditions does not remove either noxious chemicals such as detergent residues or pathogenic organisms to a satisfactory degree. During the past decade, autothermal aerobic thermophilic pretreatment processes have been introduced as a complementary sludge treatment stage. Such aerobic pretreatment processes allow both the biodegradation of chemicals that are recalcitrant to anaerobic treatment and the thermal inactivation of pathogenic organisms. However, their introduction as a total treatment process for sludges is inhibited by their relatively poor conversion efficiencies as far as mineralization is concerned. In this contribution the biodegradation bacteria under aerobic thermophilic conditions will be described and discussed and concepts for biomass yield coefficient reduction that could enhance aerobic thermophilic sludge treatment process effectiveness will be introduced.
The Effect of Activated Carbon Properties on the Adsorption of Toxic Substances
Authors: Diamadopoulos E. , Samaras P. , Sakellaropoulos G. P.
Published: May 2018

The objectives of this work were to relate the activated carbon properties to its adsorptive capacity. The activated carbon needed was produced in the lab from Greek lignite coal. Subsequently, adsorption studies were performed in order to evaluate the efficiency of the various activated carbons to remove toxic substances from water. Two organic substances were used. These were phenol and fulvic acid. Additionally, the adsorption of arsenic (V) was, also, investigated. It was found that the adsorptive capacity of the activated carbons depended primarily on the ash content and the compound. The capacity of the carbon to remove phenol, expressed as mg of phenol removed per g of activated carbon (carbon loading), decreased linearly as the amount of ash in the activated carbon increased. Ash-free activated carbons could adsorb 4 times as much phenol as the activated carbons with a high ash content. On the other hand, fulvic acid and arsenic adsorbed poorly on the ash-free activated carbons. Even for the high surface area activated carbons (over 1000 m2/g), the quantity of fulvic acid or arsenic adsorbed was significantly less than that exhibited by the high ash activated carbons (maximum surface area measured hardly exceeded 300 m2/g). As the amount of ash in the carbon increased, the carbon loading increased as well, up to a certain level, beyond which the amount of ash played no significant role. The beneficial role of ash was explained by the ability of the fulvic acid and arsenic to interact with metal oxides and metal ions, which constitute a significant fraction of the ash.
Degradation of Phenol by Immobilized Mycelium of Fusarium Flocciferum in Continuous Culture
Authors: Anselmo A. M. , Novais J. M.
Published: May 2018

Continuous phenol degradation was studied in a completely mixed reactor, at steady state conditions, using the mycelium of Fusarium Floociferum immobilized in Polyurethane foam.

Experiments at different dilution rates, 0.069, 0.118 and 0.196h−1 with an influent phenol concentration of 1g/l, showed a virtually complete substrate utilization over a period of four months. Low biomass productivity values of suspended cells were found, 0.21, 0.34 and 1.81g d.w./l. day, especially when compared with those obtained with the free cell system at similar conditions: 0.955 and 6.73g d.w./l.day for 0.063 and 0.116h dilution rates. The immobilized cells behaviour at different feed substrate concentrations was studied at D=0.196h.−1 corresponding to a retention time of 5.1h. The results indicate that above 1g/l the complete phenol removal is not achieved. A progressive increase in the outlet concentration was observed, attaining a value of 284mg/l at 1.5g/l.

Respiratory experiments made with the immobilized cells taken from the reactor along with these experiment, indicate that the viability is retained by the mycelium, pointing out its ruling part in the phenol degradation. Culture fluid viscosity measurements were made and the rheological characteristics of the two systems were investigated. A non-Newtonian fluid was observed in the free cell system, with a shear-thinning behaviour. The immobilization had a beneficial effect on the rheology of the fluid i.e. the viscosity was much lower,1.2 c.p.s. and there was a tendency to approach Newtonian behaviour.
Attempts to Improve the Sensitivity of an Enzyme-Linked Immunosorbent Assay for 2-Methylisoborneol
Authors: Chung S. Y.
Published: May 2018

