bluuebunny/crossref_metadata_2025 huggingface dataset:
Danish policy measures to reduce diffuse nitrogen emissions from agriculture to the aquatic environment
Authors: Grant R. , Blicher-Mathiesen G.
Published: May 2018

In Denmark, the first Action Plan for the Aquatic Environment (I) was introduced in 1987. The target was a 50% reduction in nitrogen emissions to the aquatic environment by 1993. Measures were directed towards the individual farmer and included the establishment of slurry tanks with 9 month storage capacity and obligations to grow winter crops on 65% of the area. In the early 1990s, it was obvious that agricultural practice had not changed towards a more efficient use of manure and fertilisers. Therefore, the Action Plan for Sustainable Agriculture was adopted in 1991, the reduction target being postponed until 2000. The plan set out restrictions on the actual utilisation of fertilisers and manure, obligations for the farmers to submit nitrogen accounts to the Ministry of Agriculture, and a levy system. However, the implemented measures were still insufficient to reach the reduction target. A second Action Plan for the Aquatic Environment (II) was adopted in 1998 and the reduction target was again postponed until 2003. This plan contained a range of measures, including reduced nitrogen standards for crops. The results from the Danish action plans confirm the need for an effective control body, and a continuous monitoring and evaluation programme.
Degradation of EDTA and DTPA in chlorine dioxide bleaching conditions
Authors: Kettunen-Knuutila A. , Saastamoinen S. , Rämö J. , Sillanpää M. , Veijonen T.-P. , Ala-Kaila K.
Published: May 2018

The decomposition of EDTA and DTPA was studied in simulated chlorine dioxide bleaching conditions. Under the investigated conditions EDTA and DTPA decomposed readily. Accordingly, feeding the chelating agents to the first chlorine dioxide stages (D0) should be reconsidered, when successful metal removal is desired. On the other hand, chlorine dioxide water may be utilized to degrade the chelating agents.
Policy development for the reduction of pollution caused by traffic experiences from The Netherlands
Authors: Berbee R. , Vermij P. , van de Laak W.J.
Published: May 2018

Road traffic is a diffuse source of heavy metals and oil that leads to pollution of verges and surface water in areas immediately surrounding roads. The Commission for Integrated Water Management (CIW) has drawn up a policy document addressing methods for managing this type of pollution. The document is based on results from numerous studies in The Netherlands targeting pollution caused by traffic. The Commission concludes that measures at the source are the only way to realise sustainable solutions. For example, attention should be devoted to the issue of zinc emissions from car tyres and crash barriers. The concept of controlled infiltration is recommended for combating pollution caused by spray and runoff from roads. This includes periodic chemical inspection of verge pollution and, where necessary, replacement of the verge's top layer. The application of porous asphalt on highways in The Netherlands has also proven highly effective in limiting pollution caused by traffic, with far less pollution caused by spray from the highway and runoff as compared to traditional asphalt.
Evaluation of a novel wind tunnel for the measurement of the kinetics of odour emissions from piggery effluent
Authors: Sohn J.H. , Smith R. , Yoong E. , Hudson N. , Kim T.I.
Published: May 2018

A novel laboratory wind tunnel, with the capability to control factors such as air flow-rate, was developed to measure the kinetics of odour emissions from liquid effluent. The tunnel allows the emission of odours and other volatiles under an atmospheric transport system similar to ambient conditions. Sensors for wind speed, temperature and humidity were installed and calibrated. To calibrate the wind tunnel, trials were performed to determine the gas recovery efficiency under different air flow-rates (ranging from 0.001 to 0.028 m3/s) and gas supply rates (ranging from 2.5 to 10.0 L/min) using a standard CO gas mixture. The results have shown gas recovery efficiencies ranging from 61.7 to 106.8%, while the average result from the trials was 81.14%. From statistical analysis, it was observed that the highest, most reliable gas recovery efficiency of the tunnel was 88.9%. The values of air flow-rate and gas supply rate corresponding to the highest gas recovery efficiency were 0.028 m3/s and 10.0 L/min respectively. This study suggested that the wind tunnel would provide precise estimates of odour emission rate. However, the wind tunnel needs to be calibrated to compensate for errors caused by different air flow-rates.
Ambient odour testing of concentrated animal feeding operations using field and laboratory olfactometers
Authors: Newby B.D. , McGinley M.A.
Published: May 2018

