bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the microbial toxicity test and its application for industrial wastewaters
Authors: Chen Chiu-Yang , Huang Jau-Bin , Chen Shing-Der
Published: May 2018

In this study, two microbial bioassays, i.e. the commercialized Microtox® test and the specific oxygen uptake rate (SOUR) method, are used to assess the individual response of existing wastewater treatment facilities in several high-intensity pollution industries. Initially, the microbial toxicity of manufacturing effluents from a petrochemical industry are assessed. The toxicant sources in the manufacturing effluents are then investigated to develop the baseline of the waste reduction in the manufacturing processes. According to these results, the amount of aldehyde group contributes the majority of the microbial toxicity in the wastewater. Therefore, the abatement of the aldehyde wastewater may be the most effective factor to release the loads for following wastewater treatment facilities.

To control the discharge sources to the treatment facilities (WWTP), WWTPs with high-intensity pollution industries and public WWTPs in three industrial districts are further evaluated with their effluents to determine the primary contributor of toxicants. From the effluent toxicity results, the relationship between organic loads and toxic effluents exhibits a positive conjunction in the high-intensity pollution industries. If these industries can enhance their removal efficiency of organic compounds in the pretreatment system, the toxicity of their effluents can be effectively reduced. Consequently, the following treatment facilities can perform more efficiently to satisfy their needs.
Chemical characterization and biotreatability of effluents from an integrated alkaline-peroxide mechanical pulping/machine finish coated (APMP/MFC) paper mill
Authors: Schnell A. , Sabourin M. J. , Skog S. , Garvie M.
Published: May 2018

As part of an extensive audit of the Alkaline-Peroxide Mechanical Pulping (APMPTM) plant at the Malette Quebec Inc. mill in St. Raymond, Que., effluents were sampled from various stages of the process for comprehensive chemical characterizations, aquatic toxicity testing and anaerobic biotreatability assessments. In addition, untreated and secondary treated combined effluent from the integrated paper mill were sampled to determine the effectiveness of a conventional activated sludge process at the mill site. During the one-day sampling period, the APMP plant processed a mixed wood furnish consisting of 50% spruce/balsam fir and 50% aspen, with a chemical charge of 3.5% sodium hydroxide and 3.8% hydrogen peroxide on oven-dry fibre, while the Machine Finish Coated (MFC) paper production rate was 100 odt/d (oven dry metric tonnes per day).

Measured production-specific contaminant discharge loadings from the novel APMP process were 56 kg BOD5/odt and 155 kg COD/odt in a combined effluent flow of 28 m3/odt. Sources of process effluent were chip washing, three stages of wood chip pretreatment and chemical impregnation (i.e., Impressafiner stages), interstate washing and pulp cleaning. The three Impressafiner pressates were found to be the most concentrated (i.e., 12-26 g COD/L) and toxic streams. Microtox testing of the pressates revealed EC50 concentrations of 0.07-0.34% v/v. The warm and concentrated effluents generated by the non-sulphur APMP process were found to be highly amenable to anaerobic degradation as determined by batch bioassay testing. Filterable BOD5 and COD(f) of the process effluents were reduced by 87-95% and 70-77%, respectively, with corresponding theoretical methane yields being attained. Acid-soluble dissolved lignin compounds exhibited biorecalcitrance, as revealed by limited removals of 34-55%, and were the main constituents contributing to residual COD(f), while resin and fatty acids (RFA) were reduced by 80-94%. The conservatively operated full scale activated sludge treatment process achieved a similar high 74% COD(f) removal from the whole mill effluent, while BOD5 and RFA reductions were virtually complete and the treated effluent was non-toxic, as measured by Microtox.
Impact of industrial discharge on the performance of a biological POTW - model development
Authors: Argaman Y. , Eckenfelder W. W. , O'Reilly A. J.
Published: May 2018

This paper describes the development of a mathematical model and its application for predicting the dimensions of an industrial wastewater pretreatment system, and its comparison with alternative solutions. The model is based on pseudo first order kinetics for both the municipal and the industrial wastewater, and also on the Monod kinetics for the industrial wastewater. In the combined treatment process the biomass is taken as a mixture of specialist microorganisms capable of degrading target compounds. The kinetic rate of the combined stream is taken as the weighted average of the reciprocal K values. The model was used to compare the alternative treatment schemes and the main conclusions were: (1) pretreatment of industrial wastewater is always the most efficient alternative, and (2) an optimal VSS concentration exists in the pretreated effluent, leading to the most efficient treatment system. Experimental studies aimed at validation of this model are strongly recommended.
Solid, slightly soluble phosphorus compounds as nutrient source in activated sludge treatment of forest industry wastewaters
Authors: Rantala Pirjo-Riitta , Wirola Hannu
Published: May 2018

The aim of the study was to determine if solid, slightly soluble compounds can be used as nutrient source in activated sludge treatment plants instead of liquid phosphoric acid. Four different solid materials were tested in lab-scale solubility tests to find compounds which are least soluble. Two materials were chosen for further studies: apatite and raw phosphate. The use of apatite and raw phosphate as nutrient source was studied in lab-scale activated sludge reactors along with a control reactor where phosphorus was added in liquid form. The phosphorus dosage, measured as elementary phosphorus, was the same for all three reactors. The reactors were fed with pre-clarified chemi-thermomechanical pulp mill (CTMP) wastewater.

