bluuebunny/crossref_metadata_2025 huggingface dataset:
Recovery of feline calicivirus infectious particles and genome from water: comparison of two concentration techniques
Authors: Gassilloud B. , Duval M. , Schwartzbrod L. , Gantzer C.
Published: May 2018

The aim of this work was to determine the recovery rate of feline calicivirus (FCV-F9) infectious particles and genome from water after a concentration step using either adsorption elution on glass wool or filtration through an electropositive membrane. The results showed that the membrane filtration technique allowed a 75% recovery rate of FCV-F9 infectious particles while the yield was only 5.3% for FCV-F9 genome. Using the glass wool adsorption-elution technique, the recovery rate of FCV-F9 infectious particles was 0.5% while the yield was 102.5% with Poliovirus 1.
Influence of porosity and composition of porous carriers on the uptake of nutrients
Authors: Khelifi O. , Kozuki Y. , Murakami H. , Kurata K. , Kono Y.
Published: May 2018

The current paper assesses the potential of industrial solid wastes utilization such as blast furnace slag (BFS) and zeolite synthesized from fly ash (ZFA), which are effective as well as economically attractive for the uptake of phosphate and ammonium from polluted seawater. The solidification of BFS and ZFA has been developed in different proportions of BFS/ZFA (30/70, 50/50 and 70/30 (w/w)) with different porosities (25%, 40% and 52%, respectively) to cylindrical porous carriers using a Hydrothermal Hot-Pressing (HHP) method. The concentrations of heavy metals in ZFA and BFS were too low to affect the aquatic environment. The main finding is that the high rate of BFS (70%) in porous carriers enhanced phosphate uptake explained by the higher percentage of calcium (35.7%) in porous carriers and high pH conditions. The efficient ammonium uptake was observed with high rate of ZFA (70%) in porous carriers. Results found through this experimental work imply that porous carriers with BFS/ZFA proportion of 70/30 are suitable for potential practical application in the aquatic environment due to their efficient uptake of phosphate and ammonium. The choice was made upon their porosity (40%) and their compressive strength (56 kgf/cm2) which are relatively higher than those with BFS/ZFA proportion of 30/70 and 50/50.
Effects of peracetic acid and monochloramine on the inactivation of Naegleria lovaniensis
Authors: Ercken D. , Verelst L. , Declerck P. , Duvivier L. , Van Damme A. , Ollevier F.
Published: May 2018

Biocidal activities of monochloramine and peracetic acid were studied on cysts of Naegleria lovaniensis. Until recently the most commonly used biocide to disinfect cooling water systems was hypochlorite. Owing to its negative impact on the aquatic environment, ecologically less harmful alternatives have been sought. As the biocidal activity of monochloramine and peracetic acid makes them good candidates for inactivation of pathogenic Naegleria species, these biocides were tested against Naegleria lovaniensis, a relative of the pathogen Naegleria fowleri, as an alternative treatment to hypochlorite. Under laboratory conditions the biocidal activity of hypochlorite was 8- 10× stronger than that of the two investigated substances. Hypochlorite, at a concentration of 0.5 mg/L, killed 100% Naegleria lovaniensis after 1 h exposure (25°C, pH 7.3- 7.4). To achieve similar results with monochloramine and peracetic acid, 3.94 mg/L or 5.33 mg/L had to be used respectively (25°C, pH 8). It was known that the in situ biota of the biofilm, along with any organic material in the water column, had a negative impact on the efficiency of the biocides. There are, however, indications that the relative efficacy of monochloramine and peracetic acid was quite good under such conditions when compared with hypochlorite.
On-line NIR monitoring during anaerobic treatment of municipal solid waste
Authors: Hansson M. , Nordberg Å , Mathisen B.
Published: May 2018

An anaerobic digester (8 l) was fed with the organic fraction of municipal solid waste and monitored intermittently for two years with on-line near-infrared (NIR) spectroscopy and traditional chemical parameters analysed off-line. The dynamics that occurred due to changes in substrate composition (changed C:N ratio) and changes in operating conditions (overloading) could be followed using principal component analysis of the obtained NIR-spectra. In addition, process disturbances such as failed stirring and increased foaming were readily detected by the NIR-spectra. Using PLS regression the propionate concentration could be predicted in the range 0.1-3.6 g/l, RMSEP 0.53 g/l with slope 0.74 and correlation coefficient 0.85. The response on changes in the digester fluid was reproducible and could be detected within 2.5 minutes, which can be considered as real-time monitoring.
In situ observation of the water-sediment interface in combined sewers, using endoscopy
Authors: Oms C. , Gromaire M.-C. , Chebbo G.
Published: May 2018

A new method for water-sediment interface observation has been designed. This system is based on a small diameter endoscope protected by a graduated plastic tube. It makes it possible to visualise in a non-destructive manner the sediments and the water-sediment interface. The endoscope was used to investigate Le Marais catchment (Paris): an immobile organic layer was observed at the water-sediment interface. This layer appears in pools of gross bed sediment, at the upstream of collectors, in zones where velocity is slow and where bed shear stress is less than 0.03 N/m2.
Anaerobic digestion of waste activated sludge combined with ozone post-treatment and recycling
Authors: Battimelli A. , Millet C. , Delgenès J.P. , Moletta R.
Published: May 2018

