bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Quality Impacts of Stormwater-Associated Contaminants: Focus on Real Problems
Authors: Fred Lee G. , Jones-Lee Anne
Published: May 2018

Water pollution control agencies are implementing control programs for chemical contaminants in urban stormwater runoff because concentrations of total forms of some contaminants in receiving water exceed numeric water quality standards. While some assert that stormwater-associated contaminants are causing water quality problems (impairment of beneficial uses), there are significant reasons to question the reliability of that claim. While urban stormwater runoff frequently contains many chemicals in sufficient concentrations to cause exceedance of numeric US EPA water quality criteria in receiving waters, exceedance of a water quality criterion/standard applied to total concentrations is not a demonstration of water quality impairment The US EPA water quality criteria were developed for worst-case or near-worst-case exposure to available forms of the contaminants. Such exposure conditions would not be expected with short-term, episodic runoff events. Substantial portions of many of the chemical contaminants in stormwater runoff are associated with particulates and would hence be expected to be largely unavailable to affect aquatic life-related beneficial uses of receiving waters. Furthermore, evidence of beneficial use impairment caused by urban stormwater runoff has not been forthcoming to document the claims. It is concluded that many of the contaminants associated with urban stormwater runoff from residential and commercial areas do not impair beneficial uses of receiving waters. The current US EPA water quality criteria have limited applicability to assessing potential water quality concerns for stormwater runoff. Guidance is presented on how urban stormwater runoff-associated contaminants should be evaluated and regulated to control use impairment without significant unnecessary expenditures for contaminant control.
Sources of Pollutants in Wisconsin Stormwater
Authors: Bannerman R. T. , Owens D. W. , Dodds R. B. , Hornewer N. J.
Published: May 2018

Rainfall runoff samples were collected from streets, parking lots, roofs, driveways, and lawns. These five source areas are located in residential, commercial, and industrial land uses in Madison, Wisconsin. Solids, phosphorus, and heavy metals loads were determined for all the source areas using measured concentrations and runoff volumes estimated by the Source Load and Management Model. Source areas with relatively large contaminant loads were identified as critical source areas for each land use.

Streets are critical source areas for most contaminants in all the land uses. Parking lots are critical in the commercial and industrial land uses. Lawns and driveways contribute large phosphorus loads in the residential land use. Roofs produce significant zinc loads in the commercial and industrial land uses.

Identification of critical source areas could reduce the amount of area needing best-management practices in two areas of Madison, Wisconsin. Targeting best-management practices to 14% of the residential area and 40% of the industrial area could significantly reduce contaminant loads by up to 75%.
Study on Statistical Characteristics of Nonpoint Pollutants Deposited in Urban Areas
Authors: Yamada Kiyoshi , Umehara Tatsuya , Ichiki Atsushi
Published: May 2018

The objective of this study is to clarify the statistical characteristics of pollutants deposited in urban areas, taking account of stages (road surfaces, street inlets and streams) and land uses where they accumulated, from surveys over a period of 16 years in Kyoto City. The result of correlation analysis showed that there are intimate relationship between grain size and such pollutants as organic matter and nutrients. It showed the dependence of pollutants on grain size. After principal component analysis, the distribution of principal factor loading showed that the first and the second components meant the type of pollution and the physical property of pollutants. The distribution of the principal factor score showed that each land use had different pollutant characteristics. On the other hand, the characteristics of the pollutants that accumulated on a road surface were shown to be affected by storms, and nutrients were more likely to run off in a storm than organic matter. The content rate of pollutants accumulated in a stream was shown to decrease in proportion to the progress of sewer construction, but it was also shown that the rate of some pollutants has not changed in the area of a separate sewer system.

As a result, some valuable information for the control of nonpoint pollutants in urban area was obtained.
Comparison and Evaluation of in-situ Bio-Denitrification Systems for Nitrate Reduction in Groundwater
Authors: Dahab M. F.
Published: May 2018

Nitrate contamination of groundwater is a growing problem in the U.S. and throughout the world. This paper examines the potential application of in-situ bio-denitrification to reduce nitrates in groundwater to an acceptable level as well as pertinent parameters that control the process. Results from laboratory experiments designed to simulate in-situ bio-denitrification using an aquifer model are compared to results of experiments reported in the literature. The results indicate that while denitrification can be effective in reducing nitrates in contaminated groundwater, serious aquifer plugging problems can be expected. Furthermore, the avoidance of the plugging problem requires that careful management schemes be implemented during in-situ treatment The results of field-scale experiments in Europe and other areas generally confirm the efficacy of bio-denitrification. However, aquifer plugging was not reported by some of these studies or appeared to be downgraded by others. In some cases, this problem was reported as having serious ramifications on the success or failure of bio-denitrification. In addition to aquifer plugging, other problems can be expected. These include residual organics and the presence of large bacterial counts in the treated water with subsequent potential effects on the water turbidity, disinfection requirements, and public health acceptability.
Pesticide Contamination of Groundwater in Virginia: BMP Impact Assessment
Authors: Mostaghimi S. , McClellan P. W. , Cooke R. A.
Published: May 2018

