bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence and removal of endocrine disrupters in landfill leachate treatment plants
Authors: Wintgens T. , Gallenkemper M. , Melin T.
Published: May 2018

Endocrine disrupting compounds can affect the hormone system in organisms. Industrial chemicals with estrogenic effects were detected in large quantities in landfill leachates. Membrane technology has proven to be an effective barrier to these substances and thus widely applied in the treatment of landfill leachate. The removal techniques under investigation are membrane bioreactors, nanofiltration, activated carbon adsorption, ozonation as well as reverse osmosis. Investigations were conducted at two different landfill leachate treatment plants with a variety of process configurations. The xenoestrogenic substances nonylphenol and bisphenol A were detected in high μg/L-ranges in raw landfill leachate. Membrane bioreactors (MBRs) were capable of removing more than 80% of the nonylphenol load. Final effluent concentrations range between 1-12 μg/L nonylphenol and 3-30 μg/L bisphenol A respectively. Reverse osmosis treatment proved to be less effective in nonylphenol and bisphenol A removal than MBRs with further polishing stages like nanofiltration and activated carbon adsorption.
Laboratory testing protocol to identify critical factors in bacterial compliance monitoring
Authors: Abbaszadegan M. , Ghatpande P. , Brereton J. , Alum A. , Narasimhan R.
Published: May 2018

This research focused on providing guidelines for water utilities on the collection and handling of routine bacteriological samples and in developing scientifically-based approaches in selecting the most representative sampling locations. A laboratory-scale pilot distribution system was designed comprising two parallel loops, one using unlined cast-iron pipe and one using PVC pipe. Each loop contained six sampling ports, including (1) a distribution main dead end faucet, (2) one long (5.5 m; 18 feet) and (3) one short (0.3 m; 1 foot) household copper service line with threaded hose-bibb taps, (4) one hose-bibb with welded faucet, (5) one dedicated sampling port (modeled after a manufacturer’s specifications) and (6) one laboratory-style (PVC) stop-cock sampling port. Residual chlorine concentrations were maintained at 0, 0.5, 1.5 and 2.0 mg/L stages during the course of the experiment. Bacterial samples were collected from the different sampling ports and assayed by membrane filtration and/or spread plate. Nutrient and R2A agars were used for heterotrophic plate counts (HPC), m-Endo agar for total coliform (TC) counts and Chromocult agar for injured bacterial analyses. Several methods of sample collection were tested using various combinations of flushing and tap disinfection, including “first flush” (no flushing, without tap disinfection), flushing only, tap disinfection only (using alcohol or hypochlorite solution) and flushing coupled with tap disinfection. The results indicated that the bacterial counts in samples drawn from dead ends were not significantly different from counts in samples from the other sample port configurations. First flush samples consistently produced the highest bacterial count results. Bacterial counts in samples from the long household copper service line were typically three orders of magnitude higher than in samples from the other sample ports. Thus, there is evidence that long copper household service connections may be unsuitable sample tap configurations for collecting samples intended to represent microbial quality in the distribution system.
A chemiluminescent immunofocus assay (CIFA) for non-microscopic enumeration of Cryptosporidium parvum infectivity in cell culture
Authors: Simmons O.D. , Sobsey M.D.
Published: May 2018

As Cryptosporidium parvum continues to cause waterborne disease, despite extensive efforts by drinking water suppliers and regulators, it is important to have reliable and convenient methods for detection of this pathogen in wastewater discharges, environmental source waters and finished drinking water supplies. In order to better understand the health risks of this organism, it is necessary that detection methods be able to distinguish between infectious and non-infectious Cryptosporidium oocysts in these environmental samples. Cryptosporidium infectivity assay systems based on infections in mice and on in vitro infections in continuous mammalian cell lines are available. Currently, these methods are impractical for routine analysis of water samples because they are tedious, lengthy and costly. These methods rely on careful microscopic examination or further analysis by PCR and then characterisation of the amplified DNA. Practical and affordable non-microscopic methods to determine Cryptosporidium infectivity are much needed for environmental analysis. A cell culture infectivity detection system was developed for infectious Cryptosporidium oocysts that does not rely on microscopic examination of samples to score results, is applicable to a variety of samples and has the potential to be used for routine water monitoring and other environmental or biomedical analysis. Using a chemiluminescent immunoassay, the discrete foci of developmental stages of Cryptosporidium in cell cultures are clearly visible as discrete objects in an image of the entire cell culture layer in a dish or on a slide. These objects are directly countable with the unaided eye and their identity can be further confirmed or verified by microscopic examination.
Effect of environmental conditions on the erosional resistance of cohesive sediment deposits in sewers
Authors: Tait S.J. , Marion A. , Camuffo G.
Published: May 2018

