bluuebunny/crossref_metadata_2025 huggingface dataset:
Sarasota Bay: Protection of a Natural Resource
Authors: Wagner R. A. , Heyl M. G.
Published: May 2018

As part of the Sarasota Bay National Estuary Program (NEP) evaluation of environmental problems, modeling tools were used to estimate pollution loadings from diverse sources, including surface runoff, baseflow, wastewater treatment plant discbarges, septic tanks, and direct deposition of rainfall on the bay surface. After assessing the relative impacts of the pollution sources, alternative management strategies were identified and analyzed. These strategies focused primarily on future development, and included structural and nonstructural best management practices (BMPs), as well as a regional wastewater treatment plan. Loading reductions, along with planning-level cost data and estimates of feasibility and other potential benefits, were used to identify the most promising alternatives.
Use of Resource-Efficient Plants to Reduce Nitrogen, Phosphorus, and Pesticide Runoff in Residential and Commercial Landscapes
Authors: Hipp Billy , Alexander Susan , Knowles Tim
Published: May 2018

Runoff from typical urban and suburban landscapes may contain significant levels of nitrogen, phosphorus, and a broad spectrum of various pesticides (mainly herbicides and insecticides) due to excessive application rates of these chemicals and high irrigation requirements of most commonly used landscape plant species. Preliminary water quality data (runoff) from a comparative study of 20 microwatersheds using 4 different levels of maintenance, show reductions in these types of pollutants in runoff for microwatersheds planted to resource efficient plants. Utilization of plants indigenous to an ecoregion (and other resource efficient plants) in landscape design and management allows considerable reduction in inputs from fertilizer, water, and pesticides. This results in lower pollutant concentrations in runoff and is estimated to result in lower total pollutant loadings from such systems. Installation of native or resource efficient plants in new developments (commercial and residential) and replacement of existing landscapes with these plants as older plants die or neighborhoods are updated could provide cities and suburban areas with a cost-effective, low-maintenance, and aesthetically-pleasing pollution control technology. Data from the comparative study should provide municipalities charged with meeting the new requirements of the National Pollutant Elimination Discharge System with a way to compare the pollution prevention effectiveness of resource-efficient landscapes with more traditional structural urban runoff controls.
Assessing the Diffuse Phosphorus Input from Subsurface to Surface Waters in the Catchment Area of the Lower River Spree (Germany)
Authors: Driescher E. , Gelbrecht J.
Published: May 2018

The proportion of nonpoint phosphorus sources in the eutrophication process of surface waters is higher than generally assumed. In the surroundings of Berlin (glaciofluvial deposits and moraine areas) the phosphorus content of some subsurface waters reaches levels of several hundred µgP/l. As surface waters are mainly fed by groundwater in this area, nutrient contents in groundwater may become of great importance when other phosphorus sources are eliminated. Investigations in unpolluted areas are a prerequisite to decide whether higher phosphorus levels in groundwater are of natural origin or the result of contamination processes. The phosphorus background was shown to be very different and dependent on the depth below groundwater surface, content of iron, and redox conditions in the aquifer. Wastewater land treatment, bank filtration, agricultural land use, and degradation of lowland bogs were found to be sources of phosphorus contamination of aquifers. The results of observations are reported.
Agricultural Chemicals: Estimating Their Occurrence in Illinois' Groundwater
Authors: Schock Susan , Ray Chittaranjan , Mehnert Edward
Published: May 2018

1The first author is now affiliated with the USEPA in Cincinnati, Ohio, but worked at the ISWS when this project was conducted.
Assumed Non-Point Water Pollution Based on the Nitrogen Budget in Polish Agriculture
Authors: Sapek A. , Sapek B.
Published: May 2018

The nitrogen balance made on a national, regional and/or farm basis provides valuable information about the surplus of nitrogen in agricultural production. This surplus of nitrogen is dispersed into the environment, causing water pollution with nitrate and other compounds of nitrogen, air pollution with ammonia and nitrous oxide. The nitrogen balance in Polish agriculture has undergone vast changes during the last few years, according to economic and social transformations after the collapse of the communist system. The surplus of nitrogen decreased from about 90 kg N/ha in 1989 to about 60 kg N/ha in 1991. More than 30% of nitrogen surplus is volatilized into the atmosphere in the form of ammonia, while similar amounts find their way into the water, particularly groundwater. The amounts of nitrogen losses due to denitrification are difficult to estimate.
Wind Erosion Prediction and Control
Authors: Nanney R. D. , Fryrear D. W. , Zobeck T. M.
Published: May 2018