An enzyme-linked immunosorbent assay (ELISA) for 2-methylisoborneol (MIB) was described previously with a sensitivity of 1 µg/ml (Chung etal., 1990). In an attempt to increase the sensitivity, the following approaches were used: (1) new high-titer antibodies raised against a camphor-ethylenediamine-BSA conjugate; (2) use of a camphor-alkaline phosphatase conjugate as the detecting system; and (3) modification of the ELISA conditions by different blocking agents, microtiter plates, and plate shaking. Despite these approaches, the sensitivity of the ELISA remained at 1 µg/ml, indicating that the sensitivity most probably related to the antibody affinity for MIB and not to the assay conditions and antibody titer.
Sensory Gas Chromatography for Evaluation of Taste and Odor Events in Drinking Water
Authors: Khiari D. , Brenner L. , Burlingame G. A. , Suffet I. H.
Published: May 2018

A sensory gas chromatography (sensory GC) procedure with appropriate quality assurance steps was developed to evaluate ng/l concentrations of odorous chemicals in drinking water. Closed loop stripping analysis was used to concentrate the chemicals in the water samples. Sensory GC analysis was completed by smelling the effluent at the exit port of an on-column injector capillary GC system. An identical and parallel GC flame ionization detector system was used to monitor the sensory gas chromatograms. The sensory GC analysis is important because it can detect some of the individual components of the odor that a sensory panel determines on a water sample. The relationship between sensory panel response and the sensory GC procedure were investigated near threshold odor concentration levels and the data shows that sensory GC does not always correlate with sensory panel evaluations. This can be caused by the concentrations differences of the chemicals in the mixture and synergistic and antagonistic effects. Two taste and odor events reported at the Baxter Water Treatment Plant of the city of Philadelphia on the Delaware river were investigated. The events were first a metallic aftertaste accompanied by a burnt rubber odor and second a cucumber odor in the drinking water. The cases studied illustrate the use of FPA, sensory GC and GC/MS to understand the chemical nature of the odors present in the samples.
Growth Characteristics of the Musty Odor Producing Alga, Oscillatoria tenuis
Authors: Hoson T.
Published: May 2018

The production of 2-methylisoborneol (MIB) by Oscillatoriatenuis Agardh often causes taste and odor problems in tap water supplied from Lake Biwa. In order to understand growth characteristics of O. tenuis, the alga was cultured under several different conditions. The maximum biomass observed in culture was about 2000 filaments/ml, whereas the standing crop measured in the lake was as low as 32 filaments/ml. The optimum temperature and pH were 25-30 C and 8-9, respectively. The concentrations of nitrogen and phosphorus which were optimum for growth in the medium were 0.31 mg/l and 0.08 mg/l and above, respectively. The concentrations of these elements in the lake were almost equal to those resulting in optimum growth. Growth of the alga was suppressed when the alga was grown in the culture medium from which chelated iron was removed. The total concentration of iron in lake water was sufficient for the algal growth; however, the concentration of soluble iron, which is available for the alga, was lower than in CT-medium. Addition of 0.03 mg/l EDTA to lake water promoted the algal growth invitro, while 3 mg/l EDTA suppressed the growth. The difference between growth under culture conditions and that in the lake may be due to the difference in the concentration of soluble iron.
Off-Flavors in Surface Waters - How Efficient is Bank Filtration for their Abatement in Drinking Water?
Authors: Chorus I. , Klein G. , Fastner J. , Rotard W.
Published: May 2018

Surface water and bank filtrate were studied from three Berlin lakes of different trophic states, two of which are being restored by phosphate elimination at their main inflow. Surface water showed time patterns of nor-carotinoids, aldehydes, alkanes and octatriene-isomers, which in most cases can clearly be attributed to specific phytoplankton populations. The variety of substances produced by algae was highest in the mesotrophic lake, because as compared to its previous hypertrophic state, restoration has caused an increase in phytoplankton species diversity as well as a more rapid seasonal succession of species. Contrary to expectations, serious odor problems occurred only at this lake, due to Chrysophyceae not found in hypertrophic waters. Therefore it is concluded that further reduction of phosphate concentrations is necessary, if not only the blue-green algae, but also the the Chrysophyte populations are to be reduced below nuisance levels.