The potential to adjust sewer network operation in order to control the level of transported sediment in sewage so as to enhance the performance of end-of-pipe treatment works is now being investigated. However for this to become a practical management option there is a need to be able to understand the processes which control the movement of sediments that are found in many combined sewers. Crucial to this understanding is an ability to predict how sediments from in-sewer deposits, are released by the action of vigorous flows. This paper reports on a laboratory investigation that aimed to investigate the effect that the environmental conditions during deposit formation can have on the ability of fine-grained organic sediment within in-sewer deposits to resist erosion and subsequent release into transport.
Population dynamics of rumen microbes using modern techniques in rumen enhanced solid incubation
Authors: Raizada N. , Sonakya V. , Dalhoff R. , Hausner M. , Wilderer P.A.
Published: May 2018

The microbial ecology of the rumen is very complex. Different species of bacteria, protozoa, and fungi are involved in digestion of plant material in ruminants. In spite of complicated interrelationships among the various groups of microorganisms in the rumen ecosystem, Bacteria and Archaea are believed to play a major role because of their numerical predominance and metabolic diversity. In this work we are presenting the results for microbial population dynamics of rumen microbes during two-stage anaerobic digestion of grass. The reactors were inoculated with fresh rumen content. Fluorescent in situ hybridization, confocal laser scanning microscopy and epifluorescence microscopy were employed for microbial investigation. It was observed that Bacteria dominated in the hydrolytic reactor (1st stage) whereas Archaea were predominant in the methanogenic reactor (2nd stage). The stability of the methanogenic reactor was result of the dominance of Methanosaeta species (mainly the filamentous type).
A method for the numerical assessment of sediment interceptors
Authors: Faram M.G. , Harwood R.
Published: May 2018

The problems associated with the presence of sediments in sewers and stormwater drainage systems represent a major engineering challenge. Their accumulation can result in operational difficulties, including flow restriction and premature overflows. Sediments themselves are known to contribute significantly to the polluting load of storm overflows. The use of sediment interceptors within sewer systems or downstream of stormwater intakes represents one way of alleviating these problems. A study of stormwater sediment interceptors using Computational Fluid Dynamics (CFD) has identified that the ability of a chamber to retain, as well as remove, sediments is an important performance characteristic. A methodology for the assessment of such characteristics using CFD is presented in the context of a study of different chamber types. This concludes that primitive chambers, for example, gully pots, are likely to be far more prone to flushing out during high flow inputs than advanced systems such as vortex separators.
Isolation and characterization of solventogenic, cellulase-free xylanolytic Clostridia from cow rumen
Authors: Sankar M. , Delgado O. , Mattiasson B.
Published: May 2018

Hemicellulolytic obligate anaerobes capable of converting a range of agricultural substrates and monomeric sugars of hemicellulose to solvents and acids were isolated from cow rumen fluid. The strains were identified as 5 strains of C. beijerinckii (3 different genotypes), 3 strains of C. acetobutylicum (2 different genotypes), 1 strain of C. butyricum and 3 strains of C. bifermentans (2 different genotypes). All of them produced cellulase-free xylanase activity. C. acetobutylicum LUI produced solvent, a high of 5.1 gl-1 and C.bifermentans LUI produced xylanase activity a high of 4.2 IU ml-1.
Automated biofilm morphology quantification from confocal laser scanning microscopy imaging
Authors: Xavier J.B. , White D.C. , Almeida J.S.
Published: May 2018

In spite of the immediate visual appeal of confocal laser scanning microscopy images, the extraction of accurate reconstitutions of biofilm morphology requires a lengthy and computational intensive succession of processing steps. However, once performed, it provides ample reward by enabling the quantitative study of biofilm structure. A software suite of image processing tools for full automation of biofilm morphology quantification was developed by integrating preprocessing, segmentation and morphology quantification operations. This software toolbox was implemented in a web server and a user friendly interface was developed to facilitate image submission, storage and sharing, its access being unrestricted for scientific applications. The image bioinformatics tool which results from the integration of the processing operations can be accessed at http://www.itqb.unl.pt:1111/clsmip/. Its use is described in this paper and is illustrated with an example of processing of experimental data describing the growth of a mixed species denitrifying biofilm.
Portable pilot plant for evaluating marine biofouling growth and control in heat exchangers-condensers
Authors: Casanueva J.F. , Sánchez J. , García-Morales J.L. , Casanueva-Robles T. , López J.A. , Portela J.R. , Nebot E. , Sales D.
Published: May 2018

Biofouling frequently involves a serious impediment to achieving optimum operating conditions in heat exchangers-condensers. The economic cost and energy losses associated with this phenomenon are significant and the environmental impact of biocides must satisfy stringent regulations. A portable pilot plant has been designed in order to carry out in-situ experimental study as biofilm is formed under thermal and hydrodynamically controlled conditions. The pilot plant has an automatic monitoring, control and data acquisition system, which automatically processes data from indirect measure of fouling in terms of increased fluid frictional and heat transfer resistances. A particular method is used and proposed for direct measuring and biofilm characterization. Once we know the actual film thickness, we can calculate the effective thermal conductivity of the layer by using the appropriate heat transfer equations.
Monitoring and characterisation of bacteria in corroding district heating systems using fluorescence in situ hybridisation and microautoradiography
Authors: Kjellerup B.V. , Olesen B.H. , Nielsen J.L. , Frølund B. , Ødum S. , Nielsen P.H.
Published: May 2018

