bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of riparian buffers in controlling ground-water discharge of nitrate to streams in selected hydrogeologic settings of the North Carolina Coastal Plain
Authors: Spruill T.B.
Published: May 2018

Water-quality and hydrologic information were collected along ground-water flow paths from two well-drained and two poorly drained Coastal Plain settings in North Carolina to evaluate the relative effectiveness of riparian buffers in reducing discharge of nitrate to streams. At one well-drained site with a 100 m buffer, little or no effect was detected on surface-water quality by discharging ground water because extensive woody vegetation in the buffer was able to take up not only most nitrate, but also most ground water before discharging to the stream during the growing season (March-October). At the second well-drained site, ground water discharging to the stream from the side with a buffer contained about 2 mg/L of nitrate-nitrogen after passing through the bed of the stream compared to 6 mg/L in ground water discharging from the side with no buffer. In the poorly drained settings, nitrate in ground water decreased from about 6 mg/L in the recharge area to less than 0.02 mg/L downgradient from the riparian buffer. Ground water discharging from the side with no buffer contained 0.83 mg/L. Riparian buffers appear effective in reducing nitrate in ground water discharging to Coastal Plain streams.
Contribution of agricultural and non-agricultural use of pesticides to the environmental impact on aquatic life in regional surface water systems
Authors: Jongbloed R.H. , Hulskotte J.H.J. , Kempenaar C.
Published: May 2018

By means of a modelling tool an analysis was made of the local variation in the use of pesticides in the province of Utrecht in The Netherlands, and the potential environmental impact of pesticide emissions on the aquatic ecosystems. The aim of this study was to identify and quantify the major sources of pesticide use and environmental impact, taking the regional variation of pesticide use into account. The analysis was targeted at different levels: detailed (individual active substances, individual agricultural crops, civil land-use types, hydrological catchment basins) and globally covering agricultural use, non-agricultural use (some civil sectors) and recreational shipping. The results can be used for the (re)design of environmental monitoring programmes of pesticides in surface waters and for the development of region based policies towards sustainable pesticide use. The analysis tool that was developed is considered to be applicable for other regions as well.
DRIPS - a decision support system estimating the quantity of diffuse pesticide pollution in German river basins
Authors: Röpke B. , Bach M. , Frede H.G.
Published: May 2018

The GIS based decision support system DRIPS - Drainage Spraydrift and Runoff Input of Pesticides in Surface Waters - has been developed to estimate the predicted environmental concentration (PECsw) of pesticides in surface waters resulting from diffuse sources. PECsw can be calculated on a catchment scale by quantifying the expected mean daily inputs of pesticides via surface runoff, tile drainage and spraydrift for various types of river basins characterized by their daily discharges. DRIPS is fitted with a Graphical User Interface (GUI) to provide easy access to the model algorithms. Model parameters like dose rate, DT50, Koc and date of pesticides application, etc. can be modified by the user in order to generate customized scenarios predicting PECsw for a choice of field crops, orchards and vineyards. Results are available as grid cell maps for the territory of Germany with high temporal and spatial resolution featuring distinct PECsw values for approximately 400 catchments.
Using ozone to reduce recalcitrant compounds and to enhance biodegradability of pulp and paper effluents
Authors: Bijan L. , Mohseni M.
Published: May 2018

The effect of ozone based oxidation on removing recalcitrant organic matter (ROM) and enhancing the biodegradability of alkaline bleach plant effluent was investigated. A bubble column ozonation tower was used in the study. The experiments were carried out at different temperatures (20°C and 60°C) and pH (9 and 11), with a number of biological and chemical parameters being monitored including BOD5, COD, TC, pH, color, and molecular weight distribution of organics (nominal cut off of 1,000 Da). Biodegradability of the effluent was determined based on BOD5/COD of the wastewater throughout the process. For all the experiments, ozonation enhanced the biodegradability of the effluent by 30-40%, which was associated with noticeable removal of ROM including high molecular weight (HMW) and color-causing organics by about 30% and 60%, respectively. While the biodegradability of HMW fraction increased by about 50%, there was no biodegradability improvement for low molecular weight (LMW) portion, which was originally readily biodegradable (with BOD5/COD of about 0.5). Statistical analysis of variance (ANOVA) revealed neither pH nor temperature played significant role on the ozonation process at 95% confidence level.
Reduction of zinc emissions from buildings; the policy of Amsterdam
Authors: Gouman E.
Published: May 2018

In Amsterdam zinc coming from the roofs and gutters of the buildings accounts for about 50% of the zinc emissions into the surface water (i.e. canals and rivers). This causes water and sediment pollution. Dumping strongly polluted sediment costs ten times more then dumping less polluted mud. Therefore the City of Amsterdam has developed a policy for reducing the zinc emissions from buildings based on the current environmental legislation and the current national targets for surface water quality. Zinc roofs on new and renovated buildings are not permitted. Run off water from zinc roofs of existing buildings is allowed to contain a maximum of 200 μg/l zinc. For the zinc gutters of houses, Amsterdam will promote measures to reduce zinc emissions. To investigate the feasibility of measures, research has been carried out on the zinc emissions of gutters and the effect of covering gutters with an impermeable foil. This research shows clearly that covering zinc gutters with EPDM foil reduces the zinc emissions by 90% from 8.5 to 0.88 gram per square metre per year including the atmospheric deposition.
Diffuse pollution of surface water by pharmaceutical products
Authors: Derksen J.G.M. , Rijs G.B.J. , Jongbloed R.H.
Published: May 2018