The aim of the study was to determine the performances of a combined ozone/anaerobic digestion system for waste activated sludge reduction. The objective was the estimation of the process efficiency and stability when keeping constant influent flow while increasing recycled chemically treated flow. The ozonation step consisted in a partial oxidation (0.16 g O3/g SS) of the anaerobic mesophilic digested sludge. Chemical treatment of digested sludge resulted in a threefold COD solubilization and a decrease of SS of 22%. Some of the advantages of digested sludge ozonation were: deodorization, better settlement and a reduction in viscosity. However there were drawbacks: foaming during ozonation and, at high ozone doses, poorer filterability. The anaerobic digestion was carried out over 6 months with an increasing recycling of ozonated flow. Suspended solids removal rate and COD removal rate were compared with initial operating conditions for the biological reactor and the whole combined process. The optimum recycling rate was 25% with increases of SS removal and COD removal of 54% and 66% respectively when considering the combined process; corresponding to a decrease of the hydraulic retention time from 24 days to 19 days.
Interactions within the wastewater system: requirements for sewer processes modelling
Authors: Langeveld J.G. , Clemens F.H.L.R. , van der Graaf J.H.J.M.
Published: May 2018

Today's focus on wastewater system optimisation necessitates the development of knowledge on the interactions between sewer systems and wastewater treatment, since these interactions have often been neglected in the past. In this paper the question is discussed to what extent it is favourable and possible to include dynamic changes of wastewater quality in wastewater system optimisation studies. The sensitivity of the wastewater treatment works to influent fluctuations proved to be the key issue in determining which sewer processes are involved in the dynamic interactions between sewer systems and treatment works. The preliminary results show the importance of a good description of the transport processes involving the soluble and suspended fractions.
Co-digestion of concentrated black water and kitchen refuse in an accumulation system within the DESAR (decentralized sanitation and reuse) concept
Authors: Kujawa-Roeleveld K. , Elmitwalli T. , Gaillard A. , van Leeuwen M. , Zeeman G.
Published: May 2018

Co-digestion of concentrated black water and kitchen refuse within the DESAR concept was the objective of this pilot research. The digestion took place in two, non-mixed accumulation reactors (AC1 and AC2) inoculated with digested primary sludge from a WWTP at a temperature of 20°C for a period of around 150 days. Reactor AC1 was fed with a mixture of faeces, urine and kitchen refuse in the equivalent amount that one individual generates per day. The AC2 was fed with a mixture of faeces and kitchen refuse in the equivalent amount that two individuals produce per day. Some contribution of urine to AC2 was not to be avoided. Detailed characterisation of waste(water) was performed. The performance of the stratified reactor was followed by monitoring the reactor content for several reactors' heights as well as being based on the biogas production. In general the system exposed good process stability. The methanisation of 34 and 61% was obtained for AC1 and AC2 respectively. The biogas yield was 26.5 and 50.8 L/p/d for the respective reactors. Proper choice of inoculum as well as good buffering capacity did not lead to accumulation of VFA and an inhibitive effect due to relatively high ammonium concentration. The chosen process is a promising technology showing good process stability especially for high strength influent.
Hydraulics of a sewer flushing gate
Authors: Bertrand-Krajewski J.-L. , Bardin J.-P. , Gibello C. , Laplace D.
Published: May 2018

This paper presents field experiments carried out in a 1.8 m height egg-shaped sewer in Lyon, France in order to contribute to the knowledge and the simulation of Hydrass flushing gates. The main results are: i) definition of an empirical relationship giving the flow discharged by the gate as a function of the upstream water level and its use in modelling the gate behaviour, and ii)observation of the flush propagation along the sewer and evaluation of the potential cleansing efficiency.
Membrane separation to improve degradation of road side grass by rumen enhanced solid incubation
Authors: Dalhoff R. , Rababah A. , Sonakya V. , Raizada N. , Wilderer P.A.
Published: May 2018

Membrane separation proved to be an excellent means to maintain high residence time of microorganisms in an anaerobic hydrolysis reactor, and relatively low concentration of hydrolysis products. The microbial biocommunity typical for the rumen environment could be maintained, and the reactor efficiency of the reactor improved. Less than 4 days were reqired to reach almost complete hydrolysis of the grass fed into the reactor. To avoid blocking of the membrane unit, a backwash system is necessary. The membranes needed to be backwashed every 20 min with 4 bar gas-pressure for 10 s. After this treatment the initial permeability was regained. The plant was operated with a flux of 12 ml h-1cm-2 on average. The transmembrane pressure was in the range of 0.8-0.9 bar. 90% of the dissolved fatty acids permeated through the membrane.
Processing and fractional utilization of lignocellulosic substrates by “pure” and “natural and defined mixed” culture C.TM1, C.SA IV and rumen mixed culture consortia CD
Authors: Sankar M. , Chandra T.S.
Published: May 2018