Few regions of the United States are entirely safe from wind erosion. Whenever the soil surface is loose and dry with limited crop residue cover, and the wind sufficiently strong, soil erosion will occur. Soil erosion by wind causes diffuse pollution, loss of topsoil, reduced crop production, and damage to both public and private facilities. Factors contributing to the wind erosion process can vary daily. This complex process presents a challenge to the science of wind erosion prediction and control. USDA Agricultural Research Service is developing a new Wind Erosion Prediction System (WEPS) to overcome the limitations of the existing Wind Erosion Equation (WEQ). WEPS is a computer based model with submodels for crops, soils, tillage, erosion, weather, hydrology, and decomposition. USDA Soil Conservation Service assisted with the characterization of changes in the temporal soil properties of the tillage zone and ground surface and erosion rates at a validation site in the Great Lakes region. The results of the data collection for the soils and erosion submodels and a discussion of a windbreak demonstration site show the dynamic nature of the wind erosion process.
Mitigation of Agricultural Water Pollution in Finland: An Evaluation of Management Practices
Authors: Rekolainen S. , Posch M. , Turtola E.
Published: May 2018

This paper summarizes the results of recent studies concerning the agricultural nutrient load to surface waters in Finland and possible management practices for reducing nutrient losses from agricultural land. Both the nitrogen and the phosphorus load exceed the loads from municipal and industrial sources together, thus being mainly responsible for the eutrophication of surface and coastal waters. 25% of the total agricultural phosphorus load is bioavailable dissolved reactive phosphorus, and 5% of the paniculate phosphorus load is available for algae. Reduced tillage, filter strips and permanent grassland on the set-aside land are means investigated for reducing erosion and nutrient losses. Based on experiments and model simulations, it is estimated that a wide adoption of all these practices would reduce total phosphorus load by about 40%. Soluble phosphorus and nitrogen losses can be reduced by adjusting the amount and timing of fertilization and manure application to the actual needs of plants. If the whole set-aside area was under permanent grassland, the nitrogen loss would decrease by about 17%, but the effect of cover or undersown crops in Finnish conditions is still unknown. More investigations are also needed of the effects of all these management practices on the soluble phosphorus load.
Preliminary Evaluation of Effects of Best Management Practices in the Black Earth Creek, Wisconsin, Priority Watershed
Authors: Walker John F. , Graczyk David J.
Published: May 2018

Nonpoint-source contamination accounts for a substantial part of the water quality problems in many watersheds. The Wisconsin Nonpoint Source Water Pollution Abatement Program provides matching money for voluntary implementation of various best management practices (BMPs). The effectiveness of BMPs on a drainage-basin scale has not been adequately assessed in Wisconsin by use of data collected before and after BMP implementation.

The U.S. Geological Survey, in cooperation with the Wisconsin Department of Natural Resources, monitored water quality in the Black Earth Creek watershed in southern Wisconsin from October 1984 through September 1986 (pre-BMP conditions). BMP implementation began during the summer of 1989 and is planned to continue through 1993. Data collection resumed in fall 1989 and is intended to provide information during the transitional period of BMP implementation (1990-93) and 2 years of post-BMP conditions (1994-95).

Preliminary results presented for two subbasins in the Black Earth Creek watershed (Brewery and Garfoot Creeks) are based on data collected during pre-BMP conditions and the first 3 years of the transitional period. The analysis includes the use of regressions to control for natural variability in the data and, hence, enhance the ability to detect changes. Data collected to date (1992) indicate statistically significant differences in storm mass transport of suspended sediment and ammonia nitrogen at Brewery Creek. The central tendency of the regression residuals has decreased with the implementation of BMPs; hence, the improvement in water quality in the Brewery Creek watershed is likely a result of BMP implementation. Differences in storm mass transport at Garfoot Creek were not detected, primarily because of an insufficient number of storms in the transitional period. As practice implementation continues, the additional data will be used to determine the level of management which results in significant improvements in water quality in the two watersheds. Future research will address techniques for including snowmelt runoff and early spring storms.
Dynamic Simulation Modelling for Evaluating Water Quality Response to Agricultural BMP Implementation
Authors: Cassell E. A. , Clausen J. C.
Published: May 2018

Dynamic simulation modelling (DSM) is a computer modelling technique that promotes description of complex natural systems, such as watersheds and BMP systems. When DSM is accomplished in an object oriented programming framework, modelling is highly interactive. The Field Phosphorus Model (FPM) was created with STELLA® II, an object oriented DSM programming environment FPM is based on sophisticated accounting of all annual inputs and outputs of phosphorus for a farm field and simulates, on a yearly basis, patterns of phosphorus export from farm fields used for manure management on dairy farms. Model inputs include atmospheric deposition, manure application and chemical fertilizer; outputs include surface runoff, crop harvest, and movement into deeper soil layers. Using two BMP scenarios, the implications for long-term phosphorus export levels from the field to surface and ground waters are discussed. Changes in the land treatment or BMP levels on the field results in a lag time between when the BMP is implemented and when the full impact on phosphorus export is seen. The Field Phosphorus Model suggests that the simultaneous reduction of long-term phosphorus output to surface and ground waters is accomplished by implementation of BMP's that limit the input of phosphorus to the field.
Nonpoint Source (NPS) Pollution Modeling Using Models Integrated with Geographic Information Systems (GIS)
Authors: Engel B. A. , Srinivasan R. , Arnold J. , Rewerts C. , Brown S. J.
Published: May 2018

