bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards sustainability in water recycling
Authors: Sala L. , Serra M.
Published: May 2018

Those like us who believe in and spread the gospel of planned wastewater reclamation and reuse usually emphasize that this is a step towards sustainability in water resource management, but this is something that is very seldom analyzed. This paper discusses, from a critical point of view, issues such as goals in water reuse and influence on water demands, ecological analysis of the cycle of the main pollutants, health aspects and treatment requirements, energy consumption and measurable environmental benefits, in order to provide a set of criteria to assess sustainability in water recycling projects and to decrease the impact of the cultural water cycle on the environment.
Strategic options for sustainable water management at new developments: the application of a simulation model to explore potential water savings
Authors: Alegre N. , Jeffrey P. , McIntosh B. , Thomas J.S. , Hardwick I. , Riley S.
Published: May 2018

Research on appropriate technologies and infrastructures to support water reuse has progressed rapidly over recent decades and there are now a wide range of source - treatment - reuse options for planners to choose from. Although the economics of water reuse schemes favours application to new developments rather than retrofit projects, there are few studies which have sought to address strategic option selection issues for large developments. The potential advantages of using treatment and reuse systems in new developments require an understanding of the relationships between a wide variety of social, environmental, technological, and operational factors. The operational effectiveness and economic efficiency of specific technology choices will vary as a function of network configuration, wastewater characteristics, how different technologies respond to dynamic loading (variability of feed strength and flow) and potential spiking, as well as equipment reliability, climate and household behaviour. Using a commercially available software package, the study reports the design and implementation of a low resolution simulation tool to explore sustainable water management options for a live case study site in the south of England (a peri-urban development of 4,500 new homes) with particular reference to opportunities for rainwater harvesting, and water reuse.
Characterisation of materials causing discolouration in potable water systems
Authors: Seth A. , Bachmann R. , Boxall J. , Saul A. , Edyvean R.
Published: May 2018

Discoloured water is one of the main causes of customer complaints received by UK water suppliers. Flushing is recognised as a means of preventing red water events by mobilising material with the potential to cause discolouration. The understanding of the mechanisms and materials causing discolouration is limited. It is therefore necessary to characterise the materials mobilised by flushing, _which are responsible for discolouration. The University of Sheffield and two UK water companies embarked on an in-depth programme of monitoring mains flushing. The programme involves collecting discrete samples during flushing of pipes of differing materials, diameters, age, source water and hydraulic regime. The results show iron to be the dominant material mobilised irrespective of pipe material. All samples indicate a direct correlation between turbidity, iron and manganese, and to a lesser extent with metals lead, copper, aluminium and zinc. Concentration of metals mobilised is independent of pipe material, diameter or age.
A field based study of ferrous metal corrosion in groundwater
Authors: McLaughlan R.G. , Stuetz R.M.
Published: May 2018

There is an increased emphasis on adopting explicit management strategies to ensure the effective use of water wells. This can be achieved through identifying the operational and maintenance needs of water wells and associated infrastructure. The types of material used for this infrastructure will impact upon the life of these assets and their maintenance needs. In groundwater environments there is often little available corrosion rate data from historical records of operating wells upon which to make choices about material selection. Under these conditions it is necessary to rely on corrosion test data to inform design choices. A long term field based immersion test using corrosion coupons was undertaken at 24 sites across Australia. The general corrosion rates of mild steel after 9 months were found to range from 0.018 to 0.624 mm per year while stainless steel was found to have minimal corrosion under the same conditions. Galvanised steel was found to offer minimal protection compared with mild steel when the pH was below 7.
Health and aesthetic impacts of copper corrosion on drinking water
Authors: Dietrich A.M. , Glindemann D. , Pizarro F. , Gidi V. , Olivares M. , Araya M. , Camper A. , Duncan S. , Dwyer S. , Whelton A.J. , Younos T. , Subramanian S. , Burlingame G.A. , Khiari D. , Edwards M.
Published: May 2018

Traditional research has focused on the visible effects of corrosion - failures, leaks, and financial debits - and often overlooked the more hidden health and aesthetic aspects. Clearly, corrosion of copper pipe can lead to levels of copper in the drinking water that exceed health guidelines and cause bitter or metallic tasting water. Because water will continue to be conveyed to consumers worldwide through metal pipes, the water industry has to consider both the effects of water quality on corrosion and the effects of corrosion on water quality. Integrating four key factors - chemical/biological causes, economics, health and aesthetics - is critical for managing the distribution system to produce safe water that consumers will use with confidence. As technological developments improve copper pipes to minimize scaling and corrosion, it is essential to consider the health and aesthetic effects on an equal plane with chemical/biological causes and economics to produce water that is acceptable for public consumption.
Role of irrigation and wastewater reuse: comparison of subsurface irrigation and furrow irrigation
Authors: Choi C. , Song I. , Stine S. , Pimentel J. , Gerba C.
Published: May 2018