Pharmaceutical products for humans or animals, as well as their related metabolites (degradation products) end up in the aquatic environment after use. Recent investigations from abroad show that low concentrations of pharmaceuticals are detectable in municipal waste water, surface water, groundwater and even drinking water. Little is known about the effects, and with that the risk, of long term exposure to low concentrations of pharmaceuticals for aquatic organisms. On the basis of the current knowledge, further attention to map the presence and effects of pharmaceutical residues on aquatic organisms is justified. To map the Dutch situation, recently a monitoring program has started.
Ultrafiltration and nanofiltration in the pulp and paper industry using cross-rotational (CR) filters
Authors: Mänttäri M. , Nyström M.
Published: May 2018

Ultra- and nanofiltration with high shear CR-filters have been utilized for cleaning of clear filtrates and effluents from the pulp and paper industry. The aim was to find out how different nanofiltration membranes operate at high shear conditions. The filtration efficiency of the membranes was evaluated by measuring flux, retention and fouling at various recovery and pH conditions. High fluxes (∼100 L/(m2h)) for nanofiltration membranes were measured when circulation waters from the paper machine were filtered at neutral conditions. In the filtration of discharge of external activated sludge treatment plants we measured fluxes around 150 L/(m2h) even at a concentration factor of 12. The best NF membranes removed over 80% of the organic carbon and of the conductivity and almost completely eliminated the color. With acidic waters fluxes and retentions were significantly lower. The NF270 membrane from Dow and the Desal-5 membranes from Osmonics had the highest flux and retention properties. However, the Desal-5 membrane lost its retention properties slowly, which restricts its use in the high shear CR-filter. CR-nanofiltration can be used in the pulp and paper industry without feed pre-treatment by ultrafiltration. This increases the attractiveness of high shear CR-nanofiltration.
Reactor scale-up in AOPs: from laboratory to commercial scale
Authors: Zalazar C.S. , Labas M.D. , Martín C.A. , Brandi R.J. , Cassano A.E.
Published: May 2018

A procedure to scale-up photoreactors employed in AOPs using laboratory information has been developed. Operating with a model compound the proposed procedure was applied to the decomposition of formic acid in water solution using hydrogen peroxide and UV radiation. With laboratory experiments the parameters of the kinetic equation were obtained in a small batch reactor operated within a recycling apparatus. The whole system was modeled employing radiation and mass balances. These balances were used together with a non-linear parameter estimator to derive the model kinetic constants. Then, these results were used in the modeling of the large-scale reactor to predict exit conversions in an isothermal, continuous, tubular flow reactor that is 2 m long and has a volume of 12 l. Once more, radiation and mass balances were used to predict formic acid output concentrations. Experimental data in the large-scale apparatus are in good agreement with theoretical predictions.
Catalyzed ozonation process with GAC and metal doped-GAC for removing organic pollutants
Authors: Oh B.S. , Song S.J. , Lee E.T. , Oh H.J. , Kang J.W.
Published: May 2018

The purpose of this study was to investigate the catalytic role of granular activated carbon (GAC), and metal (Mn or Fe) doped-GAC, on the transformation of ozone into more reactive secondary radicals, such as hydroxyl radicals (.OH), for the treatment of wastewater. The GAC doped with Mn showed the highest catalytic performance in terms of ozone decomposition into OH radicals. Likewise, activated carbon alone accelerated the ozone decomposition, resulting in the formation of .OH radicals. In the presence of promoters, the ozone depletion rate was enhanced further by the Mn-GAC catalyst system, even under aqueous acidic pH conditions.
Comparison of field olfactometers in a controlled chamber using hydrogen sulfide as the test odorant
Authors: McGinley M.A. , McGinley C.M.
Published: May 2018

A standard method for measuring and quantifying odour in the ambient air utilizes a portable odour detecting and measuring device known as a field olfactometer (US Public Health Service Project Grant A-58-541). The field olfactometer dynamically dilutes the ambient air with carbon-filtered air in distinct ratios known as “Dilutions-to-Threshold” dilution factors (D/Ts), i.e. 2, 4, 7, 15, etc. Thirteen US states and several cities in North America currently utilize field olfactometry as a key component of determining compliance to odour regulations and ordinances. A controlled environmental chamber was utilized, with hydrogen sulfide as the known test odorant. A hydrogen sulfide environment was created in this controlled chamber using an Advanced Calibration Designs, Inc. Cal2000 Hydrogen Sulfide Generator. The hydrogen sulfide concentration inside the chamber was monitored using an Arizona Instruments, Inc. Jerome Model 631 H2S Analyzer. When the environmental chamber reached a desired test concentration, test operators entered the chamber. The dilution-to-threshold odour concentration was measured using a Nasal Ranger Field Olfactometer (St Croix Sensory, Inc.) and a Barnebey Sutcliffe Corp. Scentometer. The actual hydrogen sulfide concentration was also measured at the location in the room where the operators were standing while using the two types of field olfactometers. This paper presents a correlation between dilution-to-threshold values (D/T) and hydrogen sulfide ambient concentration. For example, a D/T of 7 corresponds to ambient H2S concentrations of 5.7-15.6 μg/m3 (4-11 ppbv). During this study, no significant difference was found between results obtained using the Scentometer or the Nasal Ranger® (r = 0.82). Also, no significant difference was found between results of multiple Nasal Ranger® users (p = 0.309). The field olfactometers yielded hydrogen sulfide thresholds of 0.7-3.0 μg/m3 (0.5-2.0 ppbv). Laboratory olfactometry yielded comparable thresholds of 0.64-1.3 μg/m3 (0.45-0.9 ppbv). These thresholds are consistent with published values.
Determination of the dynamics of the odour release from a pig house, using an electronic odour sensor
Authors: Gallmann E. , Hartung E. , Brose G. , Jungbluth T.
Published: May 2018

