“Chemical characterization and multivariate analysis of atmospheric PM2.5 particles”. Ravindra K, Stranger M, Van Grieken R, Journal of atmospheric chemistry 59, 199 (2008). http://doi.org/10.1007/S10874-008-9102-5
Abstract: The new European Council Directive (PE-CONS 3696/07) frames the inhalable (PM10) and fine particles (PM2.5) on priority to chemically characterize these fractions in order to understand their possible relation with health effects. Considering this, PM2.5 was collected during four different seasons to evaluate the relative abundance of bulk elements (Cl, S, Si, Al, Br, Cu, Fe, Ti, Ca, K, Pb, Zn, Ni, Mn, Cr and V) and water soluble ions (F−, Cl−, NO2 −, NO3 −, SO4 2−, Na+, NH4 +, Ca2+ and Mg2+) over Menen, a Belgian city near the French border. The air quality over Menen is influenced by industrialized regions on both sides of the border. The most abundant ionic species were NO3 −, SO4 2− and NH4 +, and they showed distinct seasonal variation. The elevated levels of NO3 − during spring and summer were found to be related to the larger availability of the NOx precursor. The various elemental species analyzed were distinguished into crustal and anthropogenic source categories. The dominating elements were S and Cl in the PM2.5 particles. The anthropogenic fraction (e.g. Zn, Pb, and Cu) shows a more scattered abundance. Furthermore, the ions and elemental data were also processed using principal component analysis and cluster analysis to identify their sources and chemistry. These approach identifies anthropogenic (traffic and industrial) emissions as a major source for fine particles. The variations in the natural/anthropogenic fractions of PM2.5 were also found to be a function of meteorological conditions as well as of long-range transport of air masses from the industrialized regions of the continent.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S10874-008-9102-5
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“Elemental and single particle aerosol characterisation at a background station in Kazakhstan”. Hoornaert S, Godoi RHM, Van Grieken R, Journal of atmospheric chemistry 48, 301 (2004). http://doi.org/10.1023/B:JOCH.0000044432.74476.B0
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1023/B:JOCH.0000044432.74476.B0
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“Elemental composition of mineral aerosol generated from Sudan Sahara sand”. Eltayeb MAH, Injuk J, Maenhaut W, Van Grieken RE, Journal of atmospheric chemistry 40, 247 (2001). http://doi.org/10.1023/A:1012272208129
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1023/A:1012272208129
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“Single particle analysis of aerosols, observed in the marine boundary layer during the Monterey Area Ship Tracks Experiment (MAST), with respect to cloud droplet formation”. de Bock LA, Joos PE, Noone KJ, Pockalny RA, Van Grieken RE, Journal of atmospheric chemistry 37, 299 (2000). http://doi.org/10.1023/A:1006416600722
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1023/A:1006416600722
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“Single particle characterisation of the aerosol in the marine boundary layer and free troposphere over Tenerife, NE Atlantic, during ACE-2”. Hoornaert S, Godoi RHM, Van Grieken R, Journal of atmospheric chemistry 46, 271 (2003). http://doi.org/10.1023/A:1026383403878
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1023/A:1026383403878
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“Sources and transport of urban and biomass burning aerosol black carbon at the South-West Atlantic coast”. Evangelista H, Maldonado J, Godoi RHM, Pereira EB, Koch D, Tanizaki-Fonseca K, Van Grieken R, Sampaio M, Setzer A, Alencar A, Gonçalves SC, Journal of atmospheric chemistry 56, 225 (2007). http://doi.org/10.1007/S10874-006-9052-8
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S10874-006-9052-8
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“On the quasi-random entropy of linear species”. Slanina Z, Martin JML, François JP, Gijbels R, Theochem: applications of theoretical chemistry to organic, inorganic and biological problems 99, 83 (1993)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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“Analytical techniques for the detection of amphetamine-type substances in different matrices : a comprehensive review”. Drăgan A-M, Parrilla M, Feier B, Oprean R, Cristea C, De Wael K, Trac-Trends In Analytical Chemistry 145, 116447 (2021). http://doi.org/10.1016/J.TRAC.2021.116447
