bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainability of Water Supplies in Provincial Egypt
Authors: Nicholson N. F.
Published: May 2018

Life, health and hygiene all depend on access to a plentiful supply of safe drinking water. Piped water supplies in rural Egypt are insufficient to meet the demands of the existing population. This situation is worsening due to the rapid population growth and failure of existing water supply systems.

There are already areas of the country with severe piped water shortages. If corrective action is not taken soon densely populated villages will become vulnerable to outbreaks of waterborne diseases. Immediate action is needed to reverse the deterioration of water supply systems and to improve the benefits gained from capital works investments in the sector.

This paper promotes the concept that sustainable water systems in rural Egypt depends on a central government and local unit partnership. Also needed are consumer bodies to determine user needs; local units to be given powers to manage the revenue and expenditure accounts; and the central government to concentrate on setting policies and guidelines, and assisting with the implementation of major capital works.
Wastewater Treatment by Infiltration Basins. Case Study: Saint Symphorien de Lay, France
Authors: Guilloteau J. A. , Lienard A. , Vachon A. , Lesavre J.
Published: May 2018

Domestic wastewater treatment by infiltration basins is a process that is becoming common in France. In the absence of accurate operating data, we felt it would be useful to conduct a case study at an existing plant. The Saint Symphorien de Lay plant, serving a population-equivalent of 500, was chosen because the basins are watertight and drained.

The study revealed 85% TSS, COD and Total Phosphorus removal. Nitrogen yields varied over the flooding period, with a high production of nitrates at the beginning of the period. The rate of decontamination (1 to 2 Log unit) was lower than expected.

The infiltration surface should increase from 1 to 1.5 m2/p.e. and spread over three basins. Research is now focusing on finding the biologically active depth of an infiltration basin.
Second Generation Oxidation Ditches: Advanced Technology in Simple Design
Authors: Petersen G. , Nour El-Din H. , Bundgaard E.
Published: May 2018

Oxidation ditcb systems for waste water treatment at various demands for effluent quality with regard to BOD, nitrogen and phosphorus are presented.

Simple design for only BOD-removal and nitrification as well as designs for advanced treatment including biological nitrogen and biological phosphorus removal are presented, and full scale results from more than 15 years of operation are shown.

The simple design and price competitive construction can none the less produce effluent qualities below 15 mg BOD/l, 8 mg N/l and 1.5 mg P/l if the right oxidation ditcb combination is used.
Wastewater Treatment/Reuse in Rural Areas
Authors: Kuttab Atallah S.
Published: May 2018

Proper hygiene leading to good health, in urban as well as rural communities, requires that the consumption of drinking water is raised to acceptable levels (UN organizations put it at 40 liters/cap/day). The increase of water availability necessitates the provision of sewage drainage facilities. Urban areas are normally provided with sewerage schemes (sewer lines, treatment plants, etc.). However, it is unrealistic and not cost feasible to construct such sophisticated systems in villages. This is due to limited resources of public funds available to the responsible government agencies.

In rural areas, the provision of utilities to drain sewage in a safe way lags behind the provision of water for household activities, including drinking water. This creates severe contamination to the environment of the various villages and reduces the impact of water on the improvement of health.

An appropriate wastewater treatment/reuse system, called the Subsurface Drainage Technique (SDT), is described here which was successfully applied, by Save the Children/USA, in several villages on the Israeli Occupied West Bank and Gaza Strip. The system is applicable for individual households with land available in their immediate vicinity. It consists of a watertight septic tank, where primary treatment occurred, followed by a subsurface drainage field in which the secondary treatment took place. The treated wastewater in the drainage field allowed indirect irrigation (below ground level) for surface plants. Local materials were adopted for the construction of the SDT. Villagers themselves were trained to build the various units and therefore were able to maintain their efficient performance. Ongoing monitoring of the plants grown in the drainage field and the testing for bacteriological contamination ensures the safe performance of the technology.
Performance Assessment of Three Wastewater Treatment Plants Producing Effluents for Irrigation
Authors: Ghobrial Fikry H.
Published: May 2018

Three wastewater treatment plants, in Kuwait, producing effluents for irrigation were assessed. The assessment was directed to determine the characteristics of the raw wastewater, the quality of the treated effluents, and the efficiency of the various steps of treatment. The assessment of the quality of treated effluents was based on the standards established by the Ministry of Public Works (MPW) according to the reuse plans of the effluents for irrigation. Analyses were carried out for conventional parameters, trace metals, toxic trace organics as well as bacteria. Results of analyses showed that only one plant was producing effluent meeting the requirements of MPW.

