bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Operating Problems in Wastewater Treatment Plants on the Interactions Between Sewers, Treatment Plant and Receiving Water
Authors: Kappeler Jörg , Gujer Willi
Published: May 2018

Problems in wastewater treatment plants due to problems such as bulking and scum accumulation are examined by simulations of a typical Swiss sewer treatment plant system. Strategies for optimising overall system performance are indicated.
Microbial Sampling: Is It Better to Sample Many Times or Use Large Samples?
Authors: Haas Charles N.
Published: May 2018

Repeated sampling of a water (raw, Ssished, recreational) is often used to assess microbial quality. Microbial distributions have often been found to be negative binomial distributed in such repeated samples. Under these conditions, it is shown that it is better to use a large number of small volume samples than vice versa, providing that the negative binomial dispersion parameter remains unaffected by volume. Further research is needed to determine if the latter assumption, which influences the conclusion proposed, is valid for various classes of microorganisms in various types of waters.
External Quality Control for Water Virology: Is It Feasible, Is It Worthwhile?
Authors: Sellwood J. , McDermott J.
Published: May 2018

A pilot Study by eight UK laboratories demonstrated the feasibility and the value of a quality assurance scheme for virological testing of water and wastewater. However it also highlighted basic disadvantages of the test methods used.
Development of PCR Methods for Enteric Virus Detection in Water
Authors: Schwab K. J. , De Leon R. , Sobsey M. D.
Published: May 2018

This study developed a reverse transcriptase-polymerase chain reaction (RT-PCR) detection system for enteric viruses in sample concentrates obtained by conventional filter adsorption-elution methods. One liter beef extract (BE)-glycine (G) eluant seeded with poliovirus 1 and hepatitis A virus (HAV) was used as a model system and the eluant further processed for RT-PCR compatibility. Sample concentration and purification procedures consisted of polyethylene glycol (PEG) precipitation, Pro-Cipitate (Affinity Technology, New Brunswick, NJ) precipitation, a second PEG precipitation, spin-column chromatography, and ultrafiltration. Sample volumes are reduced from 1 L to 20-40 µL and purified sufficiently for viral detection by RT-PCR. As little as 3 PFU of poliovirus 1 in an initial 1 L eluate were detected by RT-PCR.
Detection of Enteroviral RNA Sequences in Different Water Samples
Authors: Tougianidou D. , Botzenhart K.
Published: May 2018

Viruses were isolated from different water samples by Sterivex-Filtration. The nucleic acids were isolated in the filter unit and purified by phenol-chloroform extraction and ethanol precipitation. Reverse transcription and polymerase chain reaction (RT/PCR) were performed with primer pairs complementary to sequences of the enteroviral 5’ noncoding region. Amplified sequences were detected by hybridisation with an oligonucleotide complementary to a part of the PCR product. The test system seems to be sensitive and specific In the detection of enteroviral RNA.
Advantages and Disadvantages of Traditional and Molecular Techniques Applied to the Detection of Pathogens in Waters
Authors: Alvarez Abdiel J. , Hernández-Delgado Edwin A. , Toranzos Gary A.
Published: May 2018

New techniques such as hybridization and the polymerase chain reaction (PCR) have been used to increase the sensitivity and specificity of detection of pathogens in waters over traditional methods. We can now detect as few as one single bacterial cell using these techniques. However, the application of state-of-the-art methodology requires a lot of expertise and high costs which most laboratories cannot afford. Thus, traditional methods will keep on being used by the great majority of laboratories. All laboratories have to keep in mind the intrinsic limitations of each and every one of the methods, and the high stringency necessary to avoid false positive results when using molecular techniques. It would be advisable, then, to use several techniques conjointly in order to determine the real public health significance of laboratory findings. It is, thus, of paramount importance to subject all new techniques to a series of Round Robin testings before raising false expectations as to their applicability to water analyses.
Disinfection of Hepatitis a Virus and MS-2 Coliphage in Water by Ultraviolet Irradiation: Comparison of UV-Susceptibility
Authors: Wiedenmann A. , Fischer B. , Straub U. , Wang C.-H. , Flehmig B. , Schoenen D.
Published: May 2018

Ultraviolet irradiation is gaining importance as a disinfection procedure for drinking water and in waste water treatment. Since water is one of the main transmission routes of hepatitis A virus the susceptibility of HAV to UV rays is of special interest. MS-2 coliphage resembles HAV in size and structure, is easy to handle, and might tlierefore serve as indicator organism for the assessment of water quality and for evaluating the quality of water treatment processes. Hepatitis A virus and MS-2 coliphage were suspended in 0.9% sodium chloride solution and were irradiated in a 20-ml quarz cuvette at 254 nm. For a reduction rate of four log units a three times liigher UV dose was required with MS-2 than with HAV.
In Situ Survival of Indicator Bacteria, MS-2 Phage and Human Pathogenic Viruses in River Water
Authors: Susan Springthorpe V. , Loh Chi Leong , Robertson W. J. , Sattar Syed A.
Published: May 2018