Abstract: This current review focuses on contributions to amphetamine-type substances (ATS) analysis. This type of synthetic illicit drugs has been increasingly present worldwide reaching 5% of the market on illicit drugs in 2019. The increment of their production in many clandestine laboratories and easy distribution among society are two of the main concerns towards the battle against synthetic drugs. Therefore, the first part of this review details the classification and mechanism of action of ATS in the human body. Second, the pharmacological and toxicological effects of ATS on human health are described to motivate the need of early detection of ATS. Subsequently, the most used laboratory-based and portable methods are presented and critically discussed along the review. Finally, a careful discussion on the advantages and disadvantages of portable techniques employed on the field are addressed as potential tools for on-site ATS detection by law enforcement officers.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Impact Factor: 8.442
DOI: 10.1016/J.TRAC.2021.116447
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“Mapping the gaps in chemical analysis for the characterisation of aptamer-target interactions”. Daems E, Moro G, Campos R, De Wael K, Trac-Trends In Analytical Chemistry 142, 116311 (2021). http://doi.org/10.1016/J.TRAC.2021.116311
Abstract: Aptamers are promising biorecognition elements with a wide applicability from therapeutics to bio-sensing. However, to successfully use these biomolecules, a complete characterisation of their bindingperformance in the presence of the target is crucial. Several multi-analytical approaches have been re-ported including techniques to describe kinetic and thermodynamic aspects of the aptamer-targetinteraction, and techniques which allow an in-depth understanding of the aptamer-target structures.Recent literature shows the need of a critical data interpretation, a combination of characterisationtechniques and suggests the key role of the characterisation protocol design. Indeed, thefinal applicationof the aptamer should be considered before choosing the characterisation method. All the limitations andcapabilities of the analytical tools in use for aptamer characterisation should be taken into account. Here,we present a critical overview of the current methods and multi-analytical approaches to study aptamer-target binding, aiming to provide researchers with guidelines for the design of characterisation protocols.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 8.442
DOI: 10.1016/J.TRAC.2021.116311
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“Present and future applications of beam techniques in environmental microanalysis”. Jambers W, Van Grieken R, Trends in analytical chemistry 15, 114 (1996). http://doi.org/10.1016/0165-9936(95)00098-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0165-9936(95)00098-4
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“A general-purpose interface between fortran and the low-level functions of the ibm-pc”. Janssens K, van Espen P, Trends in analytical chemistry 7, 128 (1988). http://doi.org/10.1016/0165-9936(88)87009-2
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0165-9936(88)87009-2
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“Mitigation strategies for radiation damage in the analysis of ancient materials”. Bertrand L, Schoeeder S, Anglos D, Breese MBH, Janssens K, Moini M, Simon A, Trends in analytical chemistry 66, 128 (2015). http://doi.org/10.1016/J.TRAC.2014.10.005
Abstract: The study of materials in cultural heritage artifacts and micro-samples benefits from diagnostic techniques based on intense radiation sources, such as synchrotrons, ion-beam accelerators and lasers. While most of the corresponding techniques are classified as non-destructive, investigation with photons or charged particles entails a number of fundamental processes that may induce changes in materials. These changes depend on irradiation parameters, properties of materials and environmental factors. In some cases, radiation-induced damage may be detected by visual inspection. When it is not, irradiation may still lead to atomic and molecular changes resulting in immediate or delayed alteration and bias of future analyses. Here we review the effects of radiation reported on a variety of cultural heritage materials and describe the usual practice for assessing short-term and long-term effects. This review aims to raise awareness and encourage subsequent research activities to limit radiation side effects.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 8.442
Times cited: 35
DOI: 10.1016/J.TRAC.2014.10.005
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“Recent trends in quantitative aspects of microscopic X-ray fluorescence analysis”. Janssens K, de Nolf W, van der Snickt G, Vincze L, Vekemans B, Terzano R, Brenker FE, Trends in analytical chemistry 29, 464 (2010). http://doi.org/10.1016/J.TRAC.2010.03.003
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 8.442
Times cited: 48
DOI: 10.1016/J.TRAC.2010.03.003
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“Antarctic fish versus human cytoglobins : the same but yet so different”. Cuypers B, Vermeylen S, Hammerschmid D, Trashin S, Rahemi V, Konijnenberg A, De Schutter A, Cheng C-HC, Giordano D, Verde C, De Wael K, Sobott F, Dewilde S, Van Doorslaer S, Journal of inorganic biochemistry 173, 66 (2017). http://doi.org/10.1016/J.JINORGBIO.2017.04.025