The results of this preliminary investigation indicated that despite the toxic constituents in the raw wastewater, they did not constitute a significant problem in the treatment process; two of the three treatment plants violated the reuse standards with respect to the conventional parameters.
Depth Filtration Assisted by Electrical Fields
Authors: Solt G. S.
Published: May 2018

Depth filtration of liquids is a well established process. Its main drawback is that it does not effectively remove particles smaller than about 2-3 µm diameter, because they do not normally approach near enough to the surface of the medium to become attached to it. A static electrical field overcomes this by promoting electrophoretic movement of the particles. The work has studied particle removal from low conductivity water through fibrous depth filters and has covered a variety of fibres with different physical properties. The results yield a fibre efficiency series, which suggest the relationship between filtration efficiency and the electrical properties of the fibre.
Transient-State Modelling of Deep Bed Filtration
Authors: Choo Chang-upp , Tien Chi
Published: May 2018

A review and comparison of five models for transient-state deep bed filtration including one which was recently developed by the present authors is presented. To facilitate the comparison, all the models are presented in a format which can be used to obtain the relationship between the increase of the filter coefficient with the extent of deposition. Comparisons between the models and between model predictions and experiments indicate the importance of the permeability of deposit layer and the deposit morphology in determining the effect of deposition.
Treatment of Septic Tank Effluent in a Subsurface Biofilter
Authors: Netter Robert , Stübner Eckhard , Wilderer Peter A. , Sekoulov Ivan
Published: May 2018

A horizontal flow biofilter to be buried in the backyard of private homes and residential areas was developed to treat effluents of septic tanks. Pilot and full scale experiments have been conducted to study the efficiency of the biofilter. A tank volume of about 0.6 m3 per capita is needed to achieve advanced COD removal, complete nitrification and up to 60 per cent nitrogen removal. The bacterial count was reduced by 2 to 3 orders of magnitude. The treated effluent may be used for irrigation or toilet flushing. Percolation is possible without negative effects on groundwater quality.
Optimum Backwashing of Filters with Air Scour: A Review
Authors: Amirtharajah Appiah
Published: May 2018

The problems occurring in the filtration facilities of water treatment plants, such as mudballs and poor initial filtrate quality are associated with the effectiveness of backwashing. Backwashing with water alone to fluidize the media is an inherently weak cleaning process. The effectiveness of backwashing is significantly improved by the use of air scour simultaneously with subfluidization water wash. When air and subfluidization water flowed concurrently through porous media, a condition termed “collapse- pulsing” occurred in which air pockets formed and collapsed within the bed. A theory has been developed that predicted the combinations of air and water flows that caused collapse-pulsing to occur. Model filter systems have shown that the fluid mechanical condition termed “collapse-pulsing” is also the condition of optimum removal of particles from the media grains during backwashing. The theoretical aspects of collapse-pulsing have been confirmed with an experimental filter system having an endoscope, high speed video system with freeze frame capability for visual observations and an XY Coordinator with computer hardware and software which enabled the determination of velocities of filter grains during air scour. Additional studies on optimum removal of particles from media during air scour have also demonstrated that the results may be extended to dual media filters and are valid at the plant scale too.
Alternative Approaches for Upgrading Effluent Quality for Lagoon Based Systems
Authors: Evans Brian , Nutt Stephen , Ho Tony , Melcer Henryk
Published: May 2018

The province of Ontario is Canada's most populous province with over 8 million residents out of a total population of 27 million. The province has 512 sewage treatment plants of which 137 or 27% are lagoons. Improved environmental effluent quality standards since the introduction of the lagoons has resulted in many of these being unable to achieve proper effluent quality.

Typical effluent quality requirements across the province require a minimum of secondary treatment, that is 15 mg/l of BOD and suspended solids and 1 mg/l of total phosphorus. The movement towards a clean environment has resulted in phosphorus levels as low as 0.3 mg/l TP and in an increasing number of cases, full nitrification year round. Because many of these lagoons serve small populations in the 100 - 3 000 population equivalents category, the cost of upgrading such lagoons to tertiary quality effluent is significant.

Two approaches for upgrading conventional lagoon systems were evaluated. They are called the Sutton and New Hamburg processes after the towns in Ontario where they were first installed. The Sutton process consists of extended aeration plant, followed by polishing lagoons with waste sludge sent directly to the lagoons, while the New Hamburg process consists of conventional lagoons followed by intermittent sand filtration.
Treatment System of Wastewater from Rural Settlements with Batch-Activated Sludge Process
Authors: Yuyama Y. , Fujino K. , Miyamoto Y. , Oonishi R.
Published: May 2018

The treatment system for rural communities with Batch-Activated Sludge Process was improved. The focus was on removal of nitrogen by intermittent aeratyion. Following the experimental results, treated water quality lower than 10 mg/l of BOD and T-N was ensured throughout the year, under the operational conditions of hydraulic retention time in aeration tank longer than 24 h and MLSS higher than 2,500 mg/l. Treated water quality of T-N was less than 5 mg/l within cumulative frequency of 66%. Removal capacity of T-N did not reach its limit under condition less than 0.05 kgN/m3d−1 of influent load. Estimating from the nitrogen removal rate, consumption of alkalinity, characteristics of biomass growth and the amount of nitrogen content in MLSS, 77% of influent nitrogen was denitrified, 18% of that was discharged as treated water and 5% of that was extracted as excess sludge or SS in treated water. Fluctuation patterns of DO and ORP in a cycle by seasonally changed water temperature were effective indices for regulation of operation. A remote monitoring system was helpful to support the management, because it enabled maintenance staff to judge urgency of management from the latest real time data.
Automatic Regulation of Activated Sludge Aeration – Single-Tank Nitrification-Denitrification
Authors: Lefevre F. , Audic J. M. , Bujon B.
Published: May 2018

Several activated sludge processes using intermittent aeration were developed during the last decade to improve nitrogen removal. Timers, oxidation-reduction or oxygen probes are often used to switch aeration on and off at preset times or by upper and lower limits. These regulation systems cannot adjust the oxygen supply to the biological oxygen demand and cannot realize the supply when “requested” by the influent. A new controller/regulator system (OGAR: Optimized manaGement of Aeration by Redox) based on the variation with time of the oxidation reduction potential was developed : EH = f(time). This OGAR system controls the aeration periods and therefore optimizes the nitrification and denitrification reactions in the sludge processes.