There were no significant differences in the reductions of organic matter between the three reactors. The mean effluent concentration of total phosphorus was 3 mg P/l in the control reactor and less than 1 mg P/1 in the other two reactors. The soluble phosphorus concentration was more than 2 mg P/l in the control reactor and less than 0.5 mg P/l in the other two. Apatite was an even better nutrient source than raw phosphate. Further lab-scale tests were conducted using two different grain sizes of apatite. No significant differences were found between the studied grain sizes (<0.074 mm and 0.074 mm-0.125 mm).

Apatite was then used in full-scale at a CTMP-mill two different times. The experiments showed that the mean concentrations of phosphorus can be reduced radically by using apatite as a nutrient source instead of liquid phosphorus. Solid phosphorus compounds are a viable alternative to reduce the phosphorus load from forest industry wastewater treatment plants.
A laboratory sludge press for characterizing sludge dewatering
Authors: Rehmat T. , Branion R. , Duff S. , Groves M.
Published: May 2018

A laboratory scale sludge press is described. Its use in measuring the specific filtration resistance of a slurry is outlined. The effects of applied pressure and press time on filtrate flow rate and sludge cake solids are discussed as are the effects of various combinations of primary and secondary sludge. Its use in optimizing the polymer formulation for improved dewaterability of sludge in a screw press is detailed. Comparisons of laboratory sludge press predictions and the results of mill scale screw press and belt filter trials are presented.
Practical experiences with aerobic biofilters in TMP (thermomechanical pulping), sulfite and fine paper mills in Canada
Authors: Kantardjieff A. , Jones J. P.
Published: May 2018

An industrial aerobic biofilter technology has been piloted extensively in Canada on several types of pulp and paper mill effluents, resulting in one full scale operational facility at one Canadian fine paper mill. In addition two industrial scale pilot plant tests were performed with the same technology, one in an integrated sulfite pulp and paper mill and one in a TMP mill. In the case of the fine paper mill, the full scale plant has two cells (8 m × 8 m × 6 m height of the media) and treats an unclarified but screened effluent with a loading of 3500 kg BOD/d. The system produces low quantities of biosludge (0.28 kg TSS/kg BOD removed), has a rapid rate of recovery after shock loadings and is very energy efficient (150 kW installed power for aeration).

Pilot plant treatability studies were performed at one integrated Canadian sulfite mill using a combination of a biofilter-aerated lagoon system. The biofilter treated the most concentrated stream (sulfite pulp mill effluent) and this stream was then combined with the remaining wastewaters of the mill and polished in an aerated stabilization basin (ASB). The high quality ASB effluent (50 mg BOD/L/30 mg TSS/L) was non toxic to rainbow trout, Daphnia magna and photoluminescent bacteria.

Integrated TMP mill effluents were treated in a 5 m3 aerobic biofilter filled with two types of media (10 to 20 mm and 20 to 30 mm). Under average loading conditions of 3.5 kg BOD/d.m3 media, the system produced effluents meeting regulation limits for BOD, TSS as well as for toxicity.
Reduction of pulp and paper mill pollution by ozone treatment
Authors: Hostachy J.-C. , Lenon G. , Pisicchio J.-L. , Coste C. , Legay C.
Published: May 2018

The pulp and paper industry is facing more stringent regulations on the quality of effluent discharges to receiving waters, especially for bleached pulp mills. In most cases, these regulations concern mainly AOX concentrations, biotoxicity and COD level in the final discharges. An effective way to improve pollution balance would be to use ozone as an external treatment to meet environmental regulations. The first part of this work has consisted in the identification of the polluting steps in pulp and paper mill processes in terms of toxic effects. After identification, effluents streams that contribute the most to the global pollution of the mill were selected for ozone treatment. For bleaching effluents, the goal was to eliminate acute toxicity and chlorophenolics to increase biodegradability. Depending on the nature of the effluent, complete detoxification and an increase of biodegradability can be obtained with low ozone doses (0.5-1 kg/ADt of pulp). Ozone has also been applied on the final effluent discharges before and after biological treatment. In hardwood and softwood pulp and paper mill final discharges, the residual COD can be eliminated with a catalyzed ozone treatment. This treatment may allow a water quality sufficient for reutilisation which could lower water consumption of the pulp processes.
Characterization of plant sterols from 22 US pulp and paper mills
Authors: Cook D. L. , LaFleur L. , Parrish A. , Jones J. , Hoy D.
Published: May 2018

