bluuebunny/crossref_metadata_2025 huggingface dataset:
A GIS planning model for urban oil spill management
Authors: Li J.
Published: May 2018

Oil spills in industrialized cities pose a significant threat to their urban water environment. The largest city in Canada, the city of Toronto, has an average 300–500 oil spills per year with an average total volume of about 160,000 L/year. About 45% of the spills was eventually cleaned up. Given the enormous amount of remaining oil entering into the fragile urban ecosystem, it is important to develop an effective pollution prevention and control plan for the city. A Geographic Information System (GIS) planning model has been developed to characterize oil spills and determine preventive and control measures available in the city. A database of oil spill records from 1988 to 1997 was compiled and geo-referenced. Attributes to each record such as spill volume, oil type, location, road type, sector, source, cleanup percentage, and environmental impacts were created. GIS layers of woodlots, wetlands, watercourses, Environmental Sensitive Areas, and Areas of Natural and Scientific Interest were obtained from the local Conservation Authority. By overlaying the spill characteristics with the GIS layers, evaluation of preventive and control solutions close to these environmental features was conducted. It was found that employee training and preventive maintenance should be improved as the principal cause of spills was attributed to human errors and equipment failure. Additionally, the cost of using oil separators at strategic spill locations was found to be $1.4 million. The GIS model provides an efficient planning tool for urban oil spill management. Additionally, the graphical capability of GIS allows users to integrate environmental features and spill characteristics in the management analysis.
The nonionic surfactant pollution profile of Israel Mediterranean Sea coastal water
Authors: Zoller U. , Hushan M.
Published: May 2018

Anionic and nonionic surfactants, as core components of detergent formulations, contribute significantly to the pollution profile of sewage and wastewaters of all kinds. In Israel about 15% of the total amount of ca. 4×108 m3/year of sewage is discharged, directly, or via receiving streams/rivers, into the Mediterranean Sea. Based on our previous findings that about 85% of the nonionic surfactants in the country's sewage are nonbiodegradable alkylphenol-based ethoxylates, we have undertaken this study, aiming at mapping the receiving eastern Mediterranean seawater with respect to its nonionic surfactant pollution profile. The total concentrations of nonionic surfactants were found – via reverse phase HPLC determinations – to be within the range of 4.2–25.0 ppb in seawater samples taken 2–3 m off the coastline at those locations where sewage-containing streams flow into the sea. Thus, neither the existing sewage treatment facilities nor natural biodegradation processes in receiving surface water systems are capable of avoiding this coastal water pollution. The potential estrogenic health risk of such concentrations of the anthropogenic EPEOs is dependent, among other things, on their specific homological distribution, biodegradation rate (slower for those having >10 EO units) and survival.
Degradation of polyvinyl alcohol (PVA) by homogeneous and heterogeneous photocatalysis applied to the photochemically enhanced Fenton reaction
Authors: Bossmann S.H. , Oliveros E. , Göb S. , Kantor M. , Göppert A. , Lei L. , Yue P.L. , Braun A.M.
Published: May 2018

The reaction mechanism of the oxidative degradation of polyvinyl alcohol (PVA) by the photochemically enhanced Fenton reaction was studied using a homogeneous (Fe2+aq + H2O2) and a heterogeneous reaction system (iron(III)-exchanged zeolite Y+ H2O2). In the homogeneous Fenton system, efficient degradation was observed in a batch reactor, equipped with a medium pressure mercury arc in a Pyrex envelope and employing 80% of the stoichiometric amount of H2O2 required for the total oxidation of PVA and a concentration ratio as low as 1 mole of iron(II) sulfate per 20 moles of PVA sub-units (C2H4O). Model PVA polymers of three different molecular weights (15,000, 49,000 and 100,000 g mol-1) were found to follow identical degradation patterns. Strong experimental evidence supports the formation of super-macromolecules (MW: 1 - 5 × 106 g/mol) consisting of oxidized PVA and trapped iron(III) at an early reaction stage. Low molecular weight intermediates, such as oxalic acid, formic acid or formaldehyde were not found during PVA degradation in the homogeneous Fenton system, and we may deduce that the manifold of degradation reactions is mainly taking place within the super-macromolecules from which CO2 is directly released. However, in the heterogeneous Fenton system, the reaction behavior was found to be distinctly different: a decrease of the molecular weights of all three tested monodisperse PVA samples was observed by the broadening of the GPC-traces during irradiation, and oxalic acid was formed. The results lead to the mechanistic hypothesis that during the heterogeneous Fenton process, the cleavage of the PVA-chains may occur at random positions, the reactive centres being located inside the iron(III)-doped zeolite Y photocatalysts.
Treatment of diglyme containing wastewater by advanced oxidation - process design and optimisation
Authors: Grossmann D. , Köser H. , Kretschmer R. , Porobin M.
Published: May 2018