The operation of the OGAR programmable controller can be summarized by three functions:

It is a true diagnostic tool and a decision making aid. Its simple design enables it to be adapted easily to any site and to be highly user-friendly.

OGAR was applied to an existing wastewater treatment plant located at Nezel-la-Falaise near Paris (west suburb). Overall performance of the plant before and after implementation of automatic aeration control by OGAR yields the following conclusions:removal of COD was improved by 45 % reduction in COD from 100 mg/l to 55 mg/lammonia nitrogen concentration was reduced from 42 mg.l-1 to 2mg.1-1 and nitrate nitrogen concentration was reduced to less than 5 mg.1-1
Small Wastewater Treatment Plants Based on Moving Bed Biofilm Reactors
Authors: Ødegaard H. , Rusten B. , Badin H.
Published: May 2018

In 1988 the State Pollution Control Authority in Norway made recommendations regarding process designs for small wastewater treatment plants. Amongst these were recommendations for biological/chemical plants where biofilm reactors were used in combination with pretreatment in large septic tanks and chemical post treatment. At the same time the socalled “moving bed biofilm reactor” (MBBR) was developed by a Norwegian company. In this paper, experiences from a small wastewater treatment plant, based on the MBBR and on the recommendations mentioned, will be presented.
Influence of Dissolved Organic Matter on Coagulation/Flocculation of Wastewater by Alum
Authors: Fettig J. , Ratnaweera H.
Published: May 2018

The influence of different humic substances and linear alkylbenzene sulfonate on chemical treatment of a synthetic wastewater was investigated at pH=6-6.5. In soft water, humus significantly inhibited particle destabilization. The additional coagulant dosages needed for efficient coagulation corresponded to the dosages required for humus removal from pure solutions. Adsorption of humus onto precipitated hydroxide was regarded as being the major mechanism of interaction here. In hard water, high concentrations of humus seemed to impair aggregation of microflocs. This was attributed to the formation of soluble calcium humate complexes in raw water that may adsorb more slowly on precipitated hydroxide than dissolved humus. Precipitation of phosphate was not affected by humus in a definite way. A clear influence of LAS on coagulation was not found.
A New Sewage Treatment System with Fluidized Pellet Bed Separator
Authors: Suzuki Tatsuhiko , Tambo Norihito , Ozawa Genzo
Published: May 2018

A new sewage treatment system which is composed of a fluidized pellet bed separator, aerobic biological filter and micro–membrane filter was studied.

In the newly proposed system, at the first stage, higher molecular weight organic substances and suspended matter are removed by way of chemical coagulation and flocculation. For the operation, a new fluidized pellet bed separator with high separation rate of 200-300 m/day is introduced to improve the treatment rate. A large percentage of organ ic substances are removed by the new coagulation/flocculation process. Hence, the total BOD load to be applied to the following biological treatment becomes very low. In addition to this, the organic substances in the effluent from the fluidized pellet bed separator are on lylower molecular weight substances which are easily biologically decomposed. Therefore easily decomposing and lower concentration pollutants enable use of a simple biological treatment p rocess such as aerobic biological filter with as short a detention time as 1 hour. Finally, effluent from the biological filter is treated by a micro-membrane filter. By the membrane process, suspended matte rs in the biologically treated water can be removed completely. Phosphate concentration of the treated water is very low, which is caused by aluminum coagulation in the first step and biological intake of the nutrient in the second step followed by complete sol id liquid separation in the third step.
Dissolved Organics Removal by Solid-Liquid Phase Separation (Adsorption and Coagulation)
Authors: Licskó István
Published: May 2018

To improve the organics removal efficiency of surface water treatment technologies, powdered activated carbon (PAC) has often been added. Some of the PAC particles with the dissolved organics already adsorbed are present in the form of a colloidal quasi-colloidal dispersion and can be removed most efficiently by coagulating and flocculating them together with the natural suspended solids. This, however, cannot be accomplished unless the PAC is added 3-5 minutes ahead under violent stirring of the water to be treated. Laboratory data demonstrated that the PAC and the Al-hydroxides formed of the coagulant (Al-salt) added remove different types of organics from the water and consequently do not compete with each other.
Variations of Environmental Parameters and Ecological Response in an Urban River
Authors: Morrison G. M. , Wei C. , Engdahl M.
Published: May 2018

Water and sediment quality deterioration in an urban river was assessed during and after stormwater runoff and sewer overflow. Stormwater runoff bad a noticeable effect on continuous measurements of water quality in the urban river; oxygen sag and increased conductivity was a typical response. Sediment toxicity was found at sites directly exposed to urban runoff, while concentrations of copper and lead exceeded sediment quality criteria. The enzyme activity of the sediment-dwelling bacteria was found to be more sensitive with inhibition downstream and upstream of urban discharge.
Biological Investigations in Receiving Waters Lead to New Strategies in Urban Drainage
Authors: Wieland Axel , Gammeter Sonja , Lange Jörg
Published: May 2018

An improved understanding (with consequent alterations to management strategies) is shown to be the result of investigations of urban receiving waters from a biological as well as chemical and hydrological perspectives.
Planning Stormwater Treatment of a Mountainous Urban Area
Authors: Michelbach S.
Published: May 2018

Within the urban drainage system the sewer system, the wastewater treatment plant and the receiving waters form a functional unit The interactions between these three systems are of importance during the whole planning cycle. In particular, the sensitivity of the receiving waters should be more taken into account than has been done up to now.