Recent concerns regarding the possible biological effects of plant sterols, especially β-sitosterol and its metabolites, prompted the development of a method for the determination of campesterol, β-sitosterol, stigmastanol, and stigmasterol in pulp and paper industry wastewaters. The method utilizes a liquid/liquid extraction with methyl-t-butyl ether followed by trimethylsilylation derivatization with GC/FID analysis. The method has been applied to wastewater samples from biological treatment systems at 22 US mills. Estimated treatment system removal efficiencies and mass discharge rates are reported. Estimated treatment system removal efficiencies ranged from 64-79% for most analytes. However, the concentration of stigmasterol was observed to increase across aerated stabilization basins. The estimated mass discharge rates for total plant sterols ranged from a low of 0.2 g/T to a high of 25.2 g/T, depending on the specific mill sampled.
A comparison of the results of freshwater aquatic toxicity testing of pulp and paper mill effluents
Authors: Bailey H. C. , Young Leslie
Published: May 2018

Freshwater short-term chronic toxicity tests were conducted quarterly on samples from pulp and paper mills under Cycle I of Canada's Environmental Effects Monitoring program. The toxicity tests included the 7-dayCeriodaphnia dubia partial life-cycle test for survival and reproduction, the 7-day rainbow trout (Oncorhynchus mykiss) embryo viability test, and the 72-hr Selenastrum capricornutum algal growth inhibition test. All three tests were performed on a routine basis with few failures. The responses of the different species were generally not correlated, suggesting that they responded to different constituents in the effluents. On a statistical basis, the algal test exhibited the greatest sensitivity, followed by the trout embryo and Ceriodaphnia tests. In general, the no-observable effect concentrations (NOECs) were lower than the corresponding IC25 estimates. Due to variability between samples from each mill, it was not possible to distinguish between different mill production processes with respect to their effect on toxicity. In general, mills that treated their effluent using aerated stabilization basins exhibited less toxicity than other treatment types. However, this observation is preliminary and also affected by variability in test results and limited sample size. Overall, the results suggest that toxicity tests have a useful role in identifying toxicity in these effluents and that Toxicity Identification Evaluations should be conducted to identify the cause of toxicity so that treatment and/or source control can be initiated as appropriate.
Environmental impacts of pulp and paper wastewater: evidence for a reduction in environmental effects at north American pulp mills since 1992
Authors: Munkittrick K. R. , Servos M. R. , Carey J. H. , Van Der Kraak G. J.
Published: May 2018

In the early 1990s, a variety of responses were reported in fish populations living downstream of bleached kraft pulp mills. This included delayed sexual maturity, smaller gonads, changes in fecundity, and a depression in secondary sexual characteristics. The changes in fish reproductive development were also associated with alterations in the endocrine mechanisms controlling the production of the sex steroid hormones. The early studies were conducted predominantly at large bleached kraft pulp mills with primitive pulping processes and little effluent treatment. Subsequent studies documented several of the changes at some sites with effluent treatment and without chlorine use, and the dominant reproductive changes (delayed maturity, reduced egg production, changes in secondary sexual characteristics) were replicated in laboratory fish exposed to secondary-treated effluent. Studies have continued to follow the responses of wild fish as these mills underwent process modifications and installed secondary treatment. Improvements in the performance of wild fish have been recorded at five North American sites after the mills modernized their waste treatment and pulping processes. However, the improvements are not complete and are not universal and the process changes resulting in the improvement in environmental conditions have not been defined and their identification remains a priority. Reductions in gonad size and depressions of sex hormones are still seen at one mill with 100% chlorine dioxide substitution and secondary treatment.
Combined biological nitrification and denitrification of high-salinity wastewater
Authors: Dahl C. , Sund C. , Kristensen G. H. , Vredenbregt L.
Published: May 2018

The focusing on the discharge of nitrogen compounds to aquifers has put pressure on power plants to look into removal of nitrogen compounds from the gas scrubbing liquors (DESOx and DENOx). The scrubber liquor has a high salinity, a high chloride content and a temperature of about 40°. Initial laboratory tests to evaluate the possibility of performing biological nitrification and denitrification showed promise and a pilot-scale test unit was established at one of the Danish coal-fired combined heat and power plant (AVEDØRE 1).

The pilot plant was operated under varying conditions with regard to temperature and chloride concentration. Maximum nitrification and denitrification rates were measured. At 30°C and 20 g Cl−/l, maximum nitrification and denitrification rates of 2 and 3 mg N/g VSS·h respectively were measured. In the effluent, concentrations of inorganic nitrogen were below 8 mg N/l.

Twice during the test period, inhibition of the biomass activity was caused by high concentrations of heavy metals. The high content of heavy metals was due to malfunction of pH control in the heavy metal removal plant. The nitrification process was more sensitive to heavy metals than the denitrification process, and during the two toxic events the nitrification rate decreased to zero.