Presence of biofilm and biocorrosion has been observed in Danish district heating (DH) systems despite very good water quality that was expected to prevent significant microbial growth. The microbiological water quality was investigated in order to identify the dominating bacterial groups on surfaces with corrosion problems. Water samples from 29 DH systems were investigated for the total number of bacteria and presence of sulphate reducing bacteria (SRBs). SRBs were found to be present in more than 80% of the DH systems. The microbial population in samples from 2 DH systems (biofilm from a test coupon and an in situ sample from a heat exchanger) was investigated with fluorescence in situ hybridisation, and the results showed significant differences in population composition. Betaproteobacteria was the dominant population in both samples. SRBs were present in both samples but were most numerous in the biofilm from the test coupon. Examination of functional groups based on uptake of radiolabelled acetate (microautoradiography) showed presence of both aerobic and anaerobic bacteria despite the fact that oxygen is not anticipated in DH systems.
Three-dimensional distribution of GFP-labeled Pseudomonas putida during biofilm formation on solid PAHs assessed by confocal laser scanning microscopy
Authors: Rodrigues A.C. , Wuertz S. , Brito A.G. , Melo L.F.
Published: May 2018

Confocal laser scanning microscopy was used to monitor the colonization pattern of the gfp-labeled derivative strain of Pseudomonas putida ATCC 17514 on fluorene and phenanthrene crystals. The in situ experiments showed that P. putida tends to grow directly on phenanthrene, forming a biofilm on accessible crystalline surfaces. On the other hand, no significant biofilm formation was observed in the presence of fluorene. The results obtained showed that substrate properties affected bacterial strategy regarding uptake.
Monitoring the active sessile-colonisation of two drinking water distribution systems based on the protein contents in native biofilm samples
Authors: Menaia J. , Alves R. , Sanches S. , Santos G. , Mesquita E.
Published: May 2018

Biofilms are present to a greater or lesser degree in virtually all drinking water distribution systems. In order to investigate the relative intensity and the spatial and temporal distributions of the active sessile-colonization, protein was determined in native biofilm samples from the Oeiras-Amadora (OADS) and the Almada (ADS) distribution systems in Portugal. Samples (25 cm2) were taken from lengths of asbestos cement pipes of different ages and diameters. Protein was detected at levels from 0.3 to 68 μg/cm2 in samples from all analysed pipe diameters and ages. At OADS, protein was found at 0.3 to 1 mg/cm2 in 99% of the samples. At ADS, protein was only found in 30% of the samples, but at significantly higher levels (0.3 to 68 mg/cm2). In addition to displaying a more intense and scattered active colonization, ADS's oldest-pipes (in use for over 30 years) solely exhibited protein at the highest levels found (>19 mg/cm2), in contrast with the younger pipes where protein levels ranged from 0.3 to 19 mg/cm2. Observed results suggest that the spatial and temporal distribution patterns of the active biofilm colonization may vary significantly among drinking water networks and may have a rather slow evolution, possibly at the decades scale.
Respiration rate measurement in a submerged fixed bed reactor
Authors: Carrión, M. , Asaff A. , Thalasso F.
Published: May 2018

A novel method is presented to measure the overall biofilm respiration rate in a submerged fixed bed reactor. The method, named “double gassing-out” is based on the measurement of the oxygen uptake rate under two different conditions: (i) replacing the air flow rate by nitrogen in the biological reactor, ensuring the conservation of the same hydraulic conditions and (ii) measuring the oxygen displacement rate by nitrogen in an identical reactor design with no microorganisms. The difference between these measurements gives the overall biofilm respiration rate. Results obtained in a nitrifying fixed bed reactor are presented, compared to classical techniques and discussed.
A novel titrimetric method for monitoring toxicity on nitrifying biofilms
Authors: Artiga P. , Oyanedel V. , Garrido J.M. , Mendez R.
Published: May 2018

A titrimetric method for monitoring toxicity in suspended biomass was applied in order to measure the activity of nitrifying biofilms and to determine the effect of several toxic compounds on the biofilm. Three typical tannery compounds, quebracho extract, NaCl and Cr+3 were selected to study their toxicity on the biofilms. The results obtained showed an acceptable repeatability of the method for all the toxicants tested with an average standard deviation of less than 10%. Biofilm systems showed higher resistance to the toxicants, when the results obtained using suspended nitrifying biomass, were compared with those found in the literature. The IC50 obtained with quebracho was 8.8 g/L of quebracho extract, while around 65% of maximum activity was attained with 8.7 g/L of NaCl or 120 mg/L Cr+3. The quebracho extract, NaCl and Cr+3 were 26%, 38% and 18%, respectively, less toxic in the biofilm system than for a suspended biomass culture.
Monitoring the influence of toxic compounds on microbial denitrifying biofilm processes
Authors: Li J. , Bishop P.L.
Published: May 2018