Two different irrigation systems, subsurface drip irrigation and furrow irrigation, are tested to investigate the level of viral contamination and survival when tertiary effluent is used in arid and semi-arid regions. The effluent was injected with bacteriophages of PRD1 and MS2. A greater number of PRD1 and MS2 were recovered from the lettuce in the subsurface drip-irrigated plots as compared to those in the furrow-irrigated plots. Shallow drip tape installation and preferential water paths through cracks on the soil surface appeared to be the main causes of high viral contamination in subsurface drip irrigation plots, which led to the direct contact of the lettuce stems with the irrigation water which penetrated the soil surface. The water use efficiency of the subsurface drip irrigation system was higher than that of the furrow irrigation system. Thus, subsurface drip irrigation is an efficient irrigation method for vegetable crops in arid and semi-arid regions if viral contamination can be reduced. Deeper installation of drip tapes, frequent irrigations, and timely harvests based on cumulative heat units may further reduce health risks by ensuring viral die-off under various field conditions.
Inter-relationships between corrosion and mineral-scale deposition in aqueous systems
Authors: Hodgkiess T.
Published: May 2018

The processes of corrosion and scale deposition in natural and process waters are often linked and this paper considers a number of instances of interactions between the two phenomena. In some circumstances a scale layer (e.g. calcium carbonate) can be advantageously utilised as a corrosion-protection coating on components and this feature has been exploited for many decades in the conditioning of water to induce spontaneous precipitation of a scale layer upon the surfaces of engineering equipment. The electrochemical mechanisms associated with some corrosion and corrosion-control processes can promote alkaline-scale deposition directly upon component surfaces. This is a feature that can be exploited in the operation of cathodic protection (CP) of structures and components submerged in certain types of water (e.g. seawater). Similar phenomena can occur during bi-metallic corrosion and a case study, involving carbon steel/stainless steel couples in seawater, is presented. Additional complexities pertain during cyclic loading of submerged reinforced concrete members in which scale deposition may reduce the severity of fatigue stresses but can be associated with severe corrosion damage to embedded reinforcing steel. Also considered are scale-control/corrosion interactions in thermal desalination plant and an indirect consequence of the scale-control strategy on vapourside corrosion is discussed.
Alternative treatment strategy for tannery water reuse and material recovery
Authors: Mijaylova Nacheva P. , Moeller Chávez G. , Juárez Herrera M.
Published: May 2018

Most tanneries use conventional systems for treatment of the mixture of all production effluents. Such an approach makes it possible to meet environmental regulations, but because of the high cost of the treatment facilities, its implementation has been scarce, especially in developing countries. With the waste reduction-elimination concept in view, an alternative strategy for water management is proposed based on individual treatment of the effluents from different processing steps to obtain multiquality recycled water for various reuse purposes, materials recovery and complete reuse of treated water. The methodology includes a database generation of tanneries in Mexico, a mass balance and pollution index determination, formulation of water management scenarios and technical-economical evaluation. To replace the traditionally used sulfide oxidation, a sulfide recovering was proposed. Chromium, grease and protein recovery were considered too. The proposed alternative allows a 90% fresh water reduction, the recovery of more than 95% of chromium and sulfide, 90% of grease, 65% of protein and zero discharge of wastewater. Simultaneous implementation of various water saving methods using in-house wastewater treatment techniques for recovering of chemicals and sub-products reduces substantially the cost of water management.
Particle size distribution as a useful tool for microbial detection
Authors: Chavez A. , Jimenez B. , Maya C.
Published: May 2018

Worldwide, raw or treated wastewater is used for irrigation. However, this practice implies that the microbial content must be controlled. Unfortunately, detection techniques for microorganisms are costly, time consuming, and require highly trained personnel. For these reasons, this study used particle size distribution to measure the microbial quality of wastewater through correlations between the number or volume of particles and the concentration of fecal coliforms, Salmonella spp. and helminth ova. Such correlations were obtained for both raw and chemically treated wastewater. The best fit was the one for helminth ova, which applies for both the influent and effluent and also for all the coagulants involved. This technique allows the on-line quantification of helminth ova at a cost of US$3 and it takes only 5 minutes, instead of the US$70 and 5 days for the standard technique. With respect to the coagulants applied, their behavior is different only for particles smaller than 8 mm, and thus this value is considered as the critical size for this particular treatment. The best coagulant was the aluminium polychloride. In addition, this work establishes the distribution of COD, TSS, nitrogen, and phosphorous for particles smaller and larger than 20 mm.
Technical and sanitary aspects of wastewater disinfection by UV irradiation for landscape irrigation
Authors: Lazarova V. , Savoye Ph.
Published: May 2018

Water reuse for landscape irrigation requires the production of high quality virus-free effluents to minimize risk for human health. In order to establish the relevance of MS2 phages as an appropriate biodosimeter for UV design, a pilot plant study has been carried out with different types of wastewater effluents. The two pilot systems tested (low-pressure high output and medium-pressure UV units) were able to achieve 4 and 5 log MS2 reduction in tertiary filtered effluent at high calculated UV doses of 170 _ 10 and 300 mJ/cm2, respectively. UV disinfection was extremely efficient for MS2 inactivation in high quality effluents after reverse osmosis: detention times as low as one second and UV dose of 40 mJ/cm2 were sufficient to reach 5 log inactivation of MS2. UV irradiation also produced rapid inactivation of human pathogens such as poliovirus type 1 and indigenous enteroviruses at UV doses up to 3 times lower that those for MS2 disinfection. It was concluded that accurate UV unit design for a given type of wastewater could be ensured by pilot tests using laboratory-propagated MS2 as biodosimeter and collimated-beam tests as the calibration-check.
Threshold scaling limits of RO concentrates flowing in a long waste disposal pipeline
Authors: Semiat R. , Hasson D. , Zelmanov G. , Hemo I.
Published: May 2018