The influence of rapid changes in the chloride and nitrite contents on nitrification was also examined. The results from the performed tests can be applied on other wastewaters with similar characteristics as these scrubber liquors i.e. with salinity. As an example fertilizer and pharmaceutical industries can be mentioned.
Antagonism of sodium toxicity by the compatible solute betaine in anaerobic methanogenic systems
Authors: Yerkes D. W. , Boonyakitsombut S. , Speece R. E.
Published: May 2018

In this paper, the compatible solute betaine is investigated for its antagonistic effects toward sodium toxicity in anaerobic methanogenic systems. Concentrations of betaine as low as 1 mM are shown to be effective at reducing the toxicity symptoms of high concentrations of sodium in the following anaerobic reactor systems: batch reactors seeded with a Methanosarcina enriched culture and batch reactors seeded with a Methanothrix culture, where the acclimation time or lag time before methane production begins is reduced significantly; CSTRs, where the acetic acid uptake rate increases dramatically; fluidized bed reactors, where gas production and pH increase and effluent COD and volatile acid concentration decrease; and UASB reactors, where gas production increases markedly. Because the phenomenon of sodium toxicity antagonism by betaine was demonstrated in anaerobic batch reactors, CSTRs, fluidized bed reactors, and UASB reactors, the usefulness of betaine in an industrial application may be feasible.
Microbial 16S rDNA diversity in an anaerobic digester
Authors: Godon Jean-Jacques , Zumstein Emmanuelle , Dabert Patrick , Habouzit Frédéric , Moletta René
Published: May 2018

The bacterial community structure of a fluidized bed reactor fed by vinasses was analysed by molecular identification. After PCR amplification, three 16S rDNA clone libraries of Bacteria, Archaea, and Procarya populations were established. Community structure was determined by phylogenetic analysis of 556 partial rDNA sequences (about 500 bp long). 139 OTUs (Operational Taxonomic Unit) were found among which 133 and 6 were from the Bacteria and Archaea domains respectively. The majority of bacterial OTUs are not closely related to all other hitherto-determined sequences. The ratio Archaea/Bacteria is 1/4 and the most frequent bacterial OTU represents less than 5% of the characterised bacterial population.
Use of 1H NMR to study transport processes in sulfidogenic granular sludge
Authors: Lens Piet , Pol Look Hulshoff , Lettinga Gatze , Van As Henk
Published: May 2018

Pulsed field gradient nuclear magnetic resonance (NMR) techniques have been applied to study diffusion and flow in a sulfidogenic granular sludge bed. When sulfidogenic granular sludge is exposed to a 20 MHz magnetic field, a multi-exponential spin-spin relaxation (T2) with at least 5 populations is observed. One of these populations (T2 ≈ 30 ms) is intracellular water. Diffusion measurements at 22°C with 1H-water as tracer indicated that sulfidogenic granular sludge contains a distribution of diffusion coefficients between 1.0 × 10−9 m2/s and 2.1 × 10−9 m2/s. Analysing the data set using a monoexponential fit gives a general parameter that can be used to describe the apparent diffusion coefficient in granular sludge. This approach showed that sulfidogenic granular sludge cultivated in different reactor configurations (UASB, USSB and baffled reactors) has comparable diffusional characteristics. Finally, the use of flow and imaging measurements in sulfidogenic granular sludge beds is discussed.
Integrated mathematical model of UASB reactor for competition between sulphate reduction and methanogenesis
Authors: Kalyuzhnyi Sergey , Fedorovich Vyacheslav
Published: May 2018

The existing mathematical models of anaerobic treatment processes were mainly developed for ideally mixed reactors with no concentration gradients on substrates, intermediates, products and bacteria inside the reactor. But for conventional UASB reactors with low upward velocity, the distribution of these components along the reactor height is very far from uniform. This paper presents an integrated mathematical model of the functioning of UASB reactor taking into account this non-uniformity as well as multiple-reaction stoichiometry and kinetics. In general, our integrated model includes the following blocks: a) kinetic block, including the growth and metabolism of acidogenic, acetogenic, methanogenic and sulphate-reducing bacteria; b) physico-chemical block, for the calculation of pH in each compartment of the liquid phase; c) hydrodynamic block, describing liquid flow as well as the transport and distribution of the components along the reactor height; d) transfer block, describing a mass transfer of gaseous components from the liquid to gas phase. This model was calibrated to some experimental studies of the functioning of UASB reactors made by in 1994. Hypothetical computer simulations are presented to illustrate the influence of different factors (recycle number, hydraulic retention time, quality of seed sludge, SO42−:COD ratio etc.) on the operation performance of UASB reactor.
Effect of rapid temperature change and HRT on anaerobic acidogenesis
Authors: Cha Gi Cheol , Noike Tatsuya
Published: May 2018

The effects of the rapid change in temperature and HRT on the characteristics of substrate degradation and bacterial population levels in anaerobic acidogenesis were investigated by using the laboratory scale anaerobic reactor. The degradation efficiency of substrate in acidogenesis was significantly affected by the rapid drop in temperature particularly at short hydraulic retention time and low temperature. The n-butyrate concentration was increased or decreased for the same change in temperature when the HRT conditions were different from each other. The numbers of acidogens, homo-acetogens and H2-utilizing methanogens were not affected in the first 3 days after temperature was rapidly dropped at all the temperature conditions. At 15°C, the complete washout of acetate-utilizing methanogens was observed. The bacterial forms varied according to the changes in the hydraulic retention time and temperature.
Survival of methanogens in air-dried paddy field soil and their heat tolerance
Authors: Ueki Atsuko , Ono Kazuhiro , Tsuchiya Aya , Ueki Katsuji
Published: May 2018