Microelectrode measurements were conducted to obtain nitrate, pH and redox potential profiles within anoxic denitrifying biofilms. The influence of a toxic organic compound (acid orange 7) on biofilm microprofiles was also monitored using microelectrodes. The data provide evidence that the denitrifying biofilms were stratified into an anoxic layer and an anaerobic layer. The anaerobic zone might provide a niche for the biodegradation of recalcitrant organic compounds in biofilms. It was found that acid orange 7 and its biodegradation byproducts had only a slight impact on biofilm nitrate, pH and redox potential profiles.
Summary and conclusions of the 2002 Stockholm Water Symposium
Authors: Falkenmark M.
Published: May 2018

Water as an engine for development. Water is the key to socio-economic development and quality of life, and therefore an essential factor to be properly linked to other development factors. Water was also one of the five priority issues at the 2002 World Summit on Sustainable Development in Johannesburg. Reaching the Millennium Declaration's ambitions to halve, by 2015, the number of people suffering from poverty, hunger and ill-health cannot be accomplished unless water and sanitation services are organized in a manner that effectively improves livelihood security, including food security.
Forward to Johannesburg and hydro-solidarity
Authors: Kasrils R.
Published: May 2018

The provision of clean drinking water and adequate sanitation is one of the simplest and most effective steps to eradicating poverty. In South Africa a major programme is underway which will ensure all South Africans have a clean water supply within six years, and access to acceptable sanitation within ten years. Total basin management, transcending national boundaries, is essential to ensure the use of water for the common good of all. The term "hydro-solidarity" illustrates water as a catalyst for co-operation.
Workshop 1 (synthesis): water as a catalyst for development
Authors: Holmes P. , Kuylenstierna J.
Published: May 2018

The problem of allocating water resources is a political one, and water management teams now need to include political lobbyists and advisors. Education, at all levels, is a crucial element in any development strategy involving water.
Workshop 8 (synthesis): urban dynamics, livable cities and water
Authors: Andersson I. , Tropp H.
Published: May 2018

A major wave of urbanisation is taking place in small- and medium-sized cities in developing countries. Water governance and integrated approaches are key factors in providing adequate services and maintaining the water resource. Intermediate technologies and practices need to be applied on a much wider scale.
Evaluation of the start-up of an integrated municipal solid waste and leachate treatment system
Authors: Libãnio P.A.C. , Costa B.M.P. , Cintra I.S. , Chernicharo C.A.L.
Published: May 2018

A pilot-scale experiment was set up in the laboratory with the purpose of investigating the most relevant aspects of the anaerobic digestion of municipal solid wastes (MSW), which are necessary for the preparation of future feasibility studies and cost-benefit analyses. The experiment consisted of a comparative analysis among three different lines of operation, each one consisting of three anaerobic MSW reactors (with unit volume of 700 L): conventional landfill (line 1), raw leachate recycling (line 2), and integrated treatment, with seeded leachate recycling (line 3). So, a UASB reactor was installed in the integrated treatment line with the purpose of removing the organic load of the leachate of the MSW reactors and utilising the biological sludge produced for inoculation of the waste digestion. The endogenous inoculation promoted in line 3, by means of recirculation of the leachate and return of the exceeding biological sludge produced in the UASB reactor, has favoured the initial fermentation stage and also the acceleration of the methanogenic phase.
Institutionalizing the option of dam removal: the New Hampshire initiative
Authors: Lindloff S.D.
Published: May 2018

For two years, the State of New Hampshire has worked to institutionalize the option of dam removal. The high gradient streams that flow through the granite hills and mountains of this small northeastern state provided ideal conditions for dam construction, particularly during AmericaÕs Industrial Revolution of the 1800s when mills were constructed throughout the area. With more than 4,800 dams in the stateÕs database, there are many opportunities for the removal of dams that no longer serve a useful purpose, have become a public safety hazard and impact the river environment. Efforts to facilitate removal of dams in New Hampshire include the formation of a River Restoration Task Force and the creation of a dam removal program within the state agency responsible for regulating dams. This has led to the removal of two dams in the past year, with approximately ten additional projects in various stages of planning. A history of this agency-led initiative, as well as a discussion of the programÕs strengths, challenges and goals for the future are presented.
Restoring biodiversity in the Gwydir Wetlands through environmental flows
Authors: Mawhinney W.A.
Published: May 2018