The Missouri Air Conservation Commission regulations include regulations that limit the amount of acceptable odor from confined animal feeding operations (CAFOs). The regulations concerning odor designate the use of a scentometer as a screening tool. The rules dictate that if an odor is detectable by an investigator at a dilution ratio of 5.4 using a scentometer then an air sample should be collected and sent to an olfactometry laboratory for an odor panel to determine the detection threshold and the intensity of the odor sample. The detection thresholds are determined following ASTM E679-91 and EN13725. The intensity is determined following ASTM E544-99. If the olfactometry laboratory determined the detection threshold of the sample to be above seven, then the CAFO would be in violation. If the olfactometry laboratory determined the intensity level to be above a level equivalent to 225 ppm of n-butanol, then the source of odor would be in violation. The CAFO odor rules came under scrutiny by representatives of the largest hog producer in the State of Missouri. Specifically, they argued that the detection threshold limit of seven in the CAFO portion of the rule was too low for the rule to realistically identify a violation. This paper presents the results of a study to find the appropriate regulatory level of odor as determined by laboratory olfactometry. The study took place from November 2001 to October 2002. Samples were collected from field locations that exhibited odor produced by confined animal feeding operations and from areas exhibiting no apparent odor. The odors were categorized based upon the scentometer level at which the odors were detectable, and then samples were sent to an odor evaluation laboratory for analysis by olfactometry.
Degradation of 4-chlorophenol mediated by Fe(III)-NTA in homogeneous and heterogeneous systems
Authors: Abida O. , Emilio C. , Quici N. , Gettar R. , Litter M. , Mailhot G. , Bolte M.
Published: May 2018

In this work, the comparison of 4-chlorophenol (4-CP) degradation by two different AOT processes has been performed: a) a homogeneous system with Fe(III)-NTA (1:1 complex), b) a TiO2/Fe(III)-NTA heterogeneous system. In both cases, NTA appears to play a positive role in the photochemical reaction. In the homogeneous system, the iron salt is the only absorbing species and is proved to be able to photoinduce 4-CP degradation ([4-CP] = 0.1-0.2 mM, [FeNTA] = 0.3-0.9 mM, pH 4, λ = 365 nm). The progress of the reaction was positively affected by the FeNTA concentration, and the reaction kept going even after the total disappearance of FeNTA. However, 4-CP complete degradation requires the presence of oxygen, otherwise the reaction stops. In the heterogeneous system ([4-CP] = 2.0 mM, [FeNTA] = 1.0-2.0 mM, [TiO2] = 0.1 and 1.0 g L-1, pH 3, λ = 300-400 nm), an important effect of the complex on the degradation extent and on the initial reaction rate can be seen, which overcomes the effect of non-complexed Fe(III). This behaviour is more important at the highest TiO2 concentration.
Effect of back-pressure on absorption efficiency of impingers used for air sampling
Authors: Wang X.
Published: May 2018

The gas-liquid absorption method, using an impinger as an extracting device, is the most common method for quantifying most gaseous pollutants. The performance of conventional impingers was studied, and several modified impingers were tested. It was found that the sampling efficiency varied from impinger to impinger, which resulted from back-pressure differences between impingers. The back-pressure of ten tested impingers ranged between 160 mm to 520 mm water gage when a 50 mL absorbing solution was used, which caused the ammonia concentration coefficients of variations to be up to 15%. It was also verified that an open bubble distribution tube could be used to eliminate back-pressure variations between impingers. Nearly identical back-pressure (44 ± 4 mm water gage) could be obtained. This modification can improve measurement repeatability significantly and reduce the coefficient of variation of measurements to 1.2%. With this modification to the impingers, greater accuracy, repeatability and comparison of results can be achieved in the measurement of gaseous pollutants in air.
Hydrogen sulfide emission in sewer networks: a two-phase modeling approach to the sulfur cycle
Authors: Yongsiri C. , Vollertsen J. , Hvitved-Jacobsen T.
Published: May 2018

Wherever transport of anaerobic wastewater occurs, potential problems associated with hydrogen sulfide in relation to odor nuisance, health risk and corrosion exist. Improved understanding of prediction of hydrogen sulfide emission into the sewer atmosphere is needed for better evaluation of such problems in sewer networks. A two-phase model for emission of hydrogen sulfide along stretches of gravity sewers is presented to estimate the occurrence of both sulfide in the water phase and hydrogen sulfide in the sewer atmosphere. The model takes into account air-water mass transfer of hydrogen sulfide and interactions with other processes in the sulfur cycle. Various emission scenarios are simulated to illustrate the release characteristics of hydrogen sulfide.
Treatment of non-biodegradable wastewater by electro-Fenton method
Authors: Chang P.-H. , Huang Y.-H. , Hsueh C.-L. , Lu M.-C. , Huang G.-H.
Published: May 2018

A novel electro-Fenton method, called the Fered-Fenton method, applying H2O2 and electrogenerated ferrous ions for treating organic-containing wastewater was investigated. By combining electrochemical reduction and chemical oxidation, the process can regenerate ferrous ions and remove organic compounds simultaneously in a batch reactor. Because the generation rate of ferrous ions is one of the key parameters in evaluating the oxidation efficiency of the reaction system, the initial current efficiencies (ηi) for iron (III) reduction are examined first. It shows that increasing initial ferric ion concentration can achieve high initial current efficiency. In addition, ηi decreased (ca. 20-100%) with increasing current density of cathode (ca. 40-199 A/m2). For illustration, the wastewater from chemical (i.e. electroless) nickel plating was treated in this investigation owing to its non-biodegradability and high organic concentration. The average pH, COD and Ni concentrations of this wastewater were about 5.0, 30,000 and 2,000 mg/L, respectively. Experimental results indicate that traditional Fenton method only removed 60% of COD when using 5,000 mg/L of ferrous ions. However, the COD removal efficiency was promoted after the electricity was introduced into the system (i.e. Fered-Fenton method). Moreover, Ni concentration was reduced from 2,080 to 0.3 mg/L, indicating that the removal efficiency was higher than 99.9%.
Comparison of different TiO2 photocatalysts for the gas phase oxidation of volatile organic compounds
Authors: Raillard C. , Héquet V. , Le Cloirec P. , Legrand J.
Published: May 2018