Disposal of RO concentrates emanating from inland brackish water desalination plants presents a difficult environmental problem. The solution adopted by Mekorot - the National Water Company of Israel - is to construct a 30 km waste disposal pipeline for collecting concentrates emanating from several RO desalination plants and discharging them into the sea. The discharged concentrates are highly supersaturated with respect to CaCO3. Scale precipitation during concentrate flow through the RO module is inhibited by the presence of anti-scalants. The retention time of the concentrate solution in the discharge pipe will exceed 100 hours. This raises the issue of the risk of scale precipitation in the discharge pipe that could impair its proper functioning. The aim of the present study was to provide data for guiding the design and operation of the disposal pipeline. The extent of the induction period prior to the onset of precipitation was measured in a pilot plant simulating flow of concentrate solutions dosed with anti-scalants. The parameters investigated were the scaling potential, the anti-scalant concentration and the presence of a mixture of several anti-scalants. The results of this study provide threshold scaling limits under various conditions.
Investigation on the behaviour of selected pharmaceuticals in the groundwater after infiltration of treated wastewater
Authors: Kreuzinger N. , Clara M. , Strenn B. , Vogel B.
Published: May 2018

In a rural arid area without suitable receiving water the treated wastewater of a low loaded municipal wastewater treatment plant with full nutrient removal and additional post treatment steps is infiltrated into the unsaturated soil for groundwater recharge. Groundwater probes at increasing distances from the infiltration point have been sampled every two months over a period of 14 months. Beside conventional parameters (nutrients, carbon, and bacterial counts) samples were analysed for pharmaceutically active substances. Depending on and corresponding to their chemical structure and their fate during wastewater treatment, the selected substances showed different behaviour in the saturated zone of the groundwater. The antiepileptic Carbamazepine behaves very conservative and only is removed negligible even after long flow times within the subsurface zone. For other substances like the tranquilizer Diazepam or the analgesics Diclofenac a partial elimination during the different steps of wastewater treatment can be observed. Further degradation could be observed during the subsequent subsurface passage. In correlation with flow time additional removal of these substances from the aqueous phase can be observed. The musk substances Galaxolide and Tonalide were removed to some extend but not as good as the previous mentioned compounds.
Investigation of biological and fouling characteristics of submerged membrane bioreactor process for wastewater treatment by model sensitivity analysis
Authors: Cho J.W. , Ahn K.-H. , Lee Y.H. , Lim B.-R. , Kim J.Y.
Published: May 2018

In this study, a mathematical model for the submerged membrane bioreactor (SMBR) was developed. The activated sludge model No. 1 (ASM1) was modified to be suitable for describing the characteristics of the SMBR, and the resistance-in-series model was integrated into the ASM1 to describe membrane fouling. Using the newly developed model, the biological and fouling characteristics of the submerged membrane bioreactor process for wastewater treatment was investigated by sensitivity analysis. The sensitivity of effluent COD and nitrogen, TSS in the reactor and membrane flux with respect to each parameter (Kh, μH, KS, KNHH, KNOH, bH, YH, μA, KNHA, bA, YA, Km and α) was investigated by model simulation. As a result, the most important factors affecting membrane fouling were hydrolysis rate constant (Kh) and cross-flow effect coefficient (Km). Heterotrophic yield coefficient (YH) had a great influence on effluent quality. Effluent quality was also somewhat sensitive to Kh. Peculiar operating conditions of the SMBR such as long solids retention time (SRT), absolute retention of solids by membrane and high biomass concentration in bioreactor could explain these model simulation results. The model developed in this study would be very helpful to optimize operating conditions as well as design parameters for a SMBR system.
California's Task Force evaluation of issues confronting water reuse
Authors: Mills R.A. , Karajeh F. , Hultquist R.H.
Published: May 2018

Water reclamation and reuse have been occurring in California for over a century. The state is arid and semi-arid in large regions and must rely on a variety of water supplies to meet its water demands. Reclaimed water is a potential source to meet a significant portion of new demands expected by 2030. However, there are issues of public health and water quality regulation, cost, public acceptance, institutional and other barriers that must be addressed. The California State Legislature adopted legislation in 2001 to convene the Recycled Water Task Force to advise the state on the opportunities for using reclaimed water in a broad spectrum of applications and in identifying impediments and constraints to increasing the use of reclaimed water. The processes for conducting the Task Force are described to illustrate the actions that were intended to increase the credibility of the Task Force. The recommendations of the Task Force are summarized.
Groundwater-borne nitrate intakes into surface waters in Germany
Authors: Kunkel R. , Bach M. , Behrendt H. , Wendland F.
Published: May 2018