Abstract: The cytoglobins of the Antarctic fish Chaenocephalus aceratus and Dissostichus mawsoni have many features in common with human cytoglobin. These cytoglobins are heme proteins in which the ferric and ferrous forms have a characteristic hexacoordination of the heme iron, i.e. axial ligation of two endogenous histidine residues, as confirmed by electron paramagnetic resonance, resonance Raman and optical absorption spectroscopy. The combined spectroscopic analysis revealed only small variations in the heme-pocket structure, in line with the small variations observed for the redox potential. Nevertheless, some striking differences were also discovered. Resonance Raman spectroscopy showed that the stabilization of an exogenous heme ligand, such as CO, occurs differently in human cytoglobin in comparison with Antarctic fish cytoglobins. Furthermore, while it has been extensively reported that human cytoglobin is essentially monomeric and can form an intramolecular disulfide bridge that can influence the ligand binding kinetics, 3D modeling of the Antarctic fish cytoglobins indicates that the cysteine residues are too far apart to form such an intramolecular bridge. Moreover, gel filtration and mass spectrometry reveal the occurrence of non-covalent multimers (up to pentamers) in the Antarctic fish cytoglobins that are formed at low concentrations. Stabilization of these oligomers by disulfide-bridge formation is possible, but not essential. If intermolecular disulfide bridges are formed, they influence the heme-pocket structure, as is shown by EPR measurements.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.348
Times cited: 7
DOI: 10.1016/J.JINORGBIO.2017.04.025
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“Elemental constituents of atmospheric aerosols in Recife, North-East Brazil”. Van Grieken R, Van 't dack L, Costa Dantas C, Moura de Amorim W, Maenhaut W, Environmental pollution: series B : chemical and physical 4, 143 (1982). http://doi.org/10.1016/0143-148X(82)90025-8
Abstract: Few data are available on the inorganic atmospheric pollution in the rapidly expanding cities of South America, like Recife, on the Atlantic Coast of North-east Brazil. Therefore, the elemental composition of atmospheric aerosols was investigated for nine sites in the Recife conurbation and a fairly remote site in the area. Total aerosol samples were collected on cellulose filters for analysis by energy dispersive X-ray fluorescence and cascade impactors were used to collect the aerosols as a function of particle size for subsequent analysis by proton-induced X-ray emission. Local soil aliquots were also analysed. About eighteen elements were quantified in all cases. The average total atmospheric concentrations appeared to be well above natural levels but usually lower than, or comparable with, those of North American and European cities. Dispersal of sea spray and of local soil (often contaminated with, for example, Cu, Zn and Pb from industrial sources) contributes predominantly to the total atmospheric load in Recife. However, the particle size fraction results also indicated strong excesses in the small particle mode for S, K, V, Mn, Ni, Cu, Zn, Br and Pb, mainly in the downtown area. Again, the corresponding enrichment factors were only moderate in comparison with other published urban data.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0143-148X(82)90025-8
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“Geometry errors in 14 MeV neutron activation analysis”. Van Grieken R, Speecke A, Hoste J, Journal of radioanalytical chemistry 13, 225 (1973). http://doi.org/10.1007/BF02514126
Abstract: The effects of inaccurate sample sizes and sample positioning on 14 MeV neutron activation analysis results are estimated for 30, 20 and 10 mm diameter targets. It appears that axial positioning is the most critical parameter and that using a larger tritium target will yield an overall improvement of the reproducibility.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02514126
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“The half-life of 28Al”. Van Schandevijl R, Van Grieken R, Hoste J, Journal of radioanalytical chemistry 9, 55 (1971). http://doi.org/10.1007/BF02514012
Abstract: The half-life of28Al was redetermined on aluminium samples of different origin. Three different counting techniques were applied. The availability of highly purified samples (up to 99.9999%), the use of very fast electronic counting equipment and a complete automatisation allowed a good precision to be obtained in the final result of 2.2405 min.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02514012
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“Simultaneous determination of silicon and phosphorus in cast iron by 14 MeV neutron activation analysis”. Van Grieken R, Speecke A, Hoste J, Journal of radioanalytical chemistry 6, 385 (1970). http://doi.org/10.1007/BF02513966