The extension of stormwater treatment for a small town in a mountainous area should be planned. A first study done by a different company working only with guidelines recommended specific volumes for stormwater tanks between 30 m3 and 70 m3 per ha impervious area Six new stormwater tanks with a total volume of 5000-6000 m3 were to be installed. For the community these values seemed to be unrealistically high. In discussion with the water management, they wanted to undertake a more realistic planning. The company Umwelt- und Fluid-Technik (UFT) was commissioned to work out a new study taking the specific conditions of the urban catchment into account
Fecal Pollution of Pearl Oyster (Pinctada radiata)
Authors: Qureshi Ateef A. , Mahasneh Adel , Al-Sayed Hashim , Al-Buflasa Amal , Al-Shuaibi Mariam
Published: May 2018

The physical parameters of the five sampling sites, such as the depth of the oyster beds, ranged from <1 to 20m; salinity, 40.98 to 56.75 g/L; pH, 7.76 to 7.95; temperature, 20.0 to 27.38°C; and dissolved oxygen, 5.60 to 5.96 mg/L. A wide range of distribution of the indicators of fecal pollution; total coliforms, 3.48 × 103 to 8.0 × 105/g; fecal coliforms, 2.97 × 102 to 3.2 × 105/g; and an enteric virus population of 0 to 4.66 virions/gof oyster meat, were detected. These observations indicate alarming levels of fecal contamination and waiiant serious concentrated efforts to contain the pollution hazards in the coastal waters.
Application of RT-PCR for the Detection of Enteric Viruses in Oysters
Authors: Jaykus L. A. , De Leon R. , Sobsey M. D.
Published: May 2018

Oyster samples processed by adsorption-elution-precipitation were seeded with poliovirus 1 and HAV, and cleaned and concentrated by Freon extraction (2X), PEG precipitation and chloroform extraction. Freon extraction resulted in recoveries of 63-76% for polio and 42-52% for HAV. PEG precipitation/chloroform extraction gave recoveries of 47-50% for polio and 15-19% for HAV. Treated extracts inhibited RT-PCR at 10−2 dilutions. Inhibitors were removed by treatment with the cationic detergent CTAB or Pro-Cipitate/UF adsorption-elution-concentration. Both treatments resulted in samples on which direct RT-PCR was possible. The CTAB procedure was able to detect 78 pfu of polio and 295 pfu of HAV. The Pro-Cipitate procedure was able to detect 70 pfu polio and 2.1×103 pfu HAV.
Study of Viral Purification of Oysters
Authors: Boher S. , Schwartzbrod L.
Published: May 2018

Oysters (Crassostrea gigas) were experimentally contaminated by immersion in seawater containing rotaviruses SAl 1 for one hour. The rotaviruses SAl 1 had previously been adsorbed over algae (Dunaliella primolecta). Oyster depuration was then studied. The depuration was performed by immersion in closed loop circuit and in semi open circuit. In the semi open circuit, the seawater is replaced every 24 hours. It was shown that the rotaviruses, whether free or fixed on algae, were inactivated very rapidly when the seawaterwascontinuously treated with U.V. (intensity ranging from 46.5 to 94 mW.s/cm2). The decontamination of the oysters in closed loop circuit starts at the first hours of immersion. For large viral contaminations, the decontamination was complete in 78 % of the cases after 72 hours. In the remaining 23 % of the cases, the contamination decrease varied from 82 % to 99.7 %. For lower viral contaminations, less than 30 viruses per gram of oyster tissue, the depuration was complete in 100 % of the cases after 72 hours. For large viral contaminations, the decontamination in semi open circuit was complete in only 82 % of the cases after 72 hours. For contaminations lower than 30 viruses per gram of oyster tissue, the dqjuration was complete in 100 % of the cases after 72 hours.
A Nude Mouse Model as an in vivo Infectivity Assay for Cryptospomdiosis
Authors: Kwa B. H. , Moyad M. , Pentella M. A. , Rose J. B.
Published: May 2018