However, for the purpose of gaining drinking water from surface water, slow bank filtration showed to be an effective measure for the elimination of terpenoids, ocatrienes and alkane molecules larger that dodecane; therefore it can be recomended as a treatment against odor problems in drinking water gained from surface waters.
Development of a Product Screening Protocol to Minimize Marine Environmental Impacts of Oil Production Chemicals Used Offshore
Authors: Vik E. A. , Berg J. D. , Bakke S. , Øfjord G. D. , Reinhard M.
Published: May 2018

This paper presents the initial results of a research project initiated by Conoco Norway, Inc. (CNI) late in 1989. The objective of the project is to develop a screening protocol for determining the potential environmental impacts of five types of chemicals typically used in offshore oil and gas production operations in the North Sea. The protocol includes tests for determination of bioaccumulation potential, oil-water distribution factor, biodegradation potential, and toxicity. When fully developed, the protocol represents one possible approach to implementing the proposed PARCOM standard testing program. Only the results for the bioaccumulation potential and oil-water distribution factor are presented here. For determination of bioaccumulation potential, the High Performance Liquid Chromatography (HPLC) is recommended. The oil-water distribution factor can be determined by surrogate parameters as total organic carbon (TOC), UV-absorption or gas chromatography (GC). This factor is critical in sample preparation and evaluation of the environmental fate and effect of oilfield chemicals. Both acute and chronic toxicity should be taken into consideration for evaluation of toxicity. The ratio between the highest likely concentration of the chemical in the environment (Potential Environmental Concentrations - PEC) and the lowest concentration, at which harmful effects are likely to be observed (Minimum Adverse Effect Concentration - MAEC) gives the size of the apparent margin of safety.
Removal of Mercury from Waste Water: Large-Scale Performance of an Ion Exchange Process
Authors: Ritter J. A. , Bibler J. P.
Published: May 2018

Duolite™ GT-73 ion exchange resin routinely reduces the mercury content of a waste water stream to less than the permitted level of 10 ppb. Effluent concentrations from the ion exchange facility (IEF) are consistently between 1 to 5 ppb, even though the feed contains a varying concentration of mercury (0.2 to 70 ppm). Two operational problems have been encountered at that facility, however. Firstly, the stated capacity of the resin for mercury was not being achieved. The abnormally low capacity was traced to analytical laboratory waste which was intermittently treated by the resin. That waste contained hydrochloric acid, stannous chloride, and potassium permanganate, among other chemicals, which presumably eluted sorbed mercury from the resin and also oxidized the thiol (SH) functional groups on the resin and rendered them inactive. The net effect was that the resin had to be replaced more frequently than anticipated. Secondly, the IEF was temporarily shut down because the mercury content of the waste water could not be reduced to below the permitted level, even with fresh resin. That problem was caused by slow settling solids composed mainly of iron which apparently adsorbed some of the mercury and allowed it to pass through the resin untreated. The solids were presumably a result of processing waste water abnormally high in iron which may have co-precipitated with mercury and other elements in the feed and caused a residual buildup of solids throughout the IEF. The problem was remedied by installing a 0.2 µm cartridge filter between the feed tank and the columns.
Characterization of Wastewater for Modelling of Activated Sludge Processes
Authors: Henze Mogens
Published: May 2018

The fractionation of organic matter in the various parts which are used for mathematical modelling is discussed. The fractions include inert soluble, readily biodegradable, rapidly hydrolysable, slowly hydrolysable, biomass and inert suspended material. Methods for measuring are also discussed. Fractionation of biomass in wastewater and in activated sludge is difficult at present, as methods are only partly developed. Nitrogen fractions in wastewater are mainly inorganic. The organic nitrogen fractions are coupled to the organic COD fractions. The fractions of COD, biomass and nitrogen found in a specific wastewater seem to be constant even when concentrations vary. Wastewater input to sewers and the sewer transport system significantly influences the raw wastewater composition at treatment plants.
Modelling Population Dynamics in Activated Sludge Systems
Authors: Gujer W. , Kappeier J.
Published: May 2018