The widely fluctuating operating conditions in pig husbandry, due to climatic and biological changes (changes in temperature and air flowrate between day and night, as well as between summer and winter, increasing animal mass during the fattening process, etc.) exert a significant influence on the amount of actual odour emission. The project presented here comprised the measurement of seasonal (fattening course), daytime-related, and short-term (feeding) dynamic effects of odour release, as well as the identification of potential factors which influence the amount of odour emitted. In parallel with “classic” olfactometry, an electronic odour sensor with a chemosensor array of ten metal oxide sensors was employed. The highest odour emissions are measured on hot summer days, while the lowest emissions were determined on cold winter days. On the one hand, the sensor signals of the electronic odour sensor exhibited considerable differences on days with large volume flow alterations. On the other hand, continuous measurement with the electronic odour sensor allowed changes in the gas- and odorant composition of the exhaust air during feeding times to be shown. From the measurement results, recommendations for odour sampling, the consideration of seasonal odour emission fluctuations, and the use of electronic odour sensors for the evaluation of odour emissions have been derived.
Odour emission inventory of German wastewater treatment plants - odour flow rates and odour emission capacity
Authors: Frechen F.-B.
Published: May 2018

Wastewater Treatment plants can cause odour emissions that may lead to significant odour annoyance in their vicinity. Thus, over the past 20 years, several measurements were taken of the odour emissions that occur at WWTPs of different sizes, treatment technology, plant design and under different operating conditions. The specific aspects of odour sampling and measurement have to be considered. I presented some of the results of my odour emission measurements 11 years ago. However, it is now necessary to update the figures by evaluating newer measurement results obtained from measurements taken from 1994 to 2003. These are presented in this paper.

Also, the paper highlights the odour emission capacity (OEC) measurement technique which characterises liquids and can be used to assess the results achieved by different types of treatment in the liquid phase, e.g. in a sewerage system. In addition, the OEC is a suitable parameter to set standards for the odorant content of industrial wastewaters that are discharged into the publicly owned sewerage system.
An innovative photocatalytic technology in the treatment of river water containing humic substances
Authors: Selcuk H. , Sene J.J. , Sarikaya H.Z. , Bekbolet M. , Anderson M.A.
Published: May 2018

This study addresses the application of a photoelectrocatalytic (PEC) system with separated hole and electron reactions to treat humic acid (HA) from river water. A TiO2 electrode, coated by the sol-gel method, is used for that purpose. The degradation of humic acid in the river water was followed with respect to time using parameters of UV254, color and total organic carbon (TOC). For comparison purposes the photocatalytic (PC) removal of HA was also studied on the same photoanode. The obtained results showed that the PEC system was much more effective than the PC method. The effect of other important reaction variables, such as external potential, oxygen and UV intensity on HA degradation were also investigated. For all the external applied potential conditions and UV intensity range over 90% removal of UV254 and color were obtained with the PEC system while TOC removal was between 58-80%.
Mass-producible and wireless wide-area networks of electronic noses: problems and solutions
Authors: Bos A.
Published: May 2018

This paper focuses on the development of a wide-area network of wireless electronic noses and the solutions found to the problems encountered, both of a technical nature and the management involved when employing large amounts of field units. Examples of field test results are given, to illustrate the abilities of such a system.
Paper mill wastewater detoxification by solar photocatalysis
Authors: Sattler C. , Funken K.-H. , de Oliveira L. , Tzschirner M. , Machado A.E.H.
Published: May 2018

In the WATER project the German Aerospace Center, and the Universidade Federal de Uberlândia, analyse the possibilities of treating paper mill effluents by solar photocatalysis for the paper mill of the Brazilian paper producer Votorantim Celulose e Papel, VCP, at Luiz Ant(tm)nio, SP, Brazil. The degradation of the bio-polymer lignin is a vast problem in paper production. The tests have shown that treatment by the photocatalyst TiO2 and solar radiation is an ecological future oriented approach to solve this problem. The treatment of lignin containing process water by solar photocatalysis was optimised and the economics for solar treatment plants of different sizes was estimated to check the possibilities for implementing the technology in industrial processes.
Evaluation of the combined solar TiO2/photo-Fenton process using multivariate analysis
Authors: Nogueira R.F.P. , Trovó A.G. , Paterlini W.C.
Published: May 2018

