bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal Efficiencies of Microorganisms in Wastewater Treatment Processes
Authors: Hirata Tsuyoshi , Kawamura Kiyoshi , Yano Kazuyoshi , Kaneko Mitsumi , Moniwa Takeo , Tosa Kohji , Taguchi Katsuhisa
Published: May 2018

The removal characteristics of indigenous microorganisms in wastewater treatment unit processes were studied at five operating wastewater treatment plants. The removal efficiencies of the selected microorganisms in each unit process were dependent upon not only the systems but also the kinds of microorganisms. In almost all processes, the removal efficiencies of total coliforms were similar to or higher than those of Clostridium perfringens except for filtration processes. In the additional survey, focussed on the comparison of removal efficiencies of total coliforms, Cl. perfringens and coliphages, little difference was found between CL perfringens and coliphages. From these results, it may be suggested that CL Perfringens is an effective indicator microorganism for evaluating microorganism removal in wastewater treatment processes and systems.
Continuous Determination of Oxygen Transfer Coefficient with an On-Line Respiration Meter
Authors: Kim Chang-won , Spanjers Henri , Klapwijk Abraham
Published: May 2018

An on-line respiration meter was applied to measure the oxygen transfer coefficient (KLa) continuously in a completely mixed aeration tank. The uniqueness of this respiration meter lies in its ability to measure the actual respiration rate of activated sludge. The calculation of KLa can be carried out continuously with steady-state and discrete non-steady state equations using actual respiration rate and DO in the aeration tank. In an activated sludge pilot plant, the oxygen transfer coefficients were determined under constant and variable loading conditions using the above procedures. The relationship between KLa and air flow was found to be linear but dependent on the wastewater loading characteristic. Under variable loading conditions, the calculated DOs in the aeration tank using the obtained KLa's were more accurate than that using the KLa's estimated from the air flow rate function. The accuracy of separately assumed saturation DO in the activated sludge was confirmed from a linear relationship between DOs in the aeration tank and corresponding actual respiration rates at a constant KLa.
Recovery of Heavy Metal from Scrap Metal Pickling Wastewater by Electrolysis
Authors: Huang Ju-Sheng , Lee I-Chung , Lin Biing-Jauh
Published: May 2018

When the influent surface loading of copper ion in the four-stage continuous-flow reactors of electrolysis were controlled at 143.9, 94.0, 52.7 and 33.2 mg/min-dm2, respectively, and current density were controlled at 3.9, 2.6, 1.3 and 1.3A/dm2, respectively, the concentration of copper decreased from 13,900 to l,900mg/l (i.e., the electro-deposition rate of copper were 2,700, 2,240, 1,500 and 750 mg/dm2-h, respectively). The purity of copper depositing on the cathode reached over 98%. When the current density was ranged from 1.3 to 3.9A/dm2, the electro-deposition rate of copper increased with the increasing current density. However, when the current density was raised above 5.2 A/dm2, the electro-deposition rate of copper decreased with the increasing current density. The increase of current density decreased the current efficiency and increased the specific energy consumption. The increase of influent surface loading of copper ion increased the current efficiency and decreased the specific energy consumption.
Patterns of Water Quality in Rural Areas of Assyut Governorate, Egypt
Authors: Platenburg Ruud J. P. M. , Zaki Magdi
Published: May 2018

In 1990-1991 an action-research programme in the field of rural water supply and sanitation was implemented with the objective “To assess to what extent childhood diarrhoea is reduced by the delivery of hardware facilities which improve water quality, water availability and excreta disposal, and also including an intensive educational package directed toward improving behaviours concerning water use and personal and domestic hygiene”.

The intervention in Assyut Governorate comprising the construction of handpumps and latrines and a health education programme, was implemented during the second half of 1990. The data collection and data evaluation have been carried out during the period 1990-1991. Data were collected from the villages served with a complete intervention package as well as in control villages.

This paper deals mainly with the water quality issues which were part of the research programme. A comparison is presented for the water quality from both traditional and new handpumps. This comparison is supported by data collection throughout the research period within certain intervals, and by data collected from other handpumps installed at earlier times in areas within Upper Egypt. Findings concerning the actual drinking water quality, and the quality control of intervention and monitoring procedures are also discussed.

Major conclusions drawn from the results of the monitoring programme are:–The design, the drilling method and a proper development of handpump wells play an important role in the quality control of its water.–The bacteriological water quality improves only gradually after construction and eventually reaches acceptable levels. However, deep groundwater is thought to be of bacteriologically excellent quality. The most probable explanation for this gradual improvement is therefore the relatively long survival times of bacteria that entered the wells during construction.–Although it is not the intention of this paper to discuss the behavioural changes in the village communities during the research period, it was observed that, while water quality from handpumps is improving with time, the water quality from in-house zirs (storage reservoirs for drinking water) remained poor.
A Complete Treatment of Slaughterhouse Wastewater Combined with Sludge Stabilization Using Two Stage High Rate UASB Process
Authors: Sayed S. K. I. , van der Spoel H. , Truijen G. J. P.
Published: May 2018

The main objectives of the present investigations were to assess the feasibility of two stage high rate UASB-reactors for complete treatment of slaughterhouse wastewater which contains approximately 55 % insoluble coarse suspended COD.