Abstract: A fast (10 min), non-destructive simultaneous determination of silicon and phosphorus in cast iron and steel by 14 MeV neutron activation was developed. The 1.78 MeV28Al activity (T=2.24 min) induced by the reaction28Si(n, p)28Al is counted on a NaI(Tl) detector. Two measurements are made to correct for the 1.81 MeV56Mn activity (T=2.58 hr) from the iron matrix. However,28Al is also produced via31P(n, α)28Al. By (n, 2n) reaction, phosphorus yields also30P (T=2.6 min), the 0.511 MeV annihilation radiation of which is counted by two opposite NaI(Tl) detectors in coincidence. Again, two successive coincidence measurements are carried out in order to take into account the53Fe activity (β+; T=8.9 min) from54Fe(n, 2n)53Fe. The28Al measurement is appropriately corrected via the computed phosphorus content. An oxygen flux monitor was used to normalize to the same flux. Nuclear interferences have been examined. Special attention has been paid to the presence of copper. The standard deviation for phosphorus being as high as ca. 0.09% P for a single determination, this technique can only be practical as an independent phosphorus analysis for high phosphorus cast irons. The precision on the28Al measurement is 5% relative for 0.2% Si and 2.5% above 1% Si.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02513966
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“Spatial neutron flux distributions around A 14 MeV neutron generator”. Van Grieken R, Speecke A, Hoste J, Journal of radioanalytical chemistry 10, 95 (1972). http://doi.org/10.1007/BF02518771
Abstract: The neutron flux distribution in the vicinity of 30, 20 and 10 mm diameter targets is measured by irradiating concentric ring-type iron monitors at different distances from the target and counting the induced56Mn activity. Considering the many uncertainties, satisfactory agreement was found between theory and experiment.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02518771
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“Relative evaluation of neutron activation, X-ray fluorescence and spark source mass spectrometry for multi-element analysis of geothermal waters”. Blommaert W, Vandelannoote R, Van 't dack L, Gijbels R, van Grieken R, Journal of radioanalytical chemistry 57, 382 (1980)
Keywords: A3 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Many electron- and hole terms of molecular ions C60n\pm”. Nikolaev AV, Michel KH, Coupling In Chemistry And Physics 44, 305 (2003). http://doi.org/10.1016/S0065-3276(03)44019-7
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.196
Times cited: 1
DOI: 10.1016/S0065-3276(03)44019-7
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“Equilibrium constants for trace elements in natural waters”. Van 't dack L, Blommaert W, Vandelannoote R, Gijbels R, van Grieken R, Reviews in analytical chemistry 7, 297 (1983)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“X-ray spectrometry”. Markowicz AA, Van Grieken RE, Reviews in analytical chemistry 56, 241r (1984)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Leaf-deposited semi-volatile organic compounds (SVOCs) : an exploratory study using GCxGC-TOFMS on leaf washing solutions”. Castanheiro A, Joos P, Wuyts K, De Wael K, Samson R, Chemosphere 214, 103 (2019). http://doi.org/10.1016/J.CHEMOSPHERE.2018.09.067
Abstract: Airborne particulate matter (PM) includes semi-volatile organic compounds (SVOCs), which can be deposited on vegetation matrices such as plant leaves. In alternative to air-point measurements or artificial passive substrates, leaf monitoring offers a cost-effective, time-integrating means of assessing local air quality. In this study, leaf washing solutions from ivy (Hedera hibernica) leaves exposed during one-month at different land use classes were explored via comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS). The composition of leaf-deposited SVOCs, corrected for those of unexposed leaves, was compared against routinely monitored pollutants concentrations (PM10, PM2.5, O3, NO2, SO2) measured at co-located air monitoring stations. The first study on leaf-deposited SVOCs retrieved from washing solutions, herein reported, delivered a total of 911 detected compounds. While no significant land use (rural, urban, industrial, traffic, mixed) effects were observed, increasing exposure time (from one to 28 days) resulted in a higher number and diversity of SVOCs, suggesting cumulative time-integration to be more relevant than local source variations between sites. After one day, leaf-deposited SVOCs were mainly due to alcohols, N-containing compounds, carboxylic acids, esters and lactones, while ketones, diketones and hydrocarbons compounds gained relevance after one week, and phenol compounds after one month. As leaf-deposited SVOCs became overall more oxidized throughout exposure time, SVOCs transformation or degradation at the leaf surface is suggested to be an important phenomenon. This study confirmed the applicability of GCxGC-TOFMS to analyze SVOCs from leaf washing solutions, further research should include validation of the methodology and comparison with atmospheric organic pollutants.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.208