Diglyme (CAS No. 111-96-6), a biorefractive ether with teratogenic properties is of considerable importance as a solvent in the synthetic chemical industry. Results of lab-scale investigations into the optimal conditions for the oxidative mineralisation of 0.05 to 1 g/L of diglyme in synthetic process waters by hydrogen peroxide and ozone based advanced oxidation processes are presented. Fenton, photo-assisted Fenton and UV/H2O2 oxidation processes show acceptable TOC removals. At 50°C the initial TOC removal rates varies between 0.07 and 6g TOC/L*h. The rates increase with the initial diglyme and hydrogen peroxide concentration as well as with the UV irradiation energy intensity. For example at a 1g/l diglyme concentration a stoichiometric H2O2 addition resulted in TOC degradation of 60% to 70% after 30 minutes under the investigated conditions. Treatment with ozone/H2O2 at a pH of 8 and 25°C required at least 100 minutes to achieve comparable mineralisation results. Biodegradability can be reached in far shorter times. Ozone on its own cannot be recommended for diglyme treatment. If complete mineralisation of diglyme is the objective, the UV/H2O2 oxidation process should be favoured. The ozone/H2O2 process might offer a viable alternative in cases where the oxidation step is followed by biological wastewater treatment, so that biodegradability is aimed at.
Comparison of advanced oxidation processes in flow-through pilot plants (Part II)
Authors: Müller J.-P. , Gottschalk C. , Jekel M.
Published: May 2018

The comparison of mechanistically different advanced oxidation processes (AOPS) UV/H2O2, UV/O3 and O3/H2O2 needs a non-specific figure-of-merit to avoid influences by system-inherent parameters. The chosen figure-of-merit consists of the electrical energy per order of magnitude in oxidation per m3, EE/O. Results from own experiments were compared with data derived from the literature. Considered were batch-experiments, pilot-plants and full-scale plants. The combination O3/H2O2 proved to be the most efficient process by means of energy consumption irrespective of the size of the plant.
Hydrolysis of wastewater colloidal organic matter by extracellular enzymes extracted from activated sludge flocs
Authors: Guellil A. , Boualam M. , Quiquampoix H. , Ginestet P. , Audic J. M. , Block J. C.
Published: May 2018

Enzymatic activities associated with the exopolymeric substances (EPSs) extracted from activated sludges were tested for their ability to hydrolyse the organic colloidal fraction of wastewater. Bacteria extracted with EPS and concentrated by wastewater microfiltration were inhibited with NaN3 or KCN. The protein hydrolysis mainly resulted from the enzymatic activity of EPS, whereas the glycolytic activity was mainly present in the organic colloidal fraction of the wastewater.
Multipurpose use and water quality challenges in Lac de Guiers (Senegal)
Authors: Cogels F.-X. , Fraboulet-Jussila S. , Varis O.
Published: May 2018

Lac de Guiers (Guiers Lake) is a shallow lake in West Africa. Its waters are used mainly for irrigation and drinking water. Recent engineering in the Senegal River Valley has changed the lakes functioning and led to new water quality conditions. This article describes the water quality effects of the management of the lake and use of its waters, with special emphasis on salinity and eutrophication.
Influence of calcium ions on the mechanical properties of a model biofilm of mucoid Pseudomonas aeruginosa
Authors: Körstgens V. , Flemming H.-C. , Wingender J. , Borchard W.
Published: May 2018

The mechanical properties of biofilms and in particular their mechanical strength is of great importance for both biofilm reactors and for the removal of undesired biofilms as in cases of biofouling and biocorrosion. By uniaxial compression measurements, it is possible to determine the apparent elastic or Young's modulus and the yield stress as parameters for mechanical stability. This was performed with a recently developed device, using model biofilms of mucoid strain Pseudomonas aeruginosa SG81. The biofilms were grown on membrane filters placed on nutrient agar medium with different concentrations of calcium ions. The compressive stress - strain behaviour up to failure was recorded at a compression speed of 1 μm s-1. The apparent Young's modulus, representing the stiffness of the biofilm, and the yield stress obtained from the stress - strain diagram were used for the description of mechanical properties of biofilms. A certain critical concentration of calcium ions was found where the Young's modulus of the P. aeruginosa biofilms increases strongly and subsequently remains constant for higher calcium concentrations. This behaviour is explained by the presence of calcium ions crosslinking alginate, which is the major component of the extracellular polymeric substances produced by the mucoid P. aeruginosa strain used in this investigation.
The role of blending in polymer conditioning of waste activated sludge
Authors: Erdinçler; A. , Koseoǧly S. , Onay T.
Published: May 2018

This paper presents the results of an investigation on the role of blending in sludge polymer conditioning by evaluating the polymer consumption, and measuring the capillary suction time of waste activated sludge samples blended for different time periods. All of the sludge samples, including non-blended control samples, were conditioned by a cationic high molecular weight polymer in desired concentrations. The protein concentrations of the sludge samples increased as a biological confirmation of cell disruption or desorption of some part of biological polymers present in sludge. Blending decreased the critical polymer dosages required to condition the waste activated sludge samples depending on the blending time applied to the samples.
Improvement of environmental health and hygiene practices - case study in the Northern Province
Authors: Mathegana M. A. , Chauke L. K. , Otieno F. A.O.
Published: May 2018