Models play an important role in the estimation of nonpoint source (NPS) pollution severity and in the identification of NPS problem areas. The use of these models has been severely limited because of the data and expertise required to operate these models. The integration of NPS pollution models with geographic information systems (GIS) can likely overcome these problems. Three NPS pollution models that were integrated with a GIS were used to simulate a watershed response to a series of rainfall events. The simulated responses were compared with observed runoff and sediment data. The simulated results matched the observed results reasonably well considering model inputs were estimated from base GIS data.
Real Time Control within a Combined Sewer System: Comparison of Practical and Theoretical Results
Authors: Weyand Michael.
Published: May 2018

Application of real time control systems within sewer networks is one of different possible measures taken against the problems with storm water runoff and combined sewer overflows (CSO) in urbanized areas. Practical investigations concerning the effect of this alternative way to reduce CSO have been made during four years in the sewer network of the community Ense-Bremen (near Dortmund). An implemented simple control strategy manages the flow and storage events aiming at an even degree of storage capacity at any detention tank and at any time. The comparison with model calculations, reveals that there are differences between both results especially those concerning the basin out-flows. These differences are mainly caused by the constraints of practical operation. Therefore it is necessary to develop control strategies considering these facts within its practical course.
Development and Scale-Up of an Aerobic Biofilm Air-Lift Suspension Reactor
Authors: Heijnen J. J. , van Loosdrecht M. C. M. , Mulder R. , Weltevrede R. , Mulder A.
Published: May 2018

A new aerobic treatment concept for the aerobic oxidation of COD, ammonia and sulphide has been developed. The concept is based on the formation of biofilms on small suspended particles in an air-lift reactor. This reactor concept enables to combine a low sludge loading with a high volumetric loading. This makes the reactor especially useful for e.g. nitrification processes. It is also feasible to operate under conditions of marginal sludge production. In this article the scale up aspects of such a process are discussed.
Low Cost Packaged Sewage Treatment Plant for Production of High Quality Effluent at Small Works
Authors: Chambers B. , Whitaker J. , Elvidge A. F.
Published: May 2018

In the UK there are over 7000 small works which treat the sewage from populations of less than 10,000. Many of these works are at risk of non-compliance with effluent quality consents and options for improving the standard of treatment are being pursued by many utilities.

WRc and Anglian Water Services have developed designs for packaged sewage treatment plants to serve populations in the range of 1000-10,000. A demonstration plant has been constructed at the Waterbeach STW of Anglian Water to serve a population of about 6,500. Target effluent quality is 15:20:5mg/l of BOD, SS and ammonia nitrogen respectively on a 95 percentile basis.

Following plant commissioning a process performance evaluation programme was commenced in February 1991. Nitrification was established after about 6 weeks of operation but suspended solids values have been affected by the presence of a stable foam on the surface of the aeration tank. Process modifications have reduced the effect of this phenomenon substantially and effluent quality has improved.
On Precaution, Clean Production & Paradigm Shifts
Authors: MacGarvin M. , Johnston P. A.
Published: May 2018

Present environmental policy in the countries around the North East Atlantic is in a state of transition; in part made up of old attitudes that assumed the environment to be largely capable of absorbing contamination, in part a new precaution that recognises that we cannot fully predict the result of such actions. Precaution will prevail, and be implemented by a form of pollution prevention, known as clean production, that emphasises the need to reduce and eliminate pollution at all stages of the manufacturing cycle. There are three reasons why change is inevitable. First, toxicological problems, along with serious ecological uncertainties, mean that we will be unable to predict ‘safe' levels of marine contamination for the foreseeable future. Second, demonstration projects make it clear that clean production is now feasible and economically attractive, even in ‘problem' industries. Third, the targets now being set for the reduction and elimination of potentially problematic substances – for instance by the 1990 North Sea Conference and the 1992 Paris Convention Ministerial meeting – have developed to the point where clean production provides the only feasible means of implementation. This change has significant implications for the water treatment industry.
The Effect of Baffle Installation on the Performance of a Single-Cell Stabilization Pond
Authors: Pedahzur R. , Nasser A. M. , Dor I. , Fattal B. , Shuval H. I.
Published: May 2018

The effect of baffles on the performance of an ineffective, single-celled stabilization pond with theoretical retention time of 5-10 days, was investigated. The efficiency of the pond was evaluated by comparing the microbiological and chemical quality of pond's influent and effluent, as well as by hydraulic tests. Removal of indicator microorganism (1 log) and BOD5 (55%) remained unchanged, regardless of the number of baffles. Tracer study findings were characterized by the appearance of a peak of tracer within 15-20 hours after injection of the tracer, followed by a long “tail” of lower concentration. These findings, along with optical observations, indicated that the baffles succeeded in channeling influent flow to the planned routes (resulting in increased traveling distance of the wastewater). However, the actual retention time of the influent, particularly a small but important fraction of it, remained short regardless of baffle installation. The lack of mixing caused by thermal stratification of the water column resulted in rapid bottom flow in the cool hypolimnion. These findings may explain, in part, the lack of success in improving treatment efficiency.
The Heterotrophic Connection in a Photoautotrophic Chlorella Vulgaris Dominant in Wastewater Oxidation Ponds
Authors: Cohen Iris , Post Anton F.
Published: May 2018