Previous studies of microbial behaviour in situ have used dialysis sacs and diffusion chambers to permit contact of contained microorganisms with the external aqueous milieu. Their main limitation is a slow response to changes in water quality, preventing adequate simulation of field conditions. This study used the ECODYNE system™, a new device responsive to real time changes in water quality. It consists of a hollow fibre membrane module and fluid reservoir which separates the test microorganisms from the external environment. Use of a mixture of Escherichia coli, Enterococcus dwans, MS-2 phage, poliovirus type 1 (Sabin) and hepatitis A virus (HM-175) allowed direct comparison of their survival in river water under identical conditions over a period of at least 24 hours. The results can be summarised as follows: a) survival patterns of E. coli in nutrient rich river water were highly variable, b) a ten-fold or greater increase in numt)ers of E. coli was sometimes observed in twth latwratory and field tests, c) no regrowth was ever observed with E. durons, and its titre declined faster than that of E. coli, and d) over the first 24 hours, the phage survival was similar to that of the human pathogenic viruses. The observations regarding the variable survival of E. coli and its potential for regrowth raise questions about its suitability as a water quality indicator. MS-2 phage shows promise as an indicator of viral pollution, but requires further study. The ECODYNE system proved highly suitable in this study, and shows potential for other environmental interaction/environmental fate studies including ecotoxicological investigations and monitoring.
Survival of Hepatitis A Virus (HAV), Poliovirus 1 and F-Specific Coliphages in Disposable Diapers and Landfill Leachates
Authors: Gray M. , De Leon R. , Tepper B. E. , Sobsey M. D.
Published: May 2018

The survival of HAV, poliovirus 1 and F+ coliphages was studied under various conditions in both fecally soiled disposable diapers and solid waste landfill leachates. Fecally soiled disposable diapers and leachates were seeded with viruses and incubated aerobically and/or anaerobically at 5, 25 and 40°C for 90 days. Under some conditions, viruses survived >90 days in fecally soiled diapers and landfill leachates, especially at lower temperatures. In both fecal suspensions and leachates at 5°C, all viruses were inactivated slowly (<1 log10 in 30 days). At 40°C, viruses were reduced to non-detectable levels (by >4 log10) in 8-29 days in diapers and in as little as 2 days in leachates. Some viruses were inactivated at different rates under anaerobic versus aerobic conditions. Under most conditions, persistence of F+ phages, HAV and poliovirus 1 was similar, thus suggesting that these phages may be useful enteric virus indicators in solid waste and leachates.
Virus Removal by Slow Sand Filtration and Nanofiltration
Authors: Yahya M. T. , Cluff C. B. , Gerba C. P.
Published: May 2018

Water utilities, especially smaller ones, are having increasing difficulties proving increased treatment requirements required in the United States for the removal of chemical and microbial contaminates in drinking water. This project sought to evaluate the virus removal potential of combined slow sand filtration and nanofiltration by a pilot plant for application to a small utility which uses a surface water supply. Nanofiltration is a relatively new water treatment technology which has become available since 1986. It is similar to reverse osmosis but has a higher molecular weight cut-off and is less costly to operate. The bacteriophages MS-2 (28 nm) and PRD-1 (65 nm) were seeded into surface water entering a pilot plant and samples collected after sand filtration, nanofiltration, and of the nanofilter reject water. These phages were selected for study because of their small size and poor adsorption to surfaces. The slow sand filter removed 99% of the MS-2 and 99.9% of the PRD-1. There was between a 4 to 6 log reduction of the phages by the nanofilters. PRD-1 was removed to a greater extent than MS-2 by both the sand filter and the nanofilters.
GIS Application to Water Quality Management in the Upper Volga River Basin: Joint TVA/Russia Project
Authors: Belyaeva Tatiana , Higgins John M. , Kirpichnikova Natalia , Lanzova Irina , Hagerman James R.
Published: May 2018

The Water Problem Institute of the Russian Academy of Science and the Tennessee Valley Authority are participating in a joint project to demonstrate the use of geographic information systems (GIS) in managing water resources under the changing economic system in Russia. The purpose is to improve decisions by better organizing, analyzing, and presenting water resource data and management options. Results to date include development of a conceptual approach and review of existing data. The project area includes the Upper Volga River Basin which encompasses the Moscow metropolitan area. Data are being managed at three levels depending on the scale and detail (i.e., regional, watershed, and local). Initial conclusions indicate a great potential for this technology, but many obstacles due to the current economic situation.
Assessment of the Effect of Acidic Deposition on Canadian Lakes: Determination of Critical Loads for Sulphate Deposition
Authors: Jeffries D. S. , Lam D. C. L.
Published: May 2018

