81 results on '"Nikolaos S. Thomaidis"'
Search Results
2. Characterization of Scrubber Water Discharges from Ships Using Comprehensive Suspect Screening Strategies Based on GC-APCI-HRMS
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Elisa García-Gómez, Georgios Gkotsis, Maria-Christina Nika, Ida-Maja Hassellöv, Kent Salo, Anna Lunde Hermansson, Erik Ytreberg, Nikolaos S. Thomaidis, Meritxell Gros, and Mira Petrovic
- Published
- 2023
3. Assessment of selected pharmaceuticals in Riyadh wastewater treatment plants, Saudi Arabia: Mass loadings, seasonal variations, removal efficiency and environmental risk
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Obaid A. Alharbi, Edward Jarvis, Aikaterini Galani, Nikolaos S. Thomaidis, Maria-Christina Nika, and Deborah V. Chapman
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Environmental Engineering ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2023
4. Handling the risk dimensions of wind energy generation
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Nikolaos S. Thomaidis, Theodoros Christodoulou, and Francisco Santos-Alamillos
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General Energy ,Mechanical Engineering ,Building and Construction ,Management, Monitoring, Policy and Law - Published
- 2023
5. LogD-based modelling and ΔlogD as a proxy for pH-dependent action of ionizable chemicals reveal the relevance of both neutral and ionic species for fish embryotoxicity and possess great potential for practical application in the regulation of chemicals
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Heinz-R. Köhler, Thomas Gräff, Mona Schweizer, Jasmin Blumhardt, Jasmin Burkhardt, Lisa Ehmann, Janine Hebel, Christoph Heid, Lone Kundy, Julia Kuttler, Miroslava Malusova, Friederike-Marie Moroff, Anne-Frida Schlösinger, Pia Schulze-Berge, Eleni I. Panagopoulou, Dimitrios E. Damalas, Nikolaos S. Thomaidis, Rita Triebskorn, Dirk Maletzki, Ute Kühnen, and Peter C. von der Ohe
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Environmental Engineering ,Ecological Modeling ,Pollution ,Waste Management and Disposal ,Water Science and Technology ,Civil and Structural Engineering - Published
- 2023
6. A novel thermophile β-galactosidase from Thermothielavioides terrestris producing galactooligosaccharides from acid whey
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Anastasia Zerva, Evangelos Topakas, Nikolaos S. Thomaidis, Anastasia S. Kritikou, Athanasios Limnaios, and Petros Taoukis
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0106 biological sciences ,Food industry ,medicine.medical_treatment ,Sordariales ,Oligosaccharides ,Bioengineering ,01 natural sciences ,Catalysis ,Pichia pastoris ,03 medical and health sciences ,Hydrolysis ,chemistry.chemical_compound ,Whey ,010608 biotechnology ,medicine ,Food science ,Lactose ,Molecular Biology ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,biology ,Chemistry ,business.industry ,Prebiotic ,Thermophile ,General Medicine ,Hydrogen-Ion Concentration ,beta-Galactosidase ,biology.organism_classification ,Enzyme ,business ,Biotechnology - Abstract
β-Galactosidases are key enzymes in the food industry. Apart from the hydrolysis of the saccharide bond of lactose, they also catalyze transgalactosylation reactions, producing galactooligosaccharides (GOS) with prebiotic activity. Here we report the heterologous production in Pichia pastoris of a novel β-galactosidase from the fungus Thermothielavioides terrestris. The enzyme (TtbGal1) was purified and characterized, showing optimal activity at 60 °C and pH 4. TtbGal1 is thermostable, retaining almost full activity for 24 h at 50 °C. It was applied to the production of GOS from defined lactose solutions and acid whey, a liquid waste from the Greek yoghurt industry, reaching yields of 19.4 % and 14.8 %, respectively. HILIC-ESI-QTOF-MS analysis revealed the production of GOS with up to 4 saccharide monomers. The results demonstrate efficient GOS production catalyzed by TtbGal1, valorizing acid whey, a waste with a heavy polluting load from the dairy industry.
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- 2021
7. The importance of in-year seasonal fluctuations for biomonitoring of apex predators: A case study of 14 essential and non-essential elements in the liver of the common buzzard (Buteo buteo) in the United Kingdom
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Shinji Ozaki, Paola Movalli, Alessandra Cincinelli, Nikiforos Alygizakis, Alexander Badry, Jacqueline S. Chaplow, Daniela Claßen, René W.R. J. Dekker, Beverley Dodd, Guy Duke, Jan Koschorreck, M. Glória Pereira, Elaine Potter, Jaroslav Slobodnik, Sarah Thacker, Nikolaos S. Thomaidis, Gabriele Treu, and Lee Walker
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Health, Toxicology and Mutagenesis ,General Medicine ,Toxicology ,Pollution - Published
- 2023
8. Non-target screening of emerging contaminants in landfills: A review
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Maria-Christina Nika, Nikiforos Alygizakis, Olga S. Arvaniti, and Nikolaos S. Thomaidis
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Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Environmental Chemistry - Published
- 2023
9. Application of High Resolution Mass Spectrometric methods coupled with chemometric techniques in olive oil authenticity studies - A review
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Marilena E. Dasenaki, Nikolaos S. Thomaidis, Natasa P. Kalogiouri, and Reza Aalizadeh
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02 engineering and technology ,computer.software_genre ,01 natural sciences ,Biochemistry ,Mass Spectrometry ,Analytical Chemistry ,Chemometrics ,Environmental Chemistry ,Olive Oil ,Spectroscopy ,Reliability (statistics) ,Principal Component Analysis ,Chemistry ,010401 analytical chemistry ,Discriminant Analysis ,Reproducibility of Results ,Experimental data ,021001 nanoscience & nanotechnology ,Linear discriminant analysis ,0104 chemical sciences ,Random forest ,Hierarchical clustering ,Support vector machine ,Principal component analysis ,Data mining ,0210 nano-technology ,computer - Abstract
Extra Virgin Olive Oil (EVOO), the emblematic food of the Mediterranean diet, is recognized for its nutritional value and beneficial health effects. The main authenticity issues associated with EVOO's quality involve the organoleptic properties (EVOO or defective), mislabeling of production type (organic or conventional), variety and geographical origin, and adulteration. Currently, there is an emerging need to characterize EVOOs and evaluate their genuineness. This can be achieved through the development of analytical methodologies applying advanced "omics" technologies and the investigation of EVOOs chemical fingerprints. The objective of this review is to demonstrate the analytical performance of High Resolution Mass Spectrometry (HRMS) in the field of food authenticity assessment, allowing the determination of a wide range of food constituents with exceptional identification capabilities. HRMS-based workflows used for the investigation of critical olive oil authenticity issues are presented and discussed, combined with advanced data processing, comprehensive data mining and chemometric tools. The use of unsupervised classification tools, such as Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA), as well as supervised classification techniques, including Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), Partial Least Square Discriminant Analysis (PLS-DA), Orthogonal Projection to Latent Structure-Discriminant Analysis (OPLS-DA), Counter Propagation Artificial Neural Networks (CP-ANNs), Self-Organizing Maps (SOMs) and Random Forest (RF) is summarized. The combination of HRMS methodologies with chemometrics improves the quality and reliability of the conclusions from experimental data (profile or fingerprints), provides valuable information suggesting potential authenticity markers and is widely applied in food authenticity studies.