The primary purpose of an improved water supply and sanitation is the achievement of acceptable health and hygiene standards as well as the sustainable improvement of the environment. Many governments recognize this and so they budget for large sums of money to improve these services to the communities. The purpose of this study was to investigate the different gaps in environmental health and hygiene practices with the aim of suggesting a strategy of improving this in the Northern Province of South Africa. To do this, 231 households and 30 schools were surveyed. Workshops and visits to different government departments were also used. This paper reports the results from this study which indicate that the situation in schools was not any better than that in households, with more than 90% of the villages still dependent on the unimproved pit latrines and 56,6% relying on standpipes which were (70% of the time) non-operational. The main problems identified seem to those associated with implementation and maintenance. The study concludes that with proper training of the water committees and their active involvement with the government and NGOs, environmental health and hygiene problems can be minimized or eliminated.
Modelling the structure and function of extracellular polymeric substances in biofilms with new numerical techniques
Authors: Horn H. , Neu T. R. , Wulkow M.
Published: May 2018

The objective of this study is the mathematical description of the structure and function of the extracellular polymeric substances (EPS) in biofilms. The basic assumptions of the EPS biofilm model are:the production of EPS in biofilms is coupled to the growth of micro-organismsthe production of EPS is additionally coupled to the substrate conditions-the EPS represent a considerable volume fraction of the matrix in biofilms and thus the density of the biofilms is strongly influenced by the EPS-sorption of biocides and pollutants in biofilms occurs mainly to EPSthe EPS can be used as an energy source during substrate limited phases.

The mathematical model has been derived as a system of partial differential equations. The numerical solution of these complex balance equations has been done by a self-adaptive Galerkin-h-p-method. It can be shown, that on the one hand the simulation of substrate conversion and biofilm growth with the EPS-biofilm model yields similar results as the known biofilm models without consideration of the EPS fraction. On the other hand the advantage of the EPS-biofilm model is a better understanding of biofilm structure, which is mainly influenced by the EPS fraction in the biofilm. Furthermore, the sorption of pollutants, such as heavy metals and chlorinated organic substances, can be simulated in more detail.
Introduction of water conservation education packages: the opportunites and constraints afftecting their success
Authors: Ryan J. , Mathew K. , Anda M. , Yuen E.
Published: May 2018

The Remote Area Developments Group in the Institute for Environmental Science at Murdoch University developed a video and booklet education package on water conservation. The package was developed after research, review of current efforts in water conservation, and consultation with communities showed that there was a need in this area. The package was distributed to all communities within Western Australia. Several different workshops were conducted with Indigenous Environmental Health Workers from around Western Australia in remote areas and in the Perth Metropolitan communities using the package. This paper will briefly describe the opportunities and constraints that exist for water conservation in remote Aboriginal communities in Western Australia as well as give an evaluation of the education package based on workshops, trials and survey instrument. This paper will explain the conclusions that have been drawn from the study: that a broad delivery style is the most advantageous style for remote communities, allowing the facilitator to assess the best style of delivery.
Methanotrophic production of extracellular polysaccharide in landfill cover soils
Authors: Chiemchaisri W. , Wu J. S. , Visvanathan C.
Published: May 2018

A bench-scale soil reactor was used to study methane oxidation and EPS production under tropical conditions. The study of pertinent environmental factors affecting EPS production was carried out by batch cultivation of methanotrophs. These factors included variations in temperature (20°C to 45°C), soil water content (5% to 33%), and the supply ratios of methane/oxygen. The bench-scale study revealed that excessive EPS was accumulating in an active methane oxidation zone located 5-45 cm below the soil surface of the reactor. The observed peak rates of oxidation could not be sustained over an extended period of time due to EPS accumulation. Results from the batch cultivation experiments confirmed the production of EPS in soils subject to methane oxidation. EPS production was found to correlate with methane oxidation rates which, in turn, were regulated by the variance of temperature and soil water content. A larger amount of EPS production was obtained at 30°C and 17% soil water content. Oxygen is required for methane oxidation; however, at high oxygen tension it may accelerate the production of EPS by methanotrophs causing limited oxygen diffusion and declining rates of methane oxidation.
Managing water supply and sanitation services to developing communities: key success factors
Authors: Schutte C.F.
Published: May 2018

A number of key success factors in the management of organisations responsible for the provision of water supply and sanitation services to developing communities have been identified as critical to the sustained success of such organisations. These factors have to receive specific and sustained attention from management. They should form the focus of management attention in addition to the many other important factors requiring management input.