The nitrogen loads entering the surface waters in Germany via the groundwater path were quantified. For this purpose, the results of a nitrogen balance model (Bach et al., 2000), which considers the most important N-inputs to the soil (manure, inorganic fertiliser, atmospheric deposition) and N-removals from the soil through crop harvest, were combined with the groundwater residence time/denitrification model WEKU (Kunkel and Wendland, 1997; Wendland et al., 2001). The modelled groundwater-borne nitrogen inputs into surface waters were validated using results from the MONERIS model (Behrendt et al., 2000) concerning riverine nitrogen retention, nitrogen inputs from point sources as well as nitrogen inputs through direct run-off (drainage etc.). In the vicinity of surface waters and in solid rock areas, the groundwater borne nitrogen inputs into surface waters are considerably high compared to the inputs into the aquifer due to predominantly unfavourable de-nitrification conditions and short residence times of groundwater. In the North German lowlands, however, the groundwater-borne nitrate inputs into surface waters are considerably low compared to the inputs into the aquifer. There, the residence time of groundwater in the aquifer is high and the groundwater is predominantly oxygen free and contains pyrite and/or organic carbon compounds, allowing a halving of the nitrate loads in the groundwater within a period of 1 to 4 years (see Wendland and Kunkel, 1999).
Modelling diffuse nutrient flow in eutrophication control scenarios
Authors: Arheimer B. , Andersson L. , Larsson M. , Lindström G. , Olsson J. , Pers B.C.
Published: May 2018

The Swedish Water Management Research Programme (VASTRA) focuses on the development and demonstration of tools for more efficient eutrophication control when implementing the EU water framework directive in Sweden. During the first half of the programme, models for nitrogen flow were developed, and at present, similar models for phosphorus are under construction (e.g. HBV-P). The programme is interdisciplinary, and scientists are collaborating in actor-games and focus group evaluations including scenario analysis. The scenarios modelled in VASTRA phase I, show that (i) changed agricultural practices can be the most effective and least expensive way to reduce nitrogen transport from land to the sea; (ii) constructed agricultural wetlands may only have small impact on riverine nitrogen transport in some regions, due to natural hydrometeorological dynamics; (iii) removing planktivorous fish may be an efficient way of reducing the algal concentrations in lakes without the undesired side-effect of increased nutrient load to the down-stream river system. In VASTRA phase II, one of the highlights will be interdisciplinary scenario-modelling of different measure strategies in a pilot catchment of southern Sweden (Rönne å).
The formation of colour during biological treatment of pulp and paper wastewater
Authors: Milestone C.B. , Fulthorpe R.R. , Stuthridge T.R.
Published: May 2018

Colour discharges are gaining renewed focus in the pulp and paper industry as increasingly strict regulatory limits are placed on wastewater quality and aesthetics. In-mill process improvements, such as ECF bleaching and oxygen delignification, have decreased wastewater colour loadings. However, a survey of 12 pulp and paper mill systems found that effluent treatment using aerated stabilisation basins (ASB) leads to average increases in colour of 20-40%. In some instances, this phenomenon may even double the influent colour levels. Activated sludge systems did not produce a colour increase. The measured increases that follow ASB secondary treatment may be sufficient for a mill to fail prescribed discharge standards. A detailed field survey focusing on sections of an integrated bleached kraft mill ASB treatment system was undertaken. The average increase in colour at the final point of discharge was 45%. The major changes in colour concentration occurred in the inlet to the main treatment pond, and in polishing ponds that followed the main treatment pond. Both of these areas receive little or no aeration. No significant change was observed in the highly aerated main pond. These results, along with literature reports, suggested that redox conditions play a major role in influencing colour behaviour. To test this, two series of paired continuously stirred reactors were used to treat whole mill effluent from two ECF bleached kraft mills in parallel. The first series initially treated under anaerobic conditions, followed by an aerobic reactor, while the second series reversed this order. With the initial anaerobic stage, effluent colour increased by 18% and 19% for the first and second series respectively. Subsequent treatment by aerobic bacteria further increased colour by 14% and 6%, for a total increase of 32% and 25%. Initial aerobic treatment, however, did not lead to any significant change in colour for either effluent. Further anaerobic treatment following aerobic conditions produced only small increases in colour. These results are consistent with the ASB and activated sludge system survey, suggesting that anaerobic conditions at the head of treatment systems initiate the observed increases in effluent colour in ASB treatment systems.
Transportation pathways of pesticides in two major watersheds of Istanbul, Turkey
Authors: Yazgan M. , Tanik A.
Published: May 2018