A biokinetic model is introduced which allows for the prediction of the development of flocforming, filamentous and ‘Nocardia' type microorganisms in aerobic activated sludge systems with a variety of different flowschemes and operating conditions. The model is based on the competition of the organisms for different organic substrates. For ‘Nocardia' a flotation process is introduced which allows for a longer residence time of these organisms as compared to the SRT. The model predicts activated sludge composition and behavior in accordance with a variety of experimental observations.
Calibration of an Activated Sludge Model Based on Human Expertise and on a Mathematical Optimization Technique – a Comparison
Authors: Wanner Oskar , Kappeier Jürg , Gujer Willi
Published: May 2018

Two alternative methods, which both can be used to estimate some of the kinetic parameters of the IAWPRC Activated Sludge Model Nr. 1, are compared. By one method, which is based on professional experience and expertise, the unknown parameter values are determined one after the other by a sequential procedure. By the other method, the parameter values are determined simultaneously by use of a mathematical optimization technique. Both methods allow a good fit of a set of 25 experimental oxygen respiration rate time-series and yield accurate estimates of the model parameters. The sequential procedure can readily be employed for the evaluation of single experiments. The optimization technique is more suitable for the evaluation of larger data sets and allows for additional analysis of the data.
Use of Methanogenic Activity Tests to Characterize Anaerobic Sludges, Screen for Anaerobic Biodegradability and Determine Toxicity Thresholds against Individual Anaerobic Trophic Groups and Species
Authors: Colleran E. , Concannon F. , Golden T. , Geoghegan F. , Crumlish B. , Killilea E. , Henry M. , Coates J.
Published: May 2018

A variety of test procedures have been reported in the literature for determination of the specific methanogenic activity profile of anaerobic sludges and for screening synthetic organic chemicals for anaerobic biodegradability. This paper reviews the methods developed and presents data obtained in the authors' laboratory using test procedures based on pressure transducer measurement of gas pressures in sealed anaerobic vials. Data on the feasibility of freeze-drying granular sludge are also presented as part of a wider study concerning the development of a standard reference sludge for anaerobic biodegradability testing. The use of the methanogenic activity test method to assess the relative toxicity of compounds, known to inhibit methanogenesis, against individual trophic groups involved in the overall digestion process is also described.
Towards a Useful Dynamic Model of the Anaerobic Wastewater Treatment Process: A Practical Illustration of Process Identification
Authors: Jones R. M. , MacGregor J. F. , Murphy K. L. , Hall E. R.
Published: May 2018

Results are reported from a dynamic modelling study conducted on a pilot scale anaerobic fluidized bed. The objective of the study was to generate data to identify, evaluate and eventually calibrate a dynamic model for on-line estimation and forecasting in a process control system. Experiments consisted of pulse inputs of glucose, propionic acid, and acetic acid during the treatment of a distillery wastewater. The dynamic response of the methane and carbon dioxide production rates, hydrogen content of the biogas, effluent volatile acid concentrations and effluent COD concentrations are shown. A model structure was postulated based on the results observed in the dynamic experiments. An extended Kalman filter state estimation algorithm was employed to provide estimates of unmeasured process states and parameters. The use of the state estimation technique improved the performance of the model, helped locate model inadequacies, and provided information to direct further model development.
Semi-Dry Anaerobic Digestion of MSW: Influence of Process Parameters on the Substrate Utilization Model
Authors: Cecchi F. , Mata-Alvarez J. , Pavan P. , Sans C. , Merli C.
Published: May 2018

In this paper the experiments carried out in a 3 m3 reactor using mechanically sorted organic fractions of municipal solid waste as substrate are described. The influence of operating parameters such as hydraulic retention time (HRT), organic loading rate (OLR) and temperature are examined. Even at the critical levels of OLR and HRT used (6 days and 20 kg TVS/m3d, respectively) the stability parameters have values which can be considered safe. A kinetic study is also carried out using the first order and step diffusional models, based on the biogas production profiles obtained after feeding the digester. The most relevant fact is the appearance of a “plateau” in these profiles. The larger the overload, the larger the plateau formed after feeding the digester. This approach could be used to control the digester stress.
New Systems for the Digestion of Solid Wastes
Authors: Wellinger A. , Baserga U. , Egger K.
Published: May 2018

Two new systems for the digestion of solid wastes at thermophilic temperatures were developped and are currently being investigated at our research institute.