As part of the Water Reforms process, environmental flow rules have been progressively implemented in New South Wales rivers. The Integrated Monitoring of Environmental Flows (IMEF) is a major project established to better understand how rivers and associated wetlands respond to environmental water allocations. The results presented here represent the vegetation data collected for the testing of the hypothesis that “protecting or restoring a portion of freshes and high flows and otherwise maintaining natural flow variability will replenish anabranches and riverine wetlands, restoring their biodiversity”. The study site is the Ramsar listed Gwydir Wetlands, located on the Gingham and Gwydir (Big Leather) Watercourses in the Lower Gwydir Valley, 100 km west of Moree. The expansion of irrigated agriculture in the lower Gwydir valley has severely altered flow regimes in the wetlands. The spread of the weed Phyla canescens (Lippia) is of major concern to landholders in the Gwydir Wetlands. Results indicate that Paspalum distichum (Water couch) and Eleocharis plana (Ribbed spike-rush) can maintain dominance over Phyla canescens if flooding occurs on a semi-regular basis. Conversely, Eichhornia crassipes (Water hyacinth) is a rampant noxious weed of open water in the Gwydir Wetlands, and has quickly spread in areas that are inundated for long periods. Management of this weed requires periodic drying of the wetlands to cause desiccation and death of the plants. The flooding requirement of individual species and plant associations in the Gwydir Wetlands are currently not fully understood. By providing better information on the consequence of different flows, the IMEF project will help to develop better management strategies to shift the dominance from introduced species such as P. canescens and E. crassipes to more desirable native plant species.
Stretching water – Queensland's water use efficiency cotton and grains adoption program
Authors: Goyne P.J. , McIntyre G.T.
Published: May 2018

The Cotton and Grains Adoption Program of the Queensland Rural Water Use Efficiency Initiative is targeting five major irrigation regions in the state with the objective to develop better irrigation water use efficiency (WUE) through the adoption of best management practices in irrigation. The major beneficiaries of the program will be industries, irrigators and local communities. The benefits will flow via two avenues: increased production and profit resulting from improved WUE and improved environmental health as a consequence of greatly reduced runoff of irrigation tailwater into rivers and streams. This in turn will reduce the risk of nutrient and pesticide contamination of waterways. As a side effect, the work is likely to contribute to an improved public image of the cotton and grain industries. In each of the five regions, WUE officers have established grower groups to assist in providing local input into the specific objectives of extension and demonstration activities. The groups also assist in developing growersÕ perceptions of ownership of the work. Activities are based around four on-farm demonstration sites in each region where irrigation management techniques and hardware are showcased. A key theme of the program is monitoring water use. This is applied both to on-farm storage and distribution as well as to application methods and in-field management. This paper describes the project, its activities and successes.
Biological nitrification and denitrification of opto-electronic industrial wastewater
Authors: Chen T.-K. , Ni C.-H. , Chen J.-N.
Published: May 2018

Development and application of biological nutrient removal processes accelerated significantly over the past decade due to more stringent nutrients (nitrogen and phosphorus) discharge limits being imposed on wastewater treatment plants. The opto-electronic industry has developed very fast over the past decade in the world. The wastewater often contains a significant quantity of organic nitrogen compounds and has a ratio of over 95% in organic nitrogen (Org-N) to total nitrogen (T-N). In this study, a 2-stage Anoxic/Aerobic pre-denitrification process was established and the efficiency of wastewater treatment was evaluated. Wastewater from an actual LCD-plant was obtained as the sample for looking into the feasibility of opto-electronic industrial wastewater treatment. Hydraulic retention time (HRT) and mixed liquor recycle rate (MLR) were controlled independently to distinguish between the effects of these two factors. Under suitable HRT and mixed liquor recycle ratio, effluents of NH4-N, NOx-N and COD can fall below 20 mg/l, 30 mg/l and 80 mg/l.
Respirometric measurement of kinetic parameters: effect of activated sludge floc size
Authors: Chu K.H. , van Veldhuizen H.M. , van Loosdrecht M.C.M.
Published: May 2018

The variation of activated sludge floc size with the mixing intensity of a mechanically stirred respirometer, expressed in terms of the mean energy dissipation rate, was characterized using a photometric dispersion analyzer. The floc size decreased rapidly when the energy dissipation rate was increased from 1.33 × 10-3 to 2.68 × 10-3 W/kg. Experiments were performed to investigate the effect of floc size on the oxygen saturation coefficient measured under the condition of acetate oxidation. The respirometric data were interpreted by considering only the kinetics of biochemical reactions. The variation of the oxygen saturation coefficient with mixing intensity was found to correlate with the variation of floc size with mixing intensity. The oxygen saturation coefficient was found to decrease from 0.23 to 0.08 mg/L when the mean energy dissipation rate was increased from 1.33 × 10-3 to 2.68 × 10-3 W/kg. The dependence of the oxygen saturation coefficient on floc size or mixing intensity suggests the presence of mass transfer resistances in large flocs.
The enzymology of sludge solubilisation utilising sulphate reducing systems: the role of lipases
Authors: Whiteley C.G. , Melamane X. , Pletschke B. , Rose P.D.
Published: May 2018

