bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrient Balances for Danube Countries: A Strategic Analysis
Authors: Somlyódy L. , Brunner P. H. , Kroiϐ H.
Published: May 2018

Issues of nutrient management were studied in ten countries of the Danube Basin in the frame of the Danube Environment Programme. Comprehensive data collection covered socio-economic and natural factors influencing nutrient balances, water quality of the Danube and its tributaries, and major features of wastewater management for municipalities. The innovative methodology of materials accounting was applied to develop nutrient balances for the countries involved and the Danube Basin, and to get insight on causes, temporal changes of stocks and early recognition. The approach was cross-checked against loads estimated from ambient water quality observations. Main dilemmas of water quality management (local problems, and the regional eutrophication of the Danube Delta and the Black Sea) were identified and options of load reductions were evaluated. Agriculture pollution of mostly non-point source origin was found as the key of developing an integrated emission reduction policy for the Basin. Municipal wastewater management strategies were studied in detail. Recommendations were given on strategy development, monitoring, research and improved international cooperation in the Danube/Black Sea Basin.
Water Quality Management and Legislation in Hungary - A River Basin Approach
Authors: Kisgyörgy Sándor , Botond György , Tyson John M.
Published: May 2018

The project summarised in this paper was aimed at developing water quality legislation in Hungary and funded through the PHARE programme of the European Union. Hungary, in common with the other former Eastern European countries, is in a period of transition as it moves from a state socialist system to a free market economy and a full member of the European Union. The project sought to explore the means whereby water quality could be managed on a river basin basis and the legislative, institutional, economic and regulatory challenges resolved. A key element of the project was the carrying out of five case studies, on different catchments, to evaluate the various approaches. An important element of these studies was the participation of all interested parties in the individual catchments. The project showed that to move to a full system of integrated river basin management would be a step too far at this stage and, instead, recommended a system of Catchment Planning Commissions, accountable to Central Government, for the development of catchment based water quality objectives and plans for their achievement together with the monitoring and reporting of progress on implementation. The concomitant legal requirements were detailed and the need for public participation emphasised.
Citizen Participation in Water Management
Authors: House Margaret A.
Published: May 2018

If rivers are to be managed sustainably, and the potential to resolve conflicts of use realised, the general public must be more involved in their management. Participation in water management in England and Wales occurs at three levels: formal consultation; public involvement; or actual direct participation by the public. Formal consultations often leave the public in the role of the “objector” and ignore the “silent majority” focusing on the more vociferous minority of the population. Public involvement is less formal and can take a variety of forms. Although not allowing the public to be directly involved in the decision making processes, it provides the public with the opportunity to comment upon plans for river works or the re-development of a river location, or to indicate what they want from the rivers that flow through their own local area and which they use for recreation and amenity. True participation is where the public are actively involved in the decision making processes. Citizen participation at all three levels provides environmental education, however, personal experience promotes a greater environmental awareness and understanding by the public.

This paper reflects upon approaches to citizen participation in the UK and provides examples of specific projects involving both formal organisations and the general public.
Deriving phosphorus export coefficients for corine land cover types
Authors: McGuckin S. O. , Jordan C. , Smith R. V.
Published: May 2018

Export coefficients for phosphorus (P) have been derived for a number of CORINE land cover classes, using data obtained for 30 subcatchments of two major rivers in Northern Ireland. Multiple regression methods have been applied, with soluble reactive P (SRP), soluble organic P (SOP) and particulate P (PP) loads as dependent variables. Arable areal losses of phosphorus were the highest, 2.33 kg SRP ha−1 yr−1 and 2.64 kg PP ha−1 yr−1. Improved and non-improved grasslands appear to export equal amounts of TP (0.8 kg ha−1 yr−1). However, the SRP export coefficient is greater for non-improved grasslands than improved grasslands, 0.62 kg ha−1 yr−1 and 0.26 kg ha−1 yr−1, respectively. This unexpected result may be due to the undrained and compacted nature of the soils associated with non-improved grasslands, which ensures that P remains in the surface layer, limits the possibility of adsorption down the profile and encourages surface runoff. In addition, the considerable amount of organic carbon present tends to reduce the P-binding capacity of these soils.
Nitrogen and phosphorus emissions from soil to surface water in the rhine and elbe basins
Authors: de Wit M. , Behrendt H.
Published: May 2018

This paper analyses the relations between nutrient emissions from soil to surface water and nutrient surplus at the soil surface that have been derived from independent water quality and emission data for numerous sub-basins in the Rhine and Elbe basins. For nitrogen (N) we found a positive relation between the long term average N surplus at the soil surface and N emissions from soil to surface water. The ratio between N emissions from soil to surface water and N surplus at the soil surface appeared to be larger for regions with consolidated rocks than for regions with unconsolidated rocks. However, no direct relation between the phosphorus (P) emissions from soil to surface water and the long term average P surplus at the soil surface was found. The results also show that changes in the N and P balance at the soil surface are not immediately reflected by changes in N and P emissions to the surface water, at lest not within five years.
Atmospheric mercury contamination of remote aquatic ecosystems in Canada
Authors: Allan R. J.
Published: May 2018