Gas-solid photocatalyzed oxidation of air contaminants is being explored more and more for possible application to decontamination, purification and deodorization of enclosed atmospheres. Indoor air is characterized by a huge number of pollutants at low concentrations. Volatile organic compounds (VOC) represent the main indoor air pollutants category, and are of great concern since some of them can act negatively on human health. Several treatments exist to reduce VOC concentrations in gaseous effluents, but photocatalytic oxidation appears to be the most appropriate regarding indoor air specific constraints. It is then necessary to develop photocatalysts, which can possibly be used in an application such as indoor air-quality improvement. In the present work, three different TiO2-based materials were studied and compared for the photocatalytic oxidation of a typical pollutant of indoor air: methyl ethyl ketone. Kinetic studies were performed for each material in dry and humid air conditions, and the Langmuir-Hinshelwood model was satisfactorily applied in almost every case. A second approach consisted of determining methyl ethyl ketone degradation by-products. Acetaldehyde was found to be the main gaseous intermediate, and could be taken into account in the general Langmuir-Hinshelwood modeling.
H2O2/UV enhanced degradation of pesticides in wastewater
Authors: Kowalska E. , Janczarek M. , Hupka J. , Grynkiewicz M.
Published: May 2018

Photodegradation of organic pesticides in industrial wastewater was examined in a UV/H2O2/air system. An experimentally determined optimal amount of hydrogen peroxide (0.008% v/v) indicates that hydrogen peroxide concentration controlled the efficiency of photodegradation. Pre-treatment operations such as sedimentation, filtration and coagulation were used to obtain better efficiency of pesticide removal and to cut down on irradiation time. Finally, scale-up experiments in the air-sparged hydrocyclone (ASH) reactor were carried out. After 5 min irradiation of 100 dm3 industrial wastewater almost all pesticides were destroyed. Thus the ASH reactor proved to be an effective contactor for carrying out photochemical reactions.
Combining photo-Fenton process with biological sequencing batch reactor for 2,4-dichlorophenol degradation
Authors: Al Momani F. , Gonzalez O. , Sans C. , Esplugas S.
Published: May 2018

The effect of the photo-Fenton process on biodegradability enhancement of 100 mg.L-1 aqueous 2,4-dichlorophenol (2,4-DCP) solution has been investigated. An initial concentration of 65 mg.L-1 H2O2 and 10 mg.L-1 Fe (II) during 35 minutes of irradiation time was sufficient for total 2,4-DCP removal. At these working conditions, biodegradability, measured as BOD5/COD ratio, was increased from 0 for the original solution up to 0.15. Biological oxidation of photo-Fenton pre-treated solutions was performed in a sequencing batch reactor (SBR). After 32 days of start-up, the reactor was fed with different pre-treated solutions and cycle duration was reduced progressively. TOC removal efficiencies in the SBR went from 30 up to 70%.
Effect of ozone, chlorine and hydrogen peroxide on the elimination of colour in treated textile wastewater by MBR
Authors: Brik M. , Chamam B. , Schöberl P. , Braun R. , Fuchs W.
Published: May 2018

In treating textile wastewater, the application of membrane bioreactor (MBR) technology showed high efficiency in COD and BOD5 removal. However, insufficient colour removal was achieved for possible reuse. The aim of the work presented in this paper was to test the performance of chemical advanced oxidation on the elimination of the colour downstream of an MBR. To improve the quality of the membrane bioreactor effluent three different oxidation treatments were tested at lab-scale: ozonation, chlorination and hydrogen peroxide oxidation. Colour, COD and BOD5 were controlled in order to assess the effectiveness of each process. For chlorination, even with 250 mg/L (active chlorine) only 80% colour removal (SACin = 14; SACout = 2.8) was achieved which is considered unsatisfactory. For hydrogen peroxide, the colour removal was even poorer; it was just 10% at a concentration of 250 mg/L. In contrast, good results were obtained by ozonation. By using only 38 mg/L within 20 minutes, it was possible to achieve the reuse recommendation with a satisfactory colour removal of 93% (SACin = 14; SACout = 0.98). The results showed that ozonation was the most promising method.
Technical and economical analysis of the conversion of a full-scale scrubber to a biotrickling filter for odor control
Authors: Gabriel D. , Deshusses M. A.
Published: May 2018