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- 2020
10. High Resolution Mass Spectrometric Suspect Screening, Wide-Scope Target Analysis of Emerging Contaminants and Determination of Legacy Pollutants in Adult Western Black-Tailed Godwit Limosa Limosa Limosa in the Netherlands – a Pilot Study
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Paola Movalli, Koos Biesmeijer, Georgios Gkotsis, Jaroslav Slobodnik, Maria-Christina Nika, Kostantinos Vasilatos, Marios Kostakis, Nikolaos S. Thomaidis, Peter Oswald, Martina Oswaldova, Nikiforos A. Alygizakis, Natalia Glowacka, Jos Hooijmeijer, Ruth Howison, Rene Dekker, Nico van den Brink, and Theunis Piersma
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
11. Target and Suspect Screening of 4,777 Per- and Polyfluoroalkyl Substances (Pfas) in River Water, Wastewater, Groundwater and Biota Samples in the Danube River Basin
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Nikiforos Alygizakis, Kelsey Ng, Andreas Androulakakis, Aikaterini Galani, Reza Aalizadeh, Nikolaos S. Thomaidis, and Nikiforos A. Alygizakis
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- 2022
12. Development of Two-Level Design of Experiments (DoE) for the Optimization of a HS-SPME-GCMS Method to Study Greek Monovarietal PDO and PGI Wines
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Maria Marinaki, Ioannis Sampsonidis, Artemis Lioupi, Panagiotis Arapitsas, Nikolaos S. Thomaidis, Kyriaki G. Zinoviadou, and Georgios Theodoridis
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- 2022
13. Making use of apex predator sample collections: an integrated workflow for quality assured sample processing, analysis and digital sample freezing of archived samples
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Alexander Badry, Heinz Rüdel, Bernd Göckener, Maria-Christina Nika, Nikiforos Alygizakis, Georgios Gkotsis, Nikolaos S. Thomaidis, Gabriele Treu, Rene W.R.J. Dekker, Paola Movalli, Lee A. Walker, Elaine D. Potter, Alessandra Cincinelli, Tania Martellini, Guy Duke, Jaroslav Slobodnik, Jan Koschorreck, and Publica
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Quality Control ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Ecology and Environment ,Quality assurance ,Workflow ,Specimen Handling ,Apex predator ,Chemistry ,European sample collections ,Freezing ,Data and Information ,Non-target screening ,Environmental Chemistry ,Digital sample freezing platform ,Environmental Monitoring - Abstract
Using monitoring data from apex predators for chemicals risk assessment can provide important information on bioaccumulating as well as biomagnifying chemicals in food webs. A survey among European institutions involved in chemical risk assessment on their experiences with apex predator data in chemical risk assessment revealed great interest in using such data. However, the respondents indicated that constraints were related to expected high costs, lack of standardisation and harmonised quality criteria for exposure assessment, data access, and regulatory acceptance/application. During the Life APEX project, we demonstrated that European sample collections (i.e. environmental specimen banks (ESBs), research collection (RCs), natural history museums (NHMs)) archive a large variety of biological samples that can be readily used for chemical analysis once appropriate quality assurance/control (QA/QC) measures have been developed and implemented. We therefore issued a second survey on sampling, processing and archiving procedures in European sample collections to derive key quality QA/QC criteria for chemical analysis. The survey revealed great differences in QA/QC measures between ESBs, NHMs and RCs. Whereas basic information such as sampling location, date and biometric data were mostly available across institutions, protocols to accompany the sampling strategy with respect to chemical analysis were only available for ESBs. For RCs, the applied QA/QC measures vary with the respective research question, whereas NHMs are generally less aware of e.g. chemical cross-contamination issues. Based on the survey we derived key indicators for assessing the quality of biota samples that can be easily implemented in online databases. Furthermore, we provide a QA/QC workflow not only for sampling and processing but also for the chemical analysis of biota samples. We focussed on comprehensive analytical techniques such as non-target screening and provided insights into subsequent storage of high-resolution chromatograms in online databases (i.e. digital sample freezing platform) to ultimately support chemicals risk assessment.
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- 2022
14. Thermally activated persulfate oxidation of ampicillin: Kinetics, transformation products and ecotoxicity
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Kosmas Lalas, Olga S. Arvaniti, Eirini Zkeri, Maria-Christina Nika, Nikolaos S. Thomaidis, Dionissios Mantzavinos, Athanasios S. Stasinakis, and Zacharias Frontistis
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Kinetics ,Environmental Engineering ,Sulfates ,Water ,Environmental Chemistry ,Ampicillin ,Chlorella ,Oxidation-Reduction ,Pollution ,Waste Management and Disposal ,Adenosine Monophosphate ,Water Pollutants, Chemical - Abstract
The heat-activated persulfate system showed encouraging results for the destruction of the widely used antibiotic Ampicillin (AMP). AMP removal follows exponential decay, and the observed kinetic constant was enhanced with persulfate (PS) dosage at the range 50-500 mg L
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- 2022
15. Evaluation of the performance of a pilot-scale solar still for olive mill wastewater treatment
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Petros Mastoras, Stergios Vakalis, Michail S. Fountoulakis, Georgia Gatidou, Panagiota Katsianou, Georgios Koulis, Nikolaos S. Thomaidis, Dias Haralambopoulos, and Athanasios S. Stasinakis
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Renewable Energy, Sustainability and the Environment ,Strategy and Management ,Building and Construction ,Industrial and Manufacturing Engineering ,General Environmental Science - Published
- 2022
16. Target and suspect screening of 4777 per- and polyfluoroalkyl substances (PFAS) in river water, wastewater, groundwater and biota samples in the Danube River Basin
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Kelsey Ng, Nikiforos Alygizakis, Andreas Androulakakis, Aikaterini Galani, Reza Aalizadeh, Nikolaos S. Thomaidis, and Jaroslav Slobodnik
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Fluorocarbons ,Environmental Engineering ,Rivers ,Health, Toxicology and Mutagenesis ,Water ,Environmental Chemistry ,Wastewater ,Biota ,Groundwater ,Pollution ,Waste Management and Disposal ,Water Pollutants, Chemical - Abstract
Per- and polyfluoroalkyl substances (PFAS) are under regulatory scrutiny since some of them are persistent, bioaccumulative, and toxic. The occurrence of 4777 PFAS was investigated in the Danube River Basin (DRB; 11 countries) using target and suspect screening. Target screening involved investigation of PFAS with 56 commercially available reference standards. Suspect screening covered 4777 PFAS retrieved from the NORMAN Substance Database, including all individual PFAS lists submitted to the NORMAN Suspect List Exchange Database. Mass spectrometry fragmentation patterns and retention time index predictions of the studied PFAS were established for their screening by liquid chromatography - high resolution mass spectrometry using NORMAN Digital Sample Freezing Platform (DSFP). In total, 82 PFAS were detected in the studied 95 samples of river water, wastewater, groundwater, biota and sediments. Suspect screening detected 72 PFAS that were missed by target screening. Predicted no effect concentrations (PNECs) were derived for each PFAS via a quantitative structure-toxicity relationship (QSTR)-based approach and used for assessment of their environmental risk. Risk characterization revealed 18 PFAS of environmental concern in at least one matrix. The presence of PFAS in all studied environmental compartments across the DRB indicates a potentially large-scale migration of PFAS in Europe, which might require their further systematic regulatory monitoring.
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- 2022
17. Enzymatic modification of triglycerides in conventional and surfactant-free microemulsions and in olive oil
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Evgenia Mitsou, Ioanna Theochari, Elpida Gad, Evdokia Vassiliadi, Evdoxia Karpenisioti, Georgios Koulis, Ioannis Martakos, Katerina Pissaridi, Nikolaos S. Thomaidis, Aristotelis Xenakis, and Maria Zoumpanioti
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Colloid and Surface Chemistry - Published
- 2022
18. Occurrence and potential environmental risk of surfactants and their transformation products discharged by wastewater treatment plants
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Nikolaos S. Thomaidis, Nikiforos A. Alygizakis, Marco Scheurer, Finnian Freeling, Jaroslav Slobodnik, Peter C. von der Ohe, Peter Oswald, Reza Aalizadeh, and Lubos Cirka
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chemistry.chemical_classification ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Linear alkylbenzene ,010501 environmental sciences ,01 natural sciences ,Pollution ,Dilution ,chemistry.chemical_compound ,Environmental risk ,chemistry ,Environmental chemistry ,Environmental Chemistry ,Sewage treatment ,Tetralin ,Ecotoxicity ,Waste Management and Disposal ,Effluent ,Alkyl ,0105 earth and related environmental sciences - Abstract
Seven-day composite effluent samples from a German monitoring campaign including 33 conventional wastewater treatment plants (WWTP) were analyzed for linear alkylbenzene sulfonates (LAS) and alkyl ethoxysulfates (AES) and were screened by wide-scope suspect screening for 1564 surfactants and their transformation products (TPs) by UHPLC-ESI-QTOF-MS. Corresponding seven-day composite influent samples of selected WWTPs showed high influent concentrations as well as very high removal rates for LAS and AES. However, average total LAS and AES effluent concentrations were still 14.4 μg/L and 0.57 μg/L, respectively. The LAS-byproducts di-alkyl tetralin sulfonates (DATSs), the TPs sulfophenyl alkyl carboxylic acids (SPACs) and sulfo-tetralin alkyl carboxylic acids (STACs) reached maximum effluent concentrations of 19 μg/L, 17 μg/L and 5.3 μg/L, respectively. In many cases the sum of the concentration of all LAS-related byproducts and TPs surpassed the concentration of the precursors. High concentrations of up to 7.4 μg/L were found for 41 polyethylenoglycol homologs. Quantified surfactants and their TPs and by-products together accounted for concentrations up to 82 μg/L in WWTP effluents. To determine the risk of individual surfactants and their mixtures, single homologs were grouped by a “weighted carbon number approach” to derive normalized Predicted No-Effect Concentrations (PNEC), based on experimental ecotoxicity data from existing risk assessments, complemented by suitable Quantitative Structure-Activity Relationships (QSAR) predictions. Predicted Environmental Concentrations (PEC) were derived by dividing effluent concentrations of surfactants by local dilution factors. Risks for all analyzed surfactants were below the commonly accepted PEC/PNEC ratio of 1 for single compounds, while contributions to mixture toxicity effects from background levels of LAS and DATS cannot be excluded. Maximum LAS concentrations exceeded half of its PNEC, which may trigger country-wide screening to investigate potential environmental risks.