The long-range atmospheric transport and deposition of metals, particularly mercury (Hg), into lakes has become a subject of increasing interest. In Canada, the sources of anthropogenic, atmospheric Hg are primarily considered to be power stations in the United States and Europe. Increases in deposition of Hg have been recorded in lake sediment cores from many parts of Canada. Where Hg input to lakes from local sources in Canada has been reduced, concentrations in lake sediments and lake biota have declined. However, in many remote lakes, fish consumption advisories are still in effect for Hg. Debate continues over the sources of this mercury, whether long-range anthropogenic, atmospheric or natural. Where studied, the same applies to remote lakes in other parts of the world.
A comparison of different methods of source apportionment of nutrients to river basins
Authors: Behrendt H.
Published: May 2018

Seven different methods of source apportionment were applied in an analysis of the nutrient emissions from point and diffuse sources of 14 river basins in Northeastern Germany. The aim was to compare the results relating to the uncertainties of the methods and to test whether the difference between the emissions and load is caused by systematical errors or by retention and loss processes in the river systems. Beside the simplest method, where the diffuse emission is the difference between the observed transport and the point source inventory, other immission methods including a nutrient retention term are applied. The emission methods used also estimate the diffuse nutrient inputs by different ways. For all methods the relative standard deviation of the estimated diffuse emission was calculated for each of the river basins. The mean standard deviation of the original data sets for all emission methods and the immission approaches with the retention term was 22% for nitrogen and 48% for phosphorus. By variation of additionally introduced coefficients this standard deviation can be reduced to 18% and 24% for nitrogen and phosphorus, respectively. Tests regarding possible systematical under- and/or overestimation of the measured load and the diffuse emissions, respectively, show indications of such a behavior for phosphorus, only. Nevertheless, a large difference between the nutrient emissions and the load remains, which can only be explained by intensive retention processes.
Agricultural practices and diffuse nitrogen pollution in Denmark: empirical leaching and catchment models
Authors: Andersen Hans E. , Kronvang Brian , Larsen Søren E.
Published: May 2018

An empirical leaching model was applied to data on agricultural practices at the field level within 6 small Danish agricultural catchments in order to document any changes in nitrogen (N) leaching from the root zone during the period 1989-96. The model calculations performed at normal climate revealed an average reduction in N-leaching that amounted to 30% in the loamy catchments and 9% in the sandy catchments. The reductions in N leaching could be ascribed to several improvements in agricultural practices during the study period: (i) regulations on livestock density; (ii) regulations on the utilisation of animal manure; (iii) regulations concerning application practices for manure. The average annual total N-loss from agricultural areas to surface water constituted only 54% of the annual average N leached from the root zone in the three loamy catchments and 17% in the three sandy catchments. Thus, subsurface N-removal processes are capable of removing large amounts of N leached from agricultural land. An empirical model for the annual diffuse N-loss to streams from small catchments is presented. The model predicts annual N-loss as a function of the average annual use of mineral fertiliser and manure in the catchment and the total annual runoff from the unsaturated zone.
Nutrient management for water quality protection: integrating research into environmental policy
Authors: Sims J. T. , Goggin N. , McDermott J.
Published: May 2018

Agriculture's impacts on water quality have been the focus of basic and applied research in Delaware for more than 25 years. Research has examined nutrient cycling in soils, nutrient transport from soils to water, and the environmental consequences of ground water contamination and surface water eutrophication by nutrients. Much of the research has specifically been oriented towards the development of agricultural management practices to prevent the degradation of water quality by nutrients. Other research has focused on increasing our understanding of the chemical, physical, and biological processes that control nutrient cycling and transport and improving the monitoring techniques needed to document how changing management practices affects water quality. Agencies responsible for water quality protection have sought to integrate this research into environmental policy, but have often been frustrated by the fragmented and sometimes contradictory nature of the information provided to them. This paper reviews key advances in research on nutrient management and water quality in Delaware and discusses the obstacles faced in translating research into widely accepted management practices and environmental policies.
Estimation of Pathogen Removal in an Advanced Water Treatment Facility Using Monto Carlo Simulation
Authors: Olivieri A. , Eisenberg D. , Soller J. , Eisenberg J. , Cooper R. , Tchobanoglous G. , Trussell R. , Gagliardo P.
Published: May 2018