The operational definition of the “critical” load for wet SO4 deposition is that which does not increase the regional percent of lakes having pH≤6 for the portion of the population that historically had pH>6. Reviews of the effects of acidic deposition on aquatic biota show that the pH=6 threshold used to determine the critical load is sufficient to protect most organisms. It is inappropriate to specify a single critical load for the whole of eastern Canada due to variability in terrain sensitivity. The Atlantic provinces and easterr Quebec generally have very low critical loads (<8 kg. ha−1.yr−1). The terrain characteristics of this area dictate a critical load very close to background deposition. Lakes in southwestern Quebec and Ontario have critical loads of <8 to >20 kg.ha−1.yr−1 reflecting the wide range in terrain sensitivities that exist in each province.
Environmental Auditing for Nonpoint Source Pollution Control in a Region of New South Wales (Australia)
Authors: Turner G. W. , Ruffio R. M. C.
Published: May 2018

The concept of environmental auditing of point source pollution has been adapted to nonpoint source pollution in rural lands. Geographic Information Systems (GIS) and other information technologies provide an effective environmental management tool for characterising nonpoint source (NPS) pollution in a regional context and thereby can assist the environmental auditing process. Nonpoint source pollution problems of rural watersheds in Australia, particularly those in the state of New South Wales, and the role of the state's environment protection agency are outlined. A case study that applies an auditing methodology using GIS in a study area within the Lachlan River catchment is presented. The suitability of the approach for land condition evaluation and the review of land use controls for nonpoint source pollution is discussed.
The Detection and Disinfection of Pathogens in Storm-Generated Flows
Authors: Field R. , O'Shea M. , Brown M. P.
Published: May 2018

A recreational water's disease-producing potential is usually assessed by bacterial indicators of human fecal contamination, however many of these indicator bacteria also originate from soils, vegetation, and animal feces. Stormwater runoff can contain high densities of the nonhuman indicator bacteria and epidemiological studies of recreational waters receiving stormwater runoff have found little correlation between indicator densities and swimming related illnesses. In addition a number of non-enteric pathogens found in stormwater runoff have been linked to respiratory illnesses and skin infections, a risk which is not assessed by the present fecal indicators. Therefore, for receiving waters with predominantly stormwater discharges, the current bacterial indicators are not suited to accurately assess the water's total illness producing capacity. The intermittent and irregular nature of stormwater discharges causes unique disinfection requirements which are discussed in connection with present practices and developments. The need for epidemiological studies to assess the risk from nonhuman and non-enteric pathogens is recommended.
Use of the Gleams Model to Estimate Pesticide Overland and Subsurface Transport in USDA Forest Service Nursery Applications
Authors: Craig J. P. , Weiss R. C.
Published: May 2018

The USDA Groundwater Loading Effects of Agricultural Management Systems (GLEAMS) model was used to estimate pesticide concentrations entering surface water systems draining USDA Forest Service nurseries and subsequent risks from human oral exposure to the stream water. The GLEAMS model was employed to determine the primary pathways of pesticide loss, pesticide build-up in soil after successive applications, and pesticide concentrations in field runoff, eroded soil, and leachate. Pesticide residues in field runoff and adsorbed to eroded soil, both estimated by GLEAMS, were diluted into runoff volumes from treated and untreated areas to determine pesticide concentrations in the stream systems draining the nurseries. Where appropriate, pesticide residues from leachate were included. Pesticide concentrations in leachate and leachate volumes, both estimated by GLEAMS, and site-specific characteristics were used to make judgements about the susceptibility of drinking water aquifers to contamination by pesticides. The results of the GLEAMS analysis indicated that the pathways for nursery pesticide loss can be determined based on pesticide-specific parameters obtained from the open literature; however, the relative magnitude of the loss through each pathway must be estimated using nursery site-specific parameters.
Integrated Soil, Crop and Water Management System to Abate Herbicide and Nitrate Contamination of the Great Lakes
Authors: Tan C. S. , Drury C. F. , Gaynor J. D. , Welacky T. W.
Published: May 2018

Corn management practices, incorporating annual ryegrass intercrop, conservation tillage and water table management, were evaluated to reduce herbicide and N0−3 losses through surface runoff and tile drainage. The integrated management system being developed at Harrow in S.W. Ontario reduced herbicide input 50% by banding the chemical over the seed row. Runoff events close to herbicide application contained high concentrations of atrazine, metribuzin and metolachlor. However, the volume of runoff was low during the 1991 growing season, therefore herbicide loss was low (<2% of applied). The three herbicides rapidly dissipated in the soil so that subsequent runoff events transported little herbicide in the runoff water. The total quantity of de-ethyl atrazine loss was lower from soil saver than moldboard plow. No water table control or intercrop effects were found in 1991 for herbicide loss because of the drought Tile drainage resulted in a greater volume of water and loss of N0−3 than with surface runoff. Consequently, over 97% of the total N0−3 loss occurred through tile drainage. The flow weighted N0−3 concentration in tile drainage water was 22.5 mg N L−1 for the drainage treatments and 15.1 mg N L−1 for the water table control treatments from Nov. 1, 1991 till April 30, 1992. During this time period, N0−3 loss through tile drainage was 57.8 kg N ha−1 from the drainage treatments and 36.3 kg N ha−1 from the water table control treatments. Therefore, the water table control treatment reduced the flow weighted N0−3 concentration in tile drainage water by 33% and total N0−3 loss by 37%. The water table control treatments combined with soil saver tillage resulted in lower concentrations and losses of N0−3 than with any other treatments.
Pollution Control and Prevention at Containerized Nursery Operations
Authors: Alexander Susan V.
Published: May 2018