Chlorella vulgaris strain C1 was grown in laboratory under autotrophic and mixotrophic conditions. Cellular division rates increased in cultures supplied with either acetate or glucose. As a direct result respiratory activity was enhanced in those cells, most pronounced in the presence of acetate. Glucose and acetate had opposed effects on the photosynthetic activity of the cells. Cells grown in the presence of acetate had a 3-fold decrease in pigment contents. Since this was mostly expressed in decreased light utilization efficiency of the cells, we conclude that fewer light harvesting antennae were synthesised. Cells grown with glucose retain high pigment contents and photosynthetic activity of the cells was strongly enhanced. It was observed that even though organic matter may support algal growth in oxidation ponds, at the same time one may expect a much stronger oxygen demand accompanied by a reduced photosynthetic potential. This must be considered a burden on the wastewater treatment operation requiring countermeasures to be taken.
Characterisation of Suspended Particles and Associated Metals in Groundwater under Natural Gradient Flow Conditions*
Authors: Ronen D. , Magaritz M. , Amiel A. J.
Published: May 2018

Microscale Eulerian variations in the flux, mineralogical composition and size of suspended particles have been found in a contaminated sandy aquifer under natural gradient flow conditions () during an 8 month study period. Particle variability has been detected along a 16 m saturated section of the aquifer at a scale of centimeters and meters in the vertical and horizontal dimensions, respectively. The average concentration of particles in groundwater varied between 1 to 70 mg/l. The particles were primarily composed of CaCO3 (11% to 57%), quartz (7% to 39%) and clays (8% to 43%). Most of the particles were within the 140 to 3,000 nm size range with size modes varying from 310 to 660 nm. The large amounts of suspended particles are considered to be related to high inputs of dissolved organic carbon into groundwater from sewage effluents which have been used for agricultural irrigation since the early 1960's. As a result of organic matter biodegradation in the saturated zone, anoxic conditions developed and the pCO2 content of groundwater increased dramatically. It is postulated that part of the carbonate cement of the rocks dissolved and detrital CaCO3, quartz and clay were released as colloidal particles. In the prevailing anoxic conditions of groundwater at the study site (DO < 1 mg/l) colloidal stability is enhanced by organic matter coating of particles. The transport of metals associated with suspended particles in the saturated zone and the interaction of these particles in the aquifer environment have been ascertained through a comparison of the distribution coefficient of 17 elements as a function of depth.

*Contribution No. 61, Department of Environmental Sciences and Energy Research, The Weizmann Institute of Science.
The Underestimated Importance of Dark Carbon Fixation to Primary Productivity in Lake Kinneret
Authors: Herzig Ronny , Butow Barbara
Published: May 2018

The rates of light and dark 14CO2 fixation by natural phytoplankton communities in Lake Kinneret were studied in situ and in vivo in the laboratory. Dark fixation (DF) contributed an important part of the total primary productivity in Lake Kinneret.

In addition, it was found that during the dark period the relative amount of fixed inorganic carbon depends upon the sampling depth and season.

The DF contribution of the dominant phytoplankton species in Lake Kinneret (Peridinium gatunense) was found to be between 3-30% of the total light carbon fixation (LF). Carbon uptake was dependent on the light history of the cells. DF and LF in photosynthetic bacteria was found to be equivalent. A time course of carbon uptake by Peridinium showed that DF increased with time.
Measures of Ecosystem Health and Integrity
Authors: Amir Shmuel , Hyman Jeffrey
Published: May 2018

The health and integrity of an ecosystem is a multifaceted concept. It can become operational and of use in setting environmental policies once it is backed up by a theory that explicates the basic mechanisms of ecosystem functioning in response to stress. Despite the fact that ecosystem health remains a theoretical construct, the theory proposes a set of observed variables, basically the biotic stocks and flows of the ecosystem, empowered by a computable model, that give rise to operational and diagnostic measures of ecosystem health. The proposed measures are shown to correlate well with several other qualitative and quantitative measures of ecosystem health.
The Influence of Pine Ash on the Germination and Early Growth of Pinus halepensis Mill. and Cistus salviifolius L.
Authors: Ne'eman G. , Meir I. , Ne'eman R.
Published: May 2018

Black ash circles are found under the burned canopies of big dead pine trees up to three years after fires. Similar circles are formed as the result of a spatial pattern of seedling recruitment after fires. It has been suggested that the accumulation of ash around the burned trees, and the differential reaction of seed germination to ash, may be a major cause for the spatial pattern of seedling recruitment after fires. The results of germination experiments in pots prove that thick cover of ash has a negative effect on germination of Pinushalepensis Miller, and on germination and growth of Cistussalviifolius L. Ash solutions in petri dishes had no effect on germination and growth of both species. Pinus seems to be more well adapted than Cistus to germination and growth in sites with high amounts of ash after fire. Our results support the hypothesis that the ash around the burned pine trees, and the differential reaction of plant species to the ash may explain the spatial pattern of seedling recruitment after fire. We suggest that the relatively high resistance of pine seed germination to osmotic stress is an adaptation to post fire germination rather than to germination in arid zones.
Water Quality Impacts of Sediment Pollution and the Role of Early Diagenesis
Authors: Lijklema L. , Koelmans A. A. , Portielje R.
Published: May 2018