The study covers the investigation of pesticides in terms of consumption, toxicological classification and various intrinsic physical and chemical properties like DT50, KOC, GUS, solubility that describe the important mechanisms prevailing in soil, namely persistence and mobility. These mechanisms help to estimate the transportation pathways of pesticides on soil till they reach the receiving water after being applied on land. Classification is done in three groups, those likely to appear in surface flow, those that appear in groundwater and those that present transient conditions. Such an approach that also takes into account toxicological levels and annual consumption values of pesticides will act as a tool to prepare the priority list of pesticides that need special care during their transportation. The fate of pesticides is a difficult task to solve, however, such a methodology, puts forth a rough estimate on their behavior in spite of uncertainties in many of the parameters describing mechanisms like persistence and mobility. The agricultural areas of two watersheds of Istanbul are selected as target areas to describe the approach, which is also checked with another approach estimating pesticide pollution potential that considers various other properties of pesticides. Almost similar findings are depicted with 85% proximity. The methodology presented in the paper illustrates and emphasizes the significant role of pesticide properties in determining their fate in soil after being applied.
Advanced treatment by anaerobic process followed by aerobic membrane bioreactor for effluent reuse in paper mill industry
Authors: Stahl N. , Tenenbaum A. , Galil N.I.
Published: May 2018

The operation of an activated sludge process at a paper mill (AIPM) in Hedera, Israel, was often characterized by disturbances. As part of a research and development project, a study on new biological treatment was initiated. The study included the operation of three pilot units: a. anaerobic treatment by upflow anaerobic sludge blanket (UASB); b. aerobic treatment by two pilot units including activated sludge and membrane bioreactor (MBR), which have been operated in parallel for comparison reasons. The pilot plant working on anaerobic treatment performed COD reduction from 2,365 to 755 mg/L, expressed as average values. Based on the pilot study, a full scale anaerobic treatment system has been erected. During a period of 100 days, after achieving steady state, the MBR system provided steady operation performance, while the activated sludge produced effluent characterized by oscillatory qualities. The following results, based on average values, indicate much lower suspended solids concentrations in the MBR effluent, 2.5 mg/L, as compared to 25 mg/L in the activated sludge. The ability to develop and maintain a concentration of over 11,000 mg/L of mixed liquor volatile suspended solids in the MBR enabled an intensive bioprocess at relatively high cell residence time. This study demonstrates that the anaerobic process, followed by aerobic MBR can provide effluent of high quality which can be considered for economic reuse in the paper mill industry.
Mass transfer and oxidation kinetics in an in situ ozone generator
Authors: Mathews A.P. , Panda K.K. , Ananthi S. , Padmanabhan K.
Published: May 2018

An in situ ozone generator design based on a novel type of corona discharge tube construction was tested to examine enhancements in mass transfer and ozonation efficiency over conventional systems. In this design, the discharge gap is kept juxtaposed to the tubular pathway through which the treatment fluid is passed. A porous inner electrode tube is employed in the discharge tube, and the generated ozone diffuses through this porous tube and dissolves and reacts with the contaminants in the fluid that is being treated. The inner porous ceramic tube is grounded while the outer glass electrode is positively charged for corona discharge. Oxidation studies conducted on Reactive Blue 19 dye indicate that the time required for 90% color removal is about half that of a conventional ozone generation and bubble diffusion system at the same ozone dosage.
The effects of dissolved organic matter on the decomposition of di-n-butyl phthalate by ozone/hydrogen peroxide process
Authors: Kosaka K. , Yamada H. , Tsuno H. , Shimizu Y. , Matsui S.
Published: May 2018

The effects of the dissolved organic matter (DOM) on the ozone decay and the di-n-butyl phthalate (DBP) decomposition during ozone/hydrogen peroxide (O3/H2O2) process were investigated (DBP-d4 was used instead of DBP). Four surface waters, two secondary municipal sewage effluents (SMSEfs) and Suwannee river natural organic matter were used as DOM. The ozone decompositions in the DOM solutions were separated by instantaneous ozone consumption and slower ozone decay. The effect of H2O2 addition on the ozone decay was clearly observed at slower ozone decay. Ozone decomposition rate at slower ozone decay increased linearly with H2O2 dose. DBP-d4 was exponentially decreased with ozone consumption. Ozone consumption required to decompose 90% of DBP-d4 ((ΔO3)90%) in SMSEFs was higher than those in surface waters. The (ΔO3)90% per DOC of DOM values were from 22 to 23 μmole/mgC for SMSEFs and from 10 to 17 μmole/mgC for surface waters. The (ΔO3)90% values were correlated to specific ultraviolet absorbance at 254 nm (SUVA254) for surface waters.
Aerodynamic performance of a low-speed wind tunnel
Authors: Frechen F.-B. , Frey M. , Wett M. , Löser C.
Published: May 2018

The determination of the odour mass flow emitted from a source is a very important step and forms the basis for all subsequent considerations and calculations. Wastewater treatment plants, as well as waste treatment facilities, consist of different kinds of odour sources. Unfortunately, most of the sources are passive sources, where no outward air flow-rate can be measured, but where odorants are obviously emitted. Thus, a type of sampling is required that allows to measure the emitted odour flow-rate (OFR). To achieve this, different methods are in use worldwide. Besides indirect methods, such as micrometeorological atmospheric dispersion models, which have not been used in Germany (in other countries due to different problems, direct methods are also used). Direct measurements include hood methods, commonly divided into static flux chambers, dynamic flux chambers and wind tunnels. The wind tunnel that we have been operating in principle since 1983 is different from all subsequent presented wind tunnels, in that we operate it at a considerably lower wind speed than the others. To describe the behaviour of this wind tunnel, measurement of the flow pattern in this low-speed tunnel are under way, and some initial results are presented here.
Application of electro-Fenton oxidation for the detoxification of olive mill wastewater phenolic compounds
Authors: Khoufi S. , Aouissaoui H. , Penninckx M. , Sayadi S.
Published: May 2018