DOI: 10.1016/J.CHEMOSPHERE.2018.09.067
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“Precision and accuracy of ST-EDXRF performance for As determination comparing with ICP-MS and evaluation of As deviation in the soil media”. Akbulut S, Cevik U, Van AA, De Wael K, Van Grieken R, Chemosphere 96, 16 (2014). http://doi.org/10.1016/J.CHEMOSPHERE.2013.06.086
Abstract: The present study was conducted to (i) determine the precision and accuracy of arsenic measurement in soil samples using ST-EDXRF by comparison with the results of ICP-MS analyses and (ii) identify the relationship of As concentration with soil characteristics. For the analysis of samples, inductively coupled plasma mass spectrometry (ICP-MS) and energy dispersive X-ray fluorescence spectrometry (EDXRF) were performed. According to the results found in the soil samples, the addition of HCl to HNO3, used for the digestion gave significant variations in the recovery of As. However, spectral interferences between peaks for As and Pb can affect detection limits and accuracy for XRF analysis. When comparing the XRF and ICP-MS results a correlation was observed with R2 = 0.8414. This means that using a ST-EDXRF spectrometer, it is possible to achieve accurate and precise analysis by the calibration of certified reference materials and choosing an appropriate secondary target. On the other hand, with regard to soil characteristics analyses, the study highlighted that As is mostly anthropogenically enriched in the studied area.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.208
Times cited: 5
DOI: 10.1016/J.CHEMOSPHERE.2013.06.086
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“Catalytic Nox reduction with simultaneous dioxin and furan oxidation”. Goemans M, Clarysse P, Joannès J, de Clercq P, Lenaerts S, Matthys K, Boels K, Chemosphere 54, 1357 (2004). http://doi.org/10.1016/S0045-6535(03)00255-8
Abstract: The engineering, construction, performance and running costs of a catalytic flue gas cleaning component in the low dust area of a municipal waste incinerator is discussed. For this purpose, the case study of a Flemish incineration plant is presented, covering the history, the design procedure of the catalyst, relevant process data and the financial aspects. A reliable PCDD/F-destruction by means of oxidation by the catalyst to typical values of 0.001 ng TEQ/Nm3 has been demonstrated. At the same time, NOx− and CO-emissions are reduced by 90% and 20% to about 50 mg/Nm3 and below 10 mg/Nm3, respectively.
Keywords: A1 Journal article
Impact Factor: 4.208
DOI: 10.1016/S0045-6535(03)00255-8
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“Catalytic Nox reduction with simultaneous dioxin and furan oxidation”. Goemans M, Clarysse P, Joannès J, de Clercq P, Lenaerts S, Matthys K, Boels K, Chemosphere 50, 489 (2003). http://doi.org/10.1016/S0045-6535(02)00554-4
Abstract: The engineering, construction, performance and running costs of a catalytic flue gas cleaning component in the low dust area of a municipal waste incinerator is discussed. For this purpose, the case study of a Flemish incineration plant is presented, covering the history, the design procedure of the catalyst, relevant process data and the financial aspects. A reliable PCDD/F-destruction by means of oxidation by the catalyst to typical values of 0.001 ng TEQ/N m3 has been demonstrated. At the same time, NOx- and CO-emissions are reduced by 90% and 20% to about 50 mg/N m3 and below 10 mg/N m3, respectively.
Keywords: A1 Journal article
Impact Factor: 4.208
DOI: 10.1016/S0045-6535(02)00554-4
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“Pioneering on single-sludge nitrification/denitrification at 50 °C”. Vandekerckhove TGL, Boon N, Vlaeminck SE, Chemosphere 252, 126527 (2020). http://doi.org/10.1016/J.CHEMOSPHERE.2020.126527
Abstract: Thermophilic nitrification has been proven in lab-scale bioreactors at 50 °C. The challenge is now to develop a solution for thermophilic nitrogen removal, integrating nitrification with denitrification and aerobic carbon removal. This pioneering study aimed at a single-sludge nitrification/denitrification process at 50 °C, through exposing nitrification in a step by step approach to anoxia and/or organics. Firstly, recurrent anoxia was tolerated by a nitrifying community during long-term membrane bioreactor (MBR) operation (85 days), with high ammonium oxidation efficiencies (>98%). Secondly, five organic carbon sources did not affect thermophilic ammonium and nitrite oxidation rates in three-day aerobic batch flask incubations. Moving to long-term tests with sequencing batch reactors (SBR) and MBR (>250 days), good nitrification performance was obtained at increasing COD/Ninfluent ratios (0, 0.5, 1, 2 and 3). Thirdly, combining nitrification, recurrent anoxia and presence of organic carbon resulted in a nitrogen removal efficiency of 92–100%, with a COD/Nremoved of 4.8 ± 0.6 and a nitrogen removal rate of 50 ± 14 mg N g−1 VSS d−1. Overall, this is the first proof of principle thermophilic nitrifiers can cope with redox fluctuations (aerobic/anoxic) and the aerobic or anoxic presence of organic carbon, can functionally co-exist with heterotrophs and that single-sludge nitrification/denitrification can be achieved.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 8.8