- Published
- 2019
19. NORMAN digital sample freezing platform: A European virtual platform to exchange liquid chromatography high resolution-mass spectrometry data and screen suspects in 'digitally frozen' environmental samples
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Nikiforos A. Alygizakis, Nikolaos S. Thomaidis, Reza Aalizadeh, Emma L. Schymanski, Peter Oswald, Tobias Schulze, Martina Oswaldova, and Jaroslav Slobodnik
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Chromatography ,Sample (material) ,010401 analytical chemistry ,Mass spectrometry ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Mass ,Screening method ,Environmental science ,Digital sample freezing platform High resolution mass spectrometry Digital archiving Suspect screening Antibiotics REACH Black sea ,Black sea ,Virtual platform ,Spectral data ,Retention time ,Spectroscopy - Abstract
A platform for archiving liquid chromatography high-resolution mass spectrometry (LC-HRMS) data was developed for the retrospective suspect screening of thousands of environmental pollutants with the ambition of becoming a European and possibly global standard. It was termed Digital Sample Freezing Platform (DSFP) and incorporates all the recent developments in the HRMS screening methods within the NORMAN Network. In the workflow, raw mass spectral data are converted into mzML, then mass spectral and chromatographic information on thousands of peaks of each sample is extracted into Data Collection Templates. The ‘digitally frozen’ samples can be retrospectively screened for the presence of virtually any compound amenable to LCeMS using a combination of information on its (i) exact mass, (ii) predicted retention time window in the chromatogram, (iii) isotopic fit and (iv) qualifier fragment ions. Its potential was demonstrated on monitoring of 670 antibiotics and 777 REACH chemicals from the Joint Black Sea Surveys (JBSS).
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- 2019
20. The impact of on-site hospital wastewater treatment on the downstream communal wastewater system in terms of antibiotics and antibiotic resistance genes
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Jaroslav Slobodnik, Luc M. Hornstra, Nikolaos S. Thomaidis, Gertjan Medema, Nikiforos A. Alygizakis, and Gabriela K. Paulus
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medicine.drug_class ,Antibiotics ,Sewage ,Wastewater ,010501 environmental sciences ,Biology ,Membrane bioreactor ,Waste Disposal, Fluid ,01 natural sciences ,Microbiology ,03 medical and health sciences ,0302 clinical medicine ,Antibiotic resistance ,medicine ,Water Pollutants ,030212 general & internal medicine ,Effluent ,0105 earth and related environmental sciences ,business.industry ,Public Health, Environmental and Occupational Health ,Drug Resistance, Microbial ,Hospitals ,6. Clean water ,Anti-Bacterial Agents ,Activated sludge ,Genes, Bacterial ,13. Climate action ,Sewage treatment ,Advanced wastewater treatment Contaminants of emerging concern Pharmafilter Antibiotic resistance ,business - Abstract
This study quantified antibiotic and antibiotic resistance gene (ARG) concentrations in hospital and communal wastewaters as well as the influents and effluents of the receiving urban wastewater treatment plants (UWWTP) in two Dutch cities. In only one city, hospital wastewater was treated on-site using advanced technologies, including membrane bioreactor treatment (MBR), ozonation, granulated activated carbon (GAC) and UVtreatment. On-site hospital wastewater (HWW) treatment reduced gene presence of hospital-related antibiotic resistance genes and antibiotic concentrations in the receiving urban wastewater treatment plant. These findings support the need for on-site treatment of high-risk point sources of antibiotic resistance genes. 13 antibiotic resistance genes, Integrase Class 1 and 16S rRNA concentrations were quantified using multiplex quantitative real-time PCR (qPCR) assays and the presence and/or concentration of 711 antibiotics were analyzed. Hospital wastewater contained approximately 25% more antibiotics and gene concentrations between 0.4 log to 1.8-fold higher than communal wastewater (CWW). blaKPC and vanA could be identified as hospital-related genes and were reduced to under the limit of detection (LOD) during on-site treatment. Advanced on-site treatment removed between 0.5 and 3.6-fold more genes than conventional biological urban wastewater treatment (activated sludge). Advanced on-site treatment was able to eliminate 12 out of 19 detected antibiotics, while urban waste water treatment eliminated up to 1 (out of 21 detected). Different advanced treatment technologies were able to target different pollutants to varying extents, making sequential alignment more effective. MBR treatment was most efficient in antibiotic resistance gene reduction and ozonation in antibiotic reduction. blaKPC could only be detected in the influent of the urban wastewater treatment plant receiving untreated hospital wastewater. Similarly, vanA was only consistently detected in this treatment plant. These results indicate a positive effect of on-site treatment of hospital wastewater on the communal sewage system.
- Published
- 2019
21. Multi-residue methodology for the determination of 16 coccidiostats in animal tissues and eggs by hydrophilic interaction liquid chromatography – Tandem mass spectrometry
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Nikolaos S. Thomaidis and Marilena E. Dasenaki
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Meat ,Swine ,Formic acid ,Eggs ,Mass spectrometry ,Tandem mass spectrometry ,01 natural sciences ,Analytical Chemistry ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Limit of Detection ,Tandem Mass Spectrometry ,Coccidiostats ,Ammonium formate ,Animals ,Sample preparation ,Chromatography, High Pressure Liquid ,Residue (complex analysis) ,Sheep ,Chromatography ,Chemistry ,Hydrophilic interaction chromatography ,Solid Phase Extraction ,010401 analytical chemistry ,Reproducibility of Results ,04 agricultural and veterinary sciences ,General Medicine ,040401 food science ,0104 chemical sciences ,Cattle ,Rabbits ,Chickens ,Hydrophobic and Hydrophilic Interactions ,Food Science - Abstract
A simple, sensitive and efficient confirmatory method was developed and validated for the determination of 16 coccidiostats in animal tissues and eggs using hydrophilic interaction liquid chromatography–tandem mass spectrometry (HILIC-MS/MS). The sample preparation consisted of a solid-liquid extraction with ACN and dispersive SPE cleanup with MgSO4 and C18. Analysis was realized in an Acquity BEH HILIC silica column, in SRM mode. Both positive and negative ionization was performed, using polarity switching. Isocratic elution was used with a mobile phase of ACN: aqueous ammonium formate 1 mM with 0.1% formic acid (80:20, v/v). Method validation was performed in eggs, poultry, bovine, ovine, porcine and rabbit tissue and exceptionally low LODs were achieved, varying from 0.004 μg kg−1 (decoquinate in porcine tissue) to 0.560 μg kg−1 (halofuginone in eggs). The developed methodology was applied in 82 muscle and egg samples through the Greek National Residue Control Plan for coccidiostats.