The present paper evaluates the technical and economical feasibility of converting wet chemical scrubbers to biotrickling filters for H2S control at the Orange County Sanitation District (OCSD), California. Results of 8 months of continuous operation of a biotrickling filter treating 16,000 m3 h-1 of foul air are analyzed. The reactor was operated at a gas contact time of 1.6 to 2.2 seconds reaching H2S elimination capacities up to 105-110 g H2S m-3 h-1, consistently maintaining outlet concentrations well below the regulatory limits (24 h average of 1 ppmv) and demonstrating to be very robust against temporary changes. Also, a cost-benefit analysis of the conversion was performed. Savings from chemicals, energy and water usage compared to a chemical scrubber operated in parallel to the biotrickling filter throughout the project indicated that the payback time of the conversion was about 1.3 years. Cost savings ranged between US$ 40,000 per year, per scrubber. While the above number may be specific to OCSD conditions, the cost analysis suggests that there is a significant benefit of converting chemical scrubbers to biotrickling filters over a wide range of operating conditions.
The effect of two ammonia-emission-reducing pig housing systems on odour emission
Authors: Mol G. , Ogink N.W.M.
Published: May 2018

Odour nuisance from agricultural activities is increasing in densely populated countries like the Netherlands. To develop adequate regulations, a large-scale, government-financed monitoring programme was started in the mid-1990s to establish odour emission levels for both conventional and low ammonia emission housing systems for cattle, pigs and poultry. The results indicate that high- and low-odour emission housing are difficult to distinguish because of the large variation within housing systems. Measurements on different farm locations within the same housing system show both a large variation between locations and within one location (in time). The latter, however, is significantly smaller, which suggests that farm management is an important determinant in odour emission that interferes with the effects of housing systems.

The current research was aimed at determining the effect of two common ammonia-reducing pig-housing systems on odour emissions compared to conventional housing systems under similar management conditions. The respective reduction principles of these systems are reducing the emitting surface of the manure pit and cooling of manure in the manure pit (both pits beneath slatted floor). Five farms that combined conventional housing with one low-ammonia system (three reduced emitting surface and two manure cooling) were selected for a direct, pair-wise comparison of (olfactometric) odour emission measurements. The results show a highly significant effect (p < 0.01) for two of the three reduced emitting surface systems and for one of the two manure cooling system. The average odour reduction percentages of these systems are 35% (from 24.9 to 16.0 OUE/s per animal) and 23% (from 30.1 to 24.0 OUE/s per animal) respectively. Although odour emission reduction through the type of housing system is possible, management factors interact with the system and thereby determine whether the system reduces odour emission or not.
Anoxic control of odour and corrosion from sewer networks
Authors: Yang W. , Vollertsen J. , Hvitved-Jacobsen T.
Published: May 2018

Anoxic processes can effectively control odour and corrosion in sewer networks. However, the absence of fundamental knowledge on the kinetics of anoxic transformation of sewage prevents the engineering applications of anoxic control in sewers. This paper focuss on a basic understanding of the anoxic transformations needed for a conceptual simulation of the water phase processes. Experiments conducted in batch reactors have shown that nitrite builds up in wastewater during denitrification. Part of the nitrate-reducing biomass is capable of utilizing nitrite after nitrate is depleted. Compared with aerobic transformation, anoxic processes have low values of maximum growth rate of the biomass and also a low endogenous respiration rate. Heterotrophic yield determined under anoxic conditions, at level of 0.25 mmol e-eq (mmol e-eq)-1, accounted for less than 40% of the corresponding aerobic values.
BTE-OX biodegradation kinetics with MTBE through bioaugmentation
Authors: Acuna-Askar K. , Villarreal-Chiu J.F. , Gracia-Lozano M.V. , Garza-Gonzalez M.T. , Chavez-Gomez B. , Rodriguez-Sanchez I.P. , Barrera-Saldana H.A.
Published: May 2018

The biodegradation kinetics of BTE-oX and MTBE, mixed all together, in the presence of bioaugmented bacterial populations as high as 880 mg/L VSS was evaluated. The effect of soil in aqueous samples and the effect of Tergitol NP-10 on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 36 hours, every 6 hours. Benzene and o-xylene biodegradation followed a first-order one-phase kinetic model, whereas toluene and ethylbenzene biodegradation was well described by a first-order two-phase kinetic model in all samples. MTBE followed a zero-order removal kinetic model in all samples. The presence of soil in aqueous samples retarded BTE-oX removal rates, with the highest negative effect on o-xylene. The presence of soil enhanced MTBE removal rate. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged from 95.4-99.7% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged from 55.9-90.1% and 15.6-30.1%, respectively.
Mass spectrometric analytical methods for the determination of endocrine disrupting chemicals (EDCs)
Authors: Stehmann A. , Meesters R.J.W. , Schröder Horst Fr.
Published: May 2018