The Nomini Creek Watershed/Water Quality monitoring project was initiated in 1985, as part of the Chesapeake Bay Agreement of 1983, to quantify the impacts of agricultural best management practices (BMPs) on improving water quality. The watershed monitoring system was designed to provide a comprehensive assessment of the quality of surface and groundwater as influenced by changes in land use, agronomic, and cultural practices in the watershed over the duration of the project. The primary chemical characteristics monitored include both soluble and sediment-bound nutrients and pesticides in surface and groundwater. Water samples from 8 monitoring wells located in agricultural areas in the watershed were analyzed for 22 pesticides. A total of 20 pesticides have been detected in water samples collected. Atrazine is the most frequently detected pesticide. Detected concentrations of atrazine ranged from 0.03 - 25.56 ppb and occurred in about 26 percent of the samples. Other pesticides were detected at frequencies ranging from 1.6 to 14.2 percent of all samples collected and concentrations between 0.01 and 41.89 ppb. The observed concentrations and spatial distributions of pesticide contamination of groundwater are compared to land use and cropping patterns. Results indicate that BMPs are quite effective in reducing pesticide concentrations in groundwater.
Sustainable Agriculture: Impacts on Nonpoint Pollution
Authors: Hatfield J. L.
Published: May 2018

Current agricultural practices are thought to contribute to nonpoint source pollution because of large inputs of pesticides and fertilizers and intensive cultivation and crop production. Trends towards sustainable practices which involve crop rotations, alternative weed and pest control measures, use of manure as fertilizers, and crop residues can lead to improved resource management. Sustainable agricultural systems should be viewed not as a reversion to past systems but as adoption of systems which promote efficient resource management and improved efficiency in the use of natural resources. Many of the aspects currently considered to be sustainable agricultural practices will lead to decreased nonpoint source pollution on both the field and landscape scale. There are large changes in the physical, chemical, and biological factors which promote these reductions. The net result of adoption of these practices will be improved environmental quality; however, to realize this benefit will require both educational efforts and improved decision making tools to aid in the management decisions required in agriculture.
Phosphorus Transport in Runoff from a Small Agricultural Watershed
Authors: Ng H. Y. F. , Mayer T. , Marsalek J.
Published: May 2018

Impacts of phosphorus (P) discharges on receiving waters depend on the magnitude of loadings and their P bioavai lability which varies for various phosphorus forms. To advance the understanding of P transport in agricultural runoff, the main nonpoint source of P, seasonal and short-term variabilities in P forms were studied. Total phosphorus (TP), total paniculate phosphorus (TPP) and total suspended sediment (SS) concentrations were measured in runoff from the Nissouri Creek agricultural watershed. About 54% of TP in runoff was associated with sediment particles (>0.45 µm). The remaining 46% of TP was transported in the dissolved form, as soluble P (SP). Significant correlations were found between TPP and the inorganic fraction of suspended sediments (IS), and SP and the organic matter concentration in suspended sediments (OS). None of the phosphorus forms studied correlated well with runoff volumes. TP, SP and TSS concentrations varied substantially during runoff events and during the year. Higher proportion of paniculate P were typically observed at the time when runoff volumes were high, often during the early phase of runoff. Highest TP and SP concentrations were measured in spring and fall runoffs exceeding those in summer runoffs by an order of magnitude. The suspended sediments concentrations in spring and fall runoffs were, however, two orders of magnitude higher than those in the summer runoffs.
Problems of Irrigation Drainage Water Utilization for the Prevention of Surface Water Pollution
Authors: Sanin M. V.
Published: May 2018

The paper analyses results of the inventory of irrigational water derivation in the former USSR. The ways of deriving return and collector-drainage waters, as well as the load exercised by these waters on water bodies, are investigated. The paper discusses the main areas of collector-drainage water re-use and utilization, the latter being regarded as a means of preventing surface water pollution and salinization in the zones of irrigation. Necessity in working out a concept of effective, ecologically substantiated use of collector-drainage waters is substantiated.
Three Types of Approaches to Controlling Non-Point Source Pollution of Agrochemicals from Golf Links in Water Resources Management
Authors: Morioka Tohru
Published: May 2018

In recent years Japan has had an opportunity to develop a strategy to control diffused pollution of agrochemicals in watersheds upstream of drinking water intakes. Three types of approaches to controlling probable pollution have been examined. These are (1) risk based assessment approach, (2) regulatory approach supported by standard setting and (3) planning based guide to land use. In this paper, based on the results of pilot studies in several golf links, the practical procedures of these approaches are systematically structured.

First, risk-based assessment approach includes typical exposure assessment and quantitative risk assessment (QRA) coupled with fate analysis of runoff into reservoirs. The basic process of QRA of indicative herbicides, insecticides and fungicides, generated the result that additional cancer risk would be around minus 5-6 order of life time risk for citizens to drink water from reservoirs receiving contaminated river water.