The first system (ANCOM) was designed to process straw-rich cattle manure with a natural dry matter content of 18% to 22%. First results demonstrated a good specific gas production of 1.2 m3 biogas per m3 digester volume and day (54% methane) corresponding to a gas yield of 400 l per kg VS.

A second digester system was developed to treat fruit, garden and vegetable (FGV-) waste. Because FGV-waste tends to float, a stirred tank reactor was designed in cooperation with an engineering firm. The reactor includes a distinguished new stirring system taking up strong shear forces and a hydraulic feeding system which guarantees that even during recirculation of the material, the hygenized digested substrate leaving the digester is not brought in contact with the fresh incoming material. First results measured at an HRT of 40 days demonstrated a specific gas production of 2.7 m3 per m3 fermenter and day.
Aspects of Surface Sediment Characteristics on an Urban Catchment in London
Authors: Butler D. , Thedchanamoorthy S. , Payne J. A.
Published: May 2018

Initial results of the field trial element of a project concerned with the exclusion and removal of sediments from drainage systems are presented. The trial sites location and characteristics are noted and the sampling and analysis methods described. Results are given for six sites in terms of total dry mass, percentage non-particulate matter, percentage volatile component and sediment gradings. Average total mass figures at 430 g/m kerb are comparable with published figures. Changes over time were negligible at some sites but considerable at others. Non-particulate matter accounted for approximately 3 % by mass with the volatile component at approximately 6%. Consistent sediment gradings were noted at all locations with both sub 63 µm and super 6 mm sizes amounting to approximately 10 % of the total mass. The average specific gravity of the smaller grain sizes was found to be 2.35.
A Model for Solid Production and Transport for Small Urban Catchments: Preliminary Results
Authors: Bertrand-Krajewski J.-L.
Published: May 2018

A conceptual model for solid production and transfer in sewer systems is proposed. It has been established for small urban catchments of less than 100 ha, which can be considered from a global point of view. Hydrological and hydraulic phenomena are simply represented with a cascade of two linear reservoirs. The first part of the solid transfer model has been established to reproduce daily and hourly suspended solids loads during dry weather periods. The second part of the model deals with solid transfer during storm events, including sediment build-up over the catchment, washoff, erosion, deposition and transport. Two classes of particles are introduced to distinguish between deposits in pipes and solids transported in suspension. The objectives are the calculation of suspended and bed loads and the evolution of the deposits. Preliminary results are satisfactory but further research is needed in order to test and verify the model for other catchments and rainfalls.
Sulfate Reduction in Sewer Sediments
Authors: Schmitt F. , Seyfried C. F.
Published: May 2018

The Institute of Sanitation Engineering and Waste Management of the University of Hannover made investigations on sediments in sanitary sewers. These were aimed to assess how sediments influence the sewer environment, with regard especially to water quality, gas atmosphere and corrosion progress. The sulfate reduction from sediments could be determined. It was 82 % higher than the reduction rate of biofilm. A prediction of sulfate reduction with equations from biofilm theory is possible. The biologically active sediment layer for sulfate reduction has a thickness of 5 to 7.5 cm. The sulfide formation in a large sanitary sewer in Hannover depends only on water temperature with a correlation of 91 %.
Comparison of Different Methods to Calculate Bed Shear Stress
Authors: Kabir M. R. , Torfs H.
Published: May 2018