The effect of combining the photocatalytic processes using TiO2 and the photo-Fenton reaction with Fe3+ or ferrioxalate as a source of Fe2+ was investigated in the degradation of 4-chlorophenol (4CP) and dichloroacetic acid (DCA) using solar irradiation. Multivariate analysis was used to evaluate the role of three variables: iron, H2O2 and TiO2 concentrations. The results show that TiO2 plays a minor role when compared to iron and H2O2 in the solar degradation of 4CP and DCA in the studied conditions. However, its presence can improve TOC removal when H2O2 is totally consumed. Iron and peroxide play major roles, especially when Fe(NO3)3 is used in the degradation of 4CP. No significant synergistic effect was observed by the addition of TiO2 in this process. On the other hand, synergistic effects were observed between FeOx and TiO2 and between H2O2 and TiO2 in the degradation of DCA.
Plant oils thymol and eugenol affect cattle and swine waste emissions differently
Authors: Varel V.H. , Miller D.N. , Lindsay A.D.
Published: May 2018

Wastes generated from the production of cattle and swine in confined facilities create the potential for surface and groundwater pollution, emission of greenhouse gases, transmission of pathogens to food and water sources, and odor. It is our hypothesis that something which inhibits microbial fermentation in livestock wastes will be beneficial to solving some of the environmental problems. Our work has concentrated on the use of antimicrobial plant oils, thymol, thyme oil, carvacrol, eugenol and clove oil. Anaerobic one-litre flasks with a working volume of 0.5 L cattle or swine manure were used to evaluate the effect of thymol and eugenol on production of fermentation gas, short-chain volatile fatty acids, lactate, and bacterial populations. Either oil at 0.2% in both wastes essentially stopped all production of gas and volatile fatty acids, and eliminated all fecal coliform bacteria. In cattle but not swine waste, thymol prevented the accumulation of lactate. However, eugenol stimulated lactate formation in cattle and swine wastes. Thus, eugenol may offer a distinct advantage over thymol, because lactate accumulation in the wastes causes the pH to drop more rapidly, further inhibiting microbial activity and nutrient emissions. We conclude that plant oils may offer solutions to controlling various environmental problems associated with livestock wastes, assuming that they are cost-effective.
A membrane bioreactor for the removal of dimethyl sulphide and toluene from waste air
Authors: Van Langenhove H. , De Bo I. , Jacobs P. , Demeestere K. , Dewulf J.
Published: May 2018

In biotrickling filters, mass transfer of hydrophobic compounds is the limiting factor. Biofilters are static systems, and so control and regulation of operational parameters such as pH and nutrient supply can be a problem. In membrane bioreactors, these drawbacks can be avoided. The hydrophobic membrane separates the waste air from the aqueous phase, thus avoiding mass-transfer limitation, while pH and nutrient supply can be directly controlled. In this contribution, an overview will be given of results obtained during a four-year project. First, the physical chemical characteristics (solubility, permeability, diffusivity) and microbial adhesion of different membranes were tested. This led to the selection of a composite membrane consisting of a porous polyvinylidenefluoride (PVDF) support layer coated with a thin (1 or 2.5 μm) dense polydimethylsiloxane (PDMS) top layer. This membrane was mounted into a module provided with four parallel rectangular channels for gas flow (in contact with the porous layer) and nutrient solution (in contact with the dense layer) respectively. After inoculation, a biofilm developed on the dense layer. Experiments were performed with dimethyl sulphide and toluene as target VOCs. Operational characteristics such as elimination capacity as a function of the volumetric load and residence time, effect of nutrient supply, long-term performance) were determined. Mass transfer was studied by measuring concentration profiles along the channels of the module in different conditions.
Applications of advanced oxidation processes: present and future
Authors: Suty H. , De Traversay C. , Cost M.
Published: May 2018

The use of advanced oxidation processes (AOPs) to remove pollutants in various water treatment applications has been the subject of study for around 30 years. Most of the available processes (Fenton reagent, O3 under basic conditions, O3/H2O2, O3/UV, O3/solid catalyst, H2O2/Mn+, H2O2/UV, photo-assisted Fenton, H2O2/solid catalyst, H2O2/NaClO, TiO2/UV etc.) have been investigated in depth and a considerable body of knowledge has been built up about the reactivity of many pollutants. Various industrial applications have been developed, including ones for ground remediation (TCE, PCE), the removal of pesticides from drinking water, the removal of formaldehyde and phenol from industrial waste water and a reduction in COD from industrial waste water. The development of such AOP applications has been stimulated by increasingly stringent regulations, the pollution of water resources through agricultural and industrial activities and the requirement that industry meet effluent discharge standards. Nevertheless, it is difficult to obtain an accurate picture of the use of AOPs and its exact position in the range of water treatment processes has not been determined to date. The purpose of this overview is to discuss those processes and provide an indication of future trends.
Volatile organic compound adsorption in a gas-solid fluidized bed
Authors: Ng Y.L. , Yan R. , Tsen L.T.S. , Yong L.C. , Liu M. , Liang D.T.
Published: May 2018

Fluidization finds many process applications in the areas of catalytic reactions, drying, coating, combustion, gasification and microbial culturing. This work aims to compare the dynamic adsorption characteristics and adsorption rates in a bubbling fluidized bed and a fixed bed at the same gas flow-rate, gas residence time and bed height. Adsorption with 520 ppm methanol and 489 ppm isobutane by the ZSM-5 zeolite of different particle size in the two beds enabled the differentiation of the adsorption characteristics and rates due to bed type, intraparticle mass transfer and adsorbate-adsorbent interaction. Adsorption of isobutane by the more commonly used activated carbon provided the comparison of adsorption between the two adsorbent types.