The study presented in this paper addresses the maximum loading rates (hydraulic and organic) the extent of sludge stabilization (i.e. conversion into methane) and the length of the sludge stabilization period (i.e. digestion time).

The experiments were performed in two stage high rate anaerobic sludge UASB-reactors. The wastewater treatment experiments were performed at an operational temperature of 18 °C, while the sludge stabilization experiments were performed at a process temperature of 30 °C. Two different types of anaerobic sludge were used in this experiment: flocculent sludge for the first stage and granular for the second stage of the system. The first stage of the reactor system consists of 2 reactors which are used alternately. In the second stage, one reactor is in operation permanently.

The results of the present study indicate that the system can satisfactorily handle organic space loads up to 15 kg COD m−3.day−1 at a liquid retention time of 4 h and 1.5 h. for the first and second stage of the system, respectively. For the whole system a treatment efficiency up to 90 % on CODtotal basis, 95 % on CODcoarse suspended solids basis, 80 % on CODcolloidal basis and 80% on CODsoluble basis was achieved. The maximum extent of sludge stabilization (i.e. conversion into methane) at 30 °C was approximately 50 % for the accumulated coarse suspended solids and colloidal fractions in the reactors of the first stage of the system. The length of the sludge stabilization period (i.e. digestion time) was 14 days.
Purification Efficiency of Danish Biological Sand Filter Systems
Authors: Nielsen J. , Lynggaard-Jensen A. , Hasling A.
Published: May 2018

During an investigation in 1989 on small low technology treatment systems, particularly reed bed and biological sand filter systems in Denmark, it appeared that biological sand filter systems offer several advantages for the treatment of small wastewater sources. These observations gave rise to a new project concerning systematic registration of all biological sand filter systems in Denmark. Besides this registration the aim of the project was to indicate the reliability of these systems concerning removal ability and to give some general guidelines on different circumstances which seem to have positive or negative effects on the removal of particularly ammonium and phosphorus.

The paper summarizes the results and experiences that have been collected since the beginning of the use of biological sand filter systems in Denmark in the late 70s. Typical purification efficiencies of 90-95% for BI5, 30-45% for nitrogen and 40-60% for phosphorus were observed. The ripening of sand filters to their maximum removal capacity is often short, within a few months, but longer periods of about 6 months may be required to achieve full nitrification. High nitrogen removal depends on the nitrification processes and also of anoxic zones in the filter with denitrification. The best way to achieve good nitrification is to use coarse-grained sand. The removal of phosphorus is indeed affected by the chemical properties of the sand in question. In ferrous enriched sand it is possible to achieve removal efficiencies of 70-90% of the phosphorus at concentrations of 10-15 mg P/l in the inlet.
Stability of Colloidal Dispersions: A Thermodynamic Approach
Authors: Rajagopalan Raj
Published: May 2018

The classical theory of coagulation relies on relating the rate of interparticle collisions to the interaction forces, and thus to the physical and chemical parameters of the dispersion, through kinetic arguments, and is restricted to dilute systems. Here, we present a modern, thermodynamic theory capable of predicting stability diagrams for dense as well as dilute dispersions. Although based on statistical thermodynamics, the method is simple to use and requires only the second virial coefficient of osmotic pressure of the dispersion. All the information necessary for applying the model to arbitrary dispersions is given. The method is illustrated for a model colloidal potential, and it is shown how static light scattering measurements can be used for predicting the stability diagrams when information about the colloidal forces are not known in advance.
Actual Experiences with the Use of Reed Bed Systems for Wastewater Treatment in Single Households
Authors: Perfler R. , Haberl R.
Published: May 2018

Within a longterm project from 1991 to 1996 investigations on the use of constructed wetlands for pollution control in rural areas will be carried out especially regarding the rather strict limiting values for nutrient elimination. The actual discussion is also relevant for very small systems applied to single households. Three reed bed systems - one vertical flow, single stage; one vertical flow double stage (parallel and in-series operation possible); one horizontal flow, double stage - have been constructed in 1991 regarding all the new experiences on optimizing this technology. Some results of inlet and outlet sampling and from sampling points within the bed, of tracer experiments and microbiological and virological testing are presented. In addition a short review on the installation costs is given. In general the experiences of one year of operation seem to prove the opportunity to meet the tightened limits by waste water treatment in constructed wetlands.
Pond Malfunction: Case Study of Three Plants in the South-West of France
Authors: Racault Y.
Published: May 2018

Three waste stabilization ponds of a size ranging between 400 and 1500 eq.inhabitants, two of which are fed by long pipes, receiving in the head pond a load of 6 to 7 g BOD/m2.day, were monitored over 15 months with a sampling frequency of 1 to 3 weeks. The aim of the study was to determine the origin of malfunction phenomena causing at certain periods unpleasant smells, detrimental to the development of the ponding process. The behaviour of the head basins was analyzed by monitoring the trends of the following parameters: thermal gradient, active and degraded chlorophyll, sulfides, pH and EH profiles.