A detailed analysis was made of chemical fractions of common agro-residues before and after pretreatment (alkali and hydrogen peroxide), and the selective utilization of components such as WSS, EBS, TSS, lignin, cellulose and hemicellulose by pure and mixed cultures of cellulolytic and xylanolytic Clostridia was monitored and correlated with the organisms' enzyme activity. For all cultures pretreatment gave higher utilization of hemicellulose and cellulose fractions; hydrogen peroxide pretreatment was more effective than NaOH treatment. Lignin utilization was not very significant even on pretreatment. C.TM1 and C.SA IV utilized hemicellulose and cellulose better than mixed cultures in selected substrates. These results help to determine the substrate composition, pretreatment conditions and enzyme system of the organism needed when designing an inoculum for agricultural waste treatment processes such as composting or biogas generation.
Anaerobic digestion of solid animal waste in an accumulation system at mesophilic and thermophilic conditions, start up
Authors: El-mashad H.M. , Zeeman G. , van Loon W.K.P. , Bot G.P.A. , Lettinga G.
Published: May 2018

The anaerobic digestion of solid animal wastes has been studied in an accumulation system (AC) at a filling time of 60 days followed by about 50 days batch digestion at 40 and 50°C. Poor mixing conditions during anaerobic digestion of solid wastes promote stratification of the substrate and intermediate products along the reactor height. The effect of layers stratification has also been followed in the AC system. The results showed a pronounced stratification of both CODdis and VFA concentrations along the AC system height. The temperature had a minor effect on the methane yield. The results also showed that methanogenesis was rate limiting in the AC system while the hydrolysis was the rate-limiting step during batch digestion.
Biofilm monitoring: a perfect solution in search of a problem
Authors: Lewandowski Z. , Beyenal H.
Published: May 2018

The main problem with monitoring biofilms is data interpretation. Biofilm heterogeneity causes monitored parameters to vary from location to location in the same biofilm, and it is difficult to assess to what extent these variations are caused by biofilm heterogeneity and to what extent they reflect other properties of the biofilm. We have used the concept of discretized biofilms, which is an integrated system of biofilm monitoring and data interpretation, to assess the effect of biofilm heterogeneity on biofilm activity. Using this approach we have estimated that a heterogeneous biofilm can be ten times more active, in terms of glucose consumption rate, than a homogeneous biofilm of the same thickness but with uniformly distributed density.
Biofouling assessment using an infrared monitor
Authors: Tinham P. , Bott T.R.
Published: May 2018

The paper details the design of an infrared monitor for detecting biofilm accumulation on surfaces in flowing systems. It is based on the principle that the amount of infrared radiation absorbed by a biofilm, is proportional to the amount of biofilm present. The test surface in the monitor has to be transparent in order to allow the passage of the radiation, so that the radiation absorbed is solely due to the presence of the biofilm. Since the biofilm structure is very dependent upon the conditions under which it was formed, e.g. fluid flow, nutrient and cell concentrations and temperature, it cannot be made to give absolute values of biofilm accumulation. Nevertheless the device is extremely useful for comparison purposes, such as the evaluation of biocide efficacy under different operating conditions. Correlations of biofilm thickness with infrared absorbance can be made, however, for specified operating conditions. The value of the monitor is demonstrated in some typical examples. The infrared absorbance shows a clear distinction between the accumulation of biofilm under two different velocity regimes, three pH values and three chlorine concentrations at two water velocities. It is suggested that in addition to laboratory use, the monitor could be used effectively for biofilm control in cooling water circuits.
Phosphorus removal from municipal wastewater in an experimental two-stage vertical flow constructed wetland system equipped with a calcite filter
Authors: Arias C.A. , Brix H. , Johansen N.-H.
Published: May 2018

Laboratory studies have indicated that calcite may be used in separate, exchangeable filter units in constructed wetland systems to remove phosphorus. Based on these studies we built a full-scale experimental constructed wetland with a calcite-based filter unit to study its performance, under real-life conditions. The system consists of a 2-m3 sedimentation tank and two vertical flow constructed wetlands. The system has three 0.09 m3 calcite filter-units to study phosphorus removal. The hydraulic loading rate varied between 1.7 and 6.2 m3/d. The residence time in filters ranged from 28 to 99 minutes. Overall the system removed 62 ± 18% of phosphorus. The removal in the calcite filter was initially good, but after three months all P-filters were saturated. The calcite increased pH by approximately half a unit and released calcium. A total of about 2.2 kg P/m3 calcite was removed by the filter. The first-stage bed receiving effluent from the sedimentation tank consistently removed phosphorus, whereas the second bed sometimes released phosphorus. The first order area-based removal rate constant for total-P in the vertical bed averaged 0.24 ± 0.20 m/d and was highly dependent on the loading rate. This shows that first order removal kinetics do not satisfactorily describe removal of phosphorus in vertical flow constructed wetland systems with unsaturated flow.
Investigations on phosphorus retention in subsurface flow constructed wetlands
Authors: Rustige H. , Tomac I. , Höner G.
Published: May 2018

62 SSF sand-based constructed wetlands in Germany, Austria and Switzerland have been evaluated for their phosphorus performance. In addition intensive investigations on the removal of phosphorus and its accumulation within the filter bed were conducted at five wetlands. For the performance of horizontal flow (HF) reed beds a regression equation could be derived. This was not possible for vertical flow (VF) reed beds. The best removal efficiency was observed from HF systems with hydraulic loading rates of 10 mm d-1 or less. 50 percent of all investigated HF wetlands had an average P output concentration of less than 2.1 mg l-1 in comparison to 3.3 mg l-1 of VF wetlands.