With the same gas residence time of 0.79 seconds in both the bubbling bed and fixed bed of the same bed size of 40 mm diameter and 48 mm height, the experimental results showed a higher rate of adsorption in the bubbling bed as compared to the fixed bed. Intraparticle mass transfer and adsorbent-adsorbate interaction played significant roles in affecting the rate of adsorption, with intraparticle mass transfer being more dominant. The bubbling bed was observed to have a steeper decline in adsorption rate with respect to increasing outlet concentration compared to the fixed bed. The adsorption capacities of zeolite for the adsorbates studied were comparatively similar in both beds; fluidizing, and using smaller particles in the bubbling bed did not increase the adsorption capacity of the ZSM-5 zeolite. The adsorption capacity of activated carbon for isobutane was much higher than the ZSM-5 zeolite for isobutane, although at a lower adsorption rate.

Fourier transform infra-red (FTIR) spectroscopy was used as an analytical tool for the quantification of gas concentration. Calibration was done using a series of standards prepared by in situ dilution with nitrogen gas, based on the ideal gas law and relating partial pressure to gas concentration. Concentrations up to 220 ppm for methanol and 75 ppm for isobutane were prepared using this method.
Technical development of UV-C- and VUV-photochemically induced oxidative degradation processes
Authors: Braun A.M. , Pintori I.G. , Popp H.-P. , Wakahata Y. , Würner M.
Published: May 2018

Technical development work is presented, where the VUV photochemically induced oxidative degradation is used: (i) for analytic purposes, and (ii) for small to medium scale (<10 m2/d) waste water treatment processes or ultrapure water production. In the first case, small Xe-excimer radiation sources with an integrated reaction space designed for optimal conditions, as far as incident photon flux density, turbulence and concentration of dissolved molecular oxygen are concerned, have been built and tested. Under conditions of exhaustive oxidation and/or mineralization of pollutants in a continuous regime, they may be used for sample pre-treatment modules prior TOC, TOX and electrochemical trace metal analysis. Under conditions of partial oxidation or mineralization, the same lamp/reactor combination may be used for functionalization purposes prior to e.g. GC or HPLC analyses. In the second case, mass transfer limitations between the non-irradiated bulk volume and the irradiated volume are overcome by the electrochemical generation of molecular oxygen within or close to the irradiated volume and by the design of the photochemical part of the reactor.
Ozone treatment and biodegradation of industrial wastewater containing thioethers
Authors: Tuin B.J.W. , Bos A.A.C.M.
Published: May 2018

Wastewater from an Akzo Nobel production site contains refractory sulfur components (cyclic thioethers). These components end up in the effluent of the existing biological wastewater treatment plant. The possibilities of (partial) oxidation and increasing biodegradability by ozone treatment for these types of compounds have been investigated. Ozonation experiments were carried out at laboratory scale, varying pH, temperature and catalysts. Biodegradability was evaluated from BOD measurements and BOD/COD ratios. Ozonation experiments at pH = 10 without catalyst addition or heating were found to give the best results with the simplest means: COD was removed for 80-90% and biodegradability increased from BOD/COD = 0.2-0.3 to > 0.7. These results could not be improved any further by adding catalysts like iron and manganese (hydr)oxides or activated carbon, by heating or by further increasing pH. Aftertreatment at pH = 10 required about 3 kg ozone per m3 for about 80-90% removal of the total COD. This results in high annual operating costs and is therefore less suitable in practice. Biodegradability already increased to 60% at COD removal of 50% and ozone consumption of 1.4 kg/m3 wastewater. On the basis of these findings, it was calculated that ozonation has potential as pretreatment for a side stream containing the major fraction of the cyclic thioethers mixture.
Combined oxidative and biological treatment of separated streams of tannery wastewater
Authors: Vidal G. , Nieto J. , Mansilla H.D. , Bornhardt C.
Published: May 2018

Leather tanning effluents are a source of severe environmental impacts. In particular, the unhairing stage, belonging to the beamhouse processes, generates an alkaline wastewater with high concentrations of organic matter, sulphides, suspended solids, and salts, which shows significant toxicity. The objective of this work was to evaluate the biodegradation of this industrial wastewater by combined oxidative and biological treatments. An advanced oxidation process (AOP) with Fenton's reagent was used as batch pretreatment. The relationships of H2O2/Fe2+ and H2O2/COD were 9 and 4, respectively, reaching an organic matter removal of about 90%. Subsequently, the oxidised beamhouse effluent was fed to an activated sludge system, at increasing organic load rates (OLR), in the range of 0.4 to 1.6 g COD/Láday. The biological organic matter removal of the pre-treated wastewater ranged between 35% and 60% for COD, and from 60% to 70% for BOD. Therefore, sequential AOP pretreatment and biological aerobic treatment increased the overall COD removal up to 96%, compared to 60% without pretreatment. Bioassays with D. magna and D. pulex showed that this kind of treatment achieves only a partial toxicity removal of the tannery effluent.
Combined ozonation and biofilm treatment for reuse of papermill wastewaters
Authors: Möbius C.H. , Helble A.
Published: May 2018