Precise velocity profile measurements were carried out in a fully developed, subcritical and supercritical flow on a smooth and a rough bed in a flume with a rectangular cross section. In both cases different approaches were used to calculate the friction velocity, u*, and comparisons were made. The influence of the reference level (hypothetical bed level) has been discussed. Friction velocities calculated from the velocity profile are very sensitive to the hypothetical bed level. For a smooth bed the determination of the reference level does not present any difficulties. However, for a rough bed this level shows dependency on the channel slope.
Rheological Measurement of the Yield Strength of Combined Sewer Sediment Deposits
Authors: Wotherspoon D. J. J. , Ashley R. M.
Published: May 2018

A definition for a working value of yield stress for sediment deposits with a cohesive nature is provided through the application of rheometrical techniques. An applied stress technique was utilised to examine the yield characteristics of sixty-one sediment samples obtained from a combined interceptor sewer. Yield strength values obtained were related to the solid/liquid phase relationships for these sediment samples. It is suggested that the yield strength presented can provide a suitable definition for material available for erosion from the sediment bed.
Flupol: A Forecasting Model for Flow and Pollutant Discharge from Sewerage Systems during Rainfall Events
Authors: Bujon G. , Herremans L. , Phan L.
Published: May 2018

For several years now, urban stormwaters have been identified as a major cause of pollution, along with wastewater. Before listing the technical solutions, it is important to assess the quantity of the effluent and spills with sufficient precision.

These are the goals set for the FLUPOL model, developed jointly by Agence de l'Eau Seine-Normandie, Syndicat des Eaux d'lle-de-France and Compagnie Générale des Eaux. This model calculates the flow rates and discharges of Suspended Solids, BOD5, COD, and Kjeldahl Nitrogen downstream from an urban catchment and its drainage system after a given rainfall, without needing too complex and expensive data. The phenomena simulated range from accumulation of polluting matter on urban surfaces during dry weather to the transit of flow and pollution in the sewer, including possible deposition or resuspension processes.

The FLUPOL model was adjusted and subsequently validated using several series of measurements carried out in France, and has been used in several sewerage studies taking into account the polluting discharges during wet weather.

Considering flow rates and pollutant discharges, the difference between the calculated results and the measurements has always been less than 20 %. The model can then be applied in other drainage systems than those used for calibration and validation.
Oceanic Disposal of the Treated Wastewater from the Camaçari Petrochemical Complex – Environmental and Technical Considerations
Authors: Fontes Lima F. J. , Neves N. M. S.
Published: May 2018

The increasing production capacity of the Petrochemical Complex of Camaçari, in the State of Bahia, Brazil, after eleven years of operation leads to an additional generation of liquid effluents that will sum up a total load of 120 tons BOD/day. The need of an environmentally safe solution involved several studies and research projects on the treatment process and environmental assessment. At first, it was suggested adopting a tertiary treatment process for the liquid effluents with the respective enlargement of the treatment plant, thus maintaining the present receiving water body. A second alternative, which contemplated the improvement of the secondary treatment with the subsequent disposal of the treated effluents off the coast through a submarine outfall was considered to be more feasible, and is discussed in detail, together with the arguments that led to this conclusion.
Membrane Separation of Raw and Anaerobically Digested Pig Manure
Authors: Bilstad T. , Madland M. , Espedal E. , Hanssen P. H.
Published: May 2018

Manure ought to be controlled and handled environmentally soundly. Volume reduction of surplus manure by reverse osmosis (RO) is a viable and economic option in certain areas where another alternative is to reduce the number of animals.

This membrane separation project arose out of an urgent need to re-establish an ecological balance between farming and the natural environment without necessarily having to decrease the number of livestock. The suggested technical solutions should not significantly reduce the standard of living of the farmers.

Dewatering of manure makes it easier to store and transport the nutrients. RO coupled to anaerobic digestion as pretreatment with inherent production of biogas energy leads to on-site production and use of biological fertilizer and humus. Such treatment will improve the hygienic conditions and general health of the farming communities compared to purchase and sole use of chemical fertilizers.