Population density of methanogens in moist paddy field soil during the cultivation period of rice was usually at the order of 105 MPN g−1 (dry soil). When the soil was air-dried and preserved under oxic condition, the population of methanogens decreased to about one fourth of that in the original moist soil after four months of storage. The population density of methanogens in the air-dried soil, however, did not decrease significantly during the following storage and the population in the soil after two years was almost identical to that in the soil preserved for four months. The population of anaerobic bacteria in the air-dried soil was 34% of that in the original moist soil after two years and that of aerobic bactertia was about 1 to 3%. When slurries of various air-dried paddy field soils which were preserved for different times were incubated anaerobically in the presence of added methanogenic substrates, production of methane usually proceeded actively. When these air-dried paddy field soils were heated at various temperatures for different times and the slurries of the soils were incubated anaerobically in the same way, it was shown that methanogens surviving in the air-dried paddy field soils could withstand temperatures up to 105°c for 10hrs or 140°c for 30 min. H2-producing bacteria in the air-dried soils also endured almost the same level of heat treatment.
Requirements for radar rainfall data in urban catchment modelling and control
Authors: Johann Georg , Verworn Hans-Reinhard
Published: May 2018

The use of radar rainfall data as input for storm runoff models can procure a real benefit if the hydrologic response of the watershed studied is strongly dependent on the spatial and temporal heterogeneity of precipitation over its area. In dynamic management of urban catchments rainfall runoff simulations are sensitive to the resolution of the input data. In this study the influence of varios time/space resolutions of radar rainfall data on the results of rainfall-runoff simulations is inverstigated. Therefore, X-band radar rainfall data with high resolution in space (0.5 × 0.5 km) and time (360° scan every second minute), are compared with radar data with 14 min time and 1 × 1 km space resolution as input for the HYSTEM/EXTRAN hydrodynamic model of a small urban catchment. The presented invstigations are realized within the research project “realtime control of a combined sewer system by radar estimates of precipitataon” carried out by the University of Hannover and the Emschergenossenschaft/Lippeverband.
Optimization of the rehabilitation of the Emscher drainage system using continuous rainfall-runoff-modeling
Authors: Pfeiffer E. , Simon M.
Published: May 2018

The northbound migration of maining activities in the Emscher Region is making the open combined sewer system obsolete. This complex task requires a large number of water resources development activities in the subcatchments of tributaries. To harmonize these single activities and to evaluate their performance as part of the complete system a detailed rainfall-runoff-model of the whole Emscher system has been set up. Intensive anthropogenic impacts made it necessary to use actual system data to run advanced modeling techniques. The model set-up and first applications have been recently completed. The reconstruction of the extreme storm event of January 1995 showed excellent results. One of the major objectives is the reduction of flood levels by decentral retention measures. An evaluation matrix will be set up for the 22 potential sites for flood storage with a total volume of 4.8 million m3. Reconstruction plans developed through interdisciplinary investigations will be ranked concerning potential for realization and water resources benefits. In the mean and long range the applicability of approaches for flood control strategies using real-time forecasting models will be checked.
Probablistic analysis of runoff simulations in a small urban catchment
Authors: Calomino F. , Veltri P. , Piro P. , Niemczynowicz J.
Published: May 2018

In Urban Hydrology, a basic question is whether or not the common methods involving the use of design storms bring to the the some results obtained by those methods that make use of real storms. In general, one can say that different design storms give good results when used with the appropriate model, or, conversely, that good results can be achieved through careful model calibration.

On the basis of 51 rainfall-runoff recordings obtained from the experimental catchment of Luzzi (Cosenza, Italy), the frequency distribution of the observed peak discharges was initially computed. Then the runoff events were simulated using Wallrus, a well known simulation model, taking as input the observed precipitations. The frequency distribution of the simulated peak discharges was compared to that of the observed ones, with the aim of calibrating the model on a statistical basis. After that, the rainfall events were analysed, obtaining the frequency distributions of the observed intensities over several durations and developing IDF curves of given frequencies and, then, the Chicago design storms.

The plotting positions of the peak discharges simulated by this way show a good agreement with the distribution of both the observed peak discharges and the peak discharges simulated through the real storms.
A storage model for the simulation of the hydraulic behaviour of drainage networks
Authors: Motiee Homayoun , Chocat Bernard , Blanpain Olivier
Published: May 2018

This paper presents a model for the hydraulic simulation of a drainage network using the storage concept. This model is easier to use than the complete Barre de Saint Venant equations and gives better results than the usual conceptual models, i.e. the Muskingum model, or than models obtained by the simplification of the Saint Venant equations (kinematic wave model and diffusion wave model).
Modeling of dissolved and particle-bound pollutants in urban street runoff
Authors: Robien Andrea , Striebel Thomas , Herrmann Reimer
Published: May 2018