A process of advanced oxidation treatment discussed here has been developed in the last seven years. A technical plant for treatment of paper mill wastewater started operation in 1999. Advanced oxidation treatment is defined here as a combination of chemical and biochemical oxidation applied to a completely biodegraded effluent. The process is a combination of ozonation with following biodegradation in a biofilm reactor. The combination makes use of the effect of partial oxidation in which with reduced use of expensive chemical oxidants persistent COD becomes biodegradable. A far-reaching elimination of AOX, colour and other disturbing substances like complexing agents is achieved simultaneously. The partially oxidized compounds, now biodegradable, are eliminated in a following biofilm reactor. Using single-stage systems, COD elimination rates of up to 60% are achieved with 0.4 to 1.0 g ozone per g COD eliminated in the combined process. With a two-stage system COD elimination of 85% with 0.65 g/g has been achieved in pilot tests. The quality of the treated effluent suits fresh water requirements for most types of paper production, so that either a total closure of the water circuits or Ð due to increasing concentrations of electrolytes, which are not eliminated by this process - a substantial closure to about 20% of the original amount of fresh water can be achieved.
Biotechnology-based odour control: design criteria and performance data
Authors: Quigley C. , Easter C. , Burrowes P. , Witherspoon J.
Published: May 2018

As neighbouring areas continue to encroach upon wastewater treatment plants, there is an increasing need for odour control to mitigate potential negative offsite odorous impacts. One technology that is gaining widespread acceptance is biotechnology, which utilises the inherent ability of certain microorganisms to biodegrade offensive odorous compounds. Two main advantages of this form of treatment over other odour control technologies include the absence of hazardous chemicals and relatively low operation and maintenance requirements. The purpose of this paper is to provide information related to odour control design criteria used in sizing/selecting biotechnology-based odour control technologies, and to provide odour removal performance data obtained from several different biotechnology-based odour control systems. CH2M HILL has collected biotechnology-based odour control performance data over the last several years in order to track the continued performance of various biofilters and biotowers over time. Specifically, odour removal performance data have been collected from soil-, organic- and inorganic-media biofilters and inert inorganic media biotowers. Results indicate that biotechnology-based odour control is a viable and consistent technology capable of achieving high removal performance for odour and hydrogen sulphide. It is anticipated that the information presented in this paper will be of interest to anyone involved with odour control technology evaluation/selection or design review.
Textile wastewater treatment and reuse by solar catalysis: results from a pilot plant in Tunisia
Authors: Bousselmi L. , Geissen S.-U. , Schroeder H.
Published: May 2018

Based on results from bench-scale flow-film-reactors (FFR) and aerated cascade photoreactors, a solar catalytic pilot plant has been built at the site of a textile factory. This plant has an illuminated surface area of 50 m2 and is designed for the treatment of 1 m3 h-1 of wastewater. The preliminary results are presented and compared with a bench-scale FFR using textile wastewater and dichloroacetic acid. Equivalent degradation kinetics were obtained and it was demonstrated that the solar catalytic technology is able to remove recalcitrant compounds and color. However, on-site optimization is still necessary for wastewater reuse and for an economic application.
Analysis and occurrence of estrogen in wastewater in Japan
Authors: Komori K. , Tanaka H. , Okayasu Y. , Yasojima M. , Sato C.
Published: May 2018

This paper describes an analytical procedure for free estrogens and their conjugates in domestic wastewater. The procedure demonstrated in this study is innovative in terms of levels of detection and quantification of the following substances: estrone (E1); 17β-estradiol (E2); 17α-ethynylestradiol (EE2); estriol (E3); estrone-3-sulfate (E1-S); β-estradiol 3-sulfate (E2-S); estriol 3-sulfate (E3-S); estrone β-D-glucuronide (E1-G); β-estradiol 17-(β-D)-glucuronide (E2-G); estriol 3-(β-D)-glucuronide (E3-G); β-estradiol 3-sulfate 17-glucuronide (E2-S&G); and estradiol 3,17-disulfate (E2-diS). The detection limits of this method ranged from 0.1 to 1.4 ng/l. The recovery efficiencies of the estrogens in the analysis from influent and effluent of the secondary settling tank in a wastewater treatment plant (WWTP) were higher than 94% for the free estrogens, but were less than 50% for the conjugated estrogens. The field study using this method was conducted at twenty WWTPs in Japan. The median concentrations of the estrogens ranged from ND to as high as >100 ng/l. In the influent and secondary effluent samples, the concentrations of E1, E2 and E3 were the same levels as those previously reported. We found that the conjugated estrogens exist at higher concentrations in the influent and the secondary effluent than in the other studies, and that the concentrations of the conjugated estrogens were higher than those of the free estrogens.
Behaviour of bisphenol A (BPA), 4-nonylphenol (4-NP) and 4-nonylphenol ethoxylates (4-NP1EO, 4-NP2EO) in oxidative water treatment processes
Authors: Lenz K. , Beck V. , Fuerhacker M.
Published: May 2018

Endocrine disrupting chemicals (EDCs) such as natural and synthetic hormones or industrial chemicals can adversely affect the endocrine system at very low concentrations. As such substances can be present in raw water used for drinking-water production, they potentially pose a health risk to humans.