Interest in water reuse for potable purposes has heightened the significance of evaluating the potential presence of microbial agents in treated water. Evaluating the public health risk from microbial agents in water after advanced water treatment (AWT) requires an estimate of the effectiveness and reliability of the treatment system in removing microbial agents. Indicator organisms such as total and fecal coliform do not provide sufficient basis to characterize the performance of the treatment system relative to the removal of pathogenic organisms such as enteric viruses and parasitic agents. Seeding studies provide an alternative experimental approach. However, when treatment systems are challenged using more specific indicators for enteric viruses, the results are often inconclusive because the organisms are reduced to non-detectable levels after the first few unit processes. In this study we provide a mathematical approach for estimating the effectiveness of the entire treatment train with respect to removal and/or inactivation of microbial agents. These estimates are insightful since standard monitoring of final effluent consistently yielded non-detectable results.
Public Health Evaluation of Advanced Reclaimed Water for Potable Applications
Authors: Rose Joan B. , Farrah Samuel R. , Friedman Debra , Riley Kelley , Hamann Carl L. , Robbins Millard
Published: May 2018

The City of Tampa in the Southwest portion of Florida is examining the development of an advanced treatment facility for supplementing their potable water supply with highly treated reclaimed water. Full-scale microbiological monitoring of a similar treatment train demonstrated that the high-pH chemical treatment process was an effective barrier for removal and inactivation of viruses (99.99%), bacteria (99.9999%) and enteric protozoa (99.9%). A constructed pilot plant and bench-scale studies of the high-pH chemical process demonstrated that the removal of Cryptosporidium oocysts was due to physical removal and no inactivation was shown with up to 180 minutes exposure at a pH of 11.2. Combination of high-pH chemical treatment and chlorination were also ineffective at kill of Cryptosporidium oocysts.
Hygienic Evaluation of Reclaimed Water Used to Irrigate Food Crops—A Case Study
Authors: Sheikh B. , Cooper R. C. , Israel K. E.
Published: May 2018

The study was designed to test the continued validity of a field pilot project (completed in 1987) that had found irrigation of food crops with tertiary-treated reclaimed municipal wastewater to be safe. It was also designed to determine whether or not pathogenic microorganisms of concern to food safety, such as E. coli 0157:H7, Cyclospora, enteric viruses and Salmonella were present in disinfected tertiary recycled water. Sampling of the tertiary water was conducted at intervals over a period of three months. In addition, at the same time, samples were taken from the raw incoming wastewater, from secondary effluent, and from a control source, local well water. The results from samples of recycled water are comparable to similar tests at other well-operated, tertiary recycled water treatment plants and compare well with sources of drinking water supply. Other parasites, of lesser concern to food safety than to drinking water safety, were either absent or were detected at extremely low concentrations of empty, non-viable cysts. The Tertiary Water Food Safety Study did not detect any Salmonella, Cyclospora and E. coli 0157:H7 in any of the samples of tertiary recycled water from the Monterey Country Water Recycling Projects (MCWRP).
The Microbial Quality of a Wetland Reclamation Facility Used to Produce an Effluent for Unrestricted non-Potable Reuse
Authors: Fujioka R. S. , Bonilla A. J. , Rijal G. K.
Published: May 2018

An auxiliary Wetland Reclamation Facility (WRF) was constructed to receive stabilization pond treated sewage and further treat it with water hyacinth ponds, chemical flocculation, filtration and ultraviolet light disinfection. This was the first facility in Hawaii which was approved to produce the highest quality reclaimed water using alternative treatment schemes. We assessed the effectiveness of the WRF by monitoring water samples after each of the WRF treatment schemes for five genetically different groups of sewage borne microorganisms (fecal coliform, enterococci, C. perfringens, FRNA phage, total heterotrophic bacteria). The concentrations of all fecal indicator microoganisms, especially FRNA phase were low in the influent water to the WRF indicating that extended pond treatment may be especially effective in removing human viruses from sewage. The WRF treatment scheme was calculated to be able to reduce >99.99% of fecal coliform and therefore was able to produce an effluent meeting the non-potable, unrestricted reuse standard of a geometric means of <1 fecal coliform/100 ml.
The Use of Free Surface Constructed Wetland as an Alternative Process Treatment Train to Meet Unrestricted Water Reclamation Standards
Authors: Gearheart R. A.
Published: May 2018

The purpose of this study was to assess the capability of constructed wetland and a UV disinfection unit to meet Title 22 California Reuse Standards for public use irrigation. This study examines fecal coliform reduction in domestic waste water after receiving treatment through: a constructed open water wetland, a slow sand filter, and a portable ultraviolet disinfection unit. The results of the one year pilot project utilized oxidation pond effluent as the influent to the test system. Effectiveness of removal of key constiuents (BOD, TSS, turbidity, fecal coliform, and nitrate nitrogen) along with the cost of the system is compared to the results and costs of other water reuse treatment systems. Long term (12 years) monitoring of the City of Arcata's (California, USA) free surface constructed wetlands has demonstrated high efficiency and reliability in removing suspended solids. The performance data for the proposed pond/wetland/UV system has been incorporated into a decision support model, WAWTTAR (Water and Wastewater Treatment Technologies Appropriate for Reuse).
Advanced Nitrogen Removal by Rotating Biological Contactors, Recycle and Constructed Wetlands
Authors: Griffin P. , Jennings P. , Bowman E.
Published: May 2018