DOI: 10.1016/J.CHEMOSPHERE.2020.126527
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“Enhancing bioflocculation in high-rate activated sludge improves effluent quality yet increases sensitivity to surface overflow rate”. Van Winckel T, Ngo N, Sturm B, Al-Omari A, Wett B, Bott C, Vlaeminck SE, De Clippeleir H, Chemosphere 308, 136294 (2022). http://doi.org/10.1016/J.CHEMOSPHERE.2022.136294
Abstract: High-rate activated sludge (HRAS) relies on good bioflocculation and subsequent solid-liquid separation to maximize the capture of organics. However, full-scale applications often suffer from poor and unpredictable effluent suspended solids (ESS). While the biological aspects of bioflocculation are thoroughly investigated, the effects of fines (settling velocity < 0.6 m3/m2/h), shear and surface overflow rate (SOR) are unclear. This work tackled the impact of fines, shear, and SOR on the ESS in absence of settleable influent solids. This was assessed on a full-scale HRAS step-feed (SF) and pilot-scale HRAS contact-stabilization (CS) configuration using batch settling tests, controlled clarifier experiments, and continuous operation of reactors. Fines contributed up to 25% of the ESS in the full-scale SF configuration. ESS decreased up to 30 mg TSS/L when bioflocculation was enhanced with the CS configuration. The feast-famine regime applied in CS promoted the production of high-quality extracellular polymeric substances (EPS). However, this resulted in a narrow and unfavorable settling velocity distribution, with 50% ± 5% of the sludge mass settling between 0.6 and 1.5 m3/m2/h, thus increasing sensitivity towards SOR changes. A low shear environment (20 s−1) before the clarifier for at least one min was enough to ensure the best possible settling velocity distribution, regardless of prior shear conditions. Overall, this paper provides a more complete view on the drivers of ESS in HRAS systems, creating the foundation for the design of effective HRAS clarifiers. Tangible recommendations are given on how to manage fines and establish the optimal settling velocity of the sludge.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 8.8
DOI: 10.1016/J.CHEMOSPHERE.2022.136294
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“Two-stage anaerobic membrane bioreactor for co-treatment of food waste and kitchen wastewater for biogas production and nutrients recovery”. Le T-S, Nguyen P-D, Ngo HH, Bui X-T, Dang B-T, Diels L, Bui H-H, Nguyen M-T, Le Quang D-T, Chemosphere 309, 136537 (2022). http://doi.org/10.1016/J.CHEMOSPHERE.2022.136537
Abstract: Co-digestion of organic waste and wastewater is receiving increased attention as a plausible waste management approach toward energy recovery. However, traditional anaerobic processes for co-digestion are particularly susceptible to severe organic loading rates (OLRs) under long-term treatment. To enhance technological feasi-bility, this work presented a two-stage Anaerobic Membrane Bioreactor (2 S-AnMBR) composed of a hydrolysis reactor (HR) followed by an anaerobic membrane bioreactor (AnMBR) for long-term co-digestion of food waste and kitchen wastewater. The OLRs were expanded from 4.5, 5.6, and 6.9 kg COD m- 3 d-1 to optimize biogas yield, nitrogen recovery, and membrane fouling at ambient temperatures of 25-32 degrees C. Results showed that specific methane production of UASB was 249 +/- 7 L CH4 kg-1 CODremoved at the OLR of 6.9 kg TCOD m- 3 d-1. Total Chemical Oxygen Demand (TCOD) loss by hydrolysis was 21.6% of the input TCOD load at the hydraulic retention time (HRT) of 2 days. However, low total volatile fatty acid concentrations were found in the AnMBR, indicating that a sufficiently high hydrolysis efficiency could be accomplished with a short HRT. Furthermore, using AnMBR structure consisting of an Upflow Anaerobic Sludge Blanket Reactor (UASB) followed by a side -stream ultrafiltration membrane alleviated cake membrane fouling. The wasted digestate from the AnMBR comprised 42-47% Total Kjeldahl Nitrogen (TKN) and 57-68% total phosphorous loading, making it suitable for use in soil amendments or fertilizers. Finally, the predominance of fine particles (D10 = 0.8 mu m) in the ultra -filtration membrane housing (UFMH) could lead to a faster increase in trans-membrane pressure during the filtration process.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 8.8
DOI: 10.1016/J.CHEMOSPHERE.2022.136537
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