In this study laboratory tests were performed to determine removal efficiencies of selected oxidative drinking water treatment processes, namely ozonation (1.4 mg/l O3) and chlorination, using sodium hypochlorite (0.5 mg/l NaClO) and chlorine dioxide (0.4-0.6 mg/l ClO2) under conditions applied in technical plants. 500-300,000 ng/l of bisphenol A (BPA), 4-nonylphenol (4-NP) and 4-nonylphenol-n-ethoxylates (NPnEO) were selected for investigations and measured by HPLC/FLD and HPLC/MS. To investigate possible oxidation by-products, adsorbable organic halogens (AOX) were determined and estrogenic activities were assessed with the help of an estrogen receptor binding assay (YES).

Ozonation and chlorination with ClO2 removed both 4-NP and BPA below detection limits, corresponding with AOX and estrogenic activity. Concerning NPnEO ozonation removed NP1EO and NP2EO up to 28% and 30%, respectively, whereas ClO2 showed high removal efficiencies, eliminating >94% and 92%, respectively. NaClO removed 4-NP and BPA below detection limits, but estrogenic activities increased and AOX could be measured. NP1EO and NP2EO were only marginally reduced corresponding to the slight decrease of estrogenic potential.
Comparison of linear alkylbenzene sulfonates removal in conventional activated sludge systems and membrane bioreactors
Authors: De Wever H. , Van Roy S. , Dotremont C. , Müller J. , Knepper T.
Published: May 2018

The potential of a membrane bioreactor (MBR) and a conventional activated sludge (CAS) system to remove polar micropollutants was evaluated using linear alkylbenzene sulfonates (LAS) as model components. Removal efficiencies over 97% were achieved in both reactor systems. The appearance of biological breakdown metabolites and the respirometric response of the sludges to LAS addition indicated that LAS removal was due to biodegradation, rather than sorption phenomena. The effect of operational variables, such as hydraulic retention time, LAS composition and hydrophobicity of the membrane used in the MBR, was negligible in the range tested. A stepwise increase in LAS influent concentration resulted in higher residual effluent concentrations but did not change the procentual removal efficiency. Because an increase in LAS and SPC effluent concentration occurred to a larger extent in the CAS than in the MBR under similar operating conditions, MBRs may turn out to be be more robust with respect to biological degradation of micropollutants than CAS.
Removal of selected non-steroidal anti-inflammatory drugs (NSAIDs), gemfibrozil, carbamazepine, b-blockers, trimethoprim and triclosan in conventional wastewater treatment plants in five EU countries and their discharge to the aquatic environment
Authors: Paxéus N.
Published: May 2018

The removal of commonly used pharmaceuticals (ibuprofen, naproxen, diclofenac, gemfibrozil, carbamazepine, atenolol, metoprolol and trimethoprim) and a biocide (triclosan) in operating wastewater treatment plants in five EU countries has been studied. Under normal operating conditions the acidic drugs and triclosan were partially removed with removal rates varying from ca. 20 to >95%. The highest removal rate was found for ibuprofen and triclosan (>90%) followed by naproxen (80%), gemfibrozil (55%) and diclofenac (39%). Ibuprofen undergoes an oxidative transformation to corresponding hydroxy- and carboxy- metabolites, which contributes to its high removal rate. Disturbances in the activated sludge process resulted in lower removal rates for all acidic drugs, mostly for diclofenac (<10% removed) but also for ibuprofen (<60% removed). The treatment of wastewaters by activated sludge usually did not result in any practical removal (<10%) of neutral carbamazepine or basic atenolol, metoprolol and trimethoprim. The removal rates of the investigated drugs and triclosan are discussed in terms of mechanisms responsible for their removal. Discharges of carbamazepine, diclofenac, gemfibrozil, naproxen, triclosan and trimethoprim from WWTPs to the aquatic environment, expressed as the average concentration in the effluent and the daily discharged quantity per person served by WWTPs were assessed.
Carbamazepine, diclofenac, ibuprofen and bezafibrate - investigations on the behaviour of selected pharmaceuticals during wastewater treatment
Authors: Strenn B. , Clara M. , Gans O. , Kreuzinger N.
Published: May 2018

Numerous investigations in different European countries observed various pharmaceutically active compounds (PhACs) in notable concentrations in the aquatic environment. Further determinations found the effluents of sewage treatment plants (STPs) to be significant sources for the entry of pharmaceutical residuals to rivers, streams and surface waters. Due to those pathways the knowledge about the elimination of these substances and their behaviour in wastewater treatment plants (WWTP) is elementary for protection of an intact aquatic environment. Since the sludge retention time (SRT) is the most important parameter for the design of STPs, its influence on the reduction rate of these PhACs in the wastewater treatment process was investigated. To study this influence of the SRT on the elimination of PhACs, lab scale plants have been operated with different sludge retention times. The results of the laboratory experiments have been validated analysing various STPs within a wide capacity range and operating at different SRTs. This report describes the determinations observed on the antiepileptic drug Carbamazepine, the two antiphlogistics and analgesics Diclofenac and Ibuprofen and the lipid regulator Bezafibrate.
Optimising design, operation and energy consumption of biological aerated filters (BAF) for nitrogen removal of municipal wastewater
Authors: Rother E. , Cornel P.
Published: May 2018