In order to develop water quality models of urban street runoff we evaluated runoff data of inorganic and organic pollutants collected in past studies. Most pollutants were quantified separately regarding particle-bound and dissolved forms. The findings of regression analysis demonstrate, that runoff parameters like total runoff and antecedent dry period are appropriate surrogate parameters to evaluate loads of dissolved and particle-bound heavy metals. The modeling of dissolved pollutants (heavy metals, macro ions) yields equations connecting runoff parameters, which are capable to approximate chemographs of conductivity and dissolved heavy metals. Our data base does not meet the requirements for modeling the chemographs of particle-bound pollutants. However, we can duplicate the chemical processes like adsorption or partitioning between the liquid and the particulate phase.
Towards a distributed physically based model description of the urban aquatic environment
Authors: Gustafsson L.-G. , Winberg S. , Refsgaard A.
Published: May 2018

MIKE SHE, a distributed physically based 3D modelling package, has recently been applied in the urban modelling area through a research project in Sweden, funded by the Swedish Water and Wastewater Works Association. The overall goal was to test if it is possible to describe the surrounding geohydrological processes and their interaction with the sewer network, similar to the way dynamic pipe flow modelling can give a detailed description of the hydraulics. The project was carried out in Vittskövle, a village outside the City of Kristianstad, Sweden. The village has extreme inflows to its treatment plant due to large amounts of groundwater infiltration into the sewer network. A MIKE SHE model was built and verified successfully for the catchment. Simulations were carried out in order to evaluate the effects from historical measures and alternative future alleviation schemes. The results indicate among others, that the construction of a new alternative drainage scheme would make it possible to reduce the inflow to the plant by as much as 75% without risk of increased groundwater levels. The application of MIKE SHE in Vittskövle shows expressively the possibilities and applicability of the model in urban areas. Compared with more simple conceptual models, MIKE SHE provides the possibility to analyse the effects from future changes in the geohydrological system.
A decision network for urban water management
Authors: Veldkamp Robin G. , Hermann Thilo , Colandini Valerie , Terwel Lucie , Geldof Govert D.
Published: May 2018

In the practice of integrated urban water management it is difficult to choose the best combination of available techniques. This paper gives the outline of a decision network to make it easier. It consists of six steps: problem definition, technologies, selection procedure, combination, ranking by sustainability and costs. It is used in an iterative way. By looking at soil characteristics, surface water, groundwater and pollution aspects and by giving priority to sustainable techniques, foundations for a decision can be achieved. It is stated that techniques are sustainable, when they handle stormwater near the source and are visible (not hidden under the ground). From this point of view rainwater utilisation and infiltration are more sustainable than separate and combined sewer systems.
The effect of decentral stormwater use in urban areas on pollution emission
Authors: Bettmann Th. , Ostrowski M.W.
Published: May 2018

Remaining emissions from urban drainage networks are often caused by combined sewer overflows. The paper demonstrates the coupling of two simulation models for urban drainage and decentral stormwater usage. Some case studies show that the implementation of stormwater usage tanks will lead to a remarkable reduction of pollutant loads emitted.
Model for the design of multilayered infiltration systems
Authors: Zimmer U. , Geiger W. F.
Published: May 2018

Infiltration and retention of rain water are used to reduce the runoff peaks in the sewerage system and in the receiving waters. At the University of Essen the efficiency of green roofs and porous pavements has been investigated. A mathematical model has been applied which allows a fast simulation for the runoff and respectively for the seepage. For linear systems the Fourier transform allows the calculation of transfer functions from measured data.
Requirements and possibilities of best management practises for storm water run-off from the view of ecological townplanning
Authors: Kaiser Mathias
Published: May 2018

The character of urban water cycle does not comply with the principles of sustainability. The task of restructuring the urban water cycle is to create a system which is close to a natural. The approached method for this research was to develop and demonstrate a new comprehensive system in two cities of Germany (Dortmund and Zwickau). Standardized types of settlement structure were developed in order to obtain transferable results and to portray the total spectrum of urban planning situations.
Experimental reedbed systems for the treatment of airport runoff
Authors: Revitt D. M. , Shutes R. B. E. , Llewellyn N. R. , Worrall P.
Published: May 2018

The relative efficiencies of pollutant removal from airport runoff by three different designs of pilot scale reedbed treatment systems located at Heathrow airport are described. The sub-surface flow and surface flow systems generally performed more effectively than the rafted systems for reduction of BOD, COD, total ammonia, nitrate, phosphate and metal concentrations. The variable removal efficiencies are explained in terms of the physical, chemical and biological processes which are relevant to each reedbed system.
Evaluation of an improvement in runoff control by means of a construction of an infiltration sewer pipe under a porous asphalt pavement
Authors: Wada Yasuhiko , Miura Hiroyuki , Tada Rituo , Kodaka Yasuo
Published: May 2018

We examined the possibility of improved runoff control in a porous asphalt pavement by installing beneath it an infiltration pipe with a numerical simulation model that can simulate rainfall infiltration and runoff at the porous asphalt pavement. From the results of simulations about runoff and infiltration at the porous asphalt pavement, it became clear that putting a pipe under the porous asphalt pavement had considerable effect, especially during the latter part of the rainfall.
Epidemiology of endemic gastrointestinal and respiratory diseases: incidence, fraction attributable to tap water and costs to society
Authors: Payment P.
Published: May 2018