Most plant materials marketed in the United States are produced in containers under controlled growing conditions at large (> 20 ha) nurseries located in southern and pacific coast states. The nursery/greenhouse business is one of the fastest growing segments of American agriculture accounting for 11% of all crop income in 1991. Runoff and irrigation return flow from containerized nursery facilities can contain nitrogen, phosphorus, bacteria, certain pesticides, various salts, and trace metals. Because of their large size, the intensity of the growing cycle, the huge volume of water needed to produce the product, and the concentration of these nurseries in certain areas, there is the potential for diffuse pollution from these nurseries to adversely impact a number of surface and ground water systems in the southern and western United States. Discharges from nursery/greenhouse operations are not federally regulated although some states require large facilities to obtain discharge permits. A number of larger nurseries in Texas, Oklahoma, and California have designed and installed pollution control and prevention systems that appear to be effective. This paper will provide background information about containerized plant culture and discuss the structural, vegetative, and management Best Management Practices that are in use at two different large containerized nurseries in Texas.
Nitrate Leaching to a Shallow Mid-Atlantic Coastal Plain Aquifer as Influenced by Conventional No-Till and Low-Input Sustainable Grain Production Systems
Authors: Craig J. P. , Weil R. R.
Published: May 2018

In December, 1987, the states in the Chesapeake Bay region, along with the federal government, signed an agreement which called for a 40% reduction in nitrogen and phosphorus loadings to the Bay by the year 2000. To accomplish this goal, major reductions in nutrient loadings associated with agricultural management practices were deemed necessary. The objective of this study was to determine if reducing fertilizer inputs to the NT system would result in a reduction in nitrogen contamination of groundwater. In this study, groundwater, soil, and percolate samples were collected from two cropping systems. The first system was a conventional no-till (NT) grain production system with a two-year rotation of corn/winter wheat/double crop soybean. The second system, denoted low-input sustainable agriculture (LISA), produced the same crops using a winter legume and relay-cropped soybeans into standing wheat to reduce nitrogen and herbicide inputs. Nitrate-nitrogen concentrations in groundwater were significantly lower under the LISA system. Over 80% of the NT groundwater samples had NO3-N concentrations greater than 10 mgl-1, compared to only 4% for the LISA cropping system. Significantly lower soil mineral N to a depth of 180 cm was also observed. The NT soil had nearly twice as much mineral N present in the 90-180 cm portion than the LISA cropping system.
Urban Water Quality: Interactions between Sewers, Treatment Plants and Receiving Waters
Authors: Lijklema Lambertus , Tyson John M.
Published: May 2018

For successful management of urban water quality it has become clear that sewers, treatment plants and receiving water must be considered, not in isolation but as (interacting) components of an integrated system.
Stormwater Loading of Greater Copenhagen Sewage Treatment Plants
Authors: Hansen O. B. , Jacobsen C. , Harremoës P. , Skat Nielsen P.
Published: May 2018

The study presented in this paper deals with the computation of the increased hydraulic loading of the treatment plants in the Greater Copenhagen area due to the installation of more storage capacity in the combined sewer system in the future. A mathematical model is set up for the entire sewer catchment and predictions of future increased hydraulic loadings are made for various development scenarios. The computed inflow conditions are presented on a statistical form. The results show a significant increase in the hydraulic loading of the plants due to increased storage volume in the sewer system. The computed inflow statistics are used in the design of the treatment plants to ensure proper plant performance during prolonged periods with full hydraulic loading due to storm water.
Sewers and the Quality of Canals and Ditches in Amsterdam
Authors: Jacobs E. , van Sluis J. W.
Published: May 2018

The surface water system of Amsterdam is very complicated. Of two characteristic types of water systems the influences on water and sediment quality are investigated. The importance of the sewer output to the total loads is different for both water systems. In a polder the load from the sewers is much more important than in the canal basin. Measures to reduce the emission from the sewers are much more effective in a polder. The effect of these measures on sediment quality is more than the effect on water quality. Some differences between a combined sewer system and a separate sewer system can be found in sediment quality.
Improving Municipal Waste Water Quality by Effluent Polishing: A Pilot Scale Experiment at Winterswijk, The Netherlands
Authors: Oesterholt F. I. H. M. , Bult B. A.
Published: May 2018

Over a period of three months two filtration methods, i.e. cross flow microfiltration and continuous sand filtrations were tested for their capacity to improve the quality of the effluent from a waste water treatment plant. The removal capacity of both methods was explored for suspended solids, COD, Kjeldahl nitrogen phosphorus, copper and zinc with and without iron flocculation. Without iron flocculation only the suspended solids can be removed. Iron has to be added prior to removal so that suspended solids and phosphorus can be removed in sufficient quantities. In that case, total P can be removed for 70% by means of continuous sand filtration, and for 90 % when microfiltration is being applied. The removal of COD, nitrogen Kjeldahl, copper and zinc is confined to 10 or 20%.