The rate of lake sediment pollution is a function of the input of pollutant and adsorbent, the areal hydraulic loading of the lake, the settling velocity of the adsorbent, the distribution between aqueous and solid phase and the release from the sediments. Early diagenetic processes cause a redistribution and new partitioning in the sediments. The ecotoxicological risks and the water quality impacts of the pollutants in water and sediment are closely related to this partitioning. The magnitude and duration of the impacts of a historical pollution period are further related to the intensity of bioturbation and to wave induced turbulence. Some quantitative relationships, field data and simulations support the discussion of the underlying principles.
Accumulation and Preliminary Inventory of Organochlorines in Great Lakes Sediments
Authors: Golden K. A. , Wong C. S. , Jeremiason J. D. , Eisenreich S. J. , Sanders G. , Hallgren J. , Swackhamer D. L. , Engstrom D. R. , Long D. T.
Published: May 2018

Sediment cores from lakes Superior, Michigan, and Ontario were analyzed to establish spatial and temporal concentrations and accumulation rates of PCBs and DDT. In this paper, we report the concentrations and accumulation rates for PCBs and DDT in the three lakes, and provide preliminary estimates of sediment inventories employing corrections for sediment focusing. Estimates of burdens of PCBs in the sediments of lakes Superior, Michigan, and Ontario are ~4900 kg, 75,000 kg, and 110,000 kg, respectively.
Polycyclic Aromatic Hydrocarbons and Mercury in Sediments from Two Isolated Lakes in Central and Northern Canada
Authors: Lockhart W. L. , Wilkinson P. , Billeck B. N. , Brunskill G. J. , Hunt R. V. , Wagemann R.
Published: May 2018

Sediment cores were taken from two isolated Canadian lakes, a southern lake in the boreal forest region of northwestern Ontario and a northern one in the tundra on the west coast of Hudson Bay, for the purpose of comparing current and historical loadings of several contaminants. There are no sources of anthropogenic contaminants within either basin, yet both lakes showed increases in polycyclic aromatic hydrocarbon and mercury in more recent sediments as compared with older, deeper sediments. We have interpreted these as indications of increased loadings as a result of atmospheric fallout. When compared on the basis of the sum of sixteen PAHs, both lakes showed peak inputs in the middle years of this century, followed by more recent declines; although current values still exceed those from deep slices. With respect to mercury, the concentrations found in the southern lake were somewhat higher than those in the northern lake, and loadings were clearly greater in the south. Both lakes showed enrichment of mercury in top layers of the cores relative to bottom layers, and this enrichment was proportionately greater in the north. Both mercury profiles showed a slow rate of increase for a long period before 1850, suggesting influences from areas industrialized before North America. The northern lake also showed increases in PAH loadings prior to 1850, but the southern lake did not.
Pollutant Release from Sediments in Sewer Systems and Their Potential for Release into Receiving Waters
Authors: McGregor I. , Ashley R. M. , Oduyemi K. O K.
Published: May 2018

A programme of work funded by the UK Water Research Centre (WRc) has been carried out to investigate the nature, occurrence and re-entrainment into the sewage flow of sewer sediments and their associated pollutants to provide data for the development of UK sewer flow quality models, MOSQITO and MOUSETRAP. Methodologies for the preparation of sewer sediment samples prior to chemical analysis are described. These methods have been developed to determine the level of pollutants released from sewer sediments which will be representative of the conditions found in the sewer environment. Application of progressively lower shear stresses to samples of sediment, from an extreme, via blending, to less severe preparative methods by means of a stirring technique, fractionate sediment samples so that the polluting potential may be assessed separately for both dissolved and resuspendable phases. Stirring preparative methods release less pollutants from a sediment sample than from the blending procedures, with the level of pollutant release being dependent upon the shear stress being applied to the sample, with higher shear values releasing as would be expected, more pollutants.
Integrating a Catchment Simulator into Wastewater Treatment Plant Operation
Authors: Gustafsson Lars-Göran , Lumley Doug J. , Lindeborg Claes , Haraldsson Jan
Published: May 2018

A catchment model which describes the hydrological and hydrodynamic processes in the catchment to the Rya wastewater treatment plant in Göteborg, Sweden is presented. The model uses hydrological models (MouseNAM) of 20 subcatchments and a hydrodynamic model (MousePIPE) of the tunnel system to make flow and CSO predictions. The catchment model has been used to evaluate several different operating strategies of the plant's pumping station and will be implemented as an operating tool. Efforts are under way to establish hydraulic and mass transport models for the pumping station and primary settling so that a loading model for the activated sludge process can be defined.
Parameter Estimation and Sensitivity Analysis of an Activated Sludge Model Using Monte Carlo Simulation and the Analyst's Involvement
Authors: von Sperling Marcos
Published: May 2018