Mechanical dewatering of raw as well as anaerobically digested pig manure yields a cake of 25 % solids and a liquid fraction containing 1 % solids. The solid cake contained virtually all the phosphorous, whereas nitrogen was dissolved equally in water in both fractions. A tubular RO membrane plant separated 95 % of the total nitrogen in the liquid fraction. The particle free permeate met the effluent criteria for direct discharge to the neighbouring fjord. The concentrate approached one tenth of the original manure volume and is considered a liquid fertilizer.

Cleaning of the membranes was performed with nitric acid and the alkaline detergent Ultrasil 11. The membrane flux was fully recovered after each chemical cleaning.
Removal of Heavy Metals from Industrial Effluent by Crossflow Microfiltration
Authors: Squires R. C.
Published: May 2018

The performance of Exxflow, a patented form of crossflow microfiltration, treating industrial wastewaters containing mixed heavy metals discharged by two types of industry is quantified and compared with the traditional technologies used for such treatment.

Pilot trial results using Exxflow are shown and compared to the performance of the full scale plants now operating on these effluents.

The operating costs of the Exxflow process are estimated for the two plants. One of which has been operating for 18 months and the other about 4 months.

The Exxflow process is described and improvements which are being developed to lower the operating costs are presented.

It is shown that industrial effluents containing mixed heavy metals are very effectively treated by the Exxflow process and since the installation of the plants the treated effluent has been of a quality suitable for discharge to the River Thames in one case and to a sewage treatment plant in the other.

Unlike other processes, Exxflow has shown that it can successfully treat effluent containing mixed metals and that removal of antimony from mixed metal waste waters is affected by the concentration of sodium sulphate in the wastewater.
An Investigation into UF Systems in the Pretreatment of Seawater for RO Desalination
Authors: Strohwald N. K. H. , Jacobs E. P.
Published: May 2018

Low-cost tubular and capillary polyethersulphone ultrafiltration modules have been developed and their use in the pretreatment of seawater for reverse osmosis desalination investigated. Mechanical and chemical cleaning regimes were evaluated for the restoration of the productivity of fouled membranes. The cost-effectiveness of using these UF membranes for pretreatment to RO, was found to depend on a combination of membrane configuration, type and frequency of cleaning regime and average productivity.
Test on Microfiltration as a Tertiary Treatment Downstream of Fixed Bacteria Filtration
Authors: Langlais B. , Denis Ph , Triballeau S. , Faivre M. , Bourbigot M. M.
Published: May 2018

Conventional methods of disinfecting sewage water are all highly sensitive to variations in the effluent quality upstream of the disinfection stage. Microfiltration was tested as a tertiary treatment downstream of biofiltration, simulating very poor biofilter efficiency, to test the limits of the microfiltration process. Despite the poor quality of the secondary effluent (COD between 100 and 400 mgO2/l, BOD5 between 30 and 150 mgO2/l and suspended solid concentrations between 15 and 90 mg/l), the microfiltration process (filtration level : 0.2 µm) eliminated all faecal germs and tenia and ascaris eggs. The total elimination of free amoeba cysts still needs to be confirmed. With the COD and BOD5 reduced by an average of 60 and 70% respectively, the effluent quality is equivalent to level e after microfiltration (COD: 90 mgO2/l and BOD5=30 mgO2/l on samples averaged over 24 hours). Turbidity, measured instead of suspended solids at outlet from the microfilter, was 99% eliminated. The colour remained between 50 and 150 mg Pt.Co/l.

Under the operating conditions applied, the minimum filtration cycle was 72 hours for a minimum permeate flow of 80 l/h/m2 of membrane.
Cycle of Halocarbons in the Air-Water Phase
Authors: Yamasaki T. , Oki N. , Okuno T.
Published: May 2018

Halocarbons are widely distributed in environment: atmosphere, hydrosphere, lithosphere and biosphere. This report presents the data on the cycle of halocarbons in air-water phase.

Low-boiling-point halocarbons were monitored and about 10 kind of substances which include chlorofluorocarbon (CFC) were detected in the environment

The concentrations of halocarbons in air are influenced by weather conditions, especially by wind speed. Three CFCs, CFC-11, CFC-12 and CFC-113, were detected at the level of 0.18-1.70 ppb on the day (wind speed 0-lm/sec), and 0.05-0.40 ppb (5-10m/sec).