From a technical point of view, microfiltration is preferred because of its high removal efficiency for all the components. On the other hand, from a financial point of view, microfiltration is not feasible. Treatment costs for sand filtration and microfiltration are calculated at f 0.15 and f 2.07 respectively per m3 water treated.
A Strategy to Meet the Nutrient (N and P) Standards of the Urban Wastewater Directive
Authors: Farrimond M. , Upton John
Published: May 2018

The implications for the UK of the forthcoming Urban WasteWater Directive 1991 will mean at many sites a tightening of existing discharge standards. At those sites classified as discharging to sensitive watercourses, limits for nutrient removal (N and P) will be imposed and for the largest works above 100,000 PE implementation is required by 1998.

Very little experience of N and P removal currently exists in the UK and water companies will need to develop the necessary investment strategies based for the most part on retrofitting well proven technologies to existing secondary treatment works.

A strategy has been developed for nutrient removal in Severn Trent Hater, a company which serves a sewered population of 8 million and controls 1043 waste water treatment plants.

The paper outlines the technologies that will be retrofitted to existing trickling filter installations and activated sludge plants to achieve the necessary standards for N and P removal.

A comparison of the various options for biological P removal is included and that the preferred UCT process configuration or sidestream Phostrip process have been selected as preferred options.
Full Scale Experiences with Nutrient Removal at Two Wastewater Treatment Plants in The Netherlands
Authors: Draaijer H. , Buunen-van Bergen A. H. M. , van't Oever E. , Schellen A. A. J. C.
Published: May 2018

Two full scale projects are described in this paper; these are the Bergambacht wastewater plant (carrousel) and the Terneuzen wastewater plant (Schreiber system). Both plants use a system of intermittent aeration to combine nitrification and denitrification processes. At the Bergambacht plant biological phosphorus removal is carried out by the introduction of the side stream process. At the Terneuzen plant it is carried out by introducing anaerobic periods in the aeration tanks. The objective is to meet the new total nitrogen and phosphorus effluent standards in The Netherlands of resp. 10-15 and 1-2 mg/l. At the Terneuzen wastewater plant the standards could not be reached for total-nitrogen, mainly due to the low BOD to Kj-N ratio of 2:8 in the feed to the aeration tanks. Adjustments are suggested to improve the denitrification rate. At the Bergambacht wastewater plant effluent concentrations of 6 - 7 mg/l total N and 0.3 mg/l total P were achieved.
Thermic Sludge Treatment
Authors: Karlsson I. , Göransson J.
Published: May 2018

Chemical pretreatment changes the composition of waste water by reducing the paniculate organic matter.

A lower biological sludge production from the sewage facilitates nitrification.

The denitrification capacity of the sewage is decreased, but the fraction of low molecular substances is not influenced by the chemical treatment.

To increase the denitrification capacity, the organic matter removed can be hydrolised into a readily degradable form and used as an electron donor. In Tampere waste water plant the sludge is hydrolysed at 150° C in a low pH environment.

The carbon source was increasing the capacity of the anoxic zone.

The sludge dewatering characteristics were improved.

The sludge is divided into two fractions, one with paniculate organic matter, the other containing a solution of organic and inorganic substances. The heavy metals can be separated and the precipitant recovered and recycled.
Modelling and Construction of a Deep Well Aqueous Phase Oxidation Process
Authors: de Bekker Pieter H. A. M. J. , van den Berg Jan J.
Published: May 2018

Aqueous phase oxidation is the process in which organic material is oxidized in the liquid phase with gaseous oxygen under elevated temperature and pressure. The VerTech-process uses a vertical subsurface oxidation vessel consisting of two concentric tubes with a length of approximately 1 200 metres. The advantages of which are: an ideal plug flow regime for a high performance, an efficient heat exchange along the reactor length and a less heavy construction compared to surface techniques. The production of residues is minimal and environmentally sound: off-gas consists mostly of carbon dioxide, solid residue is non teachable and the liquid effluent can be purified easily to a high extent. For the design of the oxidation vessel the use of mathematical models is essential: reaction kinetics, hydrodynamics and heat transfer have been brought in models in such a way that up- and downscaling is possible. On the other hand process conditions may be controlled by the model, once it has been approved. The original model has been tested at the demonstration plant at Longmont, Colorado, USA in 1985. A further development will be tested at the first commercial scale plant at Apeldoorn, the Netherlands. This plant will come into full service as of January 1993.
Sewage: Towards Realistic Environmental Protection
Authors: Johnston P. A. , MacGarvin M. , Stringer R. L. , Troendle S. , Swindlehurst R. J.
Published: May 2018

The disposal of sewage into aquatic systems is attracting increasing regulation at the European Community level. Initially, pollution control strategies focussed on the protection of rivers and inland waters from excessive oxygen demand loading. This has led to an increasing use of marine waters for the disposal of sewage effluents and sludges. The bacteriological hazards associated with these practices are now well understood and have led in turn to restrictions on such disposal activities. This problem is illustrated with data from Venice Lagoon showing extreme bacterial contamination. A less commonly appreciated problem relates to the chemical contamination of sewage from both household and industrial chemicals. Results from analyses of a variety of sewage effluents are presented in this paper and the implications of the inventory of chemicals found are discussed.
Municipal Wastewater Reuse via Soil Aquifer Treatment for Non-Potable Purposes
Authors: Kanarek A. , Aharoni A. , Michail M.
Published: May 2018

Groundwater recharge for wastewater reuse developed and practiced successfully in the Dan Region Project is rather a soil aquifer treatmemt (SAT) system which should be considered as an integral part of the municipal wastewater treatment process.