Cryptosporidium parvum is an important patliogen of diarrlieal disease which has been implicated in several outbreaks associated with contamination of surface waters. In monitoring for C. parvum in drinking water sources, it is important to asce tain the viability, and more importantly, the infectivity of low numbers of recovered oocysts. Groups of 10 Balb/C nude (nu/nu) mice, 4-8 weeks old at time of inoculation, were infected with C. parvum oocysts from naturally infected calves and purified using Sheather's sucrose gradients. Oocysts were counted using the Merifluor IFA kit (Meridian). Each group of 10 mice were infected with 1,10,100 and 1000 oocysts respectively. Numbers of oocysts per inoculation were determined by limiting dilution, and parallel inocula were counted microscopically to ascertain the accuracy of the dilutions. Two uninfected nude mice were kept in each cage to serve as controls. Mouse stools were collected every 4 days, concentrated using the Fekal Kontrate Concentration Kit (Meridian) and oocysts were counted with a UV microscope using the Merifluor IFA Kit (Meridian). Oocyst counts were expressed in terms of number of oocyst/g feces. Mice inoculated with 1000 oocysts began to shed oocysts on day 32, mice inoculated with 100 oocysts began to shed on days 44-48, mice inoculated with 10 oocysts began to shed on days 56-60, and mice inoculated with 1 oocyst shed on days 68-88. All infected mice continued to shed oocysts intermittently and with variable oocyst counts until day 180 when the experiment was terminated. This study established that it is possible to infect nude mice with very low numbers, down to a single oocyst. We are currently in the process of correlating the nude mouse assay with other viability assays.
Multiplication Characteristics of FRNA Phage and Its Utility as an Indicator for Pathogenic Viruses
Authors: Kamiko Naoyuki , Ohgaki Shinichiro
Published: May 2018

The possibility of multiplication of F-specific RNA phage (FRNA phage) multiplication in the environment was investigated. Using the Qβ strain in pure culture as a model FRNA phage, the effects of bacterial growth phase, substrate concentration and cultivation temperature on phage multiplication were studied. Similar experiments with environmental samples from raw sewage were then preformed.
The Application of Risk Assessment Techniques to Microbial Monitoring Data: A South African Perspective
Authors: Rodda N. , Amory A. , Kfir R.
Published: May 2018

The feasibility of applying microbial risk assessment techniques in South Africa was evaluated by assessing risks associated with enteric viruses in raw and treated drinking water. Maximum daily risks associated with treated drinking water were in the range 2×10−2 − 7×10−1. If levels of viruses in treated drinking water were approximated from those in raw water by assuming reductions during treatmentof 4 log, Slog and 6 log, maximum daily risk estimates were 4×10−2 - 4×10−1, 5×10−3 - 1×10−1 and 5×10−4 - 1×10−2, respectively. A number of complicating factors were identified. Detection limits were high and volumes of water monitored were low. There was no information on viral pathogen removal during treatment. Application of risk assessment techniques within these limitations clearly showed the volume of water monitored to be the most important factor limiting detection of low risk levels. The sampling and concentration of large water volumes (at least 100ℓ) for microbial analysis was identified as an urgent need.
Heterotrophic Bacteria in Chlorinated Drinking Water Distribution Systems: Detection and Identification
Authors: Hirata T. , Tosa K. , Kawamura K. , Nakajima J. , Kaneko M. , Taguchi K.
Published: May 2018

In order to determine bacterial quality of supplied water, researches on detection and identification of heterotrophic bacteria In distribution basin water and tap water were conducted In several drinking water supply systems In Japan, using pour plate technique with two agar media of SPG (Incubated at 36°C) and PGY (at 25°C). Bacterial colonies formed on SPC agar were randomly selected, purified and identified to genus. Results obtained from this study were as follow. The density of SPC bacteria ranged from 0 to 190 cfu/mL, although no colony was detected after 1-day Incubation in all of water samples tested. The density of PGY bacteria was higher than SPC and were In the range of 0 to 380 cfu/mL. Maximal values were found In first flow of water from taps In the early morning which contained lower residual chlorine. Prolonged incubation time resulted In Increased bacterial counts on both SPC and PGY plates. This tendency was more noticeable In samples collected from taps, particularly In first flow of water In the early morning. Dominant genera of the bacteria grown on SPG varied with different water supply systems and were Alcaligenes, Bacillus, Flavobacterlum, Methylobacterlum and Pseudomonas.
Assimilable Organic Carbon Concentrations and Bacterial Numbers in a Water Distribution System
Authors: Gibbs R. A. , Scutt J. E. , Croll B. T.
Published: May 2018

A three year study was conducted to investigate bacterial growth in a drinking water distribution system in the UK. Bacterial numbers were estimated using Yeast Extract Agar plate counts. Plate counts in the distribution system showed patterns of spatial and seasonal variation. The spatial pattern was that plate counts increased through the distribution system until approximately 30 to 40 hours retention time and remained constant further through the distribution system. The seasonal pattern was that plate counts were low in the winter and had large peaks in the summer and autumn. Assimi able organic carbon (AOC) concentrations were measured in the second and third years of the study using an adenosine triphosphate (ATP) assay. There appeared to be no relationship tietween AOC concentrations and the spatial and seasonal variation in plate counts. The lack of correlation may have been caused by a lack of sensitivity in the AOC technique. Another explanation is that the increase in plate counts through the distribution system was due to an increase in the culturability of bacteria on plate count media, rather than an increase in bacterial numbers. Bacteria may not have grown through the distribution system and therefore not utilised the AOC.
Investigation of Typhoid Fever and Cholera Transmission by Raw Wastewater Irrigation in Santiago, Chile
Authors: Shuval Hillel I.
Published: May 2018