A thermal stratification was evidenced in the spring and summer at the 3 plants. The comparative analysis of the behaviour of the ponds revealed that the septicity of the raw effluent is not enough to explain the malfunctions. A set of factors act in synergy, upsetting the biological equilibrium when the organic load exceeds roughly 60 % of the nominal load. Treatment of the sulfides through the network was tested in one plant and its impact on the operation of the pond was assessed.
Extended Nutrient Removal in Small One-Tank Activated Sludge Plants
Authors: Hjorth Bjarne
Published: May 2018

The general Danish standards for discharge from municipal waste water treatment plants larger than 5000 PE require extended nitrogen and phosphorus removal to 8 mg/l total-nitrogen and to 1.5 mg/l phosphorus. In many cases the local authorities require that the same standards have to be met by smaller plants down to 500 PE. In some cases even tighter standards are set. As plants for extended nitrogen and phosphorus removal for smaller communities should not necessarily look like the large plants, new concepts have been developed. Combined nitrogen and phosphorus removal based on one activated sludge tank and one clarifier has proved to be advantageous both technically and economically in order to meet the above mentioned standards given under the Danish climate conditions with water temperatures of 38°C during winter. Six plants ranging from 600-2,500 PE and further three plants from 4,000-7,300 PE are now in operation. This paper gives a general description of the design and the operation of these plants. The plants operate by means of simultaneous precipitation and a special intermittent operational strategy or nitrification/denitrification. Operational results from the five plants with up to 4 years of operation show average concentrations of nitrogen and phosphorus of 5-6 mg/l and 0.4-0.8 mg/l, thereby leaving a rather large margin to the general Danish standards. As regards competition, the concept has proven to be very competitive in the range of 1,000-10,000 PE.
Pilot Plant Study of an Upgraded Rotating Biological Contactor
Authors: Watanabe Y. , Iwasaki Y. , Masuda S.
Published: May 2018

This paper deals with the experimental results obtained by the pilot plant of an upgraded Rotating Biological Contactor(RBC). This is a two-story RBC which is designed to simultaneously achieve the biological oxidation and removal of detached biomass in the trough. The authors constructed a three-stage pilot plant with an octagonal stainless mesh contactor 2 m across to collect the design information of an upgraded RBC. The municipal wastewater treatment was conducted to examine the RBC's performance. According to experimental results, with a contactor rotating speed of 2 rpm.the effluent TOC and NH4−N concentrations were about 10 g/m3 and 5 g/m3, respectively, at the hydraulic loading of 70 l/m2/d, corresponding to a BOD loading of about 8 g/m2/d. The electrical power consumption of the RBC was 0.005 kWh/m2/d at a contactor rotating speed of 1 rpm. A jet mixed separator(JMS) was used as the physico-chemical pre-treatment unit of the RBC. With the addition of a coagulant,simultaneous flocculation and sedimentation of the suspended particles occurred in the JMS. This combined system of the JMS and RBC produced a clean effluent.
Influence of Algae and Their Exudates on Removal of Humic Substances and Optimal Dose of Coagulant
Authors: Dolejs P.
Published: May 2018

There is still not enough information about the influence of several important variables, which occur in natural systems, on the coagulation of humic substances. One of these rarely studied variables is type and concentration of algal exudates. Thi s paper presents the results of research of the influence of alga Scenedesmus quadricauda and its exudates on the results of coagulation experiments with model humic water. The arrangement of experiments should simulate one possible way how algae might influence natural water systems and water treatment.

The results demonstrate that both the residual concentration of humic substances and residual aluminium are influenced during the time which elapses after the addition of the washed algae to the model humic water. But the influence of algae on residual colour is partly different from their influence on residual aluminium. Early after the algae addition to the model humic water, they influence the system predominantly with their surfaces, because the concentration of their exudates is low. This increases the residual concentration of aluminium. On the other hand, longer “algal residence time” in model humic water decreases the residual aluminium concentrations. Systems with algae are sensitive to overdosing with respect to both residual humic substances and residual aluminium.
Removal of Organic Matter by Physico-Chemical Mechanisms in Wastewater Treatment Plants
Authors: Boller M.
Published: May 2018

Solids separation, adsorption onto participates and volatilization are the main physico-chemical mechanisms responsible for the removal of organic matter in wastewater treatment plants. In addition, solids separation as well as adsorption performance may be enhanced by chemical flocculation/precipitation with hydrolyzing metal salts. With the help of particle size distributions and other characteristics of the particulates at different treatment stages, more insight can be gained into the interactions between paniculate properties and solids separation performance. Significant removal of trace organics is achieved by adsorption onto paniculate surfaces and stripping in aeration tanks. Examples illustrate the adsorption of the relatively large quantities of substances contained in detergents and reveal the effect on water and sludge quality. Octanol/water partition coefficients of trace organics may be used together with oxygen transfer characteristics to determine the potential of volatilization into the air. The effect of flocculants on paniculate and dissolved organics removal in wastewater treatment is illustrated when Fe-salts are dosed to raw sewage, to the biological stage or to tertiary filters.
International Workshop on Origin, Occurrence and Behaviour of Sediments in Sewer Systems: Outline of Technical Conclusions
Authors: Verbanck M. A. , Ashley R. M.
Published: May 2018