Second, appropriate standard setting enhances a reasonable regulatory approach. In 1990, concentration of twenty agrochemicals in effluents from golf links and rivers at receiving outlets from golf links were evaluated in a nation-wide program in terms of the ratios of samples having higher concentrations than the tentative quality standard. Both seasonal change of observed concentration in dry weather and high concentration in rainfall events are evaluated.

Concerning a planning based guide to land use, zoning of forest conservation districts for water resources conservation would be responsible for appropriate land use management and water quality control. The author proposed the skeleton of a water resources conservation plan for safe drinking water supply for a local government as a client, especially emphasizing land use suitability mapping, development guides and mitigation techniques.
Assessing the Effect of Pesticides in Agricultural Runoff on Aquatic Life in the Sangamon River Near Monticello, Illinois
Authors: Coupe R. H. , Henebry M. S. , Branham M. R.
Published: May 2018

Stream-water samples collected from a midwest stream, following a thunderstorm during May 1991 were toxic to water fleas (Ceriodaphnia dubia), but not fathead minnows (Pimephales promelas), or a bacterium (Photobacterium phosphoreum) or green alga (Selenastrum capricornutum). It was unlikely that the toxicity to the water fleas was caused by herbicides, but it may have been caused by insecticides.
Using the Creams Pesticides Transfer Sub-Model at a Rainfall Simulation Scale
Authors: Gouy V. , Bélamie R.
Published: May 2018

The pesticide sub-model of CREAMS was tested to describe pesticides transfer into runoff generated by a rainfall simulation. Adsorption coefficient, Kd, was found to be a sensitive parameter of the model. So, we developed an experimental method in order to measure Kd in a dynamic way. We studied four pesticides (atrazine, simazine, lindane, methidathion) and three soils (loam sand, sand loam, calcareous silt loam). The values of Kd obtained were compared to the values measured on the soils by the standardized method of batches and to the values of the literature. Mean Kd measured in the runoff of a rainfall simulation were considerably greater, especially for low suspended particles loads. We ran the model with these different data for Kd and we found that predictions were more accurate with Kd obtained by rainfall simulation particularly for lindane and simazine. We improved the modelisation for atrazine and methidathion. Nevertheless, the relative error between observed and predicted concentrations was not the same according to the pesticide, which made prediction of risk dependent on pesticides classes of behaviour.
Phosphorus Export from Nonpoint Sources in the Berg River, Western Cape Province, South Africa
Authors: Bath A. J. , Marais G. v. R.
Published: May 2018

A suite of semi-empirical models has been developed to quantify the transport of phosphorus in the Berg River. This paper describes the results of the model simulations to quantify (1) the input of phosphorus from point and nonpoint sources, and (2) the transport of phosphorus in the water prism along the main river channel. Export of phosphorus from nonpoint sources is influenced by the drainage flow during storm events. Mass export under the rising limb of the drainage hydrograph is higher than under the falling limb giving rise to a hysteresis relationship between concentration and flow. Implementation of the 1 mg P/l effluent standard for point sources is shown to have a minor influence on the phosphorus budget of the river - nonpoint sources contribute over 80 percent of the annual load. In the Berg River, 80 percent of the phosphorus export takes place during storm events which occupy less than 3 percent of the annual hydrological cycle.
The Research Programme “RWZI 2000”: State of Affairs and a Look into the Future
Authors: Dirkzwager A. H. , de Jong J. , Stamperius P. C. , Rijs G. B. J.
Published: May 2018

Nowadays, in spite of the high treatment capacity in the Netherlands, problems relating to the treatment of municipal waste water are still not completely solved. They are related to stricter effluent requirements, environmental nuisance, sludge disposal and the costs of waste water purification.

A research programme entitled “Future Treatment Techniques for Municipal Waste Water” or briefly “RWZI 2000” is being carried out to develop and evaluate potential treatment techniques in different stages of development. These techniques must result in a better performance from the point of view of environmental protection and/or lower annual treatment costs than the technology available at present.

In the paper a description is given of the studies carried out and the results obtained will be presented with respect to the problems occurring in the treatment of municipal waste water.
On the Prediction of Sediment Transport in Sewers with Deposits
Authors: Kleijwegt Rob A.
Published: May 2018

There is a need for models to predict the negative effects of sewer deposits in order to improve design, maintenance and operation of sewerage systems. The lack of success of deterministic sewer sediment models in the past is caused by a lack of basic knowledge, which causes unknown uncertainties in the model's results. The basic knowledge about non-cohesive sediment transport has been studied with laboratory experiments. This has resulted in an understanding of the non-cohesive sewer sediment transport and the related subjects of bed shear stress, incipient motion, bed forms and flow resistance. This understanding can be used in the development of deterministic models for sewer systems. However, the next objective will be to develop probabilistic models.
Dynamic Design of Sewer Detention Tanks
Authors: van Luijtelaar H. , Ganzevles P. P. G.
Published: May 2018