Saturation, seasonal and redox effects could be derived from time series analysis of the performance rate and further investigations of a well monitored VF reed bed. The retention of phosphorus was highest during the warm season. A small positive effect on phosphorus removal was observed with intermittent low redox levels. Soil analyses showed the highest accumulation of P within the influent zone of either HF or VF wetlands.
Simultaneous determination of bacterial viability and identity in biofilms using ethidium monoazide and fluorescent in situ hybridization
Authors: Regan J.M. , Oldenburg P.S. , Park H.-D. , Harrington G.W. , Noguera D.R.
Published: May 2018

A protocol for simultaneously interrogating bacterial viability and identity using in situ, culture-independent methods is described. Viability is assayed using ethidium monoazide (EMA) staining of cells with compromised membranes, and identity is determined using fluorescent in situ hybridization (FISH). Experiments with planktonic cultures were used to demonstrate the compatibility of EMA staining and FISH after covalently bonding EMA to nucleic acids by photoreaction. Applications to biofilm samples showed that diffusion limitations in the biofilm matrix were not problematic and that effective discrimination of viable target cells within a mixed microbial community was possible.
Monitoring of microbial diversity by fluorescence in situ hybridization and fluorescence spectrometry
Authors: Ivanov V. , Tay S.T.-L. , Tay J.-H.
Published: May 2018

The goal of the research was the development of a simple method to quantify microbial groups in environmental samples. Fluorescence intensity was measured in the sample before and after whole cell fluorescence in situ hybridization with rRNA-targeted, fluorochrome-labeled oligonucleotide probes. To determine specific and non-specific binding of different oligonucleotide probes the following approaches have been used: (1) incubation of the sample with probes at two different temperatures; (2) hybridization of labeled probe in the presence of unlabeled probe; (3) incubation of the sample with labeled specific probe or labeled nonsense probe. Specific binding (hybridization) of the probe was calculated as the difference between total binding and non-specific binding of the probe. Specific binding was 40-50% of total binding in the environmental samples tested. The ratio of the specific binding of different probes may be used to quantify the ratio of different microbial groups in the environmental samples. This quantification is suitable for the microbiological monitoring of microbial aggregates because it is a simple technique and the results can be measured by a portable fluorometer.
Treatment of agricultural wastewater in two experimental combined constructed wetland systems in a tropical climate
Authors: Kantawanichkul S. , Somprasert S. , Aekasin U. , Shutes R.B.E.
Published: May 2018

Two designs of experimental combined constructed wetland systems were constructed: vegetated (Scirpus grossus Linn) subsurface horizontal flow bed followed by a vegetated vertical flow bed and a vegetated vertical flow bed over an unvegetated horizontal flow sand bed. The systems were used to compare the nitrification/denitrification efficiency in a tropical climate which has temperatures above an average of 25°C throughout the year. The effluent from a biogas digester of pig farm wastewater with TKN and COD concentrations of approximately 400 and 1,000 mg/L was fed every 4 hours intermittently. The effluent was recycled to the system with the ratio of 1:1 and the hydraulic loading rate was increased from 3 to 6 and 12 cm/d including recycled water. At higher hydraulic loading rates, nitrogen COD and BOD removal efficiencies were lower. The SS, TP and fecal coliform bacteria removal efficiencies were not clearly affected by the high hydraulic loading or the different layout of the system. Nitrogen uptake by plants was very low in relation to the nitrogen loading of the systems. In general, the removal efficiencies of both types were comparable but the system with a vertical flow over horizontal flow sand bed is more suitable for sites with limited land area, although its construction can be more difficult than the system with horizontal flow followed by a vertical flow bed.
Plankton composition, distribution and significance in a tropical integrated pilot constructed treatment wetland in Uganda
Authors: Luyiga S. , Kiwanuka S.
Published: May 2018

The importance of the plankton community in wastewater treatment has been under-estimated for a long time, simply because of its biomass accumulation resulting in final release of organic matter back into the system after decomposition. In a two-year 3-month periodical study on a tropical integrated wastewater treatment constructed wetland, the phytoplankton role was tested and it has been shown that, through harvesting, the phytoplankton community plays a significant role in municipal wastewater treatment. The high phytobiomass, which was dominated by green algae (Chlorophyta), enhanced high levels of dissolved oxygen and high pH within the open ponds, and because of this, the system was found to be highly efficient in BOD5 (81%) and NH4+-N (93%) removal. The high pH enhanced ammonia volatilization within the open ponds. Regression statistics between the plankton community composition and some of the physico-chemical parameters (BOD, NH4+-N, DO, pH) within the wetland system show a significant relationship. In conclusion, open treatment wetlands provide a wide variety of planktonic organisms as water quality improvement systems through the provision of oxygen and alteration of the pH for BOD5 and ammonium reduction respectively.
Opening speech of the 12th Stockholm Water Symposium
Authors: Berntell A.
Published: May 2018