The present work describes an adaptation of the regionalized sensitivity analysis based on Monte Carlo simulations for the parameter estimation and sensitivity analysis of an activated sludge model. The procedure described should be used when observed data are available for the model calibration, which is nevertheless still limited by the problems inherent to activated sludge models (uncertainty and lack of identifiability). The selection between good and bad performance of the model is judged based on the Coefficient of Determination. The application of the procedure to an 11-parameter 4-state dynamic activated sludge model used for operational control was considered satisfactory. The method is simple and yet robust, and the analyst's involvement in the interpretation of the results and decision upon the next steps to be taken increases its controllability.
Intelligent Operation Support System for Activated Sludge Process
Authors: Watanabe Shoji , Baba Kenji , Yoda Mikio , Wu Wen-Chih , Enbutsu Ichiro , Hiraoka Masakatu , Tsumura Kazushi
Published: May 2018

We have proposed the Intelligent Operation Support System (IOSS) for sewage plants, which can be applied to bulking prediction and control for the activated sludge process. The IOSS can provide guidance and control messages to operators on actions to take based on various kinds of integrated information including on-line process data, image signals on microorganisms, heuristics on plant control and data analyzed manually. To get on-line microorganism image information, a high resolution submerged microscope was developed and applied in a full scale plant. By combining image data with heuristics, the IOSS allows prediction of the symptoms of abnormal phenomena like bulking occurrence, and then provides ways to control the abnormalities thus decreasing the operators' work loads. Furthermore, diagnosis methods for detecting sensor troubles are proposed. Simulation results indicate the IOSS is effective.
MOUSETRAP — A DETERMINISTIC SEWER FLOW QUALITY MODEL
Authors: Crabtree R. , Garsdal H. , Gent R. , Mark O. , Dórge J.
Published: May 2018

Recent research into the behaviour of sediments and associated pollutants in sewers has formed the foundation for a dynamic pollutograph-based sewer flow quality simulation model called MOUSETRAP. This is a new component to the MOUSE sewer system hydraulic modelling package. MOUSETRAP has been developed by an international consortium of sewer model developers and users to predict short term variations in sewer flow quality and sediment transport in response to storm events. MOUSETRAP is composed of a series of modules to represent: the quality of surface run off; sediment and pollutant transport, erosion and deposition within pipes; and the biological and chemical processes within the sewer system. By representing the current understanding of real sewer sediments, this new tool gives the user the capability to simulate storm event pollutographs incorporating first foul flush phenomena.

The paper describes the basis of the new MOUSETRAP modules. Results of initial theoretical testing and pilot study applications are presented to illustrate the model's capabilities and potential for use in the management of urban wastewater discharges.
A STRATEGY FOR MONITORING THE IMPACTS OF COMBINED SEWER OVERFLOWS ON THE OHIO RIVER
Authors: Vicory Alan H. , Tennant Peter A.
Published: May 2018

With the attainment of secondary treatment by virtually all municipal discharges in the United States, control of water pollution from combined sewer overflows (CSOs) has assumed a high priority. Accordingly, a national strategy was issued in 1989 which, in 1993, was expanded into a national policy on CSO control. The national policy establishes as an objective the attainment of receiving water quality standards, rather than a design storm/treatment technology based approach. A significant percentage of the CSOs in the U.S. are located along the Ohio River. The states along the Ohio have decided to coordinate their CSO control efforts through the Ohio River Valley Water Sanitation Commission (ORSANCO). With the Commission assigned the responsibility of developing a monitoring approach which would allow the definition of CSO impacts on the Ohio, research by the Commission found that very little information existed on the monitoring and assessment of large rivers for the determination of CSO impacts. It was therefore necessary to develop a strategy for coordinated efforts by the states, the CSO dischargers, and ORSANCO to identify and apply appropriate monitoring approaches. A workshop was held in June 1993 to receive input from a variety of experts. Taking into account this input, a strategy has been developed which sets forth certain approaches and concepts to be considered in assessing CSO impacts. In addition, the strategy calls for frequent sharing of findings in order that the data collection efforts by the several agencies can be mutually supportive and lead to technically sound answers regarding CSO impacts and control needs.
WATER QUALITY MODELS: TOOLS FOR THE ANALYSIS OF DATA, KNOWLEDGE, AND DECISIONS
Authors: Varis Olli
Published: May 2018

Due to the rapid development of computational problem solving technologies, both in theoretical terms and in applications, the need for methodological diffusion across borders between traditional disciplines is increasingly important. Moreover, we should be able to use rationally approaches from very different methodological families. This study summarises 27 case studies on water quality and fisheries management, in which a variety of computational techniques have been used. Regarding philosophical orientation of the approaches, they are clustered to empirical, deterministic, and pragmatic ones. The roles of inductive and deductive components in inference are discussed, and the approaches are screened with respect to the applied (decision support) and theoretical (scientific) aspects of the studies. The relative roles of logical and relational thinking and experience are also considered. The decision support feature is discussed starting from the needs of directive, strategic, tactical, and operational management. Conclusions include a strong emphasis on the need to utilize a variety of problem solving tools to cope with the multiple tasks set for water quality models, including data analysis, knowledge processing, and decision support.
AQUASIM – A TOOL FOR SIMULATION AND DATA ANALYSIS OF AQUATIC SYSTEMS
Authors: Reichert Peter
Published: May 2018