In the Netherlands new regulations regarding combined sewer overflows have been proposed to reduce the pollution of surface water. These regulations will lead to the construction of ancillary sewer facilities. The current design methods are not suitable for optimizing measures to control overflow loads. Therefore a new method, called ‘Dynamic Design', is proposed. This design method is based upon the use of time series of rainfall and advanced computer programs. By using longterm continuous simulation in combination with historical time series of rainfall overflow volumes, discharge durations and frequencies can be derived. These results can be analysed statistically to obtain frequency distributions of overflow volumes and discharge flows. This procedure ensures not only the assessment of detention tanks but also the evaluation of alternative measures like real time control and flow routing strategies. Dynamic design aims at the efficient use of ancillary sewer facilities to minimise receiving water impact. Several cases are discussed to show the advantages of dynamic design in comparison with current design procedures.
Settleable Solids in a Combined Sewer System, Settling Characteristics, Heavy Metals, Efficiency of Storm Water Tanks
Authors: Michelbach S. , Wöhrle C.
Published: May 2018

Sedimentation and transportation of mineral and organic pollutions in combined sewer systems are not completely understood. For better understanding, samples of sediment, slime and urban runoff were taken from the combined sewer system of Bad Mergentheim. The settling velocity of settleable solids was measured with a settling apparatus. Typical settling curves for sediment, slime and wastewater were put together. Some of the samples were analysed for heavy metals and organic micro-pollution. By this the relationship between settling velocity and the load of heavy metals can be shown. The gained data are of interest for the design of clarifier tanks for stormwater treatment.
Evaluation of the Water Quality Effects of Combined Sewer Overflow (CSO) Control Measures
Authors: van Sluis J. W.
Published: May 2018

At present, design guidelines for combined sewer systems ere being formulated by the water pollution control authorities in the Netherlands. These guidelines are aimed at the reduction of pollutant loads by means of stormwater sedimentation tanks and the increase of storage capacity. To obtain better knowledge of the water quality aspects of the guidelines, the effects of combined sewer overflows from systems with stormwater sedimentation tanks of varying storage capacity were studied. Three receiving water bodies, with different dimensions and base flow, were reviewed.

For the evaluation of effects on the oxygen balance a combined simulation model was used to predict the pollutant load and the dissolved oxygen response of individual overflow events. Eutrophication effects and accumulation of micropollutants were judged from the annual discharge data.

It appeared that in small, stagnant ditches, the guidelines will induce a sharp reduction of the number of violations of the dissolved oxygen standard. In larger, flowing waters, the guidelines may adequately protect the water against violation of these standards.

The discharge of total phosphorus and micropollutants is largely reduced by the prescribed measures. However, other sources of phosphorus must be eliminated as well to combat eutrophication effectively.
The Influence of System-Specific Properties on the Pollutant Discharge of Combined Sewer Systems
Authors: Moens M. , Vos L. , Zuidervliet J.
Published: May 2018

The water quality policy in the Netherlands regarding discha ges from sewer systems into surface water will in the near future aim at the pollutant discharge instead of the overflow frequency. Recent practical research has shown that system-specific properties are the main influencing factors for the sediment behaviour of sewer systems. Based on this knowledge the pollutant discharge concept EMOR has been developed. A detailed description is given of the background of this concept and of how to work with it. The calculation results Include frequency distributions for the COD, peak discharges and annual load, overflow quantities, overflow frequencies, etc. An objective calculation method is provided to express the influence in the so-called depositing factor, which can be determined for a single sewer as well as for a complete sewer systems. Application of this factor in the EMOR-concept makes it possible to use a schematization of the sewer system into a multireservoir model without losing the influence of the system specific properties. Model fitting has demonstrated that with the application of the EMOR concept a reliable prediction can be made for the pollutant discharge.
Prevention of Concrete Corrosion and Odour Annoyance with Biofiltration
Authors: Heuer J. J. M. B. , Kaskens H. J.
Published: May 2018

In many Dutch sewerage systems the sewage is pumped from small villages through pipelines to larger cities. These pressurized pipelines often end up in the pump sump of another pumping-station or in another sewerage system which transports the sewage under atmospheric conditions to the waste water treatment installation.

When the waste water in these pipelines stays stationary for a longer period often sulphurous compounds are formed. At the downstream end of the pipeline, where the sewerage system meets atmospheric, aerobic circumstances, the hydrogen sulphide can be converted into sulphuric acid by micro-organisms.

The above described process(es) can lead to the following problems:corrosion of concrete caused by sulphuric acid;odour annoyance caused by hydrogen sulphide and other sulphurous compounds.

A good solution against concrete corrosion developed by HASKONING consists of stripping the sulphurous compounds out of the sewage and eliminating them. The most economic way to eliminate H2S is the use of a biological filter. Measurements carried out at a pump sump show that this type of filter is highly effective in eliminating H2S.