The technical conclusions at the IAWQ/IAHR International Workshop on Origin, Occurrence and Behaviour of Sediments in Sewer Systems (held in Brussels, Belgium, in September 1991) are briefly outlined.
The UK Urban Pollution Management Research Programme
Authors: Clifforde I. T. , Johnson I.
Published: May 2018

The paper describes the philosophy which underlies, and the work that is in hand to fulfil the objectives of, the UK Urban Pollution Management (UPM) Research Programme. The UPM Programme is the principal effort of the UK water industry to develop effective control methodology for urban pollution.
Urban Wastewater Discharge and Bacteriological Quality of Receiving Coastal Waters: Processes and Modelling
Authors: Guillaud J.-F. , Pommepuy M. , Dupray E. , Salomon J.-C. , Thouvenin B.
Published: May 2018

The aim of this paper is to present some results of bacterial studies which were developed by IFREMER in coastal discharge areas of urban wastewaters; they are focused on the determination of bacterial inputs by wastewater treatment plants, the role of environmental factors on the enteric bacteria survival in the coastal zone, and the modelling of bacteria transport and disappearance in order to provide useful management information for minimizing faecal pollution in the coastal zone.
Inactivation of Giardia by Anaerobic Digestion of Sludge
Authors: Gavaghan P. D. , Sykora J. L. , Jakubowski W. , Sorber C. A. , Sninsky A. M. , Lichte M. D. , Keleti G.
Published: May 2018

Sludge produced by a model wastewater treatment plant and anaerobically digested at 37°C in a laboratory digester was seeded with G. muris cysts. Samples from the digester were collected at 0:15, 4:00, 8:00, 11:30 and 26:00 hrs. Cyst inactivation was measured by excystation and direct counts of G. muris cysts using a hemacytometer and a phase contrast microscope. The results showed that 99.9% of the cysts were inactivated within apgroximately 18:00 hrs of exposure. This demonstrates that the standard sludge digestion (37°C for 24 hrs) will eliminate most of the cysts (greater than 99.9%).
Methodological Improvements for the Recovery of B. fragilis Phages and Coliphages from Environmental Samples
Authors: Araujo R. M. , Lasobras J. , Lucena F. , Jofre J.
Published: May 2018

The effect of different treatments and methods of titration on the recovery of phages infecting Bacteroides fragilis as well as for both somatic and male specific coliphages in environmental samples were evaluated. Recovery of phages infecting B. fragilis is highly dependent on the treatment of the samples. The influence of the treatment in the recovery of coliphages was either null or low. Titration method had some influence on the recovery of phages, mainly those of B.fragilis, from sludge and sediment samples.
Absence of Relationship between Health Effects Due to Tap Water Consumption and Drinking Water Quality Parameters
Authors: Payment Pierre , Franco Eduardo , Siemiatycki Jack
Published: May 2018

An 18-month prospective epidemiological study of gastrointestinal illnesses was conducted on 300 families consuming conventionally treated tap water and 300 consuming the same water after further treatment by reverse-osmosis. Drinking water met current bacteriological and physicochemical quality standards, but was found to be associated with a significant level of gastrointestinai illnesses: a reduction of 30% of the gastrointestinal illnesses was observed in the group consuming the filtered water. The presence or absence of total coliforms or fecal coliforms was not indicative of the health effects observed. The heterotrophic plate counts at 20°C in the distribution system were weakly associated with the duration of the symptoms when the data was analyzed by subregion. Several approaches to clustering of the family data to the nearest sampling site were attempted: no association could be demonstrated. Even if consumers of reverse-osmosis water experienced, on the average, less gastrointestinal illnesses, their illnesses were significantly associated with the number of bacteria growing at 35°C on medium R2A. The problems associated with the predictive value of the bacterial content of a water sample and in particular, the major differences between water quality at the tap and in the distribution system are presented. For example, standard procedures require analysis of the water after flushing the tap for several minutes: this is not however typical of the water that is consumed. Water that comes out of the tap has stagnated for long periods in household pipes and regrowth of bacterial contaminants can easily occur. The bacteria growing in this water might thus be responsible for some of the health effects observed in tap water.
Microflora in External Auditory Canals of Recreational Scuba-Divers and Swimmers Related to the Tropical Waterflora of a Coral Island
Authors: Haider T. , Sommer R. , Stanek G.
Published: May 2018