The Biofiltration process in wastewater treatment combines filtration and biological processes in one reactor. In Europe it is meanwhile an accepted technology in advanced wastewater treatment, whenever space is scarce and a virtually suspended solids-free effluent is demanded. Although more than 500 plants are in operation world-wide there is still a lack of published operational experiences to help planners and operators to identify potentials for optimisation, e.g. energy consumption or the vulnerability against peak-loads. Examples from pilot trials are given how the nitrification and denitrification can be optimised. Nitrification can be quickly increased by adjusting DO content of the water. Furthermore carrier materials like zeolites can store surplus ammonia during peak loads and release afterwards. Pre-denitrification in biofilters is normally limited by the amount of easily degradable organic substrate, resulting in relatively high requirements for external carbon. The combination of pre-DN, N and post-DN filters is much more advisable for most municipal wastewaters, because the recycle rate can be reduced and external carbon can be saved. Exemplarily it is shown for a full scale preanoxic-DN/N/postanoxic-DN plant of 130,000 p.e. how 15% energy could be saved by optimising internal recycling and some control strategies.
Removal of ammonium from human urine through ion exchange with clinoptilolite and its recovery for further reuse
Authors: Beler-Baykal B. , Bayram S. , Akkaymak E. , Cinar S.
Published: May 2018

Ammonium, from separately collected human urine, had been removed through transfer onto the ammonium selective natural zeolite, clinoptilolite, through ion exchange. In the subsequent treatment steps of washing with tap water, ammonium removed from urine was eluted from the surface of the clinoptilolite to be recovered for further reuse. Different quantities of clinoptilolite were used for a survey of the capacity of the zeolite for the process and to identify removal efficiencies based on initial ammonium loads. The highest surface concentration attained under experimental conditions employed was 15.44 mg ammonium per gram of clinoptilolite for an initial concentration of 110 mg ammonia per litre, and the highest removal was 98%, obtained for a loading of 1 mg ammonium per gram clinoptilolite. In the subsequent elution process, better removals were observed as pH was increased and the highest removal was attained at pH 13. The recovery was calculated as 9.73 mg ammonium per gram of clinoptilolite, corresponding to an efficiency of 63% only through washing with tap water. The results have given positive indications for the possibility of using ion exchange with clinoptilolite for the removal of ammonium from human urine and an incentive for improving methods of elution for its recovery for further reuse.
Nitrogen removal and sludge reduction in a symbiotic activated sludge system between anaerobic archaea and bacteria
Authors: Jun H.-B. , Park S.-M. , Park N.-B. , Lee S.-H.
Published: May 2018

The possible symbiosis between bacteria and anaerobic archaea was investigated in intermittent aeration (I/A) systems. Archaea solution added to I/A reactor might play an important role in biological activities as well as in improvement of mineralization of organic matter. I/A reactor with archaea solution (I/A-arch) could increase both nitrification and denitrification rate and also reduce the sludge yield remarkably. These results indicate the possibility of the symbiotic activated sludge system with anaerobic archaea by controlling the DO level in the aeration tank. In this study, DO was controlled by intermittent aeration schemes and a successful symbiotic activated sludge system was achieved to reach the following conclusions. 1) SOUR of I/A-arch system was 2.9 mg-O2/g-VSS·min. SOUR and nitrification rate of the sludge from I/A-arch was higher than those from the I/A and A/S reactors. 2) Removal efficiencies of organic matter (TCODCr) in I/A-arch, I/A and conventional activated sludge (A/S) reactors were 93, 90 and 87%, respectively. 3) Nitrification occurred successfully in each reactor, while denitrification rate was much higher in the I/A-arch reactor. Efficiencies of TN removal in A/I-arch, I/A and A/S reactors were 75, 63 and 33%, respectively. 4) Observed yield coefficients of I/A-arch, I/A and A/S reactors were 0.28, 0.41 and 0.37 g-VSS/g-COD.
Modelling and calibration of phosphate and glycogen accumulating organism competition for acetate uptake in a sequencing batch reactor
Authors: Yagci N. , Insel G. , Artan N. , Orhon D.
Published: May 2018

This paper improves the modeling of enhanced biological phosphate removal, by introducing the mechanistic description of a mixed culture of glycogen and phosphate accumulating organisms competing for acetate, and glycogen metabolism of the latter. A new process stoichiometry is defined for the mixed culture based upon previously developed metabolic concepts and models. The proposed model is tested with and used for the calibration of experimental data generated by a sequencing batch reactor operated with acetate feeding at a P/Ac ratio of 0.05 mgP mg-1COD. The calibration yielded acceptable numerical results for all the model coefficients tested and supported the validity of selected metabolic relationships for process stoichiometry. It also defined conditions that allow the system to sustain glycogen accumulating organisms with significant impact on process behaviour and performance.