Since 1989, prospective epidemiologic studies have been undertaken to evaluate if tap water can be a significant source of illness. These studies have compared groups of families consuming tap water to families drinking tap water further processed by reverse osmosis to eliminate microorganisms that could have evaded treatment. Studies have focused on a single water treatment plant and distribution system in order to reduce confounding factors. The water produced by the treatment plant meets all North-American regulations (Québec, Canada and United States). All studies are based on long observation periods (16 to 18 month) of randomly chosen families distributed randomly in the observation groups. The rate of gastrointestinal illness average was 0.7 episodes/person-year and varied between 0.2 and 3.0 episodes/person-year according to the observation periods. We have observed that 10 to 30% of gastrointestinal and respiratory symptoms were apparently associated to the consumption tap water. The annual rate of hospitalisation for gastrointestinal or respiratory diseases was 0.7% and the medical visit rate was 19%. Furthermore, 25% of the participants lost at least one day of work due to these symptoms. The costs associated to these health effects could reach several millions of dollars each year for Canada with a population of 30 million people.
Private water supplies and the local authority role: results of a UK national survey
Authors: Shepherd K.M. , Wyn-Jones A.P.
Published: May 2018

There are more than 100,000 private water supplies within the UK serving about a million people. The Private Water Regulations 1991 provide a framework for Local Authorities to monitor these supplies within their areas. Geographical distribution is variable with some Authorities responsible for large numbers of private sources. Sampling programmes are dependent on the abstraction volume or the number of consumers; some supplies may be monitored only annually or even less frequently. Seasonal variation of water quality may allow contaminated water to be consumed undetected by the Authority and may constitute a risk of illness to the consumer. This national survey of all the UK Local Authorities assesses the distribution, classification and quality of UK private water supplies. Incidence of sample non-compliance, complaints regarding water quality and suspected illness due to possible microbial contamination are addressed. The role of the Authorities in maintaining a safe potable water supply from private sources and the difficulties encountered in implementation of the Regulations are discussed.
Does hepatitis a pose a significant health risk to recreational water users?
Authors: Gammie A. J. , Wyn-Jones A. P.
Published: May 2018

In recent years recreational water use in the UK has increased dramatically and it has been estimated that more than twenty million people use the British coastline annually. In addition, there has been a marked increase in the number of people who use inland water e.g. lakes, reservoirs, rivers and canals. The ready availability of the wet suit has altered the public use of recreational water in several ways in the UK. Longer periods of immersion are now becoming normal with year-round activity now common not just during the accepted bathing season of May-September. Further factors that raise the importance of health implications are the growth of sports which involve intimate contact with water: surfing, windsurfing and boogie boarding. The raised public awareness of environmental issues in general makes health risk assessment a prime concern. Hepatitis A virus infection is transmitted by the faecal-oral route and this study compares two groups of water users, surfers and inland windsurfers. Saliva samples were tested for total antibody to hepatitis A as this indicates the immune status of the individual. All participants completed a questionnaire that elicited concomitant risk factors for previous exposure to hepatitis A. A calculated Odds Ratio of 3.03 and a Chi square of 5.3 with a probability of P = 0.02 was obtained when the non-immunised surfers were compared with the non-immunised windsurfers. This shows a statistical correlation between surfing and exposure to hepatitis A virus. It is recommended that surfers should be offered vaccination in order that they are protected from the risk of acquiring hepatitis A. They should also be given the opportunity to make a considered decision about the risks of acquiring hepatitis A recreationally.
A survey of the microbial quality of wastewaters in Ismailia, Egypt and the implications for wastewater reuse
Authors: Stott R. , Jenkins T. , Shabana M. , May E.
Published: May 2018

The occurrence of parasite ova, cysts and faecal coliforms in urban wastewater and their removal was determined after sewage treatment in gravel bed hydroponic (GBH) constructed wetlands receiving conventionally treated wastewater at Abu Attwa, Ismailia. Samples of raw wastewater and GBH influent and effluents were examined for eggs of intestinal helminths over two months in 1995. All raw wastewater samples were found to be positive for Ascaris lumbricoides but eggs of Hymenolepis spp, Trichuris spp, Ancylostoma duodenale and Toxocara spp were also detected in raw and conventionally treated wastewaters. In Ismailia, the concentration of eggs of human intestinal helminths in raw wastewater ranged from 6–42/L. In the influent to the GBH beds, the concentration of helminth eggs was reduced and ranged from 0–11/L; eggs of Ascaris were found in 28% of the samples. No helminth eggs were recovered from GBH treated effluents. Cysts of protozoa and faecal coliform bacteria were also removed by GBH beds to some degree. Raw wastewater contained cysts of the protozoa, Entamoeba coli, E. histolytica and Giardia spp. Although the density and diversity of species was reduced after treatment in the GBH beds, some amoebic cysts were found in the effluents. Faecal coliform removal averaged 2–3 logs during sewage treatment in GBH beds but effluents did not satisfy WHO guidelines for unrestricted irrigation. This survey indicates that GBH beds have the capacity to remove pathogens from wastewaters. Improvement in wastewater quality after GBH treatment satisfied WHO microbiological quality guidelines for restricted irrigation. With a retention time of 6h, GBH constructed wetlands have practical applications for wastewater treatment for safe reuse in Egypt.
Outbreak of Legionellosis in a tourist complex in Lanzarote concomitant with a treatment of the water system with megadoses of polyphosphates
Authors: Crespí S. , Ferra J.
Published: May 2018