Nevertheless, the installed biofilter did not completely avoid odour annoyance. Therefore the outcoming air after the biofilter was led back into the sewerage system. No complaints occurred anymore.
New Control Parameters and Measurement Techniques for the Activated Sludge Process
Authors: Pelkonen M. , Tenno R.
Published: May 2018

An on-line oxygen uptake and CO2-production rate measurement system was used to analyse the biomass activity. CO2-production rate corresponded well with oxygen uptake rate in the carbon oxidation process. In the nitrification process the ratio CO2-prod./O2-consumed (rq) had a larger variation, but CO2-production had a good correlation with utilized COD; variation of the rq-value indicate differences in the auto-/heterotrop-hic oxidation balarice. From this basis the oxygen uptake rate for carbon oxidation and nitrification can be separated. The comparison with two biomass determination methods based on ATP-analysis shows that for heterotrophic biomass the methods indicate clearly different changes of ATP, for nitrification process the results were more compatible. By combining the biomass and on-line measurements with biomass growth model based on IAWPRC-model equations reasonably good estimates were obtained. Best fit of model was in the nitrification process; by using VSS as the measure of biomass the fit was poor. The differences in the ATP-measurement results affect also the model coefficients.
Phosphate and Nitrogen Removal Programme in The Netherlands
Authors: den Engelse Rob
Published: May 2018

A programme of research is being conducted in the Netherlands in the period 1990-1992 to find answers to the questions and solutions to the difficulties involved in the introduction of extensive nitrogen and phosphate removal. The purpose, organisation and implementation of the programme are considered. The most important initial results are set out relating to the clogging of aeration elements on simultaneous phosphate removal in activated sludge systems, to a guide to biological phosphate removal, phosphate stripping, the relationship between softening drinking water and phosphate removal and the market situation for chemicals for phosphate removal.
Denitrification of Sewage Effluents in Deep Bed Sand Filters
Authors: Upton John
Published: May 2018

The European waste water industry will need to develop denitrification processes to remove nitrogen as pressures increase to reduce nutrient levels discharged in effluents.

In the USA deep bed filter technology has been used extensively to provide denitrification to levels less than 5 mg/l TN. This paper describes this technology and the full scale performance at some waste water plants in Florida, USA. This paper also describes a pilot study in the United Kingdom at Severn Trent Water. The results of the pilot plant study indicate that denitrification in deep bed sand filters is a sound robust technology using methanol addition. Nitrogen removals greater than the 70% required in the EC Directive 1991 are possible at winter sewage temperatures.

The process is most suitable for achieving nitrogen removal at trickling filter plants. The cost of methanol addition is calculated to be ₤10/1000m3.
Handling of Anaerobic Digester Supernatant Combined with Full Nitrogen Removal
Authors: la Cour Jansen Jes , Nyberg Ulf , Aspegren Henrik , Andersson Bengt
Published: May 2018

In order to meet future standards of 8 mg/l total-nitrogen, 0.3 mg/l total-phosphorous and 10 mg/l BOD7, the Klagshamn wastewater treatment plant in Malmö has to be upgraded. A concept where the standards could be met within the existing activated sludge plant has been found.

Primary precipitation is followed by a single sludge post-denitrifying process where methanol is added as external carbon source. The system is high rate with only 7 hours retention time in the biological reactor. In order to improve the process stability and make a future increase in load possible within the existing plant, handling of digester supernatant has been examined.

The normal operation of the sludge handling system leads to discharge of a supernatant with a high content of ammonium. The load from the supernatant made about 15% of the total-nitrogen load on the plant on an average basis but could reach up to 65% during working hours. This extra load could be recognized as peaks of ammonium and nitrate in the effluent. The digester supernatant and its impact on daily variations in ammonium and nitrate have been examined in detail and the examination has formed the basis for a mathematical modelling of the system in order to test strategies for optimized handling.

Equalization of the supernatant flow, separate nitrification of the supernatant, and completely separate treatment of the supernatant have shown to be able to improve process stability. Flow equalization seems to be as effective as the two other more expensive and complicated solutions.
Advanced Oxygen Treatment of Coastal Municipal Sewage
Authors: Eastman G. M. , Harker R. J. , Ibbetson C. C.
Published: May 2018

Design proposals for a pure oxygen based treatment system based on BOC's VITOX process are described for Anglian Water's Southend-on-Sea sewage treatment works which will be required to be uprated from primary to secondary treatment under the requirements of the E.C. Urban Wastewater Treatment Directive. There are very tight space constraints on site. The requirements of the E.C. Bathing Water Directive have to be met too and a potential ozone disinfection system is described. Results of large-scale trials are presented.
Declining Rate Filtration
Authors: Cleasby John L.
Published: May 2018

Declining rate filtration is one of several flow control alternatives available for gravity filtration plants with four or more filters. Experimental and theoretical studies of declining rate filtration have provided the foundation for rational design procedures. This paper presents design procedures for estimating the filter system head needed for a declining rate filtration plant, and to predict the water level variations that will occur during operation. The paper also discusses the choice between inlet versus outlet rate limitation, the choice of type of rate limitation device, and the impact of operation of a declining rate filtration plant below full design load.
Turbidity Related to Surface Temperature in Oxidation Ponds: Studies toward Development of a Remote Sensing Method
Authors: Dor I. , Furer O. , Adin A. , Ben-Yosef N.
Published: May 2018

Recent results obtained from a pilot plant study showed that the rate of morning temperature increase in surface water is significantly correlated with the degree of water pollution expressed as turbidity.