Recent studies described the acute diffuse external otitis frequently observed in recreational scuba-divers and swimmers in the tropics. In this study the microflora of the external auditory canal of 90 persons was determined. Additionally, a group of 17 persons was examined before, during and at the end of a two weeks vacation on a tropical coral island as well as three months after. Further, samples from sea, lagoon water and the water supplies used for the showers were microbiologically examined. 14 different and fecultatively pathogenic microorganisms were isolated from the external auditory canals. We found a temporary colonization with those microorganisms during the two weeks. Above all Pseudomonas aeruginosa was predominant during and at the end of the vacation especially in children. Before the vacation and three months after P. aeruginosa could not be found. The samples of sea and lagoon waters did not seem to be noticeably polluted, whereas the samples of the water supply were extremely contaminated with Pseudomonas aeruginosa. It was concluded that besides indirect factors such as tropical climate and intensive exposition to water, the insufficient treatment of the water from the supply could also be a reason for the temporary microbiological colonization of the external auditory canal.
An Improved Membrane Filtration Method for Enumeration of Faecal Coliforms and E. Coli by a Fluorogenic β-Glucuronidase Assay
Authors: Augoustinos M. T. , Grabow N. A. , Genthe B. , Kfir R.
Published: May 2018

A fluorogenic β-glucuronidase assay comprising membrane filtration followed by selective enumeration on m-FC agar at 44.5°C and further confirmation using tlie 4-metliylumbelliferyl-β-D-glucuronide (MUG) containing medium was evaluated for the detection of Escherichia coli in water. A total of 200 typical blue and non-typical blue colonies were isolated from sea and fresh water samples using initial selective enumeration on m-FC agar. Pure cultures of the selected colonies were further tested using the MUG assay and identified using the API 20E method. Of the colonies tested which were shown to be positive using the MUG assay 99.4% were Escherichia coli. The results of this study indicate the combination of the m-FC method followed by the MUG assay to be highly efficient for the selection and confirmation of E. coli from a wide range of environmental waters.
Rapid Identification of Enterococci with a New Fluorogenic-Chromogenic Assay
Authors: Manafi M. , Sommer R.
Published: May 2018

Enterococci are used as indicators of faecal contamination of water and food and are commonly detected using kanamycin-aesculin-azide media. Aesculin can be enzymatically hydrolysed at the β-glucose linkage to yield two products: aesculetin and glucose. Aesculetin produces a brown-black coloured compound with ferric ions. Enterococci give a positive reaction with this test but some other microorganisms can also give positve results and can be mis-identified as enterococci thus making confirmation important. A simple filter paper strip test has been developed to detect pyroglutamyl aminopeptidase and β-D-glucosidase using fluorogenic L-pyrroglutamic acid 7-amido-4-methyl-coumarin and chromogenic 5-bromo-4-chloro-3-indolyl-β-D- glucopyranoside. In contrast to the commonly used PYR test, the newly developed method needs no additional reagents. The method was found to be very successful for the rapid and specific identification of enterococci in water samples.
Evaluation of a Microbiological Water Purifier for Inactivation of Viruses, Bacteria and Giardia Cysts
Authors: Abbaszadegan M. , Gerba C. P. , Yahya M. T. , Rusin P.
Published: May 2018

Development of the need for personal water treatment devices has evolved from consumer interest in improving and ensuring the quality of drinking water. The need also extends to the quality of untreated or partially treated waters such as that used by hikers, campers, recreational home and boat owners, and families or communities having individual home and small system water sources. It is essential that such devices be capable of removing all types of pathogenic microorganisms likely to be found in contaminated water. For this reason the U.S. Environmental Protection Agency has suggested such units be capable of removing Klebsiella terriaena. Giardia cysts and enteric viruses. Three identical water purifiers were evaluated for the inactivation of rotavirus SA-11, hepatitis A virus, poliovirus type 1, the bacterial virus MS-2, Klebsiella terriaena and Giardia muris cysts. The units depend upon a thermal cycler combined with activated carbon for removal of the test organisms. The units were challenged with the organisms suspended in tapwater after 4, 76 and 240 cycles of operation. The units were also tested with a “worst case” water quality of 1500 mg/l dissolved solids, 10 mg/l organic matter and with a water turbidity of 30 NTU. In all cases, complete inactivation of the viruses, bacteria and cysts occurred after operation of the 35-minute cycle. This resulted in a greater than 3-log (99.9%) inactivation of cysts, a greater than 6 log (99.9999%) inactivation of K. terriaena and 4-log (99.99%) inactivation of viruses. In conclusion, these units would comply with CTiteria guidelines suggested by the U.S. Environmental Protection Agency for the operation of microbial water purifiers.
Use of the Direct Viable Count (D.V.C.) For the Assessment of Survival of E. Coli in Marine Environments
Authors: Dupray E. , Pommepuy M. , Derrien A. , Caprais M. P. , Cormier M.
Published: May 2018

The survival of the enterotoxigenic Escherichia coli H 10407 was observed in different marine seawaters, both in situ and in vitro by use of dialysis chambers and microcosms, exposed and not exposed to light. Survival was monitored during several days by measurement of plate counts (culturable bacteria), direct viable counts with yeast extract and nalidixic acid (DVC : viable bacteria), and acridine orange direct counts (total bacteria).