The key success factors which are critical to ensure a sustained water supply and the provision of sanitation services to developing communities centre around two main areas, i.e. the credibility of the organisation with the community it serves and the creation of an organisation culture of focusing on service to the community, on income generation and on minimising of losses.
The EPS of Acidithiobacillus ferrooxidans - a model for structure-function relationships of attached bacteria and their physiology
Authors: Gehrke T. , Hallmann R. , Kinzler K. , Sand W.
Published: May 2018

To dissolve pyrite or sulphur, leaching bacteria like Acidithiobacillus ferrooxidans attach to these substrata by extracellular polymeric substances (specifically, lipopolysaccharides). The primary attachment to pyrite at pH 2 is mediated by exopolymer-complexed iron(III) ions in an electrostatic interaction with the negatively charged pyrite surface. Cells grown on sulphur exhibit a different composition of the extracellular lipopolysaccharides, namely with increased hydrophobic properties, and do not attach to pyrite. Thus, the cells adapt the chemical composition of their exopolymers to the substrate/substratum. It is concluded that the mechanism of bacterial pyrite oxidation is basically indirect. The actual corrosive agents are iron(III) ions. Preliminary data indicate that active strains complex more iron(III) ions in their EPS than less active ones. Obviously, the exopolymeric layer comprises a reaction space for the regeneration of these ions by the activity of the iron oxidising bacteria.
Water harvesting techniques for small communities in arid areas
Authors: Yuen E. , Anda M. , Mathew K. , Ho G.
Published: May 2018

Limited water resources exist in numerous remote indigenous settlements around Australia. Indigenous people in these communities are still living in rudimentary conditions while their urban counterparts have full amenities, large scale water supplies and behavioral practices which may not be appropriate for an arid continent but are supported by extensive infrastructure in higher rainfall coastal areas. As remote indigenous communities continue to develop, their water use will increase, and in some cases, costly solutions may have to be implemented to augment supplies.

Water harvesting techniques have been applied in settlements on a small scale for domestic and municipal purposes, and in the large, broadacre farm setting for productive use of the water. The techniques discussed include swales, infiltration basins, infiltration trenches and “sand dam” basins.

This paper reviews the applications of water harvesting relevant to small communities for land rehabilitation, landscaping and flood control. Landscaping is important in these communities as it provides shelter from the sun and wind, reduces soil erosion and hence reduced airborne dust, and in some cases provides food and nutrition. Case studies of water harvesting systems applied in the Pilbara Region, Western Australia for landscaping around single dwellings in Jigalong and Cheeditha, in a permaculture garden in Wittenoon and at a college and carpark in Karratha are described.
Hybrid neural modelling of an anaerobic digester with respect to biological constraints
Authors: Karama A. , Bernard O. , Gouzé J. L. , Benhammou A. , Dochain D.
Published: May 2018

A hybrid model for an anaerobic digestion process is proposed. The fermentation is assumed to be performed in two steps, acidogenesis and methanogenesis, by two bacterial populations. The model is based on mass balance equations, and the bacterial growth rates are represented by neural networks. In order to guarantee the biological meaning of the hybrid model (positivity of the concentrations, boundedness, saturation or inhibition of the growth rates) outside the training data set, a method that imposes constraints in the neural network is proposed. The method is applied to experimental data from a fixed bed reactor.
A new approach towards modelling of the carbon degradation cycle at two-stage activated sludge plants
Authors: Winkler S. , Müller-Rechberger H. , Nowak O. , Svardal K. , Wandl G.
Published: May 2018

A pilot plant has been operated in order to investigate the performance and operating characteristics of the plant concept developed for the extension of the main Vienna STP. Due to the different operational modes included in the plant concept, modelling of the carbon degradation becomes of crucial importance. A new activated sludge model is introduced which combines parts of the carbon degradation model concepts as they have been released in the ASM1-model and the ASM3-model, respectively. A method is presented which utilises results from mass balance calculations and sludge stabilisation experiments to reduce the uncertainty in the determination of the values of the simulation model parameters.
A georeferenced river quality model
Authors: Marsili-Libelli S. , Caporali E. , Arrighi S. , Becattelli C.
Published: May 2018

Water quality models have reached a high degree of sophistication, but their weak side remains user interface and output georeferencing. The aim of this paper is to propose an interfacing procedure between two widespread but specialised programming environments: ArcVIEW as a Geographical Information System (GIS) and Matlab as a scientific programming tool for numerical analysis. The proposed solution is based on a Dynamic Data Exchange (DDE) between the two programs in order to operate a Matlab-based water quality model from within the GIS environment. It is shown how special GIS objects must be created and how they operate to achieve the goal of having quality data created by the model placed on a geographical map, together with other site features.
Practical identifiability of model parameters by combined respirometric-titrimetric measurements
Authors: Petersen B. , Gernaey K. , Vanrolleghem P. A.
Published: May 2018