The aim of the present study was to validate the above findings under field conditions. Two oxidation ponds differing in their effluent quality were investigated during the summer. In clear weather and moderate winds the ponds were thermally stratified. Continuous records of subsurface temperature and parallel measurements of turbidity provided data for statistical analysis.

The variables tested appeared significantly correlated and the more polluted pond exhibited consistently a higher rate of morning temperature increase.

Temperature measurements can be carried out remotely using airborn IR radiometric equipment. The thermal method should be applied together with visible spectrum imaging, which can identify pollution components according to the specific waveband of the reflected light.
Reduction of Aromatic Nitro Compounds in Anaerobic Ecosystems
Authors: Gurevich P. , Oren A. , Sarig S. , Henis Y.
Published: May 2018

The moderately halophilic anaerobic eubacteria Haloanaerobiumpraevalens and Sporohalobactermarismortui are able to reduce p-nitrophenol and a variety of other nitrosubstituted aromatic compounds at a high rate to the corresponding amines. p-Nitrophenol was not incorporated by the cells or degraded to acid-volatile compounds. Other compounds transformed included nitrobenzene, o-nitrophenol, m-nitrophenol, nitroanilines, 2,4-dinitrophenol, and 2,4-dinitroaniline. Also sheep rumen fluid was found to transform p-nitrophenol and a number of other nitroaromatic compounds at a high rate. At least 50% of the p-nitrophenol transformed was recovered as p-aminophenol. The findings suggest that anaerobic transformation of nitroaromatic compounds may be widespread in the bacterial world.
Dispersion of Contaminants in Fractured Permeable Media
Authors: Rubin Hillel , Dveyrin Dmitry
Published: May 2018

This paper concerns contaminant transport in aquifers comprised of fractured permeable media. In the framework of the present study a simplified method for quantitative evaluation of contaminant transport in fractured permeable media is developed. It is considered that the fracture network is characterized by two length scales, representing parts parallel and perpendicular to the flow direction. In the perpendicular part (transverse) of the fracture network an intensive mixing between the fracture flow and the permeable block flow takes place. Parameters governing this process are defined. It is shown that this process leads to contaminant dispersion. Characteristics of the contaminant transport process are defined and calculated.
Liability of Groundwater and Depth of Soil to Contamination by Pesticides and Other Organic Xenobiotics: Two Case Histories
Authors: Muszkat Lea , Raucher Daniel , Bir Lina , Magaritz Mordeckai , Ronen Daniel
Published: May 2018

We discuss the penetration of organic pollutants into the depth of soil and into groundwater under different environmental and geological conditions. In one case a field study was conducted on the impact of prolonged irrigation by effluents on groundwater and vadose zone contamination. The studied site was rich in sandy soil which allowed vertical penetration of pollutants into the depth. A significant difference has been observed in the distribution of organic pollutants in the effluent irrigated site, where the pollution increased markedly while descending from the top soil into the unsaturated zone, compared to the two control sites, where the extent of pollution decreased strongly with the depth. It seems that detergents and other surfactants present in the effluents strongly enhance the transport of organic components via the unsaturated zone.

The second case study deals with the transport of organic pollutants in a site where the subsoil is interspaced with clay layers. In this case groundwater pollution derived from the chemical waste of a pesticides plant. A long term follow up of groundwater pollution indicates that the typical contaminant distribution pattern remained unchanged during the years. The pollutants distribution indicates that in this area the penetration of organic pollutants does not occur vertically but rather by horizontal flow, due to inhibition of vertical migration by a thick clay layer present in this area.
Adsorption of Poliovirus 1 and F+ Bacteriophages onto Sand
Authors: Nasser A. M. , Adin A. , Fattal B.
Published: May 2018

This study was performed to determine the influence of water composition, virus type, pH and various salts and their concentration on the adsorption of F+bacteriophages and poliovirus to sand. Virus adsorption to sand was greater at acidic than alkaline pH values. At alkaline values (8.0, 9.0) virus adsorption was poor particularly in distilled water. The presence of divalent and trivalent cations in the medium enhanced the virus adsorption appreciably. On the other hand, the presence of humic acid at 10 and 100 mg/l reduced virus adsorption onto sand. The rate of F+bacteriophage adsorption to sand was similar or lower than that of poliovirus 1. Therefore, F+bacteriophages removal by adsorption processes is expected to be at similar or lower rates than that of pathogenic viruses. The results of this study support the initiative of proposing F+bacteriophages as anindex for virus removal through sand filtration.
Chemical Aspects of Coal Fly Ash Disposal at Sea: Predicting and Monitoring Environmental Impact
Authors: Kress Nurit
Published: May 2018