The first stage in the degradation and recycling of particulate organic matter is the solubilisation and enhanced hydrolysis of complex polymeric organic carbon structures associated with the sulphidogenic environment. An investigation into the enzymology of these processes has shown that lipase enzyme activities were found predominantly associated with the organic particulate matter of the sewage sludge. Sonication of the sludge gave an increase in enzyme activity as the enzymes were released into the supernatant. pH and temperature optimisation studies showed optima at between 6.5 and 8 and 50-60°C, respectively. All the lipase enzymes from the methanogenic bioreactors indicated extensive stability for at least an hour at their respective optimum temperatures and pH; sulphidogenic lipases reflected limited stability at these temperatures and pH during this time period. Though sulphate showed inhibitory properties towards lipases both sulphide and sulphite appeared to enhance the activity of the enzymes. It is argued that these sulphur species, liberated at different times during the sulphate reduction process, disrupt the integrity of the organic particulate floc by neutralising acidic components on the surface. The release of further entrapped enzymes from the organic particulate matter results in a subsequent enhancement of hydrolysis of polymeric material.
Polyhydroxyalkanoate (PHA) production from waste
Authors: Rhu D.H. , Lee W.H. , Kim J.Y. , Choi E.
Published: May 2018

PHA (polyhydroxyalkanoate) production was attempted with SBRs from food waste. Seed microbes were collected from a sewage treatment plant with a biological nutrient removal process, and acclimated with synthetic substrate prior to the application of the fermented food waste. Laboratory SBRs were used to produce PHA with limited oxygen and nutrients. The maximum content of 51% PHA was obtained with an anaerobic/aerobic cycle with P limitation, and the yield was estimated to be about 0.05 gPHAproduced/gCODapplied or 25 kg PHA/dry ton of food waste, assuming more than 40% of the PHA contents were recoverable. PHB/PHA ratios were 0.74 to 0.77 due to the higher acetate concentrations. Economical analysis seemed to suggest the PHA produced from the food waste could be an alternative material to produce the biodegradable plastic to be used for the collection bags for solid waste.
Urban drainage and highway runoff in cold climates: conference overview
Authors: Viklander M. , Marsalek J. , Malmquist P.-A. , Watt W.E.
Published: May 2018

This overview of research findings presented at the conference on urban drainage and highway runoff in cold climates starts with generation of urban runoff and snowmelt, followed by snowmelt and winter runoff quality, best management practices for urban snowmelt and winter runoff, and snow management in urban areas. Research on the urban hydrological cycle is lagging behind the needs in this field, particularly in terms of data availability. The current studies of winter urban runoff quality focus on road salts in the urban environment and their environmental effects. The needs for better source controls in salt applications, improved management of chloride-laden runoff, and selective adoption of environmentally safer alternative de-icers were reported. Adaptation of the conventional stormwater best management practices (BMPs) for winter operation remains a challenge. The first step in refining the existing BMPs for winter operation is to advance the understanding of their operation, as reported for some cases at the conference. Finally, snow management in urban areas may require local storage of fresh (unpolluted) snow and disposal of more polluted snow at central snow disposal sites.
Challenges, benefits and pitfalls of the independent laboratory process
Authors: Power K. , Nicholson C.
Published: May 2018

During 1998 Sydney's drinking water supply system experienced three contamination events in quick succession. These events were revealed by routine monitoring, which indicated the presence of large numbers of Cryptosporidium and Giardia in raw and treated waters. Questions were raised regarding the validity of the results produced by Sydney Water's laboratory, Australian Water Technology. In response to the incident a NSW Government Inquiry was carried out which made a range of recommendations, one of which was that “ suitably qualified independent laboratory should be established to provide accurate data for regulatory authorities.” The NSW Department of Health (DOH) was given the responsibility for interpretation and implementation of this recommendation.

The role of Independent Laboratory was awarded to the Australian Water Quality Centre (AWQC) and a monthly program of duplicate sample analysis was established. The implementation of the program and interpretation of the results have provided a challenge for all parties involved. A protocol was developed which defined conditions under which differences in results from the two laboratories were to be investigated. Over the time period of the Independent Laboratory process there has been only one occasion where a difference between results, as defined by the protocol, has been seen.

The process has provided additional assurance of quality control procedures for the laboratories. The future role of the process will need to be readdressed in light of the results of the previous 18 months and as changes in the area of testing methodologies occur.
Migration of alternative de-icers in unsaturated zone of aquifers - in vitro study
Authors: Hellstén P. , Nystén T.
Published: May 2018

The migration of organic de-icers in the shallow aquifers typical in Finland is not well known and we need to find solutions to minimise the negative impacts of de-icing on groundwater quality. The objective of the MIDAS project is to find de-icers which have the least harmful impacts on groundwater quality. Migration of sodium chloride as a tracer and five alternative de-icers in aquifers was studied. The alternative de-icers were calcium chloride, magnesium chloride, calcium-magnesium-acetate, potassium acetate and potassium formate. The research consists of leaching of heavy metals from roadsides in the area of Highway 1 in southern Finland; an in vitro study, which represented the full length of winter at low temperatures; and the subsequent on-going field research in south-eastern Finland. So far, in our studies potassium formate caused fewer changes to the quality of the infiltrated water than the chlorides and acetates. After finishing the on-going research the results will be used to choose a preferred de-icer from the existing chemicals and for the development of new less harmful de-icers. The information will be used mainly in Scandinavia and North America where the hydrogeological conditions are similar to those in Finland.
Comparison of the effects of using local and central snow deposits: a case study in Luleå
Authors: Reinosdotter K. , Viklander M. , Malmqvist P.-A.
Published: May 2018