- Published
- 2019
22. Untargeted time-pattern analysis of LC-HRMS data to detect spills and compounds with high fluctuation in influent wastewater
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Pablo Gago-Ferrero, Juliane Hollender, Nikolaos S. Thomaidis, and Nikiforos A. Alygizakis
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021110 strategic, defence & security studies ,Multivariate statistics ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,02 engineering and technology ,Replicate ,010501 environmental sciences ,01 natural sciences ,Pollution ,Bayes' theorem ,Wastewater ,Environmental Chemistry ,Hotelling's T-squared distribution ,Environmental science ,Biological system ,Waste Management and Disposal ,Predictive modelling ,Chemical database ,0105 earth and related environmental sciences ,Statistical hypothesis testing - Abstract
Peak prioritization plays a key role in non-target analysis of complex samples in order to focus the elucidation efforts on potentially relevant substances. The present work shows the development of a computational workflow capable of detecting compounds that exhibit large variation in intensity over time. The developed approach is based on three open-source R packages (xcms, CAMERA and TIMECOURSE) and includes the use of the statistical test Multivariate Empirical Bayes Approach to rank the compounds based on the Hotelling T2 coefficient, which is an indicator of large concentration variations of unknown components. The approach was applied to replicate series of 24 h composite flow-proportional influent wastewater samples collected during 8 consecutive days. 60 events involving unknown substances with high fluctuation over time were successfully prioritized. 14 of those compounds were tentatively identified using HRMS/MS libraries, chemical databases, in-silico fragmentation tools, and retention time prediction models. Four compounds were confirmed with standards from which two never reported before in wastewater.
- Published
- 2019
23. Chemometric determination of the shelf life of opened cans using the migration of specific metals as quality indicators
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Charalampos Proestos, Ioannis N. Pasias, G Petropoulos, Nikolaos S. Thomaidis, and Kalomoira Raptopoulou
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Principal Component Analysis ,Time Factors ,Chemistry ,Iron ,Spectrophotometry, Atomic ,Analytical chemistry ,04 agricultural and veterinary sciences ,General Medicine ,Shelf life ,040401 food science ,Analytical Chemistry ,law.invention ,0404 agricultural biotechnology ,Metals ,Tin ,law ,Environmental chemistry ,Food, Preserved ,Principal component analysis ,Cluster Analysis ,Statistical analysis ,Metalloid ,Atomic absorption spectroscopy ,Metalloids ,Food Science - Abstract
The aim of this work is the evaluation of quality indicators for the estimation of the shelf life of opened cans using the migration of specific metals as variables. For this reason the determination of targeted analytes such as: Cd, Pb, As, Cu, Cr, Ni, Fe, Mn and Sn in different canned samples (cardoon, tuna, green and red beans, corn, and fungi) by Electrothermal Atomic Absorption Spectrometry (Perkin Elmer, SIMAA 6000) was developed and validated. Statistical analysis was performed using SPSS version 22. Principal component analysis (PCA) and cluster analysis were performed in order to examine the correlation between the content of metals and metalloids and the storage time of opened cans. The results showed that there is a strong correlation between metal concentration and storage time, especially for Fe and Sn. The storage time ranged from hours to days and the vast number of collected data sets, led to reliable conclusions about the evaluation of a new shelf life indicator. Principal component analysis indicated the appropriate storage time for opened cans, where no significant migration was observed.
- Published
- 2018
24. Degradation of antineoplastic drug etoposide in aqueous environment by photolysis and photocatalysis. Identification of photocatalytic transformation products and toxicity assessment
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Anthoula Chatzimpaloglou, Christophoros Christophoridis, Maria Christina Nika, Reza Aalizadeh, Ilias Fountoulakis, Nikolaos S. Thomaidis, Alkiviadis F. Bais, and Konstantinos Fytianos
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General Chemical Engineering ,Environmental Chemistry ,General Chemistry ,Industrial and Manufacturing Engineering - Published
- 2022
25. Elevated levels of antibiotic resistance in groundwater during treated wastewater irrigation associated with infiltration and accumulation of antibiotic residues
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Steffen Kunze, Jaroslav Slobdonik, Damiano Cacace, Nikolaos S. Thomaidis, Thomas U. Berendonk, Ioannis D. Kampouris, Nikiforos Alygizakis, Shelesh Agrawal, Uli Klümper, and Susanne Lackner
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Irrigation ,Veterinary medicine ,Environmental Engineering ,medicine.drug_class ,Health, Toxicology and Mutagenesis ,Antibiotics ,Wastewater ,Antibiotic resistance ,RNA, Ribosomal, 16S ,medicine ,Environmental Chemistry ,Groundwater ,Waste Management and Disposal ,Relative species abundance ,biology ,Chemistry ,Sulfamethoxazole ,Drug Resistance, Microbial ,Contamination ,biology.organism_classification ,Pollution ,Anti-Bacterial Agents ,Genes, Bacterial ,Bacteria ,medicine.drug - Abstract
Treated wastewater irrigation (TWW) releases antibiotics and antibiotic resistance genes (ARGs) into the environment and might thus promote the dissemination of antibiotic resistance in groundwater (GW). We hypothesized that TWW irrigation increases ARG abundance in GW through two potential mechanisms: the contamination of GW with resistant bacteria and the accumulation of antibiotics in GW. To test this, the GW below a real-scale TWW-irrigated field was sampled for six months. Sampling took place before, during and after high-intensity TWW irrigation. Samples were analysed with 16S rRNA amplicon sequencing, qPCR of six ARGs and the class 1 integron-integrase gene intI1, while liquid chromatography tandem mass spectrometry was performed to detect antibiotic and pharmaceutical residues. Absolute abundance of 16S rRNA in GW decreased rather than increased during long-term irrigation. Also, the relative abundance of TWW-related bacteria did not increase in GW during long-term irrigation. In contrast, long-term TWW irrigation increased the relative abundance of sul1 and intI1 in the GW microbiome. Furthermore, GW contained elevated concentrations of sulfonamide antibiotics, especially sulfamethoxazole, to which sul1 confers resistance. Total sulfonamide concentrations in GW correlated with sul1 relative abundance. Consequently, TWW irrigation promoted sul1 and intI1 dissemination in the GW microbiome, most likely due to the accumulation of drug residues.
- Published
- 2022
26. Ecological and spatial variations of legacy and emerging contaminants in white-tailed sea eagles from Germany: Implications for prioritisation and future risk management
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Gabriele Treu, Maria-Christina Nika, Alexander Badry, Nikiforos Alygizakis, Nikolaos S. Thomaidis, Georgios Gkotsis, Christian C. Voigt, and Oliver Krone
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Baltic Sea ,Eagles ,Wildlife ,Persistent organic pollutants ,JANUS tool ,Birds of prey ,Chemicals of emerging concern ,Stable isotopes ,Context (language use) ,Risk Assessment ,biology.animal ,Animals ,Humans ,media_common.cataloged_instance ,GE1-350 ,European union ,General Environmental Science ,Apex predator ,media_common ,Trophic level ,biology ,Haliaeetus albicilla ,Ecology ,Bioaccumulation ,Polychlorinated Biphenyls ,Environmental sciences ,Habitat ,Environmental science ,Environmental Monitoring - Abstract
The increasing use of chemicals in the European Union (EU) has resulted in environmental emissions and wildlife exposures. For approving a chemical within the EU, producers need to conduct an environmental risk assessment, which typically relies on data generated under laboratory conditions without considering the ecological and landscape context. To address this gap and add information on emerging contaminants and chemical mixtures, we analysed 30 livers of white-tailed sea eagles (Haliaeetus albicilla) from northern Germany with high resolution-mass spectrometry coupled to liquid and gas chromatography for the identification of >2400 contaminants. We then modelled the influence of trophic position (δ15N), habitat (δ13C) and landscape on chemical residues and screened for persistent, bioaccumulative and toxic (PBT) properties using an in silico model to unravel mismatches between predicted PBT properties and observed exposures. Despite having generally low PBT scores, most detected contaminants were medicinal products with oxfendazole and salicylamide being most frequent. Chemicals of the Stockholm Convention such as 4,4′-DDE and PCBs were present in all samples below toxicity thresholds. Among PFAS, especially PFOS showed elevated concentrations compared to other studies. In contrast, PFCA levels were low and increased with δ15N, which indicated an increase with preying on piscivorous species. Among plant protection products, spiroxamine and simazine were frequently detected with increasing concentrations in agricultural landscapes. The in silico model has proven to be reliable for predicting PBT properties for most chemicals. However, chemical exposures in apex predators are complex and do not solely rely on intrinsic chemical properties but also on other factors such as ecology and landscape. We therefore recommend that ecological contexts, mixture toxicities, and chemical monitoring data should be more frequently considered in regulatory risk assessments, e.g. in a weight of evidence approach, to trigger risk management measures before adverse effects in individuals or populations start to manifest.