This paper describes a method for the determination of endocrine disrupting chemicals (EDCs) in waste water. The method involves a SPE-C18 extraction followed by a SPE-silica gel column clean up and elution of the analytes with a mixture of acetone/pentane (2+1). Thereafter derivatisation of the analytes with heptafluorobutyric acid anhydride (HFBA) and analysis by gas chromatography/mass spectrometry (GC/MS) with positive electron impact ionisation (EI) or negative chemical ionisation (NCI) using methane as reactant gas was performed. The two different ionisation techniques were compared and the negative chemical ionisation technique proved significant lower limits of detection (LODs) and quantitation (LOQs) than positive electron impact ionisation. Recoveries of the analytes in various spiked waste water samples ranged from 75.4 to 96.9%. The concentrations of the EDCs in feed waste water from three different waste water treatment plants (WWTPs) ranged from non-detectable up to a concentration of 10,305 ng/L for 4-NP and in the corresponding effluent samples from non-detectable to 723 ng/L for BPA.
Start up of deammonification process in one single SBR system
Authors: Li X. , Zen G. , Rosenwinkel K.H. , Kunst S. , Weichgrebe D. , Cornelius A. , Yang Q.
Published: May 2018

A process for autotrophic nitrogen removal named aerobic/anoxic deammonification wherein NH4+ is oxidized by nearly 50% to NO2- and subsequently the ammonia is converted together with the nitrite to molecular nitrogen (N2 gas), has come to full-scale application within the last few years. In this research, sludge from a biological rotation disk located at a landfill leachate plant at Mechernich, Germany, which is capable of performing the deammonification process, was used as seed sludge for acclimating deammonification activities in laboratory scale batch-reactors. In parallel, the same tests were performed with normal activated sludge. Research results indicated that deammonification activities could be obtained from the seeded reactor and also, with limited performance, from normal activated sludge in a single SBR system after several months acclimation. It was also seen that oxygen is an important factor that influences the deammonification from both the acclimatization process and process running. Further results were approved that report an impact of nitrite as a process intermediate on the closely related process of anaerobic ammonia oxidation (“Anammox”). However, limiting concentrations on a bacteria population performing deammonification were found to be different to those reported for a pure Anammox-culture. Also the influence of another intermediate, hydrazine, was tested for speeding up the acclimating process by inducing the deammonification activities and recovering the activities of deammonification from nitrite inhibition.
Agricultural reuse of the secondary effluent polished by an algal pond system coupled with constructed wetland
Authors: Kim Y. , Lee D.-R. , Giokas D.
Published: May 2018

In this paper, reuse potentials of the secondary effluents as irrigation water was evaluated through field sampling trips. Water quality parameters significantly deviating from its guidelines were Total coliform bacteria and organic matter. Even though nutrients are not regulated in Korea, their removal would be required because they have been a barrier for secondary effluent irrigation through governmental intervention. The results of treatment study with aquatic ponds show that in spite of its poor biodegradability, organic matter in soluble form was reduced by 20% during 10 days of HRT. On the other hand, reduction of nutrients was remarkable. On average 85% of total nitrogen and 89% of total phosphorus were removed, respectively, which abates the worries of farmers for overgrowth or reduction in crop yield. However, coliform bacteria, although slightly reduced due to their propagation at the constructed wetlands still need further treatment.
Application of a sponge media (BioCube) process for upgrading and expansion of existing caprolactam wastewater treatment plant for nitrogen removal
Authors: Chae K.J. , Yim S.K. , Choi K.H.
Published: May 2018

For the upgrade and expansion of an existing caprolactam wastewater treatment plant, a freely floating sponge media (BioCube) process was selected based on extensive pilot-plant tests, due to extreme space constraints. In order to protect nitrifier inhibition caused by high strength organics in caprolactam wastewater, the pilot plant consisted of an organics removal reactor, which functioned as a pretreatment for nitrification, and followed the nitrogen removal reactor. The suspended MLSS was 1,800-4,000 and the media attached MLSS was maintained at 22,000-26,000 mg/L. The final effluent COD was noticeably low, around 20.4-37 mg/L, even with fairly large fluctuations in the feed levels, between 1,400-6,770 mg/L. The removal of total nitrogen with the system, when denitrification was close to completion, was approximately 97.6%. For the entire run, complete nitrification of 99.6% was achieved, which might have been due to well-acclimatized nitrifiers attached in the BioCube media. Specifically, after adaptation, the nitrification continuously increased in the organics removal reactor, even under high residual organics conditions. From the numerous experimental results, the BioCube process seemed to be an effective method for the upgrading and expansion of the existing wastewater treatment plant, with minimum reactor enlargement.
Automatic control and remote monitoring system for biological nutrient removal on small wastewater treatment plants in Korea
Authors: Lee H. , Min Y.M. , Park C.H. , Park Y.H.
Published: May 2018