Santiago, the capital city of Chile, has suffered for years from high rates of typhoid fever, reaching peaks as high as 210 cases/100,000 in 1977 and 1982. Many officials suspected that the use of raw wastewater to irrigate 13,500 ha of vegetables and salad crops may have been one of the modes of transmission. However, control measures have in general been ineffective. In April, 1991 an outbreak of 41 cases of cholera occurred in Chile probably initiated by the penetration of cholera cases from adjacent Peru which was undergoing an explosive cholera epidemic. Investigations showed that there was strong circumstantial evidence supporting the hypothesis of typhoid and cholera transmission by wastewater irrigated crops. From data gathered it is shown that while there was little seasonal typhoid fever variation in the rest of the country, there was a decided summer peak in Santiago that coincided with the peak irrigation season and harvesting of sewage irrigated vegetables. In the 1991 cholera outbreak, which occurred during the irrigation season, 68% of the cases had consumed wastewater irrigated salad crops eaten uncooked. Salmonella typhi and Vibrio cholerae were isolated by “Moore” pads from raw wastewater in canals leading to irrigated vegetable plots. Other direct and indirect evidence supports the case of wastewater irrigated vegetables as the main mode of transmission. Emergency cholera control measures, including heavy chlorination of raw wastewater, partially settled by flowing in slow moving irrigation canals, are reviewed.
Bather Morbidity from Recreational Exposure to Sea Water
Authors: Von Schirnding Y. E R. , Strauss N. , Robertson P. , Kfir R. , Fattal B. , Mathee A. , Franck M. , Cabelli V. J.
Published: May 2018

Rapid urbanisation in the coastal areas of South Africa has led to increasing concern about the potential health effects on bathers resulting from exposure to contaminated seawater. Water quality criteria in South Africa are not epidemiologically derived; consequently a major programme has been launched to develop health-related criteria and policies pertaining to wastewater and stormwater management in the coastal areas of South Africa. In the first phase of the project, an epidemiological-microbiological study was carried out at a moderately polluted beach and a relatively clean beach, in the Western Cape. Individuals present at the beach in family groups were interviewed and follow-up telephone interviews were conducted 3-4 days after the beach outing. Water quality indicators measured on the same day as the beach interviews revealed significantly higher levels of enterococci and faecal coliforms at the moderately polluted beach. Symptom rates for gastrointestinal, respiratory and skin effects were substantially higher among swimmers relative to non-swimmers at the polluted beach, although they did not reach statistical significance.
Virus Isolation and Identification by PCR in an Outbreak of Hepatitis A: Epidemiological Investigation
Authors: Divizia M. , Gnesivo C. , Bonapasta R. A. , Morace G. , Pisani G. , Panà A.
Published: May 2018

An outbreak of hepatitis A in a school and in a college in Rome, involving 13 cases, is described. Anti-HAV IgM were identified in 13 out of 14 cases and the epidemic curve suggested a person to person transmission of the virus. Hepatitis A virus was identified in a well-water sample of the college using traditional methods and the PCR test. This water, depending on bacteriological analysis, was classified as undrinkable.

The epidemiological investigation showed that the principal risk factors were to be full-time at the State school and boarders at the college. These differences were statistically significatives.
Application of PCR to the Detection of Adenoviruses in Polluted Waters
Authors: Girones R. , Allard A. , Wadell G. , Jofre J.
Published: May 2018

A method for the detection of adenovirus in environmental samples has been developed. We tested several systems for concentrating viral particles by adding adenoviruses 2 and 12 to different sewage samples. The method selected was as follows: centrifugation of the sample in order to pellet adenovirus viral particles and all suspended solids, elution of the pelleted viruses by treatment with 0.25N glycine buffer pH 9.5, removal of solids from the sample by a short centrifugation and ultracentrifugation of the resulting supernatant. Elution with glycine buffer avoided inhibitors and showed more sensitivity than ultrasonication or filtration through a low binding protein filter to retain bacteria and suspended solids. Sewage samples were treated by this selected method and recovered viral particles were analyzed both by a two-step DNA amplification reaction and by infecting Hep-2 cells. About 50% of the samples were positive in a two-step PCR and these data were confirmed by tissue culture amplification and one step PCR. Two pairs of primers (external and nested) from the hexon region were used, which are able to detect human adenovirus from all subgenera. Although more studies are needed, the two-step PCR developed appears to be a quick and reliable method for adenovirus detection in environmental samples.
Comparison of Methods for Isolating Campylobacter SPP from Sewage
Authors: Dousse C. , Schneider E. , Schwartzbrod J.
Published: May 2018

Various Campylobacter isolation methodologies from wastewater samples have been tested. Considering the results obtained, an experimental method is suggested combining a filtration on a 0.45 µm membrane with an enrichment in Preston's broth with 6 h at 42°C of incubation followed by an isolation on Preston's agar after a 48 hours incubation at 42° C in a microaerophilic atmosphere. This technique has been applied to 116 samples of raw wastewater taken from the Nancy treatment plant. Campylobacter have been isolated in 43.9 % of the samples. The species distribution was 94.1 % C. jejuni and 5.9 % C. coli.
Glass Wool for Virus Concentration at Ambient Water pH Level
Authors: Vilaginès Ph. , Sarrette B. , Husson G. , Vilaginès R.
Published: May 2018