An earlier study on theoretical identifiability of parameters for a two-step nitrification model showed that a unique estimation of the yield YA1 is possible with combined respirometric-titrimetric data, contrary to the case where only one type of measurement is available. Here, the practical identifiability of model parameters was investigated via evaluation of the output sensitivity functions and the corresponding Fisher Information Matrix (FIM). It appeared that the FIM was not sufficiently powerful to predict the practical identifiability of this case with combined measurements as parameters could indeed be identified despite the fact that the FIM became singular. The accuracy of parameter estimates based on respirometric and titrimetric data and combination thereof was also investigated. Estimation on titrimetric data (Hp) was very accurate and a fast convergence of the objective function towards a minimum was obtained. The latter also holds for estimation on oxygen uptake rate data (rO), however with a lower accuracy. Parameter estimation based on oxygen concentration data (SO) was more complex but resulted in a higher accuracy. Thus, when the highest accuracy is needed it is recommended to estimate parameters initially on Hp and/or rO data, and to subsequently use these parameters as initial values for final, and more accurate estimation on SO data.
Methanol conversion in high-rate anaerobic reactors
Authors: Weijma J. , Stams A.J.M.
Published: May 2018

An overview on methanol conversion in high-rate anaerobic reactors is presented, with the focus on technological as well as microbiological aspects. The simple C1-compound methanol can be degraded anaerobically in a complex way, in which methanogens, sulfate reducing bacteria and homoacetogens interact cooperatively or competitively at substrate level. This interaction has large technological implications as it determines the final product of methanol mineralization, methane or carbon dioxide. The degradation route of methanol may be entirely different when environmental conditions change. Direct methanogenesis from methanol seems the predominant mineralization route under mesophilic conditions both in the absence and the presence of sulfate. Under thermophilic conditions methanol oxidation to carbon dioxide and hydrogen appears to play an important role. The UASB technology for mesophilic digestion of methanolic waste has presently reached full-scale maturity. The potential of methanol as feedstock for anaerobic processes is discussed.
Future perspectives in bioreactor development
Authors: Mulder R. , Vereijken T.L.F.M. , Frijters C.M.T.J. , Vellinga S.H.J.
Published: May 2018

The paper discusses conversion capacities of both anaerobic and aerobic wastewater treatment systems in relation to growth kinetics, hydrodynamics and biomass concentration. In the current modern anaerobic high-rate reactors the conversion potentials are optimally exploited. This is not yet true for aerobic systems since operation of aerobic systems under conditions of low biomass growth reduces the maximum applicable loading rates significantly. Both the concept of granulation and the introduction of fluidised bed systems have increased conversion capacities for both anaerobic and aerobic systems significantly. One of the latest development concerns the SBR with granular biomass. The grazing concept, in which ciliates convert aerobically grown dispersed cells, offers a possibility for significant improvement of aerobic systems. In the fields of psychrophilic and thermophilic anaerobic treatment, specific reactor development may contribute to further enhance volumetric conversion capacities. Due to reduced water usage, both COD and salt concentrations tend to increase for industrial effluents. As a consequence, there is a need for the development of anaerobic reactors retaining flocculant biomass. The membrane bioreactors offer a solution for certain niches in wastewater treatment. However the oxygen transfer economy is poor. There is a need for fundamental knowledge development to obtain a realistic image of this technology.
Biosorptive flotation for metal ions recovery
Authors: Zouboulis A. I. , Matis K. A. , Rousou E. G. , Kyriakidis D. A.
Published: May 2018

The solid/liquid separation of suspended, metals-loaded biomass was studied extensively by successfully applying flotation. Industrial non-living biomass samples of different origin have been tried in the laboratory as sorbents of metal ions, with the main stress on Streptomyces rimosus, an effective actinomyces. Flotation was used as the harvesting technique downstream, following the biosorption stage. Important parameters of the investigation were the solution pH, the surfactant type and concentration, the applied modification of biomass, etc. The reuse and recycling of biosorbent following elution was proved possible. As a result cleaned water was produced as underflow of the flotation process.
Digestion and degradation, air for life
Authors: Lettinga G.
Published: May 2018

Anaerobic degradation of dead biomass is a natural gasification process, an anaerobic crematorium producing a very useful end-product composed of methane and carbon dioxide, generally polluted with small amounts of some malodorous and quite toxic volatile S-compounds. It leads to the production of essential building elements for new life. This exciting field became my faith, vision, hope and expectation. This paper intends to present a reflection of more than three decades of research, teaching and advertisement in the field of sustainable environmental protection technologies, particularly of systems based on anaerobic digestion and the biological sulphur cycle. Considerable progress has been made during these decades worldwide, both in the basic understanding of the various processes and concepts, but also in the implementation of these systems, despite the fact that particularly the implementation frequently proceeded very laboriously. The difficulties certainly can no longer be attributed to technological limitations and/or insufficient understanding of the microbiology and chemistry only, but mainly to the frustrating social rigidity and short-term self-interest in all sectors of our society. By combining anaerobic processes with other microbiological degradation or transformation processes, like those based on the biological sulphur cycle, micro-aerobic and conventional aerobic and anoxic processes, ideal conditions can be created to valorise residues (wastes) from domestic, industrial and agricultural origin. It is simply not just ‘technology’, but also a route to achieve more sustainability and justice in society. It is a fight against conservative establishments. Decomposition, disintegration disbandment, it also stands for deliverance and liberation, space and air for continuation of life.
Sustaining our rivers in crisis: setting the international agenda for action
Authors: Petts G.
Published: May 2018

The history of streams and rivers is as much a social and technological history as it is a scientific one. Rivers are the lifeblood of nations and the control of their waters has been fundamental to the building of human civilisations. The control or regulation of rivers embodied the advancement of institutions, administration and co-ordination; it was a manifestation of military and economic power.