Polyphosphates are the most universally used chemical agents in anticorrosion treatment of drinking water supply systems, as their addition is generally permitted by law because they lack toxicity at the recommended doses. In this work, we describe an outbreak of Legionellosis in a hotel in Lanzarote in 1993 where the water system had been treated with very high doses of polyphosphates.
Evaluation of chlorine dioxide (ClO2) for the control of biofilms
Authors: Walker J. T. , Morales M.
Published: May 2018

A continuous culture chemostat model was used to simulate a flowing water pipe system such as those found in buildings. A primary vessel was set up to grow an inoculum that would represent a water storage tank feeding secondary and tertiary vessels downstream that simulated the water system. Filter-sterilised tap water was used as the growth medium in the continuous culture vessels with no exogenous carbon sources. In addition, the microbial culture consisted of a mixed consortium obtained from a potable water system. Secondary and tertiary vessels enabled the biofilms to be formed before being challenged with appropriate biocides. Even when testing the efficacy of the different biocides, the vessels were still being challenged with the microbial consortium which was constantly flowing from the primary reservoir vessel. This configuration ensured the reproducibility of the model when testing to destruction in the secondary vessels. The flexibility of the system enabled chlorine dioxide to be tested.
Enumeration of E. coli in environmental waters and wastewater using a chromogenic medium
Authors: Ho B. S. W. , Tam T.-Y.
Published: May 2018

CHROMagar Liquid ECC (CLECC) was compared with membrane lauryl sulphate broth plus urea (mLS-UA) used routinely in Hong Kong for E. coli enumeration. E. coli appear as distinctive greenish-blue colonies on CLECC while other faecal coliforms are red in colour. CLECC performance was comparable to mLS with mixtures of faecal coliforms, E. coli and non-faecal coliforms. Beach, river, ground and waste water samples were used for further comparison. Results given by the two media were significantly correlated (P = <0.001). CLECC was superior to mLS-UA in sensitivity (99.1% vs 87.2%) and specificity (96.9% vs 59.8%) for detecting E. coli. On CLECC 95% of E. coli colonies were correctly identified but only 66.9% on mLS-UA. On average, time required for performing one E. coli enumeration test with CLECC was 1.2min/sample less than with mLS-UA. CLECC may enable the development of complete automation for enumerating E. coli.
Impact of chlorine injury on reaction kinetics of coliforms and E. coli in colisureTM and LTB
Authors: McFeters G. , Pickett M. , Broadaway S. , Pyle B.
Published: May 2018

This study compared a chromogenic and fluorogenic substrate based medium, Colisure, with the conventional fermentation based medium, lauryl tryptose broth (LTB), for the recovery of chlorine-injured and non-injured coliforms and E. coli. Mixed natural populations of coliforms from sewage, with and without chlorine exposure, and untreated surface water samples were examined following a USEPA established procedure. Colisure and LTB were examined after 20, 24, 28 and 48h incubation and reactions verified. There were slight increases in positive reactions over time with unchlorinated samples, for which the two media gave similar kinetic patterns. The increases over time with chlorinated samples were much greater than with unchlorinated samples. LTB gave significantly lower total positive responses and had a more pronounced lag period than did Colisure. Total coliform bacteria from surface water samples gave somewhat different reactions with more of an increase with time. Colisure recovered comparable or higher numbers of total coliforms and E. coli in 20–28h than LTB after 48h. These results confirm that Colisure gives improved recovery of chlorine-injured total coliforms and E. coli under conditions simulating treated drinking and source water, resulting in a more realistic estimate of the actual population of indicator bacteria in public water supplies.
Round robin investigation of glass wool method for poliovirus recovery from drinking water and sea water
Authors: Vilaginès Ph. , Sarrette B. , Champsaur H. , Hugues B. , Dubrou S. , Joret J.-C. , Laveran H. , Lesne J. , Paquin J. L. , Delattre J. M. , Oger C. , Alame J. , Grateloup I. , Perrollett H. , Serceau R. , Sinègre F. , Vilaginès R.
Published: May 2018

This study was initiated by the AFNOR water microbiology working group to evaluate the performance of the glass wool method for virus recovery. Its reliability was tested with drinking and sea water by respectively nine and thirteen laboratories. In both trials, six were actively involved in water virology research, one was designated as a central laboratory, the others had no experience in virological practices. Analysis of reproducibility and repeatability according to NF-ISO 5725-2 were realized. For drinking waters (24 assays), the average recovery efficiency was 72%, mean standard deviations: repeatability 12.4%; reproducibility 33.6%; inter-laboratories 21%. For sea waters (39 assays), the average recovery efficiency was 75% and the mean standard deviations 6.9%, 17.9% and 11% respectively.