It is a great pleasure for me to welcome you all to the 12th Stockholm Water Symposium and to the World Water Week. This annual event has indeed developed dramatically from its beginning in 1991 until today. I doubt that any of the 200 participants in the first Symposium could then imagine the size of the event today, or the importance it has had over the years for the international policy debate on water-related issues. Today, we are very grateful to those involved, in the city of Stockholm and in the Stockholm Water Company and amongst the founding companies, for the far-sighted decision in 1990 to start the Stockholm Water Symposium and to establish the Stockholm Water Prize.
Opening address of the 12th Stockholm Water Symposium
Authors: Karlsson J.O.
Published: May 2018

We have a huge and inspiring task ahead of us. By the year 2015, together we shall have contributed to halving the number of people on earth who do not have access to safe drinking water. Also by then we shall have halved the number of people living in poverty. Those are two of the Millennium Declaration Goals set by the UN General Assembly. These goals do not just show the tremendous responsibility we bear. The goals also point out how central water is for a decent life and a life in dignity.
Hydrologic dynamics and ecosystem structure
Authors: Rodríguez-Iturbe I.
Published: May 2018

Ecohydrology is the science that studies the mutual interaction between the hydrological cycle and ecosystems. Such an interaction is especially intense in water-controlled ecosystems, where water may be a limiting factor, not only because of its scarcity, but also because of its intermittent and unpredictable appearance. Hydrologic dynamics is shown to be a crucial factor for ecological patterns and processes. The probabilistic structure of soil moisture in time and space is presented as the key linkage between soil, climate and vegetation dynamics. Nutrient cycles, vegetation coexistence and plant response to environmental conditions are all intimately linked to the stochastic fluctuation of the hydrologic inputs driving an ecosystem.
Acclimation of mesophilic anaerobic sludge to thermophilic conditions: PCR genera detection methodology
Authors: Cabirol N. , Fernández F.J. , Mendoza L. , Noyola A.
Published: May 2018

In Mexico, sludge from wastewater treatment plants is a public health problem, especially for the infant population due to the presence of pathogens and parasite eggs. Therefore, it is of great interest to apply proper treatment methods for those wastes. An option proposed for the removal of possible infectious sources is thermophilic anaerobic digestion, even though a limitation for its acceptance is the slow start-up of the reactors. The transformation of a mesophilic anaerobic sludge for its utilization as a thermophilic inoculum, by means of direct temperature increase up to 55°C and feeding of the inoculum with synthetic medium was possible in two months. As a main part of the work and with the objective of evaluating the changes in the methanogenic microbial population during the sludge treatment, a specific detection technique for these bacteria has been developed and validated, based on the use of the polymerase chain reaction (PCR).
Making markets work for clean water
Authors: Carpenter G.
Published: May 2018

Part of the solution to close the gap to meet the UN Millennium safe water goal lies in the domestic consumer marketplace. Multinational corporations must design products for low income consumers to deliver clean water at a household level. The future of business is linked to improving the lives of developing country consumers and to the improved economic status of those consumers.
Micro enterprise initiative in water sector and poverty reduction
Authors: Jose T.K.
Published: May 2018

The author reports on the Kerala model for water sector development, broadly adopted as a role model for poverty reduction and build up of social capital. It is a community based organisation with its focus on facilitating a stable income to the poor, and composed of a People's Plan Campaign, the Kudumbashree (women-based poverty eradication programme), with grassroot level neighbourhood groups, federated into an area development society. It promotes savings and credit channelling, capacity building and entrepreneurship development. Activities include awareness raising on water conservation and hygiene, utilization of student power, promotion of small, cheap and low technology projects that people can understand and undertake (small reservoirs, tanks, rainwater harvesting structures, water meters), as well as microenterprises, and training of women-based repair groups.
Workshop 3 (synthesis): water, poverty alleviation and social programs
Authors: Biswas A.K. , Shady A. , Lundqvist J. , Takahashi K.
Published: May 2018

Poverty is a complex issue, which must be understood in a holistic manner. Low and variable income is certainly a key element, but it is far from enough to portray poverty. The various characteristics of poverty and their relative strength are determined through contextually specific circumstances, in terms of history, environmental preconditions, socio-cultural traits, etc. Much of this context is made up of local and national circumstances. The consequences of globalisation must, however, increasingly to be taken into account. At a larger scale, it is also relevant to mention that climate change will have a negative, although largely unpredictable, impact for the people in some parts of the world. For those who are already living on marginal lands or who are exposed to water problems, climate change is likely to create considerable adverse effects.
Anaerobic degradation kinetics of a cholesteryl ester
Authors: Gutiérrez S. , Viñas M.
Published: May 2018