- Published
- 2022
27. Change in the chemical content of untreated wastewater of Athens, Greece under COVID-19 pandemic
- Author
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Aikaterini Galani, Nikolaos I. Rousis, Reza Aalizadeh, Meletios-Athanasios Dimopoulos, Nikiforos Alygizakis, and Nikolaos S. Thomaidis
- Subjects
Biocide ,Environmental Engineering ,food.ingredient ,Coronavirus disease 2019 (COVID-19) ,Surfactants ,Wide-scope screening ,Wastewater-based epidemiology ,Wastewater ,High resolution mass spectrometry ,Article ,Toxicology ,food ,Pandemic ,Humans ,Environmental Chemistry ,Pandemics ,Waste Management and Disposal ,Greece ,SARS-CoV-2 ,business.industry ,Food additive ,COVID-19 ,Chemical industry ,Pesticide ,Pollution ,Illicit drug consumption changes ,Communicable Disease Control ,Environmental science ,Sewage treatment ,business - Abstract
COVID-19 pandemic spread rapidly worldwide with unanticipated effects on mental health, lifestyle, stability of economies and societies. Although many research groups have already reported SARS-CoV-2 surveillance in untreated wastewater, only few studies evaluated the implications of the pandemic on the use of chemicals by influent wastewater analysis. Wide-scope target and suspect screening were used to monitor the effects of the pandemic on the Greek population through wastewater-based epidemiology. Composite 24 h influent wastewater samples were collected from the wastewater treatment plant of Athens during the first lockdown and analyzed by liquid chromatography mass spectrometry. A wide range of compounds was investigated (11,286), including antipsychotic drugs, illicit drugs, tobacco compounds, food additives, pesticides, biocides, surfactants and industrial chemicals. Mass loads of chemical markers were estimated and compared with the data obtained under non-COVID-19 conditions (campaign 2019). The findings revealed increases in surfactants (+196%), biocides (+152%), cationic quaternary ammonium surfactants (used as surfactants and biocides) (+331%), whereas the most important decreases were estimated for tobacco (−33%) and industrial chemicals (−52%). The introduction of social-restriction measures by the government affected all aspects of life., Graphical abstract Unlabelled Image
- Published
- 2021
28. Proteo-metabolomic journey across olive drupe development and maturation
- Author
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Ioannis Ganopoulos, Christina Skodra, Marilena E. Dasenaki, Martina Samiotaki, George Stamatakis, Evangelos Karagiannis, Georgia Tanou, Nikolaos S. Thomaidis, Athanassios Molassiotis, and Michail Michailidis
- Subjects
Proteomics ,Biology ,Carbohydrate metabolism ,01 natural sciences ,Analytical Chemistry ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Metabolomics ,Oleuropein ,Olea ,Food science ,Secondary metabolism ,Drupe ,Chlorophyll A ,010401 analytical chemistry ,Primary metabolite ,04 agricultural and veterinary sciences ,General Medicine ,040401 food science ,0104 chemical sciences ,Tyrosol ,chemistry ,Fruit ,Malic acid ,Food Science - Abstract
Maturity is one of the most important factors associated with the quality of olive products, however the molecular events underlying olive drupe development remain poorly characterized. Using proteomic and metabolomic approaches, this study investigated the changes in the olive drupes (cv. Chondrolia Chalkidikis) across six developmental stages (S1-S6) that characterize the dynamics of fruit growth and color. Primary metabolites, including carbohydrates and organic acids (i.e., xylose, malic acid), showed significant accumulation in the black maturation stage. Temporal changes in various secondary metabolites (e.g., oleuropein, oleacin and tyrosol) were also observed. Proteins involved in oxidation-reduction (i.e., LOX1/5), carbohydrate metabolism (i.e., GLUA, PG) and photosynthesis (i.e., chlorophyll a-b binding proteins) significantly altered in the turning black compared to the green mature stage. By providing the first proteometabolomic study of olive drupe development, this investigation offers a novel framework for further studies on this economically relevant crop.
- Published
- 2021
29. LC-MS based metabolomics for the authentication of selected Greek white wines
- Author
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Alexandros Tzachristas, Charalampos Proestos, Nikolaos S. Thomaidis, Marilena E. Dasenaki, and Reza Aalizadeh
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Wine ,Authentication ,Computer science ,business.industry ,010401 analytical chemistry ,Pattern recognition ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Random forest ,Metabolomics ,Liquid chromatography–mass spectrometry ,Statistical analysis ,Artificial intelligence ,0210 nano-technology ,business ,Spectroscopy ,Winemaking ,Targeted metabolomics - Abstract
LC-MS based metabolomics provide a new perspective in wine authentication enabling a thorough investigation of its chemical composition. In this study, 97 monovarietal white wines derived from four indigenous Greek grape varieties (Assyrtiko, Moschofilero, Malazouzia and Savatiano) and produced in two PDO and one PGI winemaking regions were analyzed with the use of ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS). A targeted metabolomics method was developed, validated and applied to the analyzed wine samples for the identification and quantification of 22 metabolites. Another 79 compounds were tentatively identified using a “smart” suspect screening workflow based on an in-house developed database. Then, the random forest algorithm was applied on the normalized peak areas of both target and suspect data for supervised statistical analysis. A robust classification model was built enabling the classification and prediction of the varietal origin of the wine samples in acceptable levels. Specific biomarkers, contributing significantly to the discrimination of wine variety, were recognized.
- Published
- 2021
30. Exploring the mean-variance portfolio optimization approach for planning wind repowering actions in Spain
- Author
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José A. Ruiz-Arias, David Pozo-Vázquez, J. Usaola-García, F. J. Santos-Alamillos, and Nikolaos S. Thomaidis
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Engineering ,Wind power ,Renewable Energy, Sustainability and the Environment ,business.industry ,020209 energy ,Yield (finance) ,Repowering ,Environmental engineering ,02 engineering and technology ,Environmental economics ,Work (electrical) ,0202 electrical engineering, electronic engineering, information engineering ,Portfolio ,Energy supply ,Portfolio optimization ,business ,Productivity - Abstract
The repowering of already installed wind farms is considered one of the most promising and cost-effective short-term strategies to scale-up wind capacity. In this study, we apply Markowitz's mean-variance (MV) portfolio optimization theory to explore alternative repowering actions in Spain. The efficient portfolios – a direct outcome of the MV optimization – offer optimal repowering alternatives to current wind farm generation mixes. They deliver the highest possible average power output (yield) for a given level of supply risk. Different repowering scenarios are considered in this paper that range from a full restructuring of the existing wind generation mix to restricting by certain amounts the percentage of down-/uprating of each reference region. Results show that, depending on the configuration of the MV portfolio optimization problem, hourly fluctuations in the aggregate power supply can be reduced as much as 12–31%, while retaining the current level of energy productivity. In addition, for the level of energy supply risk experienced with the existing portfolio of Spanish wind farms; we can derive more efficient mixes that boost-up productivity by 16–55%. This work aims at providing valuable insight for energy policy-making in the direction of optimally repowering future renewable generation.