The sewage treatment facility at Himley comprises Rotating Biological Contactors (RBCs) and subsurface flow constructed reed beds in series. A recycle facility returns RBC effluent to the influent flow. Effluent total nitrogen (TN) has always been low since commissioning and the reasons were investigated. Denitrification was observed to occur in the primary settlement tank. High hydraulic loadings in the RBC biozone deteriorated BOD5 and TSS removal, but good nitrification was obtained. The relatively poor effluent from the RBC gave a carbon source allowing further denitrification through the reed beds. Ammonification caused an increase in ammoniacal nitrogen across the primary reed bed in summer. At this time strongly reducing conditions occurred within the reed beds which, in the absence of dissolved oxygen and oxidised nitrogen compounds, led to sulphate reduction and sulphide formation with odour generation. These problems were not observed at low winter temperature conditions. Effluent TN was always below 0 mg/l.
UV treatability test for chemical and petrochemical wastewater
Authors: Castillo L. , Khorassani H. El , Trebuchon P. , Thomas O.
Published: May 2018

There is a tendency to design biological units for chemical or petrochemical wastewater treatment. Some of these treatment plants are even sometimes used for the degradation of any external industrial sewage transported for the purpose. In this case, the decision to accept or refuse the waste must be rapid and sure. The aim of this paper is to propose a new treatability test based on a direct far UV photooxidation of the sample, coupled with a UV spectrophotometric survey of the waste quality. The test has been applied on different samples from chemical and petrochemical industries and the results have been compared to those obtained with more classical tests, as for example, biodegradation tests using either air or pure oxygen. For most of the samples, quite good correlation has been observed between the photooxidation test and biodegradation. The UV treatability test is currently used for checking up on petrochemical wastewater and chemical sewage.
A simple UV spectrophotometric procedure for the survey of industrial sewage system
Authors: El Khorassani Houda , Trebuchon P. , Bitar H. , Thomas O.
Published: May 2018

A simple UV spectrophotometric procedure is proposed for the survey of an industrial sewage system. Simple, fast and reliable, this technique has been first designed for natural and waste water. It is based on the assumption that any UV spectrum of a sample can be decomposed by using a set of reference spectra. The main application is the determination of specific compounds such as nitrate or anionic surfactants (expressed as DBS) or the estimation of global parameters such as COD, TOC or TSS. Another interest can be found in process control or alarm detection. Based on the UV light absorption by all unsaturated compounds and particularly anthropogenic organic matter, the method is obviously limited by the nature of organics. So, its use for industrial application needs a good knowledge of wastewater composition -and variation- for the choice of the dedicated spectra library. This paper will present the industrial application of UV spectrophotometry including the methods for the definition of the spectra libraries. Its application in the wastewater survey of a large petrochemical site, located in the South of France, is also presented.
Ranking of toxics release inventory chemicals using a level III fugacity model and toxicity
Authors: Edwards F. G. , Egemen E. , Brennan R. , Nirmalakhandan N.
Published: May 2018

In an effort to lessen the environmental impact of chemicals discharged by industry, some countries rank chemicals according to mass released each year and then set environmental protection policy based upon this ranking. These rankings have driven industries and companies to change their process configurations and their chemical releases to reduce the release of higher ranking chemicals. But, chemicals that are higher ranked due to mass release may not be particularly toxic nor persistent in the environment; conversely, lower ranked chemicals may be substantially more toxic and persistent in the environment.

The physical/chemical properties of forty five organic chemicals from the EPA's Toxic Release Inventory were used as inputs to a Level III fugacity model to estimate fate, transport, and steady state concentrations of chemicals in the environment. The resulting concentrations in the air and water, for each chemical, were determined using the fugacity model and were then compared with toxicity data, the ratio was used as an indication of the environmental impact of the release of each chemical. The chemicals were then ranked according to the degree of environmental impact and the results were compared to other ranking systems reported in the literature.
Case study on the bioeffluent of petrochemical wastewater by electro-fenton method
Authors: Huang Yao-Hui , Chou Shanshan , Perng Ming-Ging , Huang Gaw-Hao , Cheng Sheng-Shung
Published: May 2018

The electro-Fenton method, in which ferrous ion is produced at the anode and used as a catalyst of H2O2, was applied for treating the bioeffluent of petrochemical manufacturing wastewater. The major pollutant in the bioeffluent was identified as hexamine, which was nonbiodegradable and contributed 65% of COD. The goal of this study was to treat the biotreatment effluent with more than 50% of COD removal efficiency. Oxidants that involved ozone, ozone/H2O2, sodium hypochlorite, and Fenton's reagent were employed to treat this effluent by jar tests. However, none could meet the goal in the range of operating conditions used. On the other hand, more than 80% of COD was removed with the electro-Fenton process. These screening tests indicated that only the electro-Fenton process was compatible with the goal.
Evaluation of ozonation and cryptic growth for biosolids management in wastewater treatment
Authors: Egemen E. , Corpening J. , Padilla J. , Brennan R. , Nirmalakhandan N.
Published: May 2018