A survey over the capabilities of a new simulation and data analysis program for laboratory, technical and natural aquatic systems is given. In this program, the spatial configuration of a model system is represented by compartments, which are connected by links. The program allows the user to define an arbitrary number of substances to be modelled and it is extremely flexible in the formulation of transformation processes. It not only offers the possibility of performing simulations of the time evolution of the user-specified system, but it provides also methods for system identification (sensitivity analysis and automatic parameter estimation) and it allows us to estimate the uncertainty of calculated results. These features, together with the user-friendly interface, very much support scientist in analyzing their data. Three examples illustrate the capabilities of the program.
MODELING THE ORGANIC REMOVAL AND OXYGEN CONSUMPTION BY BIOFILMS IN AN OPEN-CHANNEL FLOW
Authors: Li Shiyu , Chen Guang Hao
Published: May 2018

A mathematical model is proposed to predict the removal of dissolved organic substances and the consumption of dissolved oxygen by attached biofilms in an open-channel flow. The model combines the biofilm equations with the conventional Streeter–Phelps type equations of river water quality by considering the mass transfer of organics and oxygen in the river water through the diffusion layer into the biofilm. It is assumed that the diffusion and reaction within the biofilm are of steady-state, and follow Monod kinetics. The model is solved numerically with a trial-and-error method. The simulation results of the model for an ideal case of river flow and biofilm show that the organic removal rate and oxygen consumption rate caused by the biofilm are greater than that by suspended biomass. The effects of diffusion layer thickness, flow velocity, and biofilm thickness on the change of river water quality are discussed.
ASSESSMENT AND UNCERTAINTY ANALYSIS OF EUTROPHICATION FOR TE-CHI RESERVOIR, TAIWAN
Authors: Wang Yu-Ming , Wu Ming-Chun , Kuo Jan-Tai
Published: May 2018

This paper describes the development and application of uncertainty analysis to evaluate the risk of eutrophication for Te-Chi Reservoir, Taiwan. Two methods, probabilistic model and first-order analysis of uncertainty (FOAU), were used to quantify the expected variability of the total phosphorus concentration in the reservoir. Based on the load-resistance analysis, these two methods were applied and compared to calculate the risk of eutrophication for Te-Chi Reservoir. An approach is also proposed herein to evaluate the trophic state in the future. Since the trophic state for Te-Chi Reservoir is strongly dependent on hydrologic conditions, incorporating an annual ARM A inflow model with the empirical total phosphorus model developed in previous work, the trophic state in the future was investigated. The significant advantage of the proposed approach is that it provides a simplified and useful procedure to evaluate the risk of eutrophication for the reservoir in the future.
DYNAMIC TEMPERATURE CHANGES IN NUTRIENT REMOVAL PLANTS
Authors: Brønd Søren , Scherfig Jan
Published: May 2018

Nitrification and denitrification processes are very sensitive to temperature changes below 10 °C. Because of severe eutrophication problems in e.g. Northern Europe Nitrogen removal must be kept throughout the winter. To aid in the design and optimization of treatment plants a dynamic temperature model has been developed. The major findings is that the temperature variation is very dependent on local wind conditions. The model can be used in the design process to minimize factors causing temperature drops during cold weather periods.
Impact of Hydrology and Water Chemistry on Floodplain Lake Communities along the Lower Rhine and Meuse
Authors: van den Brink F. W. B. , van der Velde G.
Published: May 2018

Within the scope of a research programme on the ecological rehabilitation of the large rivers in The Netherlands the impact of hydrology on aquatic communities in floodplain lakes along the Lower Rhine and Meuse has been studied. Apart from the nutrient status of the Lower Rhine and Meuse water the hydrology was found to exercise a major impact on the water chemistry, the phytoplankton development, the vegetation and the zoobenthos communities in the floodplain lakes. The increased input of N and P from the eutrophic main channels to the floodplain lakes via floods has resulted in an increase in phytoplankton biomass and a shift from a macrophyte dominated community towards a community dominated by planktonic algae (Chlorophyta, Cyanobacteria), especially in frequently flooded lakes and with the main channel connected lakes.
Trends of Priority Pollutants in the Rhine during the Last Fifty Years
Authors: Beurskens J. E. M. , Winkels H. J. , de Wolf J. , Dekker C. G. C.
Published: May 2018