- Published
- 2017
31. Fate of antimicrobials in duckweed Lemna minor wastewater treatment systems
- Author
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Georgia Gatidou, Nikolaos S. Thomaidis, Dimitrios Damalas, Evangelia I. Iatrou, and Athanasios S. Stasinakis
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Water Purification ,Hydroxylation ,Hydrolysis ,chemistry.chemical_compound ,Bioreactors ,Anti-Infective Agents ,Toxicity Tests ,Environmental Chemistry ,Photodegradation ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Demethylation ,021110 strategic, defence & security studies ,Alismatales ,Photolysis ,Lemna minor ,Chromatography ,Sorption ,Biodegradation ,Pollution ,Biodegradation, Environmental ,chemistry ,Environmental chemistry ,Sewage treatment ,Adsorption ,Water Pollutants, Chemical - Abstract
The fate of four antimicrobials (cefadroxil, CFD; metronidazole, METRO; trimethoprim, TRI; sulfamethoxazole, SMX) was studied in Lemna minor systems and the role of different mechanisms on their removal was evaluated. All micropollutants were significantly removed in batch experiments with active Lemna minor; the highest removal was observed for CFD (100% in 14 d), followed by METRO (96%), SMX (73%) and TRI (59%) during 24 d of the experiment. Calculation of kinetic constants for hydrolysis, photodegradation, sorption to biomass and plant uptake revealed significant differences depending on the compound and the studied mechanism. For METRO, TRI and SMX the kinetic constants of plant uptake were by far higher comparing to those of the other mechanisms. The transformation products of antimicrobials were identified using UHPLC-QToF-MS. Two were the main degradation pathways for TRI; hydroxylation takes place during both phyto- and photodegradation, while demethylation occurs only in absence of Lemna minor. The operation of a continuous-flow duckweed system showed METRO and TRI removal equal to 71 ± 11% and 61 ± 8%, respectively. The application of mass balance and the use of published biodegradation constants showed that plant uptake and biodegradation were the major mechanisms governing METRO removal; the most important mechanism for TRI was plant uptake.
- Published
- 2017
32. Organic complexation of copper in throughfall and open field bulk deposition: Influence of the tree canopy of Mediterranean forest ecosystems
- Author
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Marta Plavšić, Sotirios Karavoltsos, Manos Dassenakis, Michael Scoullos, Aikaterini Sakellari, Panagiotis Michopoulos, Athanassios Bourletsikas, Kostas Kaoukis, Fotios Fotiadis, and Nikolaos S. Thomaidis
- Subjects
Mediterranean climate ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,Forests ,010501 environmental sciences ,01 natural sciences ,Trees ,Forest ecology ,Environmental Chemistry ,Organic complexation ,Throughfall ,bulk deposition ,copper complexing capacity ,apparent stability constant ,canopy ,Ecosystem ,0105 earth and related environmental sciences ,Tree canopy ,Greece ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Copper ,chemistry ,Stability constants of complexes ,Environmental chemistry ,Deposition (chemistry) - Abstract
The complexing capacity for Cu ions ( L T ) and the apparent stability constant values (log K app ) were measured in throughfall (TF) and open field bulk deposition (BD), at two Mediterranean forest ecosystems of western Greece. L T was measured for the first time in the TF of natural forests. Concentrations of L T were three-to-four-fold higher in TF (mean ± st.dev: 2014 ± 769 nM for Varetada and 1565 ± 595 nM for Karpenissi) compared to those in BD (531 ± 517 nM and 468 ± 321 nM, respectively). In all TF and BD samples, L T concentrations were significantly higher than the corresponding total Cu concentrations, indicating that Cu was fully complexed. The L T /TOC ratios in TF were found comparable between the two study sites (235 ± 149 nM mg −1 C for Varetada and 256 ± 233 nM mg −1 C for Karpenissi) and with those of BD (226 ± 257 and 163 ± 163 nM mg −1 C, respectively). The determined mean log K app values were almost identical in TF (6.8 ± 0.7 at Varetada; 6.8 ± 0.6 at Karpenissi) and BD (6.5 ± 0.6 at Varetada; 6.8 ± 0.3 at Karpenissi), pointing to the fact that regardless of the enrichment of TF in ligands ( L T (TF) > L T (BD) ) the type of binding sites remain the same. The log K app values which were obtained herewith are similar to those obtained for humic-like substances (HULIS), indicating them as the most widespread type of ligands in BD and TF.
- Published
- 2017
33. Fundamental Pricing Laws and Long Memory Effects in the Day-Ahead Power Market
- Author
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Nikolaos S. Thomaidis and Pandelis N. Biskas
- Subjects
Economics and Econometrics ,Cointegration ,business.industry ,020209 energy ,05 social sciences ,Univariate ,Linear model ,Regression analysis ,Allowance (engineering) ,Context (language use) ,02 engineering and technology ,Nonlinear system ,General Energy ,Law ,0502 economics and business ,Covariate ,0202 electrical engineering, electronic engineering, information engineering ,Econometrics ,Economics ,Electricity market ,Electricity ,050207 economics ,business - Abstract
We apply linear and nonlinear panel models to investigate fundamental pricing laws in the Greek day-ahead electricity market. We link the persistence behaviour and other dynamic properties of electricity price trajectories to an extended array of fundamental variables reflecting market conditions and the price course of energy commodities in global markets. Assuming that the dynamics of the intraday power pricing curve is adequately specified within a panel modelling framework with long memory and common unobserved stochastic effects, we are able to provide consistent estimates of price responsiveness to the main fundamental drivers and thus avoid biases induced by other popular modelling approaches. We also device a panel variant of the standard smooth-transition regression model to investigate regime switching effects in the price responsiveness mechanism. Empirical results suggest that Greek day-ahead electricity market prices respond significantly to hour-specific (load, marginal generation capacity) and global (Brent price, emission allowance rights cost) fundamental variables. In some intraday power delivery zones, these covariates are in a fractional cointegrating relationship with electricity prices being responsible for their drifting behaviour. The strength and type of cointegration changes across intraday trading periods in response to market conditions. The results of the nonlinear model demonstrate the ineffectiveness of linear model designs (either univariate or panel) to accurately estimate the levels of price risk and associate it with changes in the market climate.
- Published
- 2019
34. Elements of toxicological concern and the arsenolipids’ profile in the giant-red Mediterranean shrimp, Aristaeomorpha foliacea
- Author
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Nikolaos S. Thomaidis, Veronika Sele, Rie Romme Rasmussen, Eleni Stathopoulou, Ioannis N. Pasias, Vassilia J Sinanoglou, Georgia Soultani, and Jens Jørgen Sloth
- Subjects
inorganic chemicals ,Mediterranean climate ,0303 health sciences ,Cadmium ,animal structures ,030309 nutrition & dietetics ,Aristaeomorpha foliacea ,fungi ,010401 analytical chemistry ,chemistry.chemical_element ,01 natural sciences ,0104 chemical sciences ,Mercury (element) ,Shrimp ,03 medical and health sciences ,chemistry ,Environmental chemistry ,Cephalothorax ,Selenium ,Arsenic ,Food Science - Abstract
The aim of this study was to determine lead, mercury, cadmium, arsenic and selenium in muscle and cephalothorax of giant red Mediterranean shrimp (Aristaeomorpha foliacea). Arsenic was also determined in the lipid fraction of the shrimp to provide an estimate of the arsenolipids. The results indicated that Pb and Cd were higher in cephalothorax than in muscle (p
- Published
- 2021
35. Use of δ-manganese dioxide for the removal of acetaminophen from aquatic environment: Kinetic – thermodynamic analysis and transformation products identification
- Author
-
Maria-Christina Nika, Tryfon Kekes, Fotios Tsopelas, Nikolaos S. Thomaidis, and Constantina Tzia
- Subjects
Arrhenius equation ,Abundance (chemistry) ,Process Chemistry and Technology ,Dimer ,Inorganic chemistry ,chemistry.chemical_element ,Trimer ,02 engineering and technology ,Manganese ,Activation energy ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,Endothermic process ,chemistry.chemical_compound ,Electron transfer ,symbols.namesake ,chemistry ,symbols ,Chemical Engineering (miscellaneous) ,0210 nano-technology ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
High δ-manganese dioxide’s initial concentration (800 mg/L), temperature (50 °C) and acidic pH (3.0–3.5) were found to be the optimum conditions for the removal of acetaminophen. Additionally, acetaminophen was found to be removed more rapidly at high initial concentrations (70−100 mg/L). The kinetic analysis of the experiments revealed that the two tested kinetic models, the one assuming the electron transfer and the other assuming the complex formation as the rate-limiting step, provided a good fit. The positive value of activation energy estimated by the Arrhenius equation indicated that the reaction is endothermic. The transformation products analysis by means of RPLC-QToF, revealed the formation of acetaminophen’s dimer and trimer in the early stages of the reaction, followed by their complete removal in the latter stages of the reaction. Furthermore, four new compounds were detected. Three isomeric compounds fit the formulas C14H11NO4, attributed to aggregates of 1,4-benzoquinone and N-Acetyl-p-benzoquinone Imine, and one additional transformation product was attributed to C17H8N3O5. The abundance of the isomeric compounds was increasing after 60 min of the reaction, and decreasing during the last stages of the reaction, while the latter’s abundance was increasing during the reaction process.