Many small-size wastewater treatment plants in KoreaÕs rural communities are designed to remove organic and suspended matter only, and they generally show a large fluctuation in the influent loading compared to municipal wastewater treatment plants (MWWTPs). They also have no professional engineers stationed for efficient operation against mechanical breakdown. For those reasons, the wastewater treatment plants have low efficiency in treatment of nitrogen and phosphorus as well as organic matter. In order to solve those problems, this study developed an automatic control system and RMS (remote monitoring system), which can keep efficiency stable despite any change in the small plants' loading rates and are capable of removing nutrient materials such as nitrogen or phosphorus. According to the results of the Experimental SBR system of the automatic control program, complete nitrification was made under oxic conditions and denitrification occurred as NO3-N concentration decreased by 0.5 mg/l in anoxic conditions and excellent nitrogen removal efficiency was seen generally. The Experimental SBR system created “phosphate release and uptake” effectively and displayed phosphate-removing efficiency up to more than 80% as the concentration of effluent was kept low by 0.4 mg/l. RMS developed in this study transmits a plants data and operation states to clients in remote locations in real-time interval through the Internet. Therefore, although you are in a remote location, it allows you to see if a plant is properly operated or there is any breakdown.
Nutrient removal and microbial granulation in an anaerobic process treating inorganic and organic nitrogenous wastewater
Authors: Ahn Y.-H. , Kim H.-C.
Published: May 2018

The sustainable anaerobic nitrogen removal and microbial granulation were investigated by using a laboratory anaerobic granular sludge bed reactor, treating synthetic (inorganic and organic) wastewater and piggery waste. From inorganic synthetic wastewater, lithoautotrophic ammonium oxidation to nitrite/nitrate was observed by an addition of hydroxylamine. Also, the results revealed that the Anammox intermediates (particularly, hydrazine) contents in the substrate would be one of the important parameters for success of the anaerobic nitrogen removal process. The results from organic synthetic wastewater show that if the Anammox organism were not great enough in the startup of the process, denitritation and anaerobic ammonification would be a process prior to the Anammox reaction. The anaerobic ammonium removal from the piggery waste was performed successfully, probably due to the Anammox intermediates contained in the substrate. This reactor shows a complex performance including the Anammox reaction and HAP crystallization, as well as having partial denitritation occurring simultaneously. From the activity test, the maximum specific N conversion rate was 0.1 g NH4-N/g VSS/day (0.77 g T-N/g VSS/day), indicating that potential denitritation is quite high. The NO2-N/NH4-N ratio to Anammox is 1.17. The colour of the biomass treating the piggery waste changed from black to dark red. It was also observed that the red-colored granular sludge had a diameter of 1-2 mm. The settleability assessment of the granular sludge revealed that the granular sludge had a good settleability even though it was worse than that of seed granular sludge.
Treatment of nitrogen and phosphorus in highly concentrated effluent in SBR and SBBR processes
Authors: Pambrun V. , Paul E. , Spérandio M.
Published: May 2018

Various sludge treatment processes produced supernatant with high ammonia concentration from 500 to 2,000 mgN/L and generally high phosphate concentration. Conversion of ammonia into nitrite via partial nitrification has proven to be an economic way, reducing oxygen and external COD requirements during the nitrification/denitrification process. Two processes with biomass retention are studied simultaneously: the sequencing batch reactor (SBR) and the sequencing batch biofilm reactor (SBBR). At a temperature of 30°C, the inhibition of nitrite-oxidizing bacteria due to high ammonia concentration has been studied in order to obtain a stable nitrite accumulation. This work has confirmed the effect of pH and dissolved oxygen on nitrite accumulation performance. During a two month starting period, both processes led to nitrite accumulation without nitrate production when pH was maintained above 7.5. From a 500 mgN/L effluent, the performance of the SBR, and the SBBR, reached respectively about 0.95gN-NO2−/gN-NH4+, and 0.4gN-NO2−/gN-NH4+. The SBBR appears to be more stable facing disturbances in dissolved oxygen conditions. Finally, the maximal phosphate removal rates obtained in the SBR reached 90%, and 70% in the SBBR, depending on ammonium accumulation in the reactor. Ammonium phosphate precipitation is likely to occur, as was suggested by crystals observation in the reactor.
Enhanced nitrogen removal in the combined activated sludge-biofilter system of the Southpest Wastewater Treatment Plant
Authors: Jobbágy A. , Tardy G.M. , Literáthy B.
Published: May 2018

In 1999 the existing activated sludge unit of the Southpest Wastewater Treatment Plant was supplemented by a two-stage biofilter system aiming for nitrification and post-denitrification. In this arrangement excess biomass of the filters is wasted through the activated sludge unit, facilitating backseeding, and recirculation of the nitrate-rich effluent of the N-filter serves for decreasing the methanol demand of the DN-filter and for saving aeration energy at the same time. The paper reports on the development of an ASM1-based mathematical model that proved to be adequate for describing the interactions in the combined system and was used to compare the efficiency of different treatment options. Full-scale results verified that backseeding may considerably improve performance. However, nitrification ability of the activated sludge unit depends on the treatment temperature and, if unexpected, can be limited by insufficient oxygen supply. The upgrading possibilities outlined may serve as a new perspective for implementation of combined activated sludge-biofilter systems.
Nutrient removal process development and full implementation at the 4 million p.e. main treatment plant of Vienna, Austria
Authors: Kroiss H. , Klager F. , Winkler S. , Wandl G. , Svardal K.
Published: May 2018