Other halomethanes, chloroform and carbon tetrachloride, were detected at the level of 0.06-0.72 ppb and 0.03-0.06 ppb; a haloethane, 1,1,1-trichloroethane, was 0.50-5.3 ppb and 0.12-0.95 ppb; and haloethylenes, trichloroethylene and tetrachloroethylene, were 0.02-4.1 ppb and 0.01-1.8 ppb on days of wind speed below lm/sec and 5-10m/sec, respectively.

Substances found in air were also detected in water phase. Concentration of above-mentioned halocarbons in water were at the level of 0.001-0.0095 ppb in river water, 0.002-0.06 ppb in ground water, 0.001-0.036 ppb in seawater, and 0.001-0.53 ppb in rain water.

In comparison with concentration of halocarbons of environmental measurement and estimation value by using the predictive fate model of chemical substances, haloethanes and haloethylenes in air exceeded the value of estimation. On the other hand, halomethanes in air almost agreed with its value, and in water phase were quite similar to the estimation.
Enzyme-Catalyzed Complex Formation of Chlorinated Anilines with Humic Substances
Authors: Tatsumi K. , Liu S.-Y. , Bollag J.-M.
Published: May 2018

The reactions between 4-chloroaniline or 3,4-dichloroaniline and various phenolic humus constituents were investigated in the presence of a laccase isolated from the fungus Rhizoctoniapraticola. The anilines were not oxidized when incubated with laccase; however, if phenolic acids were included in the reaction mixture, cross-linking occurred.
Rainfall Runoff Characteristics and Risk Assessment of Agro-Chemicals Used in Golf Links
Authors: Morioka T. , Cho H. S.
Published: May 2018

A rainfall runoff model described in this paper which is based on Basin-wide Ecological Model(BAWEM) calculates the fate of agro-chemicals in a watershed located on golf links. The rainfall runoff coefficients of agro-chemicals, which are the dominant parameters to predict the movement of agro-chemicals from soil and turfgrass to downstream water, are estimated. Also, the model is used to estimate the level of health risks the residents around golf links are exposed to. The fidelity of rainfall runoff model of agro-chemicals was validated by the observed data obtained during rainy period. The calculated results from this model were found to be in the same order as that of the observed. The rainfall runoff coefficients of four agro-chemicals used in golf links were 5.4×10−3, 1.9×10−3, 3.0×10−4 and 4.4×10−3 for flutolanil, isoprothiolane, chlorpyrifos and simazine, respectively. The health risk level to the residents around golf links is evaluated to be rather low: the ratio of estimated dose through drinking water to the 10% of ADI value or VSD for 10−6 life time risk varied in the range of 0.005~0.04 and 0.003~0.11, respectively, for both the annual mean and maximum monthly mean cases.
Aquatic Environmental Fate of Deltamethrin
Authors: Maguire R. J.
Published: May 2018

Deltamethrin [(S)-α-cyano-3-phenoxybenzyl (1R,3R)-cis-2,2-dimethyl-3-(2,2-dibromovinyl) cyclopropanecarboxylate] is a powerful pyrethroid insecticide which exhibits very high toxicity to aquatic organisms. Major routes of degradation or dissipation of parent deltamethrin in natural water are chemical and photochemical conversion to a mixture of inactive and active stereoisomers, and hydrolysis with subsequent oxidation of products. Chiral high performance liquid Chromatographic analyses revealed that the parent 1-deltamethrin in natural water in the dark is subject to cis/trans isomerization yielding the α-S, IS eis isomer 2'-deltamethrin, which is inactive against mice and insects. Sunlight photolysis of deltamethrin in natural water is only a partial detoxification step since although it produced the inactive 2'-deltamethrin isomer as well as the inactive α-S, IS trans isomer 4’-deltamethrin, it did produce in addition the α-S, 1R trans isomer 3-deltamethrin, which does retain some activity toward mice, insects and Daphnia magna, albeit less than the parent 1-deltamethrin.