- Published
- 2020
36. Do current wind farms in Spain take maximum advantage of spatiotemporal balancing of the wind resource?
- Author
-
F. J. Santos-Alamillos, Nikolaos S. Thomaidis, S. Quesada-Ruiz, David Pozo-Vázquez, and José A. Ruiz-Arias
- Subjects
Wind power ,Meteorology ,Renewable Energy, Sustainability and the Environment ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,020209 energy ,Reliability (computer networking) ,02 engineering and technology ,Grid ,Wind speed ,Power (physics) ,Offshore wind power ,Electricity generation ,Physics::Space Physics ,Principal component analysis ,0202 electrical engineering, electronic engineering, information engineering ,Astrophysics::Solar and Stellar Astrophysics ,Environmental science ,business ,Physics::Atmospheric and Oceanic Physics - Abstract
Optimal siting of wind farms based on a pre-assessment of the spatiotemporal variability of wind resources is considered a suitable method for reducing fluctuations in the delivered output. In this study, we explore the potential for balancing wind energy generation in the Iberian Peninsula using Principal Component Analysis (PCA). This technique permits the discovery of possibly new promising locations for wind power harvesting and an evaluation of the existing wind farm network in terms of reliability in energy generation. Data input to the PCA consists of hourly wind capacity factor in a 5-km spatial resolution grid covering the entire peninsula. These data are derived from an equivalent wind farm power curve fed by modeled wind speed data from 80 m above ground level. PCA reveals three significant balancing patterns prevailing over the IP, where half of the currently operating wind farms in Spain are placed. Hence, among the many constituents of the existing wind farm network, these spots offer the best opportunity for stable power supply. The paper concludes by making proposals on an optimum wind capacity allocation based on the idea of equally distributing installed power between positive/negative dipoles emerging from balancing principal components.
- Published
- 2016
37. Identification of biotransformation products of citalopram formed in activated sludge
- Author
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Nikolaos S. Thomaidis, Aikaterini K. Psoma, Pablo Gago-Ferrero, Reza Aalizadeh, Kathrin Fenner, and Vasiliki G. Beretsou
- Subjects
Environmental Engineering ,Carboxylic acid ,0211 other engineering and technologies ,02 engineering and technology ,Citalopram ,010501 environmental sciences ,Mass spectrometry ,01 natural sciences ,Biotransformation ,Tandem Mass Spectrometry ,Waste Management and Disposal ,Retrospective Studies ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,chemistry.chemical_classification ,021110 strategic, defence & security studies ,Chromatography ,Sewage ,Ecological Modeling ,Hydrophilic interaction chromatography ,Reversed-phase chromatography ,Pollution ,Activated sludge ,chemistry ,Wastewater ,Environmental chemistry ,Sewage treatment ,Water Pollutants, Chemical - Abstract
Citalopram (CTR) is a worldwide highly consumed antidepressant which has demonstrated incomplete removal by conventional wastewater treatment. Despite its global ubiquitous presence in different environmental compartments, little is known about its behaviour and transformation processes during wastewater treatment. The present study aims to expand the knowledge on fate and transformation of CTR during the biological treatment process. For this purpose, batch reactors were set up to assess biotic, abiotic and sorption losses of this compound. One of the main objectives of the study was the identification of the formed transformation products (TPs) by applying suspect and non-target strategies based on liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). The complementary use of reversed phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC) for the identification of polar TPs, and the application of in-house developed quantitative structure-retention relationship (QSRR) prediction models, in addition to the comprehensive evaluation of the obtained MS/MS spectra, provided valuable information to support identification. In total, fourteen TPs were detected and thirteen of them were tentatively identified. Four compounds were confirmed (N-desmethylCTR, CTR amide, CTR carboxylic acid and 3-oxo-CTR) through the purchase of the corresponding reference standard. Probable structures based on diagnostic evidence were proposed for the additional nine TPs. Eleven TPs are reported for the first time. A transformation pathway for the biotransformation of CTR was proposed. The presence of the identified TPs was assessed in real wastewater samples through retrospective analysis, resulting in the detection of five compounds. Finally, the potential ecotoxicological risk posed by CTR and its TPs to different trophic levels of aquatic organisms was evaluated by means of risk quotients.
- Published
- 2016
38. Multi-residue determination of 10 selected new psychoactive substances in wastewater samples by liquid chromatography–tandem mass spectrometry
- Author
-
Viola L. Borova, Nikolaos S. Thomaidis, Constantinos Pistos, and Pablo Gago-Ferrero
- Subjects
Multi residue ,Psychotropic Drugs ,Chromatography ,Chemistry ,Solid Phase Extraction ,Reproducibility of Results ,Chromatography liquid ,Wastewater ,Tandem mass spectrometry ,Analytical Chemistry ,Tandem Mass Spectrometry ,Liquid chromatography–mass spectrometry ,Lc ms ms ,Solid phase extraction ,Water Pollutants, Chemical ,Chromatography, Liquid - Abstract
New psychoactive substances (NPSs) have become increasingly popular in recent years. The analysis of these substances in influent wastewater (IWW) can be used to track their use in communities. In addition, an evaluation of the amount of NPSs released to the aquatic environment can be performed through the analysis of effluent wastewater (EWW). This study presents the development, validation and application of an analytical methodology, based on solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), for the determination of 10 NPSs in IWW and EWW. Synthetic cannabinoids, cathinones, piperazines and pyrrolidophenones are included among the target analytes. To the authors' knowledge, it is the first time that eight out of these substances (4'-methylpyrrolidinobutyrophenone (MPPP), a-pyrrolidinopentiophenone (a-PVP), 2-[(1S,3R)-3-hydroxycyclohexyl]-5-(2-methyl-2-octanyl) phenol (CP47,497), (1-naphthyl(1-pentyl-1H-indol-3-yl) methanone (JWH-018), (1-butyl-1H-indol-3-yl)(1-naphthyl) methanone (JWH-073), (4-ethyl-1-naphthyl)(1-pentyl-1H-indol-3-yl) methanone (JWH-210), (4-methyl-1-naphthyl) (1-pentyl-1H-indol-3-yl) methanone (JWH-122) and 2-(2-methoxyphenyl)-1-(1-pentyl-1H-indol-3-yl) ethanone (JWH-250)) are investigated in wastewater. The optimized conditions for the analysis of this set of compounds included a SPE clean-up step using a polymeric sorbent and the use of a pentafluorophenyl (PFP) chromatographic column. Despite the broad range of physicochemical properties of the analytes the method allowed acceptable absolute recoveries (40-109%) for all the studied compounds at different levels of concentration. Low method limits of detection (MLODs) were achieved, ranging between 0.3 and 10 ng/L except for BZP and CP47,497 (20 and 23 ng/L, respectively), allowing a reliable and accurate quantification of the analytes. The method was successfully applied to the analysis of IWW and EWW samples from five wastewater treatment plants (WWTPs) located in Santorini Island (a highly touristic resort in Greece). Four out of 10 compounds (a-PVP, CP47,497, JWH-122 and JWH-210) were detected at least in one sample, being the first evidence of their presence in wastewater. CP47,497 was the most ubiquitous and abundant compound, showing concentrations up to 634 ng/L in some cases.