Sediment cores from Lake Ketelmeer, a sedimentation area of the River Rhine were analyzed for priority pollutants (8 metals, 8 polycyclic aromatic hydrocarbons (PAHs), 7 polychlorinated dibenzo-p-dioxins, 10 polychlorinated dibenzofurans, 6 planar and mono-ortho polychlorinated biphenyls and 11 polychlorinated benzenes) in order to determine trends in the last 50 years. Post-depositional changes in pollutant levels were verified. Metal and PAH levels reflected the unchanged historical inputs. Concentrations were high in the late 1930s, low during the second world war and reached a maximum between 1955 and 1975. As an example, mercury levels changed from 3 to 2 mg/kg and reached 13 mg/kg in these successive periods. Levels in recently deposited sediment are ca. 2 mg/kg again. Some chlorinated aromatics proved to be persistent as well. For example, the highly toxic 2,3,7,8-tetrachlorodibenzo-p-dioxin had concentrations ≤10 ng/kg in the early 1940s, a maximum of ca. 400 ng/kg in the 1960s and again very low levels (≤10) in recently deposited sediment. On the other hand, post-depositional changes were observed for a few higher chlorinated dioxins and furans and several biphenyls and benzenes. This appeared upon comparison of concentrations in sediment layers collected recently and 20 years ago respectively and was possibly caused by microbial dechlorination. The historical inputs of these pollutants will be underestimated by the sediment core data.
HCB Load on Suspended Solids and in Sediments of the River Rhine
Authors: Keller M.
Published: May 2018

At the ICPR monitoring station Koblenz (Rhine-km 590.3) the load of hexachlorobenzene (HCB) on suspended solids has been measured for several years. In addition, sediments from impoundments on the Upper Rhine were analysed for HCB. The results show that the HCB load on suspended solids in the river Rhine has decreased to nearly half the initial value between 1985 and 1991. The still relatively high HCB concentrations amounting in average to 40 µg/kg on the suspended solids sampled at Koblenz can only be explained by recalling that sediments in the impoundments and in other contaminated sites of the Upper Rhine constitute a historic HCB storage, which contributes to the HCB load on suspended solids through remobilization during flood events.

With regard to future trend monitoring activities for HCB in suspended solids, a minimum sampling interval of 14 days is recommended.
Accidental Spills – Frequency, Importance, Control, Countermeasures
Authors: Malle Karl-Geert
Published: May 2018

Since pollution of the Rhine has been greatly reduced by the construction of sewage treatment plants, the significance of accidents for water quality has become obvious. Most accidents are of only local importance, but after an incident in 1969 the water for fighting the Sandoz warehouse fire caused the second long distance death of fish in the river in 1986.

Many waterworks are effectively protected from pollution surges by a bank filtration for the water. Waterworks with direct water intake shut their intakes down temporarily when a pollution wave is flowing past.

Both wastewater discharges and the river Rhine are continuously and carefully monitored. Rapidly responding biological tests and screening processes are being used to an increasing extent. A well equipped water protection police service is an additional important control element.

Safety during transport and transfer of goods by ship is controlled by the regulations on transporting hazardous goods on the Rhine. Special care and safety measures are taken for loading and unloading of ships. Routine cost-free bilge emptying is an important contribution to water protection too.

Accidental pollution incidents with cooling water discharges or from the outlet from treatment plants can occur from the bank. Rapid recognition and elimination of faults are essential for cooling water protection.
Review of Environmental Accidents and Incidents
Authors: Lindgaard-Jørgensen Palle , Bender Klavs
Published: May 2018

This paper reviewed the environmental consequences reported in more than three thousand accidents. Fifty-nine of the accidents reported environmental consequences, seven reported no environmental consequences, and for the remaining accidents, no information was available. Generally, the properties of a chemical, the dilution of the amount released, and the environmental conditions at the spill site are the parameters that determine the short-term environmental consequences. To evaluate the long-term effects, which have almost never been studied in the accidents reviewed, persistence, the tendency to accumulate in sediment and biota, and the long-term sub-lethal and chronic effects are the main parameters to be considered. While ecological consequences of accidents have been investigated more frequently in recent years, there has been no consistency in reporting methodology. An accident investigation methodology and a reporting format should therefore be developed and implemented on a broad international scale.
PRODUCTION DEPENDENT SPECIFIC DATA OF PAPER MILL WASTEWATERS: INFORMATION FOR TREATMENT AND REUSE
Authors: Möbius Christian H. , Cordes-Tolle Maria
Published: May 2018

Specific data on paper mill wastewaters, especially ratios of BOD, COD and TOC as weU as specific loads of these parameters in mechanically treated production wastewater of paper mills, depend strongly on the type of paper produced in the mill. These data and the respective correlations are known from previous research of the authors. The selection of suitable wastewater treatment processes, which are state of the art or best available technology (BAT) in the paper industry, depends on the type of wastewater characterized by these specific data. Minor or major parts of the wastewater - depending on the type of paper produced - can be reused in the production prior to external treatment.

When the proportion of water reused prior to external treatment tends to be high, due to anoxic degradation in the internal circuits the type of dissolved organics may change. This can be easily detected by calculation of the BOD/COD ratio. For a certain system, the specific amount of water needed depends on the intensity of use for production, compared with other, not production dependent, uses. This may be detected by a calculation given here.

When no discharge to the sewer is suitable, the excess amount has to be treated biologically for discharge to surface water or for further reuse. Treatment processes discussed are: activated sludge treatment, anaerobic treatment followed by activated sludge treatment, high capacity trickling filter followed by activated sludge treatment, aerobic submerged biofilters, low capacity trickling filters. Advanced treatment processes are combined with these processes, when BAT is required. For reuse of the biologically treated water, for all types of treatment except biofilters, a sand filter or similar equipment has to be added.