The aim of the study was to determine if an increased use of local land-based snow deposits would be more sustainable than the use of a central snow deposit. The study focused on transport related emissions, costs for transporting the snow, technical attendance, local effects, public acceptance, land use, effects on the recipient environmental control and potential for accidents. General information was obtained from an inventory regarding snow handling that was made in 14, geographically spread, Swedish municipalities during 2001. The comparison of costs for transporting snow and transport-related emissions was based on information gathered from the municipality of Luleå. The study showed that using local land-based snow deposits would decrease traffic-related emissions such as CO2, CO and NOx by 40% annually and would decrease the annual cost for transporting snow by nearly 80%. On the other hand local snow deposits may lead to an increased risk of accidents and to negative local effects such as delayed growing season, flooding and drainage problems. Available land for local snow deposits in the cities is hard to find, and is usually expensive. Therefore a combination of local and central snow deposits is likely to be the most realistic option.
Grassed swales for stormwater pollution control during rain and snowmelt
Authors: Bäckström M.
Published: May 2018

The retention of suspended solids, particles and heavy metals in different grassed swales during rain events and snowmelt is discussed. The experimental results derived from investigations performed in existing grassed swales in the Luleå region, Northern Sweden. During high pollutant loading rates, grassed swales retain significant amounts of pollutants, mainly due to sedimentation of particulate matter. Low to moderate removal efficiencies could be expected for heavy metals, especially metals in solution (i.e. the dissolved phase). When grassed swales receive urban runoff with low pollutant concentrations, they may release rather than retain pollutants. Swales are important snow deposit areas in the city and particle bound pollutants do to a large extent remain in the swale after snowmelt. However, dissolved pollutants (i.e. dissolved heavy metals) are likely to escape the swale with the melt water. Grassed swales may be regarded as facilities that even out the peaks in pollutant loads without being capable of producing consistent high removal rates. This suggests that swales should be considered as primary treatment devices. Possible design parameters for grassed swales are mean hydraulic detention time, surface loading rate or specific swale area.
Modelling of temperature effects on removal efficiency and dissolved oxygen concentrations in stormwater ponds
Authors: German J. , Svensson G. , Gustafsson L.-G. , Vikström M.
Published: May 2018

The performance of stormwater ponds, operated under winter conditions, was modelled using the commercial software Mike21 and MOUSE. Direct and indirect effects of changing temperature were investigated. The most important effect of winter conditions is the changed hydrology, characterised by long periods with no runoff followed by snowmelt events with large runoff volumes during several days. This gives lower removal efficiencies than during a period with the same precipitation but without winter conditions. For the concentration of dissolved oxygen, wind is an important factor. Consequently the most important effect of an ice cover on the pond is that it prevents the oxygenation effects of the wind. The direct temperature effects on the removal processes are negligible compared to the indirect effects in changed hydrology and forming of ice cover.
Kinetics of biodegradation during remediation of consecutive accidental spills of chlorophenols in a sandy aquifer
Authors: Antizar-Ladislao B. , Galil N.I.
Published: May 2018

Kinetics of biodegradation of chlorophenols were studied in six sandy aquifer columns (0.06 m I.D.; 1.00 m L). Remediation of chlorophenols was enhanced by using a “closed-loop” configuration system, where local groundwater was recirculated through the polluted site in a controlled manner. Consecutive accidental spills of phenol, 2-monochlorophenol (2-MCP) and 2,4,6-trichlorophenol (2,4,6-TCP) as single pollutants were removed following first order kinetics. The removal of chlorophenols increased by one order of magnitude following consecutive accidental spills demonstrating adaptation of the resident micro flora. The biodegradation rate constants in this study were in the same range and agreed with those reported in the literature for biodegradation in aerobic aquifers. Following the fate of the resident micro flora (enhanced by adding NH4Cl and KH2PO4 at a ratio C/N/P equal to 120:10:1), biomass growth was observed in the sandy aquifer columns and particle size analyses of the aqueous phase recirculated through the polluted site experimentally proved aggregation of cells. Aggregation of cells has been hypothesized as one of the causes for low biodegradation rates found in the field compared to those calculated using biodegradation rate constants determined in batch culture.
Chemical destruction of MTBE using Fenton's Reagent: effect of ferrous iron/hydrogen peroxide ratio
Authors: Burbano A. , Dionysiou D. , Suidan M. , Richardson T.
Published: May 2018