The ultimate disposal of biosolids has been and continues to be one of the most expensive problems faced by wastewater utilities. The objective of this research is to develop a process configuration for reducing the waste sludge generation in an activated sludge plant by promoting cryptic growth conditions (i.e., biomass growth on intracellular products). For this purpose, excess biosolids from a continuous flow activated sludge system were solubilized using ozone as the cell lysis agent, and then returned to the aeration tank. It is hypothesized that growth under such cryptic conditions will result in low net microbial yields, and hence, minimal net solids wastage. The results of these preliminary studies indicate that the proposed process configuration has the potential to reduce the waste sludge production by 40% to 60%.
Modelling heavy metal mobilisation in solid waste deposits - a predictive tool for environmental risk assessment
Authors: Petersen J. , Petrie J. G.
Published: May 2018

The release of heavy metal species from deposits of solid waste materials originating from minerals processing operations poses a serious environmental risk should such species migrate beyond the boundaries of the deposit into the surrounding environment. Legislation increasingly places the liability for wastes with the operators of the process that generates them. The costs for long-term monitoring and clean-up following a potential critical leakage have to be factored in the overall project plan from the outset. Thus assessment of the potential for a particular waste material to generate a harmful leachate is directly relevant for estimating the environmental risk associated with the planned disposal operation.

A rigorous mechanistic model is proposed, which allows prediction of the time-dependent generation of a leachate from a solid mineral waste deposit. Model parameters are obtained from a suitably designed laboratory waste assessment methodology on a relatively small sample of the prospective waste material. The parameters are not specific to the laboratory environment in which they were obtained but are valid also for full-scale heap modelling. In this way the model, combined with the assessment methodology, becomes a powerful tool for meaningful assessment of the risks associated with solid waste disposal strategies.
Biological monitoring and assessment of rivers as a basis for identifying and prioritising river management options
Authors: Roux D. J. , Kleynhans C. J. , Thirion C.
Published: May 2018

The output of monitoring programmes such as the National Aquatic Ecosystem Biomonitoring Programme must be used in the management of aquatic ecosystems. To achieve this, collected data must, through a systematic framework, be linked to measurable management objectives. This paper demonstrates how the results obtained with biological indices and system-specific knowledge, are combined to derive semi-quantitative assessments of ecosystem condition. These assessments provide the basis for responding to the results of a river monitoring programme.
A simple test for monitoring biodegradable industrial pollution in a receiving stream
Authors: Zagorc-Končan Jana , Šömen J.
Published: May 2018

Microbial purification capacity is an important factor in natural self-regulation in water. Evaluating the fate of biodegradable organic pollution downstream from the discharge seems an appropriate way to follow the effect of pollution and its hazard assessment, which dictates the needed sanitation measures. We suggest a simple test for such monitoring. A modification of the additional oxygen demand test, standardised in Ausgewählte Methoden der Wasseruntersuchung, was applied in two river case studies. The additional oxygen demand is a measure of the capability and rate of biodegradation of known organic substance as well as of the amount and activity of heterotrophic organisms in the river. The original test using peptone and glucose as additional feedings of BOD samples was modified by the use of other organic biodegradable model substances characteristic for individual industrial pollutants. The test was found to be an excellent indicator of adapted microorganisms, which are essential for the biodegradation of the appointed organic substances downstream of their discharge into the receiving stream.
Integrative Assessment of Sediment Quality History in Pulp Mill Recipient Area in Finland
Authors: Kähkönen Mika A. , Liukkonen Mikko , Wittmann Christoph , Suominen Kimmo P. , Salkinoja-Salonen Mirja S.
Published: May 2018

Sediments were dated and the quality assessed by polyphasic approach in an area of Lake Saimaa, which has received waste water from bleached kraft pulp production since 1954. The chosen nonrecipient forest Lake Pyylampi was situated in the same area. The activities of the enzymes butyrate-esterase and aminopeptidase were depressed at the depth of 2 to 8 cm in the recipient but not in the forst lake sediment. In the same layers the contents of EOX-C1 and toxicity to Vibrio fischeri were very high compared to those above or below. Toxicity to microbial community in the 2 to 8 cm layer was also indicated by a gap in the ATP content and a drop in diatom species richness from the 70 species to < 50 reflecting decreased water quality of the pelagic area. All these changes dated to the period of heavy organic halogen discharges, from 1960 to late 1980s, which led to sediment accumulation of solvent soluble halogen at a depth of 2 to 8 cm, to 6.4 g m−2 (cm)−1. In the most polluted sediment layers heavy metal accumulation was too little to be related to the toxicity of these layers. Almost complete recovery of both the sediment microbial ecosystems and of the pelagic diatoms occurred after elemental chlorine was completely substituted by chlorine dioxide and biological treatment adopted for wastewaters. Butyrate-esterase and aminopeptidase, but not phosphatase, activities correlated positively with the ATP content of the sediment. Butyrate-esterase may be used as a tool to estimate microbial biomass.
Decentralized and centralized wastewater management: a challenge for technology developers
Authors: Wilderer P.A. , Schreff D.
Published: May 2018