The most important components of wool scouring effluent grease are esters of sterols. Cholesteryl palmitate (CP) is the main ester in this grease. In this paper, the influence of the ester concentration in the anaerobic digestion and the relative rate of the different degradation steps, are studied. The experiment was carried out to measure methane production in the anaerobic degradation of acetate, palmitic acid (PA) and CP. A first-order kinetic model was assumed for hydrolysis and Monod models were assumed for both the methanogenic and acetogenic steps. Maximum hydrolysis rate was found to be around 20 times faster than the maximum methanogenic reaction rate during the experience. The lanolin emulsion drop size effect was also evaluated employing fine and coarse stock lanolin emulsions and no adapted sludge. Concentrations of 13.7 to 4.6 gCOD.l-1 were employed. In a previous study, the effect of palmitic acid emulsion size was found important when similar sludge was tested. When esters are degraded, a significant effect of drop size on the degradation rate was not found. The difference between CP and PA emulsions behavior could be due to the fact that cholesterol produced during the ester degradation has a protective effect on the sludge.
Biodegradation of octylphenol polyethoxylates by denitrification
Authors: Jiménez-González A. , Siles-Alvarado S. , Monroy O.
Published: May 2018

The biodegradation route of the octylphenol ethoxylates (OPEOs) by denitrification in an upflow anoxic sludge blanket (UASB) reactor was studied. An anaerobic sludge adapted to denitrifying conditions with acetate was adapted with increasing amounts of OPEOs and diminishing amounts of acetate until only 300 mg.L-1 of OPEOs were fed. Only 70% of stoichiometric NO3- was fed so partial removal was expected. The total OPEOs fed was transformed with 70% COD removal. HPLC and GC-MS analyses showed that octylphenol (OP) was immediately formed but disappeared while other intermediates, the ethoxylated moieties; mono and diethoxylate (OPEO1 and OPEO2 respectively) led to the cleavage of the alkyl chain to form propylphenol triethoxylate (PPEO3) and heptylphenol diethoxylated (HPEO2). These last two compounds are produced due to an attack to both sides of the molecule; the hydrophilic and the hydrophobic. These findings suggest three simultaneous routes of OPEO degradation.
Workshop 5 (synthesis): stakeholder participation in decision making - institutional forms
Authors: Morrison K.E. , Söderbaum P.
Published: May 2018

Water problems have a human dimension where the ideas, perceptions, values and life-styles of individuals in their different roles have an impact. A many-sided set of stakeholders is preferable in any decision process, with empowerment of those less able to make their views known.
From Rio via The Hague to Johannesburg: the role of multi-stakeholder dialogues
Authors: Dodds F.
Published: May 2018

The Stakeholder Forum will contribute a number of partnership initiatives in the areas of food security, freshwater, energy and health. These will demonstrate that stakeholders, working in partnership, can play their roles and meet their responsibilities in delivering sustainable development agreements.
Linking stakeholders and decision makers with science in managing the coastal water environment: case studies from urban, industrial and rural subtropical catchments in Australia
Authors: Fearon R.
Published: May 2018

The dynamics of stakeholder participation and effective dialogue processes vary markedly between and within catchment areas. Decision support tools and conflict resolution skills are essential in developing consensus in complex and conflicting issues. Undertaking relevant research requires genuine inclusion of all stakeholders at all stages of the process including development and implementation of management plans. Providing a scientifically integrated and participative approach increases the ability to understand the social and economic dimensions.
Report from the poster session and list of posters presented
Authors: Brattberg Gunilla
Published: May 2018

This year we had more than twice as many contributions as previously and among many good posters it was really a challenge to find out the best one. I wish to specifically thank my colleagues on the jury (Professor Egboka of Nigeria, Dr Hagebro of Denmark, Professor Rahman of the USA, and Peter Nyberg from Stockholm Water Company) for carrying out a very ambitious and thorough job.
Influence of flocculation conditions in the performance of an experimental domestic sewage treatment plant consisting of an anaerobic expanded bed reactor followed by dissolved air flotation
Authors: Penetra R.G. , Reali M.A.P. , Campos J.R.
Published: May 2018

This paper presents the results of a study performed with an experimental domestic sewage treatment plant (240 m3.d-1 flow) consisting of expanded bed anaerobic reactor (EBAR) followed by dissolved air flotation (DAF) unit. For the flotation step, the anaerobic reactor effluent was previously coagulated with 50 mgFeCl3.l-1 and flocculated under different conditions (mean velocity gradient, Gf, and flocculation time, Tf). The Gf values were from 60 to 100 s-1 associated with 13 and 20 min Tf values. During the tests, the following operational conditions of the flotation unit were maintained: chemical addition (50 mgFeCl3.l-1), 18% recirculation rate associated with a pressure of 450 ± 10 kPa in the saturation chamber and overflow rate of 180 m3.mÐ2.d-1. Temperature ranged from 23.8¡C to 30.01/4C. Best results were achieved for Gf = 80 s-1 and Tf = 20 min. For these conditions, the DAF unit removal efficiencies were: 94.4% for chemical oxygen demand (with 53 mg.l-1 COD residual), 87% for phosphorus (with 0.80 mgP.l-1 residual), 96.7% for total suspended solids (with 9 mg.l-1 TSS residual) and 96.4% for turbidity (with 12.9 NTU residual), when the anaerobic reactor effluents have worst quality during the whole day.
The development of an historical baseline of water balance and environmental flows
Authors: Papworth M.P. , Lewis B.
Published: May 2018