Yet the history of human development is also characterised by the degradation of the basic resource - polluted water, increased flooding, and the loss of biological diversity. Many early civilisations collapsed in the face of environmental degradation, manifest by flood, drought, famine and plague. The Industrial Revolution upon which modern societies are founded was based upon a short-term vision that has left rivers in crisis, marked by a legacy of pollution, slums, a loss of confidence in civic life, and a loss of ownership of places and spaces - once seen to be at the heart of civilised society.

Within this global or international context of water management, this paper examines the impacts and future of rivers and water within the United Kingdom, establishing some principles for such management in other settings.
Managing the Brisbane River and Moreton Bay: an integrated research/management program to reduce impacts on an Australian estuary
Authors: Abal E. G. , Dennison W. C. , Greenfield P. F.
Published: May 2018

The Brisbane River and Moreton Bay Study, an interdisciplinary study of Moreton Bay and its major tributaries, was initiated to address water quality issues which link sewage and diffuse loading with environmental degradation. Runoff and deposition of fine-grained sediments into Moreton Bay, followed by resuspension, have been linked with increased turbidity and significant loss of seagrass habitat. Sewage-derived nutrient enrichment, particularly nitrogen (N), has been linked to algal blooms by sewage plume maps. Blooms of a marine cyanobacterium, Lyngbya majuscula, in Moreton Bay have resulted in significant impacts on human health (e.g., contact dermatitis) and ecological health (e.g., seagrass loss), and the availability of dissolved iron from acid sulfate soil runoff has been hypothesised. The impacts of catchment activities resulting in runoff of sediments, nutrients and dissolved iron on the health of the Moreton Bay waterways are addressed. The Study, established by 6 local councils in association with two state departments in 1994, forms a regional component of a national and state program to achieve ecologically sustainable use of the waterways by protecting and enhancing their health, while maintaining economic and social development. The Study framework illustrates a unique integrated approach to water quality management whereby scientific research, community participation and the strategy development were done in parallel with each other. This collaborative effort resulted in a water quality management strategy which focuses on the integration of socioeconomic and ecological values of the waterways. This work has led to significant cost savings in infrastructure by providing a clear focus on initiatives towards achieving healthy waterways. The Study's Stage 2 initiatives form the basis for this paper.
Removal and decomposition of malodorants by using titanium dioxide photocatalyst supported on fiber activated carbon
Authors: Nozawa M. , Tanigawa K. , Hosomi M. , Chikusa T. , Kawada E.
Published: May 2018

Effective and compact deodorization systems have been required for the measure of small-scale emission sources of offensive odors usually found in urban areas. We have developed a sheet material with titanium dioxide (TiO2) photocatalyst supported on fiber activated carbon (FAC) for a compact deodorization system. In the deodorization system using the TiO2 /FAC sheet and a ultraviolet lamp, malodorants can be collected on the TiO2 /FAC sheet by adsorption and then decomposed by photocatalysis with UV-irradiation. In this study, we obtained basic information about the removal and the decomposition of malodorants in the photocatalytic deodorization system using the TiO2 /FAC sheet. The malodorants used in this study were methyl mercaptan, ammonia, and hydrogen sulfide. In addition, two kinds of light sources, a black light bulb (BLB; dominant wavelength: 365 nm) and an ultraviolet germicidal lamp (UV2; dominant wavelength: 254 nm) were used to analyze the effect on removal and decomposition characteristics by different dominant wavelengths. The removal rates of malodorants from the gas phase were determined in the deodorization system in the presence or absence of the TiO2 /FAC sheet and UV-irradiation in order to study each removal effect due to adsorption onto the TiO2 /FAC sheet, direct photolysis by UV-irradiation, and photocatalytic decomposition. The effect of adsorption onto the TiO2 /FAC sheet was pronounced in this batch-type experiment. The effect of photocatalysis was observed from the removal rates of methyl mercaptan. The percent oxidation of ammonia to nitrate and that of methyl mercaptan to sulfate were examined by determining products, i.e. nitrate and sulfate ions, with purified water after the reaction. The formation of nitrate or sulfate was not observed without UV-irradiation using the BLB, while the reactions progressed in the presence of the TiO2 /FAC sheet. When the UV2 lamp was used, the oxidation of methyl mercaptan to sulfate occurred without the TiO2 /FAC sheet. This suggests that the decomposition characteristics of malodorants were dependent on the wavelength of the light source.
Classifying urban rivers
Authors: Daenport A. J. , Gurnell A. M. , Armitage P. D.
Published: May 2018