Monitoring studies at a deep sea fly ash dumping site found that the ash accumulates at the sea bed, causing a physical change in the sediments. Partial leaching of cadmium and chromium to seawater was detected in laboratory experiments, but no evidence of it was found in the sediments or benthic fauna sampled at the dumping site.
The Effect of PCB on the Induction of Cytochrome P450 Enzyme, Detected by Monoclonal Antibody against the P450IA1 Gene Products, in Barn Owl and Marsh Turtle Hepatic Microsomes
Authors: Yawetz A. , Goldman D. , Stegeman J. J. , Woodin B.
Published: May 2018

Induction of P450 species belonging to the P450IA1 gene family was demonstrated in liver microsomes of the barn owl Tytoalba and the marsh turtle Mauremyscaspicarivulata, after treatment with Aroclor 1254, using immunoblotting technique with monoclonal antibody (Mab) specific to P450IA1 (anti scup P450E, 1-12-6 Mab).

P450IA1 could hardly be detected in barn owls collected from their natural habitat. Significant induction (p<0.05), of up to three times, in the content of the barn owls hepatic microsomal P450IA1 was recorded after intraperitoneal injection of Aroclor 1254, although the proportion of P450IA1 from total P450 content, did not exceed 5 percent.

The content of P450IA1 in liver microsomes of marsh turtles collected from their natural habitat was relatively high, and values up to 225 pmol/mg protein were recorded. Treatment with Aroclor 1254 increased the mean content of P450IA1 in the turtle livers up to 5 times, and the proportion of P450IA1 from total hepatic P450 was about 20 percent.
Rodent Populations Recovering from Fire in an East Mediterranean Woodland*
Authors: Izhaki I. , Haim A. , Zohar O.
Published: May 2018

Fire in woodlands causes a dramatic decrease in rodent populations. The aim of this study was to detect rodent succession in three different management regimes of a post-fire habitat on Mount Carmel: (1) a control area of mixed woodlands of burnt pine and oak; (2) a mixed burnt woodland in which the burnt pine trees were cut and left in situ; and (3) a mixed burnt woodland in which burnt pines were cut and removed from the plot. Two plots in an unburnt mixed woodland were used as controls.

The first invader species observed in the post-fire habitats were Mus macedonicus, which was the most abundant species in all burnt plots, Gerbillus dasyurus, which was mainly trapped in plots where the burnt pine trees were removed, and Meriones tristrami, which was mainly trapped in plots where the burnt pine trees were left in situ. The highest species diversity was recorded in the control plots of the burnt pine and oak woodland. In these burnt control plots the field mice (Apodemus) of both species reappeared. However, the numbers of trapped A. flavicollis were rather higher than of A. mystacinus. It is thus assumed that the invading species will be replaced by the originial woodland rodent species through resilience.

*This study is dedicated in the memory of our colleague Mr. D. Banin.
Evaluation of the Extent of Contaminated Sediments in the West Branch of the Grand Calumet River, Indiana-Illinois, USA
Authors: Cahill R. A. , Unger M. T.
Published: May 2018

The extent of contamination in river sediments is often not rigorously evaluated. In many cases, only surface sediment samples are taken. In other cases, entire sediment cores are composited for analysis, an approach that limits the ability to identify discrete zones of contamination. In addition, few studies include information on the rate of sedimentation. Composited sediment cores, subsamples of cores made at discrete intervals, and surface samples were obtained from locations in the West Branch of the Grand Calumet River. The organic carbon content and concentrations of up to 26 major, minor, and trace elements were determined. Sedimentation rates at the ten locations were estimated using 137Cs. The mean concentrations of metals in the surface samples were considerably higher than concentrations in samples obtained by the two coring approaches. Only by analyzing discrete subsamples was it possible to plot the concentrations by depth and location. This approach was used to demonstrate that high levels of organic carbon and trace elements are confined between river miles 5 and 7.5. Sedimentation rate information combined with chemical analyses of the same cores indicate that contamination of this part of the river began in the 1930s.
A Source-Receptor Method for Determining Non-Point Sources of PAHs to the Milwaukee Harbor Estuary
Authors: Singh A. K. , Gin M. F. , Ni F. , Christensen E. R.
Published: May 2018

The purpose of this work is to determine non-point sources of PAHs to the Milwaukee Harbor Estuary. Sediment samples were collected from the Milwaukee River, the Menomonee River, the Kinnickinnic River, and the Inner and Outer Harbor of the Milwaukee Harbor Estuary. Source samples were collected from a major highway, a leaking underground storage tank, and two river banks. All samples were analyzed for sixteen PAHs, which are identified as priority pollutants by the U.S. EPA. In addition to this, literature values of concentrations of PAHs in known non-point sources viz. coal tar, coal tar air emissions, No. 2 fuel oil, and gasoline engine exhaust tar were considered. A computer program, using the mathematics of least-squares, was adopted to determine the best combination of sources to the mixed PAH signature of the sediment, and to calculate the contribution of each source to the concentration of total PAHs. Chi square and the multiple correlation coefficient were used to evaluate the fits. For apportionment of sediment PAHs into sources, only those PAHs are considered whose concentrations are above the instrument's (GC-MS) detection limit. Of the 211 regressions considered, about half present good fits to the proposed sources. Highway dust is found to be a significant source in 88%, gasoline engine exhaust tar in 33%, coal tar air emissions in 23%, and coal tar in 17% of the successful regressions.
The Prediction of Rainfall and the Direction of Rainfall by a Narrow Area Radar Rain Gauge
Authors: Kondo Shinichi
Published: May 2018