This paper has been motivated by a desire to put some numbers beside the label of sustainability as is currently applied to water related issues. Of particular interest is a general estimate of the water balance and environmental flows during the time intervals before Aboriginal arrival, when the land was being managed in an environmentally sustainable manner by the Aboriginals, and most recently following European settlement. This will be considered in an Australia-wide context, because the continent is geographically diverse, being mostly arid desert, with limited areas of fertile soils. Climate variation ranging from a hot tropical north to a cool temperate south will also be discussed. Attention will be given to the major factors that have influenced the water balance, including the extinction of Australian megafauna, the effects of “fire-stick” farming and the clearance of land for European agriculture with its consequences. It is hoped that the findings will increase our understanding of Australian water resources, and promote a greater appreciation of the fragility of this ancient landscape on which we dwell.
The Aral Sea: problems, legends, solutions
Authors: Kamalov Yu.
Published: May 2018

A lot of legends have been created around the Aral Sea. Some of them were born during the Soviet time but there are already new ones that have arrived recently. Those legends came to be the barriers to solving the problem. There are also barriers created by the status quo mentality of local authorities. But mutual understanding is the biggest problem among countries sharing water resources. It is suggested to create an Ecological Economics Unit of the Biosphere (EEUB) managed by an executive body not affiliated to any country. Despite the borders the EEUB should unite the economics of neighborhood countries to protect the nature.
Nitrogen fixation in the activated sludge treatment of thermomechanical pulping wastewater: effect of dissolved oxygen
Authors: Slade A.H. , Anderson S.M. , Evans B.G.
Published: May 2018

N-ViroTech, a novel technology which selects for nitrogen-fixing bacteria as the bacteria primarily responsible for carbon removal, has been developed to treat nutrient limited wastewaters to a high quality without the addition of nitrogen, and only minimal addition of phosphorus. Selection of the operating dissolved oxygen level to maximise nitrogen fixation forms a key component of the technology. Pilot scale activated sludge treatment of a thermomechanical pulping wastewater was carried out in nitrogen-fixing mode over a 15 month period. The effect of dissolved oxygen was studied at three levels: 14% (Phase 1), 5% (Phase 2) and 30% (Phase 3). The plant was operated at an organic loading of 0.7–1.1 kg BOD5/m3/d, a solids retention time of approximately 10 d, a hydraulic retention time of 1.4 d and a F:M ratio of 0.17–0.23 mg BOD5/mg VSS/d. Treatment performance was very stable over the three dissolved oxygen operating levels. The plant achieved 94–96% BOD removal, 82–87% total COD removal, 79–87% soluble COD removal, and >99% total extractives removal. The lowest organic carbon removals were observed during operation at 30% DO but were more likely to be due to phosphorus limitation than operation at high dissolved oxygen, as there was a significant decrease in phosphorus entering the plant during Phase 3. Discharge of dissolved nitrogen, ammonium and oxidised nitrogen were consistently low (1.1–1.6 mg/L DKN, 0.1–0.2 mg/L NH4+-N and 0.0 mg/L oxidised nitrogen). Discharge of dissolved phosphorus was 2.8 mg/L, 0.1 mg/L and 0.6 mg/L DRP in Phases 1, 2 and 3 respectively. It was postulated that a population of polyphosphate accumulating bacteria developed during Phase 1. Operation at low dissolved oxygen during Phase 2 appeared to promote biological phosphorus uptake which may have been affected by raising the dissolved oxygen to 30% in Phase 3. Total nitrogen and phosphorus discharge was dependent on efficient secondary clarification, and improved over the course of the study as suspended solids discharge improved. Nitrogen fixation was demonstrated throughout the study using an acetylene reduction assay. Based on nitrogen balances around the plant, there was a 55, 354 and 98% increase in nitrogen during Phases 1, 2 and 3 respectively. There was a significant decrease in phosphorus between Phases 1 and 2, and Phase 3 of the study, as well as a significant increase in nitrogen between Phases 2 and 3 which masked the effect of changing the dissolved oxygen. Operation at low dissolved oxygen appeared to confer a competitive advantage to the nitrogen-fixing bacteria.
Evaluation of biomass production in unleaded gasoline and BTEX-fed batch reactors
Authors: Acuna-Askar K. , Englande A.J. , Ramirez-Medrano A. , Coronado-Guardiola J.E. , Chavez-Gomez B.
Published: May 2018

BTEX removal under aerobic conditions by unleaded gasoline acclimated biomass and BTEX acclimated biomass, and the effect of surfactant on BTEX biodegradation were evaluated. The effect of BTEX concentration as the sole source of carbon for biomass acclimation and the effect of yeast extract on cell growth in unleaded gasoline-fed reactors were also evaluated. For the unleaded gasoline acclimated biomass, benzene was shown the most recalcitrant among all BTEX, followed by o-xylene and toluene with 16–23%, 35–41% and 57–69% biodegradation, respectively. Ethylbenzene was consistently the fastest BTEX chemical removed with 99% biodegradation for the four bioreactor acclimated biomasses tested. For the 1,200 ppm BTEX acclimated biomass, benzene showed the highest removal efficiency (99%) among the four biomass environmental conditions tested, along with 99% toluene and 99% ethylbenzene biodegradation. O-xylene showed 92–94% removal. In all bioassays tested Tergitol NP-10 was fully removed, and did not have a substantial effect on BTEX biodegradation at the end of a 10-day evaluation.
Sequential sorption and desorption of chlorinated phenols in organoclays
Authors: Kim J.-H. , Shin W.S. , Kim Y.-H. , Choi S.J. , Jeon Y.W. , Song D.-I.
Published: May 2018