In previous laboratory experiments Fenton's Reagent (FR) was successfully used as the source of hydroxyl radicals (OH•) for chemical treatment of low concentrations of methyl tert-butyl ether (MTBE) in water. Although under certain conditions MTBE degradation levels as high as 99.99% were achieved, none of these experiments resulted in complete MTBE mineralization. In all cases, these experiments applied FR as an equimolar concentration of ferrous iron (Fe2+) and hydrogen peroxide (H2O2). The present study investigates the effect of H2O2/Fe2+ molar ratio on the extent of degradation of MTBE and intermediate products in water at pH = 3.0. The initial concentration of MTBE studied was 0.0227 mM (approximately 2 mg/L). Initially, the dose of Fe2+ was kept constant at a Fe2+/MTBE molar ratio of 10:1 and the dose of H2O2 was varied to achieve different H2O2/Fe2+ molar ratios. The results revealed that higher degradation efficiency was achieved when FR was used as an equimolar mixture (H2O2/Fe2+ molar ratio = 1.0). The extent of MTBE degradation decreased when the H2O2/Fe2+ molar ratio was changed to values higher or lower than 1.0. These results suggest that a stoichiometric relationship (1:1) between the FR components optimizes the degradation process for this reactant system. It is hypothesized that an excess of H2O2 enhances the effect of reactions that scavenge OH•, while a decreased amount of H2O2 would be a limiting factor for the Fenton Reaction.
Wastewater treatment from a motor-oil reforming company using a sequencing batch reactor (SBR)
Authors: Drillia P. , Kornaros M. , Lyberatos G.
Published: May 2018

The main aim of this work was to study the ability of an aerobically operated sequencing batch reactor (SBR) to effectively treat the wastewaters produced by a motor-oil reforming company. In fact, the most important goal was to substantially reduce the organic load of these wastewaters before their disposal to an open trench, since the currently installed wastewater treatment plant, that includes an API separator followed by physico-chemical pre-treatment and an oxidation ditch, has proved today to be completely inefficient. The wastewater to be treated was mainly composed of five different streams from various points of the motor-oil reforming plant (e.g. gas washing tanks, cooling pumps, used motor oils holding tanks, etc). The major problem faced in this work was the high organic load (about 12,000 mg COD/L) and the free and dissolved oil contained in the wastewater (around 6-7%). Moreover, two of the streams, contributing to the mixed wastewater up to 30%, were unable to sustain dissolved oxygen and unfortunately their mixing with the other three streams resulted in the same detrimental effect. Therefore, experiments were conducted using either three or all of the contributing streams. The mixed wastewater was fed to the reactor either untreated or pre-treated with ceramic membranes in order to exclude all the free and dissolved oil. The application of pre-treated wastewater with membranes to the SBR system resulted in 75.2% and 81.9% total and dissolved COD reduction, respectively.
Improvement of pre- and post-processing environments of the dynamic two-dimensional reservoir model CE-QUAL-W2 based on GIS
Authors: Ha S.-R. , Bae G.-J. , Park D.-H. , Cho J.H.
Published: May 2018

An Environmental Information System (EIS) coupled with a Geographic Information System (GIS) and water quality models is developed to improve the pre- and post-data processing function of CE-QUAL-W2. Since the accuracy of the geometric data in terms of a diverse water body has a great effect on the water quality variables such as the velocity, kinetic reactions, the horizontal and vertical momentum, to prepare the bathymetry information has been considered a difficult issue for modellers who intend to use the model. For identifying Cross Section and Profile Information (CSPI), which precisely contains hydraulic features and geographical configuration of a waterway, the automated CSPI extraction program has been developed using Avenue Language of the PC Arc/view package. The program consists of three major steps: (1) getting the digital depth map of a waterway using GIS techniques; (2) creating a CSPI data set of segments in each branch using the program for CE-QUAL-W2 bathymetry input; (3) selecting the optimal set of bathymetry input by which the calculated water volume meets the observed volume of the water body. Through those approaches, it is clear that the model simulation results in terms of water quality as well as reservoir hydraulics rely upon the accuracy of bathymetry information.
A European scale monitoring system to assess water quality of multi-national river basins in the accession countries
Authors: Fehér J. , Lázár A.
Published: May 2018

In the middle of the 1990s the European Environment Agency (EEA) started to develop a data collecting system for surface and subsurface water resources for assessing pressures, states and impacts on European water resources. The main objective of this system was to provide reliable, comparable, homogenous information, and support integrated environmental assessments at European level. The data collecting system for water is called Eurowaternet. The extent and information content of the network makes not only pan-European, but also regional or thematic environmental assessments possible. An extensive programme started in 1997 to support the Phare countries in their accession to the EU with implementation of this data collecting system in their countries.

The paper briefly introduces the methodology of the system, but it focuses more on the application of the system in the accession countries, highlighting, through examples, the usefulness of the implemented network and assembled database. The examples present - among several other possible ones - trends of average nutrient concentrations; relationships between catchment size and annual average nutrient concentrations; relationships between catchment size and agricultural usage.