SAT consists of controlled passage of effluent through the unsaturated zone and the aquifer, mainly for purification purposes. The recharge operation is carried out by means of spreading basins which are surrounded by adequately spaced recovery wells which permit segregation of the recharge zone from the rest of the aquifer.

A very high quality of reclaimed water is obtained after SAT which is suitable for a variety of non-potable uses such as unrestricted agricultural uses, industrial uses, non-potable municipal uses and recreational uses.
Groundwater Contamination by Detergents and Polycyclic Aromatic Hydrocarbons – A Global Problem of Organic Contaminants: Is the Solution Locally Specific?
Authors: Zoller Uri
Published: May 2018

The ever-increasing demand of our technological society has generated a global problem of groundwater pollution by man-made products and/or their metabolites. The penetration of detergents and polycyclic aromatic hydrocarbons (PAH) originating from anthropogenic sources constitutes a major issue of environmental and health concern.

In Israel, the concentrations of nonbiodegradable nonionic detergents in sewage influents, effluents, and water wells were found to be in the range of 1-2.60, 0.25-0-50 and 0.12-0.78 mg/liter respectively. These results translate the global problem of groundwater pollution into the local problem of groundwater contaminated by synthetic detergents with all the environmental, health, societal, technological, economic and political issues involved. The respective base-line data concerning PAHs is not available as yet.

Although some of the solutions are locally specific they cannot be applied independently of what is being done in this respect worldwide. The long-term solution requires international cooperation and collaboration.
Aspects of the Law of International Water Resources
Authors: Hirsch M. , Housen-Couriel D.
Published: May 2018

As a result of the nature of lakes, rivers and aquifers, which ignore national boundaries, states are often presented with the problem of how to share and manage these limited resources. The role of law is to clarify the rights and responsibilities of states in such situations. Two aspects of the law of international water resources will be explored in this article. The point of departure for the analysis is public international law itself, which contains principles and guidelines for the utilization and management of water resources by the states which share them. The international legal regime applying to surface water will first be discussed. The second part of the article will consist of a comparison of several treaty regimes which presently apply in a situation of shared water resources between states.
Respiratory Problems among Schoolchildren Living in the Vicinity of an Industrialized Zone
Authors: Goren A. , Hellmann S. , Brenner S.
Published: May 2018

Purpose: This study was carried out in the framework of a health monitoring system set up in the vicinity of a 1400 MW coal-fired power plant in Israel.

Methods: Second, fifth and eighth grade schoolchildren were followed up every three years; they performed pulmonary function tests (PFT) and their parents filled out ATS-NHLI health questionnaires.

A subgroup of children living near an industrial zone was studied separately and compared with children from another relatively clean part of the town.

Results: Children growing up in the vicinity of the industrial zone showed a higher prevalence of almost all respiratory symptoms compared with children residing in the unpolluted part of the town. Part of the symptoms, such as 1. sputum with cold, 2. sputum without cold and 3. cough accompanied by sputum were significantly more common among the schoolchildren from the industrialized zone; their prevalences being: 1. 27.3% in the industrialized compared with 12.5% in the cleaner area, 2. 12.7% compared with 2.5% and 3. 18.2% compared with 6.3%, respectively.

No significant differences could be shown for the prevalence of respiratory diseases among the children from the two zones; asthma was more common among children from the industrial zone but the difference was not statistically significant. No consistent trend of reduced pulmonary function tests could be shown for the four subgroups of studied children (e.g. boys and girls from fifth and eighth class).

Conclusions: Children residing in the vicinity of the industrialized zone had significantly more respiratory symptoms compared with children from a cleaner part of the town. No permanent physiological changes were obvious.
Effect of Low Water Level on the Water Quality of the Littoral Zone in Lake Kinneret
Authors: Gafny Sarig , Gasith Avital
Published: May 2018

Water quality in the shallow littoral of Lake Kinneret was examined during a period of low water levels in 1989-1990. On calm days, no significant difference was found between the water quality on different sites around the lake or between the littoral and the open water. Lowering of the lake level in Lake Kinneret is associated with a major change in the nature of the bottom of the littoral zone in many sites, from rocky substrate in high lake levels (>212m below sea level) to sandy or clay in lower levels. During north-easterly storms, in winter, the concentrations of suspended solids and total phosphorus were markedly higher in leeward littoral sites compared to other regions of the littoral zone. This may be attributed to resuspension of sediments by the wave action over the soft bottom. In rainy winters, runoff, mainly Jordan River input, may locally affect the water quality and result in a north-south gradient.
Assessment of Turbulent Processes in Lake Kinneret by the Two-Dimensional Reservoir Water Quality Model “Better”
Authors: Oziransky Y. , Shteinman B.
Published: May 2018