The traditional wastewater management concept (urban wastewater collection system plus treatment of the wastewater in a central treatment plant) has been successfully applied over many decades in densely populated areas of industrialized countries. Whether this technology is of ultimate wisdom must be questioned, especially considering the urgent need for improved sanitary infrastructures in developing countries. The problem is that the costs for implementing a centralized system in mega-cities, in particular the investment costs for the sewer system, are exorbitant. Decentralized wastewater management systems, with the wastewater treated close to where it is generated, are being considered by various researchers and institutions including the World Bank as an alternative to the traditional centralized system. The degree of technological sophistication that should be applied is under dispute, however. In this paper, we advocate development and application of high-tech on-site treatment plants, designed and fabricated by modern industrial methods. When mass produced, the costs for manufacturing such package plants can presumably be kept at a relatively low level. The plants should be delivered in a “user ready” state. Local plumbers may connect toilet bowls and sinks and washing machines, but may not be involved in the manufacturing of the treatment system. The plant should produce an effluent which is hygienically safe and can subsequently be utilized for toilet flushing, washing clothes, cleaning floors or watering lawns. In order to keep the plants operating properly, they should controlled by remote sensing, and maintained by specialized service enterprises. The conceptual design of such a compact plant is discussed in the form of a case study.
Feasibility of the on-site treatment of sewage and swill in large buildings
Authors: Zeeman Grietje , Sanders Wendy , Lettinga Gatze
Published: May 2018

Three concepts are proposed for the on-site treatment of sewage and swill in large buildings, like hospitals. The production and anaerobic treatment of night soil in combination with swill in a slurry digestion system and separate production and treatment of grey water is the most attractive concept. The slurry digestion could either be carried out in a CSTR-system at mesophilic conditions or in an Accumulation-system at ambient temperatures. The reactor volume needed for the digestion of a mixture of swill and night soil (or primary sludge) in an Accumulation (AC)- and Completely Stirred Tank Reactor (CSTR)-system at different process temperatures is calculated based on literature values. From the results it should be concluded that mesophilic digestion (30°C) and a SRT of 20–30 days is to be recommended for the digestion of a mixture of night soil and swill in a CSTR system. The latter coincides with the installation of 40–60 l reactor volume per person. Depending on the applied temperature and therefore the minimum storage time and percentage inoculation, a r eactor/storage volume of 431 or 951 litres per person should be installed at 20 and 15°C, respectively when an Accumulation system is applied. An Accumulation-system has the advantage that storage and digestion are combined, implying a completely closed system, also for the storage. The latter is of highest importance for the indoor treatment, as proposed in the paper.
Field investigations on reactive settling in an intermittent aeration sequencing batch reactor activated sludge process
Authors: Kazmi A.A. , Furumai H.
Published: May 2018

The overall reactions during settling in an intermittent aeration SBR activated sludge process have been studied on a full scale. Several field investigations were conducted during settling in different seasons. Nitrate, MLSS, phosphate and TOC profiles were obtained at specified depths. Mass balances of nitrogen were made in order to evaluate the effect of different MLSS and seasonal conditions on nitrogen removal during settling. Total nitrogen reduction of more than 30% was achieved during settling by maintaining high MLSS in order of 3000 mg/L. Residual DO plays an important role in causing delay of denitrification for lower MLSS sludge concentration. Phosphorus release was observed in the bottom of the reactor and its occurrence was well coincident with the pH decrease. Denitrification rates and their temperature dependency were determined. Temperature coefficient θ was found to be 1.083 (valid in the range of 17–27°C). Mass transfer limitation during batch sludge settling was discussed. It was found out from batch tests with and without mixing, that denitrification rate was reduced by 40% under mass transfer limiting conditions.
Development of odour impact criteria for sewage treatment plants using odour complaint history
Authors: Kaye R. , Jiang K.
Published: May 2018

Odour impact from a sewage treatment plant has been predicted using a Gausian plume atmospheric model (Ausplume). A wind tunnel system was used to determine the odour emission from processing units. An improved technique for odour emission rate modelling is proposed to take account of wind speeds and atmospheric stability classes. A new technique is proposed to define odour impact criteria for sewage treatment plants. The dispersion model was calibrated using two years of odour complaint data. An odour concentration of 23 OU/m3 as a one hour averaged 99.5th percentile was found to be appropriate to minimise adverse community impacts, assuming lognormal human nose response to odours and a “zero complaints” community objective. The proposed method can also be used to develop odour impact criteria for other industries.
Application of dispersion modelling to odour assessment: a practical tool or a complex trap?
Authors: McIntyre A.
Published: May 2018