Classification systems have been developed over the last century as a tool to aid managers in the preservation, conservation, enhancement and management of rivers. The classification systems developed to date have been designed to differentiate between relatively unimpacted, mainly rural rivers. Urban rivers typically show poor water quality and biological diversity, and so most current classification systems tend to group urban rivers into a single “poor” category. In this paper we describe a hierarchical framework for recording information about urban rivers that allows a more sensitive description of these rivers enabling subdivision into several classes according to the purpose of the classification. The different levels in the hierarchy, the types of attributes that are to be recorded at each level, and the relational database structure for storing the data are described. The 100-500 m river stretch level in the hierarchy relates to the engineered modification of urban rivers and is the key to their classification. An example classification at this scale illustrates a link between engineering modification, bank and bed materials and the number and diversity of physical habitats present. This classification underlines the importance of adopting a hierarchy of nested spatial scales for data collection, classification and interpretation since it illustrates a clear link between characteristics at the stretch scale and at the finer habitat scale. The classification also illustrates the varied nature of urban rivers and the fact that even quite heavily engineered stretches can contain a diversity of habitat types.
Development of an odorant emission model for sewage treatment works
Authors: Gostelow P. , Parsons S.A. , Cobb J.
Published: May 2018

In the field of odour assessment, much attention has been paid to the measurement of odour concentration. Whilst the concentration of an odour at a receptor is a useful indicator of annoyance, the concentration at the source tells only half the story. The emission rate - the product of odour concentration and air flow rate - is required to appreciate the significance of odour sources. Knowledge of emission rates allows odour sources to be ranked in terms of significance and facilitates appropriate selection and design of odour control units. The emission rate is also a key input for atmospheric dispersion models. Given the increasing importance of odour to sewage treatment works operators, there is a clear need for predictive methods for odour emission rates. Theory suggests that the emission of odorants from sewage to air is controlled by mass transfer resistances in both the gas and liquid phase. These are in turn controlled by odorant and emission source characteristics. The required odorant characteristics are largely known, and mass transfer from many different types of emission sources have been studied. Sewage treatment processes can be described by one or more of six characteristic emission sources, these being quiescent surfaces, channels, weirs and drop structures, diffused aeration, surface aeration and flow over media. This paper describes the development of odorant mass transfer models for these characteristic emission types. The models have been applied in the form of spreadsheet models to the prediction of H2S emissions and the results compared with commercial VOC emission models.
Conditioning, thickening, and dewatering: research update/research needs
Authors: Dentel S. K.
Published: May 2018

The production of sludges that are amenable to beneficial reuse (and thereby merit the term “biosolids”) has become a high priority concern in wastewater treatment. Regulations in many countries have become stringent in this regard, and the production of suitable biosolids now influences the selection, design, and operation of upstream processes. Among these are the conditioning, thickening, and dewatering of sludges. This paper briefly reviews current technology trends in these process areas, placing them in the context of overall needs for improved biosolids management. It is foreseen that conditioning, thickening and dewatering processes will need to operate at higher performance and reliability levels to maintain disposal and reuse flexibility. The chemistry of conditioning must be more clearly determined since secondary interactions of the conditioning additives may be important in ways that are not currently recognized.
Extractability and fractionation of heavy metals in chemically treated sewage sludges
Authors: Hsiao P.C. , Lo S.L.
Published: May 2018

Four chemically treated sludges, lime-treated (LS), lime/sodium silicate-treated (LSS), cement-treated (CS), and cement/sodium silicate-treated (CSS) were produced form the chemical treatment of aerobic digested sewage sludge cake, using lime, cement, and sodium silicate as additives. Ex tractability and fractionation of the heavy metals (Cu, Pb, Cr, and Zn) in these products and untreated sludge (S) were investigated using sequential extraction, single extraction, and 13C cross-polarization magic angle spinning nuclear magnetic resonance analysis (13C-NMR). These approaches revealed that chemical treatment of sewage sludge makes sludge Cu, Pb, and Cr more extractable. It was attributed to the irreversible dissolution of a portion of organics at very high pH during chemical treatment of sludge. The enhanced extraction of some metals having higher affinity to organics, e.g. Cu and Pb, from the chemically treated sludges was due to their complexion with the above soluble organics.
Stabilization of heavy metals in sewage sludge composting process
Authors: Chiang K.-Y. , Yoi S.-D. , Lin H.N. , Wang K.-S.
Published: May 2018