Olive mill wastewaters are powerful pollutants that are difficult to treat as they contain high concentrations of recalcitrant and toxic polyphenolics of different molecular masses. We report in this paper that pre-treatment of phenolic fractions extracted from olive mill wastewaters as well as a synthetic phenolic mixture by the electro-Fenton method is a highly efficient procedure in which low mass phenolics are polymerised to polyphenolics and removed by precipitation. This decreases the toxicity load by 78% and makes the waste amenable to further anaerobic post-treatment.
Analysis of sulfur and nitrogen odorants using solid-phase microextraction and GC-MS
Authors: Turkmen M. , Dentel S.K. , Chiu P.C. , Hepner S.
Published: May 2018

An analytical method involving solid-phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) was applied to analyze biosolids odors. A selective ion monitoring (SIM)-based MS method was developed, using SPME injections of odorant standards under the full-scan mode to select the quantification and confirmation ions for each odorant. The odorants analyzed in this study include: dimethylsulfide, dimethyldisulfide, methyl mercaptan, hydrogen sulfide, carbon disulfide, trimethylamine and dimethylamine. We have used this method to quantify parts-per-billion levels of odorant vapors produced during anaerobic incubation of digested wastewater sludge. Important considerations for expedient and accurate calibration under static and dynamic flow conditions are discussed. The SPME-GC-MS method may give a positive intercept in the calibration curve, especially under static sampling conditions, which sets a practical detection limit for odor analysis.
Homogeneous (Fe(III)) and heterogeneous (TiO2) photocatalytic systems for pollutant removal from the aquatic compartment: comparison and complementarity
Authors: Mest'ankova H. , Mailhot G. , Krýsa J. , Jirkovský J. , Bolte M.
Published: May 2018

Kinetics of the oxidative photodegradation of monuron (3-(4-chlorophenyl)-1-1-dimethylurea) in both homogeneous solution of Fe(ClO4)3 and heterogeneous suspension of TiO2, were investigated and compared. In the homogeneous system (Fe(III)), the speciation of Fe(III) aquacomplexes was shown to play an essential role in the rate of photodegradation. For high concentrations of TiO2 (> 500 mg L-1), the photodegradation rate was similar to the reaction rate obtained with a freshly prepared solution of Fe(III) (3 × 10-4 mol L-1). In the combined system (TiO2 + Fe(III)), a synergy effect accelerating the monuron photodegradation was observed. Actually, in the presence of Fe(III) (in concentration compatible with a safe environment), a similar reaction rate for monuron photodegradation was obtained with a TiO2 concentration lower by a factor of 20.
A novel synthetic method for nanosized crystalline titania for use in the decomposition of dyes
Authors: Yun C.Y. , Moon J. , Chung K. , Kang M. , Shin C.B. , Choi K. , Yi J.
Published: May 2018

Photocatalytically active nanocrystalline titania particles were prepared using a hydrothermal process, by controlling the particle size and crystallinity. The crystalline structures and morphologies of the particles were characterized by X-ray diffraction and transmission electron microscopy. The BET method was used to determine the surface area and verify the grain size. To estimate the photocatalytic activity of the synthesized particles, a dye photodegradation experiment was carried out and the activity of the particles was compared with that of conventional titania. The results show that synthesized nanocrystalline titania particles had a higher photocatalytic activity than that of conventional titania. These findings provide a basis for the preparation of more effective and useful materials for use in AOP applications.
Sludge treatment by ozonation Ð evaluation of full-scale results
Authors: Sievers M. , Ried A. , Koll R.
Published: May 2018

Ozonation of industrial and sewage sludge is a suitable process for minimizing the sludge production of activated sludge processes. The ozonation has the advantage for complete oxidation of volatile suspended solids (VSS) of combining partial sludge oxidation with subsequent biological oxidation. This paper describes the evaluation of two full-scale sewage sludge ozonation investigations for subsequent aerobic stabilisation as well as for subsequent anaerobic stabilisation compared to different sludge treatment processes. For both the anaerobic and aerobic application, sludge liquefying by release of 110 and 160 mg COD per g total suspended solids (TSS) has been reached at specific ozone consumption of 0.03 and 0.06 kg O3 per kg TSS, respectively. The subsequent biological treatment has reached a mass reduction of 20-35% for the aerobic and 19% for the anaerobic stabilisation. For both applications the specific ozone consumption was about 0.05 kg O3 per kg TSS to be treated. A comparison with mechanical and thermo-chemical sludge mass reduction methods shows that the mass reduction potential of ozonation is presently higher. Even though costs for sludge ozonation are higher compared to other methods, the optimisation potential for cost reduction of sludge ozonation is obvious from the results presented in this paper.
Application of TAML® catalysts to remove colour from pulp and paper mill effluents
Authors: Wingate K.G. , Stuthridge T.R. , Wright L.J. , Horwitz C.P. , Collins T.J.
Published: May 2018