The use of modelling techniques for predicting the dispersion of odours from wastewater treatment plants is considered in relation to both the resolution of odour problems and the design requirements for new facilities. The issues of community odour annoyance and nuisance are discussed in the context of modelling averaging times, short-term odour peaks and the nature of the individual odours. In addition, the derivation of acceptable odour annoyance criteria is discussed with a comparison of different international approaches and a practical approach to resolving design criteria is proposed. Four case studies include the analysis and resolution of severe odour problems at two major wastewater treatment facilities and the evaluation of “Cordons Sanitaire” in the planning of new housing developments. In the first two cases, modelling was used to identify the most significant processes in terms of off-site effects and then to assess the required abatement level to achieve an acceptable complaints frequency. Inthe third case, dispersion modelling was used to assess the effectiveness of planned odour control measures in the release of land for residential development. The fourth case study demonstrates how an overly-stringent approach to odour control can cause problems.
An integrated aerobic/anaerobic approach for prediction of sulfide formation in sewers
Authors: Hvitved-Jacobsen T. , Vollertsen J. , Tanaka N.
Published: May 2018

A conceptual framework for microbial transformations of organic matter and sulfur components in sewers has been developed. This concept is a new basis for integrated process engineering analysis, planning, design and management of the urban wastewater system. Based on the concept, a model (WATS, WastewaterAerobic/anaerobic Transformations in Sewers) has been developed for simulation of wastewater quality transformations and sulfide formation in sewers. The paper will outline the concept and give examples of engineering applications. The model has been used as a design tool for simulation of carbon and sulfur wastewater transformation under dissolved oxygen limited conditions in a 50 km intercepting gravity sewer being planned in the Emscher catchment, Germany.
Inactivation of Cryptosporidium spp. oocysts with ozone and ultraviolet irradiation evaluated by in vitro excystation and animal infectivity
Authors: Kanjo Y. , Kimata I. , Iseki M. , Miyanaga S. , Okada H. , Banno C. , Shimada Y.
Published: May 2018

Cryptosporidium parvum and Cryptosporidium muris oocysts were exposed to ozone and/or ultraviolet(UV) lamp in bench-scale batch reactors. The effect of ozone, UV, and sequential disinfection method on two kinds of oocysts were determined with in vitro excystation and animal infectivity test. The results of ozone exposure experiments showed that the required Ct values were about 3 and 8 mg · min./L for 2-log and 3-log reduction ininfectivity of C. parvum oocysts at room temperature, respectively. But larger values of Ct were needed at low temperature. In the case of sequential disinfection methods with ozone and UV, more than 1-log reduction in infectivity was achieved with 15 sec. of UV irradiation. There was no significant correlation between the excystation ratios and the reduction ratios in infectivity. Moreover, the results of dose-response of animal infectivity test indicated the possibility of a new method to evaluate the infectivity of Cryptosporidium parvum oocysts.
Elimination of Giardia cysts, Cryptosporidium oocysts, turbidity and particles in a drinking water treatment plant with clarification and double filtration
Authors: Ribas F. , Bernal A. , Perramón J.
Published: May 2018

The basic parameters of turbidity and counts of particles, Giardia cysts and Cryptosporidium oocysts are monitored in their evolution through a drinking water treatment plant. Sulphite- reducing clostridia spores and groups of bacteriophages are also monitored in relation to their potential use as indicators.
Effects of high temperature melting on the porosity and microstructure of slags from domestic sewage sludge
Authors: Abu-Kaddourah Z. , Idris A. , Noor M. J. , Ahmadun F. R.
Published: May 2018

Sewage treatment plant sludges continue to pose great problems in terms of volume, odour and method of disposal. Thermal treatment of sewage sludge is considered as an attractive method in reducing sludge volume, which at the same time produces reusable by-products. Studies on high temperature melting of sewage sludge, above 1200°C, show promising results where by stable and inert by-products are produced. This paper presents a part of a big project on thermal treatment of sewage sludge, carried out in University of Putra Malaysia, this part highlights the changes in the microstructure of domestic sewage sludge when subjected to different meltingprocedures; heating temperature, cooling rate, and holding time. The heating temperatures ranged between 1250°C–550°C, and the rate of cooling was between 2.5°C–10°C per minute. Using XRD analyses, itwas found that the melted slags were amorphous despite the different melting procedures applied. The SEM microphotographs indicated that some crystallization had occurred under the melting procedures; 1350°C with a cooling rate of 5°C per minute and a holding time of 45 minutes, 1400°C with a cooling rate of 2.5°C per minute and holding time of 45 minutes, and 1400°C with a cooling rate of 5°C per minute and without holding time.
Full scale implementation of post denitrification at the Blue Plains AWT in Washington D.C.
Authors: Sadick T. , Bailey W. , Tesfaye A. , McGrath M. , Daigger G. , Benjamin A.
Published: May 2018