The Main Treatment Plant of Vienna is in extension for 4 million p.e. and very stringent nutrient removal requirements. The existing high rate BOD removal activated sludge plant (in operation since 1980) is extended by a second stage activated sludge plant and a newly developed flow scheme for nitrogen removal optimisation adaptable to the temperature variations over the year. For this plant pilot investigations have been performed for the development of a specific mathematical model (ASMV) and a specific aeration control strategy. The civil work of the extension is already finished and the installation of the equipment has started. Operation should start in 2004. The whole project will cost about €264 million of which about one half is for civil work. The effluent standards correspond to the requirements for sensitive areas in EU Directive for Municipal Waste Water. The raw primary and excess sludge are incinerated after thickening and dewatering. This paper tries to condense the already existing literature with the construction progress and the cost situation.
Improvement of nitrogen removal at WWTP Zürich Werdhöelzli after connection of WWTP Zürich-Glatt
Authors: Siegrist H. , Rieger L. , Fux Ch. , Wehrli M.
Published: May 2018

Optimisation of nitrifying activated sludge plants towards nutrient removal (denitrification and enhanced P-removal) leads to a substantial reduction of operating costs and improves effluent and operating conditions. At WWTP Zürich-Werdhöelzli, initially designed for nitrification only, an anoxic zone of 28% of total activated sludge volume was installed and allowed 60% nitrogen elimination besides several other optimisations. In 2001 the operation of WWTP Zürich-Glatt was stopped and the wastewater was connected to WWTP Werdhöelzli. To improve nitrogen removal, WWTP Werdhöelzli co-financed two research projects; one for separate digester supernatant treatment with the anammox process operating two SBRs in series and the other applying NH4 sensors for aeration control in order to decrease energy consumption and raise effluent quality. The results of both projects and the consequences for WWTP Werdhöelzli are discussed in this paper.
Hygienization of municipal sludge in automatically operated chamber filter presses with thermal vacuum drying
Authors: Sagberg P.
Published: May 2018

This paper presents the state of the art of thermal vacuum drying in chamber filter presses for unattended automatic operation. The achieved results are exemplified by the treatment of the two stage digested combined primary, chemical and biological sludge created by the VEAS concept for nutrient removal from municipal wastewater at VEAS. The water removal rate in each stage of the drying process is described, with comments on the low energy needs. The advantages of one-sided heating, the capacity and the drying potential are discussed. The hygienization potential of the process is demonstrated by the effect on thermostable coliform bacteria, Escherichia coli, salmonella, the spores of sulfite reducing anaerobic bacteria, f-specific bacteriophages, the seeds of the weed, wild oat, Avena fatua, and the parasite eggs of the potato cyst nematode, Globodera rostochiensis. A more complete paper with the VEAS-concept is found on the VEAS homepage (www.veas.nu).
Commissioning and operational experiences for the 160ML/d Woodman Point Sequencing Batch Reactor - control of settleability and denitrification using bioselectors
Authors: Bagg W.K. , Newland M.C. , Rule H.
Published: May 2018

Achieving and maintaining good biomass settling characteristics is a critical process design objective for any activated sludge wastewater treatment plant (WWTP), whether intermittent or continuous technology. One way of ensuring good sludge settleability in intermittent WWTPs is the incorporation of bioselectors in the process. A bioselector is essentially a small discrete reactor volume designed primarily for carbon absorption, in which activated sludge organisms are exposed to a high substrate concentration for a relatively short time. It is normally very much smaller than an anoxic zone and the activated sludge recycle is only a fraction of that typically adopted in continuous plants. With proper conditioning, recycled biomass rapidly absorbs and stores soluble organic wastewater components before transfer to the main treatment basin. This absorption and storage mechanism, and careful management of aeration throughout the intermittent treatment cycle, plays a crucial role in many subsequent growth and treatment processes, including sludge floc formation, denitrification and biological phosphorus removal. This paper examines some design considerations, and reviews the benefits of bioselectors by reference to the commissioning and initial operation of the new 160ML/d Woodman Point Sequencing Batch Reactor in Perth, Western Australia. The applicability of bioselectors in continuous plants is discussed.
Reduction of coagulant amount added to activated sludge for phosphorus removal
Authors: Nakajima J. , Mishima I.
Published: May 2018

Adding coagulant to the activated sludge process is effective in maintaining the stability of phosphorus removal. However, the precise mechanisms of the reaction and behavior of coagulants and phosphorus are not well known. By introducing a new phosphorus removal model (PRM), the behavior of coagulant and phosphorus in the process could be described. The experimental data of the effluent phosphorus concentration and Fe content in the activated sludge agreed with the values calculated by PRM. The amount of coagulant addition to the activated sludge process for phosphorus removal is reduced with the enhanced biological phosphorus removal process. It is suggested that the amount of reduction is determined by using PRM.
International evaluation of current and future requirements for environmental engineering education
Authors: Morgenroth E. , Daigger G.T. , Ledin A. , Keller J.
Published: May 2018