Without light, culturable E. coli counts decreased slowly (1.5 log unit), whereas viable and total bacteria counts remained almost the same through 8 days. When light stress emphasized the sea-water stress, the difference between culturable and viable counts increased from the very first two days (4 log units). In all the experiments, the number of viable bacteria remained very high. On the other hand, one experiment using dialysis chambers held in a turbid and brackish estuarine water showed no marked decrease in the initial counts. This better survival was probably due to the presence of organic matter. So culturability and viability of E. coli can change according to its environment. And because of the consequences for sanitary monitoring of seawaters, it must be kept in mind that viability of E. coli can be preserved within several days, in drastic conditions.
Comparative Survival of Indicator Viruses and Enteric Viruses in Seawater and Sediment
Authors: Chung H. , Sobsey M. D.
Published: May 2018

Laboratory studies quantified the relative survival of F+ coliphages, B. fragilis phages, hepatitis A virus, poliovirus, and rotavirus in seawater and seawater-sediment mixtures. Samples of each matrix were seeded with mixed populations of the viruses and incubated at 5 and 25°C for 60 days. F+ coliphages were inactivated faster than three enteric viruses in seawater at 25°C. In seawater-sediment mixture at 5 and 25°C or at 5°C in seawater, their survival was comparable to those enteric viruses that died off rapidly. In contrast, B. fragilis phages survived comparable to or better than enteric viruses in all conditions. Except for HAV, greater percentages of total detectable viruses were distributed in sediment over time. The effect of sediment on survival of viruses differed among viruses. Survival rates were significantly greater at 5°C than at 25° for all five viruses.
Detecton of Viruses in Coastal and River Water Systems in Sydney, Australia
Authors: Grohmann G. S. , Ashbolt N. J. , Genova M. S. , Logan G. , Cox P. , Kueh C. S W.
Published: May 2018

Two prospective studies on the occurrence of human viruses in samples of coastal & river origin have been undertaken since September 1989. Viruses were detected using concentration methods & cell culture techniques. Water samples (100L) were reduced to 1L using hollow fibre ultrafiltration and then treated with PEG. Sewage and sediment samples were treated with PEG only. Over a two year period, viruses were detected in 24/202 (12%) of water samples and 29/60 effluents from the river system. Coastal waters have been contaminated by cliff edge discharge of sewage for at least the last 70 years. Recently, deepwater ocean outfalls have been installed to discharge effluent some 3 km away from the coast. Prior to the installation of deepwater ocean outfalls viruses were detected in 28% of water samples compared to 9% post installation. In sediment samples viruses were isolated in 87/260 (34%) samples, the discharge via the new outfalls having no effect on the isolation rate. The data points to long term survival of viruses sediments and/or contamination from other sources such as storm water discharge: 10-25% of storm water drains were also found to be positive for viruses. The viruses isolated were enteroviruses, adenoviruses & reoviruses. Although viruses were consistently isolated with some seasonal trends, comparisons between the detection of viruses in clinical and environmental samples over this two year period were inconclusive.
The Difficulties and Promise of an Interagency Public Information Campaign for Water Quality Issues
Authors: Miller Michelle
Published: May 2018

The following case study addresses the difficulties and promise of developing a statewide interagency public information campaign to raise general awareness of water quality issues and governmental programs to address them. Due to only moderate success of voluntary programs to curb nonpoint source pollution, agencies are looking toward information and education programs to motivate the public toward conservation behavior. One of the biggest obstacles in developing an effective information/education program is institutional barriers to interagency cooperation, mirroring difficulties local conservationists encounter in their work to restore and maintain water quality at the watershed level. Cooperation between federal agencies, and resource commitment to public information is necessary at the federal level, as well as state and local levels. Agencies involved to date include the United States Department of Agriculture-Soil Conservation Service; Wisconsin State Departments of Natural Resources, and Agriculture, Trade and Consumer Protection and Administration; University of Wisconsin-Extension; Wisconsin Land Conservation Association.
Broiler Litter Application to Land in an Agricultural Watershed: A GIS Approach
Authors: Xu Feng , Prato Tony , Fulcher Chris
Published: May 2018

This paper studies broiler litter utilization in an agricultural watershed using a Geographical Information System (GIS) and an optimization model. An optimization model is developed which selects broiler litter management practices that maximize total net returns to land and management and estimates economic value of litter as a fertilizer substitute for an agricultural watershed experiencing rapid growth in broiler production. Land application rates are determined based on crop nutrient requirements, fertilizer source, and litter cleanout schedule. Results indicate that litter as a fertilizer is economically favored over commercial fertilizer. Land area required for current litter application does not exceed suitable land application areas after excluding sensitive areas such as streams, roads and sink holes. However, litter from further growth in broiler production will soon reach the maximum capacity of suitable land areas in the watershed. Nutrients in current litter amounts do not exceed crop nutrient requirements, but would equal crop requirements if broiler production is doubled (tripled) and litter application rates are determined on a phosphate (nitrogen or potash) basis. GIS is a powerful analytical tool for analyzing economic and environmental problems. Litter is an inexpensive substitute for commercial fertilizer and its value varies with the nutrient basis used to determine application rates, litter cleanout schedule and litter availability.
Predicting Attainable Water Quality Using the Ecoregional Approach
Authors: Schonter Rebecca , Novotny Vladimir
Published: May 2018