A TAML® catalyst (0.5 μM, 0.23 mg/L of effluent) combined with hydrogen peroxide (6.5 mM, 0.19 g/L of effluent) were capable of permanently removing 46% of the colour from bleach plant effluent (Eop, pine-derived) in one hour at 5,000 L effluent per day. Increasing concentrations to 2 μM catalyst (0.9 mg/L of effluent) and 22 mM peroxide (0.75 g/L of effluent), resulted in removal of 78% of the colour. In addition, 29% of the chlorinated organic material (AOX) was also removed. A laboratory investigation indicated that the oxidative process predominantly removed phenolic structures. The low aromatic content of the effluent meant that the majority of the organic material was not substantially altered during treatment. Thus chemical oxygen demand was essentially unchanged. This technology was able to remediate colour from effluents derived from both softwood (pine) and hardwood (eucalypt). Laboratory studies on catalyst life-time during effluent treatment, demonstrated that activity was maintained for a sufficient period to eliminate all the chromophore available to the active species, but that the catalyst did not survive long enough to be discharged into the receiving environment. Microtox tests showed that catalyst degradation products were not toxic to the receiving environment.
Comparison of AOPs for the removal of natural organic matter: performance and economic assessment
Authors: Murray C.A. , Parsons S.A.
Published: May 2018

Control of disinfection by-products during water treatment is primarily achieved by reducing the levels of organic precursor species prior to chlorination. Many waters contain natural organic matter at levels up to 15 mg L-1; therefore it is necessary to have a range of control methods to support conventional coagulation. Advanced oxidation processes are such processes and in this paper the Fenton and photo-Fenton processes along with photocatalysis are assessed for their NOM removal potential. The performance of each process is shown to be dependent on pH and chemical dose as well as the initial NOM concentration. Under optimum conditions the processes achieved greater than 90% removal of DOC and UV254 absorbance. This removal led to the THMFP of the source water being reduced from 140 to below 10 mg L-1, well below UK and US standards. An economic assessment of the processes revealed that currently such processes are not economic. With advances in technology and tightening of water quality standards these processes should become economically feasible options.
Combined chemical analyses and biomonitoring at Avedoere wastewater treatment plant in 2002
Authors: Jacobsen B.N. , Kjersgaard D. , Winther-Nielsen M. , Gustavson K.
Published: May 2018

Influent - effluent monitoring by comprehensive chemical analyses was conducted at the Avedoere wastewater treatment plant (WWTP) during 2002. In one programme, the same samples were tested for algal toxicity by the ISO 8692 method. Based on evaluation of 17 hazardous substances (including 7 heavy metals), there was a quite good agreement between calculated and measured toxic units. In another programme, influent - effluent monitoring for 11 pharmaceuticals and specific hormones showed high removal rates, except for sulphamethizol and furosemide. High removal is probably due to WWTP operation with long SRTs. Effluent biomonitoring of freshwater mussels showed only bioaccumulation for: diethyl-phthalate, LAS, EOX as well as Cr and Ni. Surprisingly, no bioaccumulation could be observed for 100 other specific organic compounds and 8 other heavy metals (including Hg, Cd and Pb).
Removal of persistent polar pollutants through improved treatment of wastewater effluents (P-THREE)
Authors: Knepper T.P. , Barcelo D. , Lindner K. , Seel P. , Reemtsma T. , Ventura F. , De Wever H. , van der Voet E. , Gehringer P. , Schönerklee M.
Published: May 2018

The EU-project P-THREE started with the establishment of analytical methods for persistent polar pollutants (P3) and quality assurance, followed by screening of P3 in influents and effluents of known wastewater (WW) treatment plants (TP), receiving waters and tap water produced thereof in several European countries. A final selection of analytes for further studies has been performed. Model MBR reactors have been constructed and an optimisation on synthetic wastewater spiked with P3 (linear alkylbenzene sulfonates (LAS), naphthalene sulfonates) has been performed. An initial dynamic modelling of treatment processes has also started. Advanced oxidation process (AOP) treatment has been done in groundwater with isoproturon and nonylphenol ethoxylates (NPEO). The analysis of individual P3 and potential degradation products was also performed. An integrated systems analysis of the WW treatment processes has also been initiated.
Bioavailability of a nonylphenol isomer in dependence on the association to dissolved humic substances
Authors: Vinken R. , Höllrigl-Rosta A. , Schmidt B. , Schäffer A. , Corvini P.F.-X.
Published: May 2018