Data of high spatial and temporal resolution, and a special sampling program are essential for successful application of mathematical models designed to reproduce observed seasonal patterns of temperature, dissolved oxygen, nutrients, pH, and algal biomass for both vertical and longitudinal gradients in a water body. Lake Kinneret suspended solids are of great potential value for estimating transport, exposure to water body elements, and fate of many toxic substances. Therefore the distribution of admixtures in two longitudinal and five vertical segmentation schemes were examined with the two-dimensional water body quality box model “BETTER” (Bender et al, 1990).

The transects were taken in the north-western part of Lake Kinneret close to the Jordan River mouth and the National Water Carrier (NWC) head pumping station. The outflow volumes were given according to regular sampling of natural speed of water outflow from different lake layers under calm conditions. Temporal distribution of mixing concentrations as well as turbulent diffusion horizontal coefficients due to the spatial distribution of turbulent scale were obtained during the model's run with the December 1991 data.
Spatial and Temporal Changes in Habitat Conditions in the Na'aman Stream Ecosystem, Israel
Authors: Jennings Jean-Jacques , Gasith Avital
Published: May 2018

Nahal Na'aman is a small, shallow coastal stream in northern Israel. A three year study was conducted to examine the effect of habitat conditions on the biological structure and function of the stream ecosystem. Here we describe temporal and spatial changes in the water regime and water quality as measures of the stream's habitat conditions.

Habitat condition is strongly influenced by the hydrological regime and the water quality. In dry years the water level drops and the upper section of the stream may dry up completely. Inflow of polluted water from various sources increasingly reduces water quality downstream. In general, the Na'aman may be categorized as oligo- to mesohaline stream, highly enriched with organic matter and nutrients. Sporadic pollution events markedly affect the water quality resulting in hypertrophic conditions, particularly at times of low stream levels. Low water quality was detected also in association with the drying and refilling of the stream's sections in late summer and in fall, respectively, and following runoff in winter.

The oligohaine nature of the stream a priori reduces species diversity relative to other freshwater, lowland streams/Based on water quality conditions, highest species diversity may be expected in the spring area and the upper section of the stream. However, habitat conditions in this section are most unstable due to changes of the hydrological regime. This, in turn, is expected to further reduce species richness and diversity. The extreme conditions are expected to determine the limit for the development of plant and animal life in the stream.

This study illustrates the inherent problems of the coastal streams of Israel, namely, diminishing natural flow which is often replaced by discharge of effluent or sewage. Rehabilitation of the Na'aman and other coastal streams demands a radical solution for these problems.
Cholinesterase Enzymatic Profiles and the Exposure of Fish to Organophosphorus and Carbamate Pesticides in Israel
Authors: Yawetz A. , Manelis R. , Gasith A.
Published: May 2018

In the tilapia as well as in the carp, gill acetylcholinesterase (AChE) was more sensitive than brain AChE to organophosphorous (OP) and carbamate (CB) compounds, and the threshold levels for residue detection by the biochemical method were lower in the gills, compared to the brain. The sensitivity of tilapia gill AChE to paraoxon was extremely high, and enabled detection of paraoxon residues in the gills at the ppb level.

The carp showed higher resistance than the tilapia for poisoning by both the OP compound parathion and the carbamate methomyl.

The residual post-mortem brain and gill AChE activities from tilapia killed by either parathion or methomyl poisoning were low, and could easily be differentiated from brain AChE activity in the control ish, which remained normal until 18 hours after death, providing that fish were held at temperature up to 10°C.

Detection of poisoning with OP and CB compounds, in fish that are being marketed, is of extreme importance, especially in Lake Kinneret, where illegal fishing with insecticides occurs occasionally.
Costs and Benefits of Vegetative Propagation in the Desert Tulip
Authors: Boeken Bertrand
Published: May 2018

The effects of vegetative propagation on plant performance in the desert tulip Tulipa systola were studied experimentally. A differentiation was made between immediate effects (possible tradeoffs between vegetative propagation and seed production) and ultimate costs or benefits (reduction in overall plant growth and biomass production efficiency per unit leaf mass, and within-clone competition). The results of a garden experiment with either single bulbs (single-ramet genets) and clusters of bulbs (multi-ramet genets) of the same total size, exposed to three levels of irrigation, did not show immediate nor ultimate disadvantages of vegetative propagation in terms of seed production or plant growth parameters. Competition between ramets of the same genet seemed to occur at low soil moisture availability, but it did not cause a disadvantage to multi-ramet genets relative to single-ramet genets. Vegetative propagation as a safeguard against complete genet consumption by porcupines is also discussed. Finally, the hypothesis is proposed that, in stead of influencing sexual reproduction negatively, vegetative propagation may in fact increase lifetime seed production, because multi-ramet genets may produce more fruits than single-ramet genets having the same level of genet growth.
Historical Accumulation of Atmospherically Derived Pollutant Trace Metals in the Arctic as Measured in Dated Sediment Cores
Authors: Hermanson M. H.
Published: May 2018