To more adequately protect receiving water bodies, government policy is leading toward adaptation of integrated management approaches that protect the integrity of the ecosystem as a whole. Approaching natural water quality is a goal of integrated water resource management. Ecoregions represent geographical areas of relatively similar land surface form, mineral availability, natural vegetation and land uses, and therefore, represent areas of relatively similar background water quality. Water quality at relatively unimpacted reference locations is representative of regional natural water quality and may be reasonably extrapolated to other similar locations within the ecoregion. These concepts were applied to the Southeastern Wisconsin Till Plains ecoregion and the Milwaukee River, Wisconsin.
Water Protection in Acid Sulphate Soils
Authors: Hooli J. , Lakso E. , Palko J.
Published: May 2018

Acid sulphate soils cause acidification of the adjacent watercourses, which is harmful for the fishing industry, for example. With the aim of reducing acidity problems the effects of drainage on acid soils have been estimated and the possibilities of liming acid sulphate soils after digging ditches have been studied. Means for reducing acidity in connection with drainage by either doing the work in stages or preventing an excessive drop in the groundwater table have been considered. Methods for the direct liming of watercourses have been examined and their effects evaluated.
Efficiency of Best Management Practices for Controlling Priority Pollutants in Runoff
Authors: Scholze Richard , Novotny Vladimir , Schonter Rebecca
Published: May 2018

All priority pollutants are removed from runoff via one or more of the following pathways: adsorption or precipitation and/or complexation followed by sedimentation or filtration, volatilization, biodegradation or photolysis. The more appropriate removal mechanism may be determined by examining certain chemical parameters, especially the octanol-water partitioning coefficient Kow, Henry's law constant KH, vapor pressure and biodegradability. Best Management Practices may be divided into categories based on the pollutant removal mechanisms within the BMP. The most appropriate BMP may be selected by matching the process most likely to remove the pollutant to the removal process.
Groundwater Contamination from Agricultural Sources in Northern Italy: Long-Term Monitoring and Mathematical Modelling
Authors: Fortina Luigi , Capodaglio Andrea G. , Baldi Marco
Published: May 2018

The province of Pavia, in Northern Italy, is an intensively cultivated agricultural area with substantial urban development Groundwater supplies constitute almost all the potable water available to the resident population. Concern exists about the fate of herbicides applied to farm fields that have been found in measurable quantities in drinking water supplies. This paper describes at first the general environmental conditions and land use activity pattern in which the diffuse contamination occurs, history of contaminant detection is correlated to external interventions, such as government regulations, and the findings of the monitoring process are then illustrated. A mathematical model of groundwater transport is then illustrated and its predictions are compared with monitoring findings.
Long-Term (15 Years) Results of NPS Controls in an Agricultural Watershed upon a Receiving Lake's Water Quality
Authors: Garrison Paul J. , Asplund Timothy R.
Published: May 2018

Nonpoint source controls were installed in a 1215 ha agricultural watershed in northeastern Wisconsin in the late 1970. Changes were made in handling of animal wastes and cropping practices to reduce runoff of sediment and nutrients. Modelling results predicted a reduction in phosphorus runoff of 30 percent. The water quality of White Clay Lake has worsened since the installation of NPS controls. The lake's phosphorus concentration has increased from a mean of 29 µg L−1 in the late 1970s to 44 µg L−1 in recent years. Water clarity has declined from 2.7 to 2.1 m and the mean summer chlorophyll levels have increased from 9 to 13 µg L−1 with peak values exceeding 40 µg L−1. Increased phosphorus loading is not the result of elevated precipitation but instead the failure of the control measures to sufficiently reduce P loading. Most of the effort was placed on structural changes while most of the P loading comes from cropland runoff. Further, soil phosphorus concentrations have increased because of artificial fertilizers and manure spreading. The White Clay Lake experience is discouraging since the majority of the polluters in this watershed utilized some NPS control practices, including 76 percent of the farms which installed waste management control facilities.
A Simplified Computer Model for Nonpoint Source Pollution in a Small Urban Area
Authors: Kuo Jan-Tai , Yan Yeou-Lih , Li Kung-Cheh
Published: May 2018

In this study, a simplified computer model for nonpoint source pollution that can be easily used by engineers on a personal computer was developed. In this model, the urban drainage basin was divided into several drainage subareas according to hydrological conditions. Manning's equation was used to simulate the overland flow and flowrate in the channel system. Mass balance equation was used for flow condition at channel junction points such as manholes. Data samples between 1986 and 1987 from the simulating area were used to calibrate and verify the model. The simulation results showed that the simplified model was capable of predicting the runoff and nonpoint source pollution from the small urban area quickly on a personal computer. The advantages of the model are simplicity, and less input data and computer time required, compared to some other complex models. For a small urban area, it satisfies the basic requirements to access the loading of nonpoint source pollution for planning and preliminary pollution control purposes.
Interactions of Sewerage and Waste-Water Treatment: Practical Examples in The Netherlands
Authors: van der Graaf J. H. J. M.
Published: May 2018

Various interactions of sewerage and waste-water treatment are discussed for the typical situation in the Netherlands.