This study investigated the stabilization of heavy metals in a sewage sludge composting process using kaoline addition. The results indicate that the temperature increased rapidly to the thermophilic phase (>55°C) at day 1. The additives enhanced the rate of biodegradation and microbial activity during the co-composting process. The changes in pH (ranging from 8 to 8.5) and electrical conductivity (EC) (≤3 mS/cm) were in compliance with the best conditions during the co-composting process. The C/N ratio was determined in each co-compost sample as an indicator of the co-compost maturity. From the end product of the co-compost experiment, changes in the ratios indicate that the additives promote the co-compost maturation rate. Based on the physicochemical characteristics of the co-compost, the potential use for sewage sludge resource recovery as manure is suggested. The total concentrations of Pb, Cd, Cr, Cu, and Zn in the co-compost product were far below the limit values for agricultural use. The leachability of Pb, Cu, and Cr decreased with increasing co-composting time. That is, the kaoline additive has an inhibitory capacity for leaching heavy metals. The Cd concentrations in the sludge compost were below the detection limits. Because the total concentration of Zn was high in the sludge compost and most soluble Zn was leachable, the leachability of Zn ranged from 25% to 29%. As a result of the physicochemical characteristics and heavy metal stabilization, the selected additive was shown to improve the sewage sludge compost quality and provide information for agricultural applications.
From sewage water treatment to wastewater reuse. One century of Paris sewage farms history
Authors: Védry B. , Gousailles M. , Affholder M. , Lefaux A. , Bontoux J.
Published: May 2018

The irrigation fields of Paris have been used for 100 years. Their soils mainly contain heavy metals in the topmost layer. Metals come from raw sewage as well as from digested sludge of biological treatment plants which have been diluted for years in raw water. Vegetables that are cultivated in the irrigation fields concentrate metals but their average contents, however, are lower than the recommended limit values. Some vegetables concentrate more specifically one type of metal. Corn seeds accumulate less metal than green vegetables. The SIAAP keeps operating irrigation fields by delivering clariflocculated water with a low metal content from the new Seine Centre plant, with the purpose of keeping some 2,000 ha of green zone in an otherwise heavily constructed area and to prevent a metal release from the soil should irrigation be interrupted. Maintaining irrigation fields also relieves the biological treatment plant and then contributes to preserve the quality of the Seine river, especially in summer.
Production and transformation of volatile fatty acids from sludge subjected to hydrothermal treatment
Authors: Shanableh A. , Jones S.
Published: May 2018

The production of useful organic matter from sludge expands the potential for utilizing the product as a resource. This paper is focused on the accumulation and removal of volatile fatty acids (VFAs) produced from primary, secondary and a mixture of both sludges using hydrothermal treatment with and without the use of oxidants. The results confirmed that the maximum accumulation of VFAs was achieved at moderate hydrothermal treatment temperatures below 200°C, and was dependent on the composition of sludge and the amount of oxidant used for treatment. The maximum accumulation reached 0.26-0.36 mg VFAs as COD per mg VS from the three sludge types. Acetic acid dominated the VFAs and was followed by propionic acid, with the other VFAs accounting for less than 5% of the total VFAs. As hydrothermal treatment progressed in terms of COD removal, the contribution of acetic acid to the total VFAs increased while the contributions of the other VFAs decreased. The VFAs constituted a major component of the accumulated dissolved organic matter, which reached a maximum of 0.5-0.7 mg soluble COD per mg VS from the three sludge types.
Bacterial responses to ultraviolet irradiation
Authors: Blatchley E. R. , Dumoutier N. , Halaby T. N. , Levi Y. , Laîne J. M.
Published: May 2018

The UV dose-response behavior of laboratory cultures of waterborne bacteria were examined for UV doses ranging from ca. 0 -100 mW•s/cm2 using a collimated-beam reactor. Specific physiological responses measured in these tests included viability (ability to reproduce) and respiration (oxygen uptake rate). The results of these exposures indicated that resistance to UV-imposed loss of viability in E. coli cultures can be partially attributed to agglomeration during the irradiation process. From these results, it is conjectured that a bacterial population may be comprised of two sub-populations: one with low resistance (discrete or paired cells) and a second with high resistance (bacterial aggregates). A small fraction of the high-resistance portion of the population appears to be essentially unaffected by UV irradiation, thereby causing a discontinuity in the measured dose-response behavior. Moreover, the dose-response behavior of the highly resistant fraction is variable and difficult to describe quantitatively. The basis of these statements and most information in the literature is microbial viability as quantified by the membrane filtration assay. In contrast to these findings, the results of analyses for bacterial activity (respiration) suggest that comparatively little change in the population can be found to result from UV irradiation. This suggests that UV radiation accomplishes inactivation of the bacteria, but does not “kill” the bacterial cells per se, thereby highlighting the importance of considering bacterial repair processes in the design of UV disinfection systems.
Biological control tools for wastewater reclamation and reuse. A critical review
Authors: Salgot M. , Campos C. , Galofré B. , Tapias J. C.
Published: May 2018

The health related risk of wastewater reclamation and reuse is usually defined by laws, rules or regulations by using only biological tools; i.e. bacteria, viruses, or other pathogens or indicators determination. Those determinations exert some influence in the costs of the mentioned practices, and it seems probable that in the near future more determinations will be required. Nevertheless, a total indication of wastewater biological quality is not given by such organisms; in fact, long-term toxicity is not detected by such means. The future of biological control of reclamation and reuse systems and the price associated to such determinations is examined through a practical application case.