The Chesapeake Bay Agreement of 1987 calls for an overall reduction in nutrient loading to the Bay of forty percent of 1985 levels by the year 2000. Signatories to the agreement include the states located in the Bay's watershed and the District of Columbia. The District's 16.2 m3 /sec (370 mgd) Blue Plains Advanced Wastewater Treatment (AWT) Plant is the single, largest point source of nitrogen load to the Bay, currently discharging approximately 18 metric tons (40,000 lbs) per day. In an effort toward meeting the nitrogen reduction goal, a post-denitrification demonstration project was recently undertaken to access its potential for long-term implementation. The denitrification demonstration project involved operating half of the nitrification facilities in a nitrification-denitrification mode using methanol as a carbon source for post-denitrification. The remaining half continued operation in a nitrification-only mode as a control. The two-year demonstration project was successful in meeting nitrogen reduction goals while meeting all other permit conditions. The District of Columbia Water and Sewer Authority is now proceeding to voluntarily implement the post denitrification process on a permanent, full-scale basis.
Alternative schemes for the management of the sludge produced at Psyttalia WWTP
Authors: Christoulas D. G. , Andreadakis A. D. , Kouzeli-Katsiri A. , Aftias E. , Mamais D.
Published: May 2018

The paper presents the conclusions of a study sponsored by the Ministry of Environment and Public Works and conducted by a research team of the National Technical University of Athens, aiming to investigate alternative management schemes for the sludge produced and expected after the operation of the second phase of the Psyttalia Sewage Treatment Works. The alternative management schemes examined include agricultural use, co-disposal of dewatered sludge with solid wastes, co-disposal of dried sludge with solid wastes, disposal of dewatered sludge at a separate landfill, disposal of dried sludge at a separate landfill, use of dried sludge as fuel for cement or electricity production and finally incineration. On the basis of the evaluation, the production of dried sludge which can be subsequently used for agricultural purposes or as a fuel stands out as the best long term option.
An assessment of sewage sludge stability with a specific oxygen utilization rate (SOUR) test method
Authors: Samson K. A. , Ekama G. A.
Published: May 2018

Sewage sludge treatment systems are intended to stabilize the sludge so that its disposal or reuse can be environmentally acceptable. However, stabilized sludges may still contain residual biodegradable organic matter that can be environmentally a nuisance. This paper presents a specific oxygen utilization rate [SOUR, mgO2/(gVSS·h)] batch reactor test method to quantify the residual biodegradable organic matter content of the treated (stabilized) sewage sludges. The results of the study, in which 37 SOUR batch tests were done on 10 different sewage sludges, show that the SOUR, when determined over a prolonged period (4 to 5 days), gives an indirect measure of sludge stability defined as the % soluble and particulate residual biodegradable organics in the sludge; to determine % sludge stability, it is necessary to simulate the experimental SOUR data by means of a general activated sludge model. The % sludge stability obtained for the 10 different sludges, taking due account of their soluble and particulate constituents, was consistent with that expected from the stabilization treatment systems to which the sludges were subjected.
Uprating of Mogden Sewage Treatment Works
Authors: Koodie A.V. , Kirkaldy I.J.
Published: May 2018

Mogden Sewage Treatment Works treats a population equivalent of approximately 1.8 m people from a catchment area of 160 sq. kilometres in North and West London. Substantial improvements have been undertaken over recent years including the automation of the works and major process improvements providing new sludge thickening facilities. In order to satisfy new obligations on treatment capacity set by the EC Urban Wastewater Treatment Directive a series of trials evaluating innovative and novel alternatives to conventional design were conducted. The “Mogden Trials” as they became known were granted a £1m research budget from the Thames Water capital release committee, however, substantial cost savings from an original capital control cost of £85m (NPV £141m) were considered possible. This paper describes how the savings were achieved through the trials and the assessment of options and provides details on the process of uprating the treatment plant including the successful partnering agreement between the owner/operator Thames Water and the US based company Black and Veatch.
Optimization of nutrient removal in the WWTP Zürich-Werhölzli
Authors: Siegrist H. , Brack T. , Koch G. , Nussbaumer A. , Gujer W.
Published: May 2018

Optimization of nitrifying activated sludge plants towards nutrient removal (denitrification and enhanced P-removal) will lead to substantial reduction of operating costs and improves effluent and operating conditions. At the WWTP Zürich-Werdhölzli, initially designed for nitrification, an anoxic zone of 28% of total activated sludge volume was installed in the initially fully aerated activated sludge tanks and allowed with optimization of the sludge blanket in the secondary clarifiers a nitrogen elimination of 60–70%. Parallel, different small process alterations at the grit removal tank, the primary clarifiers and return sludge pumps reduced odour problems and oxygen input and improved denitrification. Separate treatment of the digester supernatant, that contains about 20% of the inlet nitrogen load, will increase nitrogen elimination to about 75% and allows partial enhanced biological O-removal in the activated sludge system which will reduce precipitant feed and excess sludge production.