Operating conditions for using oiled sodocalcic glass wool (Saint Gobain R. 725) to concentrate enteroviruses in 100 to 1000 liters samples were determined. These filters recovered from 62 to 75% of several enteroviruses (laboratory strains or field isolates) and rotavirus SA11 that were added to tap water. The technique permitted the recovery of 62% and 57% of poliovirus added respectively to river water and treated waste water. The results of a 44 months survey of the Seine and Mame river waters are reported. Being efficient at ambient pH, the use of glass wool may permit continuous virological monitoring of water samples.
Removal of Salmonella Typhi, Shigella Dysenteriae, Vibrio Cholerae and Rotavirus from Water Using a Water Treatment Tablet
Authors: Rodda N. , Bateman B. , Kfir R.
Published: May 2018

Chlor-floc tablets are intended for purification of small quantities of water for individual use by combined flocculation and disinfection. Removal of Escherichia coll E25, various viruses and Giardia cysts from polluted water by Chlor-floc has been previously demonstrated. This study evaluated the efficiency of removal of Salmonella typhi, Shigella dysenteriae, Vibrio cholerae and rotavirus from simulated hard water of high organic content and colour. All four pathogenic microorganisms were successfully removed within the recommended treatment time. Log removals of 7-8 log were achieved for bacterial pathogens, and a removal of 6.5 log was obtained for rotavirus.
Evaluation of the Efficiency of a UV Plant for Drinking Water Disinfection
Authors: Sommer R. , Cabaj A.
Published: May 2018

The effective UV-dose in a UV-reactor depends on the transmission and the flow rate of the water being irradiated as well as on the design of the plant and the hydraulic behavior. Since there is no possibility for a direct and simple dose measurement in such a system, it is necessary to develop a testing procedure which estimates the hygienic safety of such a plant. B. subtilis (ATCC 6633) spores were suspended in potable water and irradiated in a commercially available drinking water UV plant with varying flows (0.5 to 7.5 m3/h) and transmission (3 to 80 %; thickness 10 cm).

Sodium thiosulfate and adenosine were used as transmission reducing substances. Because of the known UV sensitivity of the spores it was possible to calculate the effective dose in the reactor as space radiant exposure for each test. The data resulted in an individual diagram of efficiency. It was shown that this testing procedure is suitable for the evaluation of the disinfection capacity of UV plants and the estimation of the field of application depending upon transmission and flow rate of the water being irradiated.
Inactivation of Bacteria and Coliphages by Ozone and Chlorine Dioxide in a Continuous Flow Reactor
Authors: Botzenhart K. , Tarcson G. M. , Ostruschka M.
Published: May 2018

The antimicrobial activity of ozone (OZ) and chlorine dioxide (CD) is difficult to determine, not only due to the short inactivation times, but also because the concentrations of the disinfectants decrease during the reaction time. These difficulties were avoided by designing a continuous flow reactor, where steady state concentrations of the antimicrobial agents as well as of the microorganisms can be obtained, depending on the inactivation velocity. From the inactivation velocity, the time necessary for a 99.99% reduction and corresponding Ct values can be derived. This was done at different concentrations for E. coli, L. Qineumophila, B. subtiüs at pH 6 and pH 8 and at 5°C and 15°C, and for the Coliphages MS 2 and PhiX 174 at pH 8 and 5°C. The inactivation rates obtained this way are rather short as compared to results of other authors. Ct values decrease with increasing concentrations of OZ and of CD (n> 1), except with B. subtilis. The relative susceptibilities to CD are: B. subtilis < E. coll < L. pneumophila < PhiX 174 < MS 2. The greater susceptibility of Legionella as compared to E. coli was confirmed in a batch test. CD proved to be more efficient at the higher temperature and at the higher pH. The relative susceptibilities to OZ were: B. subtilis < L. pneumophila < MS 2 < PhiX 174 < E. coli. OZ seemed to be somewhat more effective at the lower temperature, while higher pH resulted in faster destruction.
Significance of Specific Bacterial Pathogens in the Assessment of Polluted Receiving Waters of Sydney, Australia
Authors: Ashbolt N. J. , Grohmann G. S. , Kueh C. S W.
Published: May 2018

The impact of primary sewage released from Sydney's ocean outfalls and chlorinated tertiary treated sewage effluent discharged into Sydney's main river system (Hawkesbury-Nepean) have been studied for faecal microorganisms over two years. Faecal indicator bacteria and a range of potential bacterial pathogens (Aeromonas spp., Campylobacters, Pseudomonas aeruginosa, Staphylococcus aureus and salmonellae) were also cultured. Diverting primary-treated sewage from cliff edge release to deepwater (80m) ocean release some 3 km offshore resulted in significant reductions in all bacterial groups examined, with spores of Clostridium perfringens (C.p) being the most sensitive indicator of water quality improvement. In contrast, contamination of inshore sediments has not markedly declined. Campylobacters were not isolated from effluents or seawater, and numbers of S. aureus and P. aeruginosa were very low if detected. Inland river waters were dominated by motile aeromonads, and along with C.p were the most resistant organisms to chlorination following tertiary sewage treatment. However, aeromonads appeared to grow throughout the river system. Campylobacters were associated with areas of agricultural input whereas salmonellae appeared to be associated with significant urban sewage input. Of the indicator bacteria, C.p correlated best with salmonellae, while viruses correlated poorly with the bacterial groups examined. Further work is required to identify possible sources of virulent aeromonads, Campylobacters and salmonellae.
Bacteriophage Monitoring in Drinking Water: Do They Fulfil the Index or Indicator Function?
Authors: Armon Robert
Published: May 2018