The field of environmental engineering is developing as a result of changing environmental requirements. In response, environmental engineering education (E3) needs to ensure that it provides students with the necessary tools to address these challenges. In this paper the current status and future development of E3 is evaluated based on a questionnaire sent to universities and potential employers of E3 graduates. With increasing demands on environmental quality, the complexity of environmental engineering problems to be solved can be expected to increase. To find solutions environmental engineers will need to work in interdisciplinary teams. Based on the questionnaire there was a broad agreement that the best way to prepare students for these future challenges is to provide them with a fundamental education in basic sciences and related engineering fields. Many exciting developments in the environmental engineering profession will be located at the interface between engineering, science, and society. Aspects of all three areas need to be included in E3 and the student needs to be exposed to the tensions associated with linking the three.
The ACCEND program: a combined BS and MS program in environmental engineering that includes co-operative work experience
Authors: Bishop P.L. , Keener T.C. , Kukreti A.R. , Kowel S.T.
Published: May 2018

Environmental engineering education has rapidly expanded in recent years and new teaching methods are needed. Many professionals and educators believe that a MS degree in environmental engineering should be the minimum in order to practice the profession, along with practical training. This paper describes an innovative program being offered at the University of Cincinnati that combines an integrated BS in civil engineering and an MS in environmental engineering with extensive practical co-operative education (co-op) experience, all within a five-year period. The program includes distance learning opportunities during the co-op periods. The result is a well-trained graduate who will receive higher pay and more challenging career opportunities, and who will have developed professionalism and maturity beyond that from traditional engineering programs.
Environmental management master's programme in Kazakhstan: course structure and content
Authors: Druz N.N. , Heaven S. , Istamkulov M.R. , Tanton T.W.
Published: May 2018

The paper briefly considers changes in the higher education system in Kazahkstan since the break-up of the former Soviet Union. At that time master's programmes did not exist and there was no unified system for their introduction. The one-year environmental management course described was the first of its type and was set up with special permission from the Ministry of Education and Science, Republic of Kazakhstan to run on an experimental basis. The course differs significantly from other programmes and, under regulations introduced by the ministry in 2001, it is difficult to see how a broad-based programme aimed at introducing graduates from a variety of backgrounds to environmental issues could be achieved within a one-year period. The permission to run the course is periodically reviewed, however, and has been extended due to the excellent results. The course structure and the philosophy behind it are presented along with some of its history. The aim is not to produce specialists in any one area of environmental management, technology or engineering, but individuals with a broad foundation to build on as their professional careers progress.
Environmental engineering education in Spain
Authors: Rodríguez-Roda I. , Castells F. , Flotats X. , Lema J. , Tejero I.
Published: May 2018

There is a growing demand for engineers and technologists who show multidisciplinary expertise to deal with environmental issues. As a result of this demand, most countries are adapting their old university programs on environmental engineering education. In Spain an official environmental engineering degree does not yet exist, but the Council of Universities is working to present a proposal, based on Bologna agreement concepts. The paper summarizes not only the future perspectives of environmental engineering education in Spain, but also the evolution of the approach during the last decades, which includes the role of the private initiative, the environmental sciences degree, and the intensification in different traditional engineering degrees. Finally, the paper briefly details and compares the syllabus developed in the only four Spanish universities where environmental engineering is offered as a non-official post-graduate course lasting two years.
Some aspects of the environmental labour market in five European countries and conclusions with respect to environmental curricula
Authors: Fettig J.
Published: May 2018

The environmental labour market in the Czech Republic, Germany, Italy, Sweden and the Netherlands was evaluated by analysing up to 120 job advertisements in each country. The conditions and requirements were grouped into 11 categories showing clear similarities and differences between the five countries. Further evaluation of the data gives evidence that the private sector plays a significant role for technical environmental professionals in Europe. As a central task, conclusions regarding degree and knowledge requirements, respectively, and the importance of a variety of skills are drawn. Suggestions are made how the findings can be accounted for in environmental curricula. Furthermore the role of networks for the graduates' entry into the labour market is emphazised.
EEE in changing times: new B/M study programs, increasing specialization and interdisciplinarity for fewer students
Authors: Schmitt T.G.
Published: May 2018

Scope and organisational aspects of environmental engineering education in Germany as part of civil engineering are described. The structure of conventional diploma courses is compared with study programs structured in bachelor and master's courses. The current discussion and first steps of reorganisation in Germany are outlined. Intensifying interdisciplinarity and internationalisation, limited resources and increasing specialisation of research work together with a decreasing number of students are identified as future challenges to be met by innovative study programs. Cooperation in education between EE programs and networking of universities - together with enhanced student mobility - seem to be promising and necessary to achieve high quality and efficient EE education.