Sewerage and waste-water treatment are no longer necessary when each house has its own integrated waste-water system; however, costs seem to be high.

The same applies for small-scale waste-water treatment versus centralisation.

However, centralized waste-water treatment plants suffer from specific problems due to high fluctuations, not only in hydraulic but also in biological load.

With stringent effluent standards the need increases for complete treatment instead of by-passing the peak flows.

Besides, the application of buffering tanks may change in favour of an increase in the hydraulic capacity of the waste-water treatment plant.

Finally, a new, integrated, attitude on water-cycle problems must be advocated.
Investment Planning for Second Generation Sewerage Systems
Authors: Eadon Andrew R.
Published: May 2018

The first part of this paper deals with the technical improvements which have been made in the United Kingdom to ensure that sewerage rehabilitation is both effective and efficient. Severn Trent Water Ltd, which was one of the first organisations to employ a strategic approach to sewerage rehabilitation, has responsibility for the management of some 52,000 kms of sewer, 2250 pumping stations and serves a population of 8.3 million people. Planning and the progress made on implementing new methods for structural and hydraulic analyses within Severn Trent Water Ltd are illustrated. These elements together with the provision of high quality sewer records comprise a Drainage Area Study from which the investment needs of existing sewer systems are derived and programmed.

The second part of the paper deals with the topic of macro-planning of sewerage rehabilitation in a large organisation. At this level it is necessary to balance financial and manpower resources to obtain an overall programme for investment which is steady and sustained. The programme also embodies clear aims and objectives which provide adequately for customer needs.

The manner in which this has been achieved by Severn Trent Water Ltd is described and illustrated. The paper includes details of the programme of Drainage Area Studies and how the resulting information is collated to produce an overall investment programme. The main objectives are to clear the backlog of problems of flooding, pollution and sewer dereliction by a prescribed date, and thereafter to provide an improved service to customers by being able to respond to new problems quickly. The resulting increased activity in construction work creates extreme disruption to some communities. The perception of customers has been researched and the measures' introduced recently by Severn Trent to provide appropriate care for these customers who are inconvenienced by the works are described.
An Appraisal of Suspended Sediment Transport Modelling Methods for an Interceptor Sewer
Authors: Coghlan B. P. , Ashley R. M. , Jefferies C.
Published: May 2018

The data from a two and a half year field study were used to assess the performance of various suspended sediment transport modelling methods. The models selected for this purpose were those proposed by Ackers-White and by Sonnen and these have been assessed following site specific calibrations. A modified version of the Ackers-White model and a rating curve based on a regressional analysis of flowrate versus total suspended solids were also tried. The calibrated verion of the Ackers-White model was selected as giving the best overall accuracy for storm and dry weather conditions. A validation of the selected model using further data for the same site gave approximately 69% of predicted concentrations between 1/2 and 2 times the observed values.
Experience with Vortex Separators for Combined Sewer Overflow Control
Authors: Brombach H. , Xanthopoulos C. , Hahn H. H. , Pisano W. C.
Published: May 2018

In 1987 the first vortex solids separator facility in Germany was installed for combined sewer overflow (CSO) control. The separation efficiency was optimized in the hydraulic laboratory using scaled down models with artificial tracers to simulate typical sewage particulates. The station has two parallel operating vortex separators and serves a connected and impervious area of about 11 hectares (ha) and 1,500 people. The specific storage volume of the station is 7.2 m3 per ha. Two evaluation programs were conducted. The first evaluation phase noted the operational reliability, hydraulic loads, overflow frequencies and water mass balances. The second phase monitored separation efficiencies. The evaluation showed that vortex solids separators are now ready for use in CSO control.
Optimising the Efficiency of Storm Water Settling Basins by Means of Bypassing
Authors: Clemens F. H. L. R. , van Mameren H. J. , Kollen J.
Published: May 2018

The reduction in pollutional load realised by storm water settling basins is potentially reduced due to the occurrence of a partially mixed situation in the basin or due to resuspension of settled material. The decrease in efficiency can theoretically be avoided by means of partially bypassing the basin. In order to quantify the potential increase in efficiency a settling basin in Amersfoort is taken as an example. This basin seems to behave like an almost completely mixed system, bypassing would increase the overall efficiency from ca. 34 % to ca 39 % for three overflows.

The dynamic behaviour of settling basins, scouring conditions and the boundary conditions for which settling basins are to be designed are the research needs for further development in the field of storm water settling basins.