2,187 drinking water samples from various locations in northern part of Israel were tested for bacteriophages presence/absence. Three major groups of bacteriophages were monitored (as related to bacterial host) : Somatic coliphages (host E.coli CN13), F-specific coliphages (host E.coli F+ amp), and Bacteroides fragilis phages (host B.fragilis HSP40). Simultaneously, monitoring of total coliforms and fecal coliforms has been performed. Correlation between bacteriophage group types and the standard water indicators such as coliforms and fecal coliforms was poor. The poor correlation may be attributed to dilution factor (large distance from the pollution source) and/or disinfection process. Presence frequency of the three bacteriophage groups was : 11.5 % somatic coliphages, 6.46 % F-specific coliphages and 5.48 % B.fragilis phages. Bacteriophages' presence plotted against presence of total coliforms, fecal coliforms, or both, revealed that F-specific coliphages and B.fragilis phages are closely related, whereas somatic coliphages group is different. Concentrates of several high volume water samples were tested for enteric viruses and B.fragilis phages presence correlation. All the samples were found negative for both parameters, however positive samples have not been detected. It is expected that continuous monitoring of drinking water for enteric viruses and concurrently for bacteriophages, will elucidate the index potential of bacteriophages. Bacteriophages presence in drinking water points to inadequate water treatment or contamination during the supply practice. Using human specific bacteriophages such as B.fragilis phages, will enable us to differentiate between pollution sources that contaminate drinking water. Future studies should be focused on phages presence as related to health risk assessment, similarly to human pathogens (bacteria, viruses and protozoa). Based on the collected data, F-specific and B.fragilis phages indicate towards reliable future index-organisms of drinking water pollution by sewage.
Occurrence of Resistance to Antibiotics and Metals and of Plasmids in Bacterial Strains Isolated from Marine Environments
Authors: Avilés M. , Codina J. C. , Pérez-García A. , Cazorla F. , Romero P. , de Vicente A.
Published: May 2018

Tlie resistance patterns to different antibiotics and lieavy metals of bacterial strains isolated firom marine environments (seawater, sediments and shellfishes) were studied. Pseudomonas aeruginosa showed the widest resistance profile, both to antibiotics and metals. In general, the resistance profiles of Gram-negative I microorganisms include the resistance to arsenic, copper, amoxycillin and tetracydine. Some associations of resistance to different antimicrobial agents were frequently observed. An important proportion of the studied strains harboured plasmids; and the association between the occurrence of plasmids and the resistance to arsenic, amoxycillin, carbencillin and streptomycin was observed.
Technical Guidance for Implementing BMPs in the Coastal Zone
Authors: Frederick R. E. , Dressing S. A.
Published: May 2018

The U.S. Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA) released the Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters on January 14, 1993. This document is EPA's technical guidance on the best affordable ways to reduce or prevent nonpoint source (NPS) pollution in the coastal zone. The authors believe that it is currently the most comprehensive summary of best management practices (BMPs) available. The guidance contains BMPs for the control of NPS pollution from agriculture, forestry, urban areas, marinas, and hydromodification (channels, dams, and stream and shoreline erosion). Wetlands, riparian areas, and vegetated treatment systems are addressed in the guidance as additional options to control nonpoint pollution. The guidance also includes monitoring and compliance tracking techniques to accompany the management measures.

EPA and NOAA are developing approaches to help states, local governments, and affected parties understand and use the technical guidance in their coastal nonpoint source programs. Although final decisions have not yet been made, this paper summarizes the current thinking regarding this technical assistance.
Zelivka River Storage and Treatment Complex Supplying the Prague Agglomeration with Drinking Water: Addressing Point and Non-Point Pollution Problems
Authors: Chour V. , Holas J. , Korab J. , Srb O.
Published: May 2018

Gradual deterioration of stored-water quality and actual danger of critical breakdown of the treatment technology supplying some 1.5 M inhabitants of the Prague-Agglomeration with drinking water are addressed by the conceited governmental action programme proposed in 1992 jointly by the Ministries of Environment and Agriculture of the Czech Republic. The programme is based on hitherto long-term extensive studies and includes additional research, investigation and monitoring works, design and implementation of abatement projects as well as policy, legislation and institutional activities.

Massive growth of phytoplankton biomass throughout the dam reservoir promoted by the unwanted luxurious supply of phosphorus and nitrogen compounds was traced both to point and non-point pollution sources in the watershed. While phosphorus was found to be primarily borne by communal point sources, nitrogen in the yearly amount of 2-3,000 t is mainly an indirect by-product of actual agricultural cropping systems. Long-term research has brought the evidence of complex microbial transformation, mineralization, nitrification and other processes involved in the nitrogen transport to the reservoir. To date other pollutants, e.g. chlorides, sulphates, heavy metals and organics have neither reached safety limits nor displayed excessive growing trends in the reservoir.