Sediment cores were collected from an undisturbed arctic lake on the Belcher Islands in southeastern Hudson Bay in order to assess the history of trace metal deposition from the atmosphere. Since there is no industry or agriculture on the islands, the only local source of any pollutant trace metals is a native Inuit community established there in 1967. Most of the mass of anthropogenic trace metals found there is carried through the atmosphere from distant sources. Sediment cores collected in 1983 and 1990 were dated using Pb-210 and Cs-137, and analyzed for lead, cadmium, zinc, copper and mercury. Sediment redistribution (focusing) was estimated by measurement of Cs-137 burden in sediment and compared to estimated total atmospheric inputs. Consistent background fluxes for each metal, corrected for redistribution, were found in each core at layers dated up to World War II. Inputs during the post-War period, emphasized here, have increased apparently from anthropogenic inputs through the atmosphere. The mass of metals input follows the pattern zinc > copper > lead > cadmium > mercury, typical of remote areas. The pattern and values of surface sediment flux enrichment of these metals relative to background is lead, 3.5, mercury, 3.2, cadmium, 1.8, zinc, 1.6, copper, 1.6.
Multiple Model Analysis of Sediment Transport and Contaminant Distribution in the Clinch River/Watts Bar Reservoir, Tennessee, USA*
Authors: Rose K. A. , Brenkert A. L. , Schohl G. A. , Onishi Y. , Hayworth J. S. , Holly F. , Perkins W. , Beard L. , Cook R. B. , Waldrop W.
Published: May 2018

Three models of sediment transport and contaminant distribution (CHARIMA, HEC-6, and TODAM) are being applied to the Clinch River/Watts Bar Reservoir system as part of a CERCLA remedial investigation. Planned uses of model results are to identify high deposition areas of the river, forecast the effects of various remedial actions and climatic events on contaminant distribution, and aid in the design of future data collection efforts. The three models share some similarities but also differ in several important details. All three models are one-dimensional and include similar processes for sediment deposition and resuspension. Differences among the models include steady-state versus unsteady flow, the complexity of the channel network permitted, and the level of detail of contaminant-related fate processes represented. As part of our multiple model strategy, some aspects of the three models are configured using common information on the system (e.g., spatial geometry), while other aspects of the models, including some modeler decisions and calibration methods, are allowed to differ. Comparison of results among the three models can lead to increased confidence in predictions and in recommendations for future data collection. The general approach of using multiple models is described and preliminary results of the Clinch River/Watts Bar application are presented to illustrate the utility of using a multiple model approach for complex environmental assessments.
Sources and Delivery of Sediments Contaminated by Toxic Metals to the North Avenue Dam, Milwaukee, WI, USA
Authors: Novotny V. , Wawrzyn W. G. , Bachhuber J. , Grant S. , Windstrup K. , Schonter R.
Published: May 2018

Sediments which have accumulated in the Milwaukee River North Avenue urban impoundment in Milwaukee, Wisconsin over a period of more than one hundred years were investigated. After the drawdown of the water level in the impoundment, extensive investigations focused on determining sediment volume, characteristics and contamination. It was found that the accumulated sediment has a fine texture and contains higher levels of toxic metals.

Analysis of sources of sediments and sediment contamination considered the background sources, including impact of agriculture, and urban sources such as urban runoff and combined sewer overflow. Cadmium, copper and lead were identified as metals of concern both in the water, using log-normal statistics of the data and in the sediment by the sediment-pore water concentration partitioning. Urban runoff was found to be the most significant source of contamination.

The North Avenue Dam represents a typical example of urban impoundments which have now reached the end of their usefulness.
Desorption of Chlorobenzenes from Natural Suspended Solids and Sediments
Authors: Koelmans A. A. , de Lange H. J. , Lijklema L.
Published: May 2018

The desorption of chlorobenzenes from heterogeneous suspended solid mixtures and sediments at nonequilibrium conditions was investigated, using a gas purge method. This technique offers the possibility to measure equilibrium and rate data from adsorbent suspensions, without phase separation. The desorption patterns were interpreted and fitted in terms of multiple box models. The results show that when the equilibration time for sediment suspensions contaminated in the laboratory is longer, desorption is slower. At nonequilibrium conditions, the more hydrophobic chlorobenzenes are released faster than the less hydrophobic ones.

For ten suspended solid samples the model parameters were related to adsorbent characteristics, such as organic matter, phytoplankton and clay content by means of correlation analysis, and compared to similar desorption data for algal cultures obtained in earlier studies in our laboratory. It was found that all desorption data could be described with a two-compartment desorption model. The partition coefficient was proportional to the content of organic matter, which in turn was mainly determined by the concentration of phytoplankton in the samples. The desorption rate was positively correlated with the phytoplankton content as well. This suggests that phytoplankton cells form an easily accessible fraction of the total adsorbent.