Effect of pH on the sorption and desorption of the chlorinated phenols (2-chlorophenol and 2,4-dichlorophenol) in HDTMA-montmorillonite organoclays was investigated using sequential batch experiments. 2,4-dichlorophenol exhibited higher affinity in both sorption and desorption than 2-chlorophenol at pH 4.85 and 9.15. For both chlorophenols, the protonated speciation (at pH 4.85) exhibited a higher affinity in both sorption and desorption than the predominant deprotonated speciation (about 80% and 95% of 2-chlorophenate and 2,4-dichlophenate anions at pH 9.15, respectively). Desorption of chlorinated phenols was strongly dependent on the current pH regardless of their speciation during the previous sorption stage. No appreciable desorption resistance of the chlorinated phenols was observed in organoclays after sequential desorptions. Affinity of both chlorophenols in bisolute competitive sorption and desorption was reduced compared to that in a single-solute system due to the competition between solutes. The ideal adsorbed solution theory coupled with the single-solute Freundlich model successfully predicted the bisolute competitive sorption and desorption equilibria.
Seasonal variations in road runoff quality in Luleå, Sweden
Authors: Westerlund C. , Viklander M. , Bäckström M.
Published: May 2018

In regions with cold climate the urban drainage and highway runoff processes become much more complex, compared to temperate regions. Therefore, climatic conditions should be taken into account in planning and design of BMPs and snow handling strategies. In order to increase the knowledge of road runoff quality during melt and rain periods, respectively, measurements were carried out at a field site during a two-month period. The field site was situated at Södra Hamnleden, a road with 7,400 vehicles/day, in the central part of Luleå. Runoff samples were analysed for suspended solids and heavy metals (Pb, Cu, Cd, Ni and Zn). The results showed that the concentrations of suspended solids, lead, copper and cadmium were higher for the melt period, compared to rain generated runoff on the catchment without snow, and the highest concentrations were found during the rain-on-snow events. The results indicate a flow dependent increase in the concentration of suspended solids during the melt period. A comparison of the total mass of suspended solids over a one-month period showed that the melt period produced about 3 times more suspended solids. Metal elements during melt period were more particulate bound as compared to the rain period characterised by a higher percentage of the dissolved fraction.
Response surfaces for climate change impact assessments in urban areas
Authors: Semadeni-Davies A.
Published: May 2018

Assessment of the impacts of climate change in real-world water systems, such as urban drainage networks, is a research priority for IPCC (Intergovernmental Panel of Climate Change). The usual approach is to force a hydrological transformation model with a changed climate scenario. To tackle uncertainty, the model should be run with at least high, middle and low change scenarios. This paper shows the value of response surfaces for displaying multiple simulated responses to incremental changes in air temperature and precipitation. The example given is inflow, related to sewer infiltration, at the Lycksele waste water treatment plant. The range of plausible changes in inflow is displayed for a series of runs for eight GCMs (Global Circulation Model; ACACIA; Carter, 2002, pers. comm.). These runs are summarised by climate envelopes, one for each prediction time-slice (2020, 2050, 2080). Together, the climate envelopes and response surfaces allow uncertainty to be easily seen. Winter inflows are currently sensitive to temperature, but if average temperature rises to above zero, inflow will be most sensitive to precipitation. Spring inflows are sensitive to changes in winter snow accumulation and melt. Inflow responses are highly dependent on the greenhouse gas emission scenario and GCM chosen.
Innovative developments in the selective removal and reuse of heavy metals from wastewaters
Authors: Veeken A.H.M. , Rulkens W.H.
Published: May 2018

Sulphide precipitation of heavy metal containing wastewaters results in low effluent concentrations. However, sulphide precipitation is not widely applied in practice because the dosing of sulphide cannot adequately be controlled. A new process was developed where the combination of a sulphide-selective electrode (pS-electrode) and pH electrode controls the sulphide addition. Precipitation experiments were performed on a laboratory-scale in batch and continuous reactor systems with synthetic wastewaters containing Cd, Cu, Ni, Pb or Zn. The response of the pS-electrode during precipitation was unique for each heavy metal and was directly related to the solubility product of the corresponding metal sulphide. The metals were removed to levels <0.05 mg.l-1 at pH 6.0 by sulphide precipitation while maintaining a total sulphide concentration <0.02 mg.l-1. By the control of pS at different levels and keeping the pH constant at 6.0, the metals in solutions of both Cu and Zn could be precipitated selectively from solution in a batch and continuous reactors. The use of a membrane reactor in combination with control of pH and pS offers a simple, cheap, efficient and sustainable technique with respect to obtaining very low effluent concentrations and selective removal of metals as pure metal sulphides which can be reused.