Humic substances are important environmental components since they represent a very large part of organic compounds on earth. According to many reports, dissolved humic substances are a determinant parameter for the bioavailability of xenobiotic compounds. For the present bioavailability studies, two kinds of dissolved humic substances, a commercially available humic acid and fulvic acids isolated from peat were used. As the relevant xenobiotic, a defined branched nonylphenol isomer, 4(3′,5′-dimethyl-3′-heptyl)-phenol (p353NP) was synthesised according to Friedel-Crafts alkylation. Equilibrium dialysis studies were implemented in order to investigate the association between 14C-labelled p353NP and dissolved humic substances. The biodegradability in the presence of dissolved humic substances was examined in experiments with the nonylphenol degrading bacterium strain Sphingomonas TTNP3 and with p353NP as sole carbon source. The results showed that p353NP-humic acid associates were formed in high amounts, whereas no adducts with fulvic acids occurred. In the degradation studies with Sphingomonas TTNP3, no effects of dissolved humic substances on the bioavailability of p353NP could be observed. It was assumed that the association between nonylphenol and humic acids occurs rapidly and is reversible. Thus, the formation of "labile" complexes did not influence biodegradation rates, which were quite low.
Endocrine disrupters in the aquatic environment: the Austrian approach - ARCEM
Authors: Bursch W. , Fuerhacker M. , Gemeiner M. , Grillitsch B. , Jungbauer A. , Kreuzinger N. , Moestl E. , Scharf S. , Schmid E. , Skutan S. , Walter I.
Published: May 2018

A consortium of Austrian scientists (ARCEM) carried out a multidisciplinary environmental study on Austrian surface and ground waters including chemical monitoring, bioindication, risk assessment and risk management for selected endocrine disrupters: 17β-estradiol, estriol, estrone, 17α-ethinylestradiol, 4-nonylphenol, 4-nonylphenol ethoxylates (4-NP1EO, 4-NP2EO) and their degradation products, ocytlphenol, ocytlphenol ethoxylates (OP1EO, OP2EO) as well as bisphenol A. To obtain data representative for Austria, a material flow analysis served to select relevant compounds and water samples were collected monthly over one year at those sites routinely used in Austrian water quality control. The following results were obtained and conclusions drawn:1. Chemical monitoring: As compared to other countries, relatively low levels of pollution with endocrine disrupters were detected.2. Bioindication: In the surface waters under study, male fish showed significant signs of feminization and demasculinization (increased production of the egg-yolk protein and histological changes of the gonads.3. Risk assessment: For humans, exposure via either drinking water abstraction (ground water) or fish consumption was considered. The exposure levels of the compounds under study were below those considered to result in human health risks. Likewise, for bisphenol A and octylphenols, there was no indication for risk posed upon the aquatic environment (fish). However, nonylphenol or 17a-ethinylestradiol exposure along with results of bioindication (2) suggest a borderline estrogenic activity in a considerable number of surface waters. Consequently the emissions of these substances into the surface waters affected have to be reduced.4. Risk management: Waste water treatment experiments revealed a positive correlation between the removal rate of endocrine disrupters from the waste water and the sludge retention time in the treatment plants. These substances are removed to a higher extend at low loaded plants designed for nutrient removal than at plants that remove carbon and/or employ nitrification only. As to drinking water treatment, chlorine dioxide and ozone were found to eliminate all investigated substances, except nonylphenol ethoxylates. (For the complete study see: www.arcem.at)
Analysis and fate of insect repellents
Authors: Knepper T.P.
Published: May 2018

During summer months the insect repellent N,N-diethyl-m-toluamide (DEET) could always be detected in influents and effluents of wastewater treatment plants (WWTP) and anthropogenically influenced surface waters. In Germany the concentrations have decreased constantly since 1999, when DEET was substituted by Bayrepel. DEET can be degraded in WWTP, but only after an adaptation period and values in the influent above the threshold value. Since the year 2000 Bayrepel could also be detected during the summer months in the influents of WWTP, whereas in the effluents Bayrepel was not present.
Freeze concentration for enrichment of nutrients in yellow water from no-mix toilets
Authors: Gulyas H. , Bruhn P. , Furmanska M. , Hartrampf K. , Kot K. , Luttenberg B. , Mahmood Z. , Stelmaszewska K. , Otterpohl R.
Published: May 2018

Separately collected urine (“yellow water”) can be utilized as fertilizer. In order to decrease storage volumes and energy consumption for yellow water transport to fields, enrichment of nutrients in yellow water has to be considered. Laboratory-scale batch freeze concentration of yellow water has been tested in ice-front freezing apparatus: a stirred vessel and a falling film freeze concentrator (coolant temperatures: -6 to -16°C). With progressing enrichment of the liquid concentrate, the frozen ice was increasingly contaminated with yellow water constituents (ammonia, total nitrogen, total phosphorus, TOC, and salts determined as conductivity). The higher the initial salinity of the yellow water and the lower the mechanical agitation of the liquid phase contacting the growing ice front, the more the frozen ice was contaminated. The results indicate, that in ice-front freezing devices multistage processes are necessary, i.e. the melted ice phase has to be purified (and the concentrates must be further enriched) in a second or even in a third stage. Energy consumption of this process is very high. However, technical scale suspension freeze concentration is reasonable in centralized ecological sanitation schemes if the population exceeds 0.5 million and distance of yellow water transportation to fields is more than 80 km.