Narrow area radar rain gauges are currently used for measuring rainfall. These radar gauges can measure rainfall accurately in a small area. In sewage plants it is important to predict stormwater. To calculate predicted stormwater the results of rainfall and a prediction of the near future are necessary. Recently urbanization has made the arrival time of flooding to the sewage plant much shorter. This paper deals with system technologies for the near future prediction of radar rain gauge rainfall. The method of prediction of rainfall, calculation of results and other considerations are described.
Evaluation of Sensitivity and Observability of the State Vector for System Identification and Experimental Design
Authors: Ayesa E. , Flórez J. , Larrea L. , García-Heras J. L.
Published: May 2018

This paper presents two new algorithms to evaluate numerically the state and coefficient's observability and sensitivity in dynamic models. The observability algorithm computes the numerical condition of observability matrix as an index of the ability to identify the unknown states or coefficients. The sensitivity algorithm quantifies dynamically the influence of unknown variables on measurable variables. Both algorithms are useful tools to predict the identification accuracy and to design the best operational conditions to estimate each one of the unknown parameters. The algorithms have been applied to discuss the identification of kinetic coefficients in the IAWPRC biodegradation model, using an experimental procedure based on changing the values of reactor volumes.
Activated Sludge Control Adviser
Authors: Stimson K. R.
Published: May 2018

This paper concerns the development and use of a computer-based expert system (ASCA) to advise operators of activated sludge wastewater treatment plants in the event of an actual or potential effluent problem. The system provides a diagnosis of problems and gives advice on remedial actions. An incident database facility permits the recording and later inspection of problematic events. The system contains a general knowledge base applicable to all such treatment works. This is supplemented by site-specific knowledge when customised to particular plant. Development required close collaboration with users. On-site trials are being performed at two sites. Early results indicate both usability and usefulness, and demonstrate that the system can be readily customised for further sites. Further possible enhancements are discussed.
Integration of Multi AI Paradigms for Intelligent Operation Support Systems – Fuzzy Rule Extraction from a Neural Network
Authors: Enbutsu I. , Baba K. , Hara N. , Waseda K. , Nogita S.
Published: May 2018

Some artificial intelligence (AI) paradigms have been applied to water and wastewater treatment systems. An artificial neural network (ANN), which can learn historical data of a plant, provides operational guidance for plant operators, and a fuzzy system (FS) provides a framework to put operators' heuristics into practical use as fuzzy rules in a fuzzy rulebase. In application, however, the practical problems remain that the ANN is a blackbox model which is unfamiliar to plant operators, and the FS usually requires much time-consuming work by system engineers and operators for knowledge acquisition and rulebase maintenance. The authors think that integration of the paradigms can give appropriate solutions to these problems. As one method which realizes such integration, an automatic fuzzy rule extraction method using an ANN is proposed. Simulation results of the proposed method using full-scale plant data demonstrated that an FS whose rulebase was modified automatically with extracted rules had better performance than a conventional FS whose rulebase included only operators' heuristics. This effect is thought to be realized by enhancement of knowledge source with the proposed method.
A New Sensing Technique for Optimum Sludge Conditioning for Waste Sludge Dewatering
Authors: Yasukawa Y. , Totoki T. , Shigemi H.
Published: May 2018

A new sensing technique using a Hot-Film sensor for determining the optimum polymer dosage for sludge dewatering has been developed. Correlations between the behavior of the Hot-Film sensor and dewaterability of sewage and night soil sludge were investigated. The results of the study revealed the following: the Hot-Film sensor values depended on the filtrate characteristics related to the sludge dewaterability which is measured by the filterability of the conditioned sludge and by the moisture content of the dewatered sludge cake; the optimum polymer dosage for sludge dewatering corresponded with the minimum output value on the characteristics curve of the Hot-Film sensor. This paper describes the observations of the measurement test by the Hot-Film sensor as well as the results of the laboratory test of sludge dewatering for optimum sludge conditioning.
Control Strategies for a Highly Loaded Biological Ammonia Elimination Process
Authors: Teichgräber B.
Published: May 2018

A nitrification/denitrification process was applied to reject water treatment from sludge dewatering at Bottrop central sludge treatment facilities of the Emschergenossenschaft. On-line monitoring of influent and effluent turbidity, closed loop control of DO and pH, and on-line monitoring of nitrogen compounds were combined to a three level control pattern. Though on-line measurement of substrate and product showed substantial response time it could be used to operate nitrification/denitrification within process boundaries.