- Published
- 2015
39. Explaining the rationale behind the risk assessment of surfactants by Freeling et al. (2019)
- Author
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Lubos Cirka, Finnian Freeling, Marco Scheurer, Jaroslav Slobodnik, Reza Aalizadeh, Peter C. von der Ohe, Peter Oswald, Nikolaos S. Thomaidis, and Nikiforos A. Alygizakis
- Subjects
medicine.medical_specialty ,Environmental Engineering ,business.industry ,MEDLINE ,Environmental Chemistry ,Medicine ,business ,Intensive care medicine ,Risk assessment ,Pollution ,Waste Management and Disposal ,Surface-active agents - Published
- 2020
40. Evaluation of chemical and biological contaminants of emerging concern in treated wastewater intended for agricultural reuse
- Author
-
Despo Fatta-Kassinos, Nikolaos S. Thomaidis, Vasiliki G. Beretsou, Branislav Vrana, Peter Oswald, Ioannis D. Kampouris, Aikaterini Galani, Nikiforos A. Alygizakis, Thomas U. Berendonk, Martina Oswaldova, Jaroslav Slobodnik, and Jakub Urík
- Subjects
lcsh:GE1-350 ,010504 meteorology & atmospheric sciences ,Agriculture ,Wastewater ,010501 environmental sciences ,Contamination ,Reuse ,Membrane bioreactor ,Pulp and paper industry ,01 natural sciences ,Biological hazard ,6. Clean water ,12. Responsible consumption ,Tandem Mass Spectrometry ,13. Climate action ,Hazardous waste ,Environmental science ,Sewage treatment ,Solid phase extraction ,lcsh:Environmental sciences ,Water Pollutants, Chemical ,Environmental Monitoring ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
The occurrence of chemical and biological contaminants of emerging concern (CECs) was investigated in treated wastewater intended for reuse in agriculture. An agarose hydrogel diffusion-based passive sampler was exposed to the outlet of a wastewater treatment plant (WWTP) located in Cyprus, which is equipped with membrane bioreactor (MBR). Passive samplers in triplicate were exposed according to a time-series exposure plan with maximum exposure duration of 28 days. Composite flow-proportional wastewater samples were collected in parallel with the passive sampling exposure plan and were processed by solid phase extraction using HORIZON SPE-DEX 4790 and the same sorbent material (Oasis HLB) as in the passive sampler. The analysis of passive samplers and wastewater samples enabled (i) the field-scale calibration of the passive sampler prototype by the calculation of in situ sampling rates of target substances, and (ii) the investigation of in silico predicted transformation products of the four most ecotoxicologically hazardous antibiotics (azithromycin, clarithromycin, erythromycin, ofloxacin). Additionally, the wastewater samples were subjected to the analysis of seven preselected antibiotic resistant genes (ARGs) and one mobile resistant element (int1). All extracts were analyzed for chemicals in a single batch using a highly sensitive method for pharmaceuticals, antibiotics and illicit drugs by liquid chromatography tandem MS/MS (LC-QQQ) and for various other target compounds (2316 compounds in total) by liquid chromatography high-resolution mass spectrometry (LC-HRMS). 279 CECs and all investigated ARGs (except for blaCTX-M−32) were detected, highlighting potential chemical and biological hazards related to wastewater reuse practices. 16 CECs were prioritized following ecotoxicological risk assessment, whereas sul1 and the mobile resistant element (int1) showed the highest abundance. Comprehensive monitoring efforts using novel sampling methods such as passive sampling, wide-scope target screening and molecular analysis are required to assure safe application of wastewater reuse and avoid spread and crop uptake of potentially hazardous chemicals. Keywords: Hydrogel-based passive sampler, Wastewater reuse, Contaminants of emerging concern, Transformation products, Antibiotics, Antibiotic resistance genes
- Published
- 2020
41. Biodegradability assessment of food additives using OECD 301F respirometric test
- Author
-
Athanasios S. Stasinakis, Nikolaos S. Thomaidis, Niki Vazaiou, and Georgia Gatidou
- Subjects
Preservative ,Environmental Engineering ,food.ingredient ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,Xylitol ,01 natural sciences ,chemistry.chemical_compound ,food ,Environmental Chemistry ,Food science ,Organisation for Economic Co-Operation and Development ,Saccharin ,0105 earth and related environmental sciences ,Sewage ,Potassium sorbate ,Aspartame ,Chemistry ,Sodium cyclamate ,Food additive ,digestive, oral, and skin physiology ,Public Health, Environmental and Occupational Health ,food and beverages ,General Medicine ,General Chemistry ,Benzoic Acid ,Pollution ,020801 environmental engineering ,Biodegradation, Environmental ,Sweetening Agents ,Maltitol ,Food Additives - Abstract
The ready biodegradability of twenty food additives, belonging to the classes of artificial sweeteners, natural sweeteners, preservatives and colorings, was investigated using activated sludge as inoculum and OECD 301F respirometric test. According to the results, saccharin, aspartame, sodium cyclamate, xylitol, erythritol, maltitol, potassium sorbate, benzoic acid and sodium ascorbate are characterized as readily biodegradable compounds, partial biodegradation (60% during the test) was noticed for steviol, inulin, alitame, curcumin, ponceau 4R and tartrazine, while no biodegradation was observed for the other five compounds. The duration of lag phase before the start of biodegradation varied between the target compounds, while their ultimate biodegradation half-life values ranged between 0.7 ± 0.1 days (benzoic acid) and 24.6 ± 1.0 days (curcumin). The expected removal of target compounds due to ultimate biodegradation mechanism was estimated for a biological wastewater treatment system operated at a retention time of one day and percentages higher than 40% were calculated for sodium cyclamate, potassium sorbate and benzoic acid. Higher removal percentages are expected in full-scale Sewage Treatment Plants (STPs) due to the contribution of other mechanisms such as sorption to suspended solids, (bio)transformation and co-metabolic phenomena. Further biodegradation experiments should be conducted under different experimental conditions for the food additives that did not fulfill the requirements of the applied protocol. Future studies should also focus on the occurrence and fate of food colorants and natural sweeteners in full-scale STPs.
- Published
- 2020
42. Determination of bisphenol A in canned food by microwave assisted extraction, molecularly imprinted polymer-solid phase extraction and liquid chromatography-mass spectrometry
- Author
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Michael A. Koupparis, Georgios Theodoridis, Eugenia Lampi, Niki C. Maragou, and Nikolaos S. Thomaidis
- Subjects
Spectrometry, Mass, Electrospray Ionization ,Clinical Biochemistry ,030226 pharmacology & pharmacy ,01 natural sciences ,Biochemistry ,High-performance liquid chromatography ,Analytical Chemistry ,Molecular Imprinting ,03 medical and health sciences ,0302 clinical medicine ,Phenols ,Endocrine disrupting compound ,Limit of Detection ,Liquid chromatography–mass spectrometry ,Food, Preserved ,Sample preparation ,Solid phase extraction ,Benzhydryl Compounds ,Microwaves ,Chromatography, High Pressure Liquid ,Chromatography ,Chemistry ,Solid Phase Extraction ,010401 analytical chemistry ,Extraction (chemistry) ,Molecularly imprinted polymer ,Reproducibility of Results ,Cell Biology ,General Medicine ,0104 chemical sciences ,Surface coating ,Linear Models - Abstract
Bisphenol A (BPA), a known potential endocrine disrupting compound (EDC) is expected to be present in low quantities in canned food due to its migration from the inner surface coating of cans made of epoxy resins. A selective and confirmatory analytical method, based on microwave assisted extraction (MAE), molecularly imprinted solid phase extraction (MISPE) using a polymer prepared by a non-covalent molecular imprinting technique and liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI/MS) was developed for the determination of BPA in canned pineapple, tuna and mushrooms. First, the effect of the loading medium of hydro- organic solutions on the binding of BPA and its deuterated analogue on the MISPE sorbent was investigated. Subsequently, the effects of the experimental conditions of the microwave assisted extraction (solvent, sample mass/solvent volume, time and temperature) on the obtained recovery of BPA from canned food were assessed and the parameters were optimized to provide maximum recovery and selectivity. It was demonstrated that the combination of MAE with MISPE permits the use of a selective extraction solvent (methanol/water, 4/6, v/v), simplifying the sample preparation steps and enhancing sample clean-up of complex food matrices. The method was validated in different food matrices, using BPA-d16 as internal standard and quantitative relative recoveries were determined. The precision (RSD %) of the method ranged from 7% to 10% and the limit of detection was at low ng/g level for all food matrices. The determined concentration of BPA in commercial canned samples ranged between 7.3 and 42.3 ng/g.
- Published
- 2020
43. Cultivation and safety aspects of Arthrospira platensis (Spirulina) grown with struvite recovered from anaerobic digestion plant as phosphorus source
- Author
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Raffaele Taddeo, Dimitrios Arapoglou, Anthi Panara, Athanasios Balafoutis, Giorgos Markou, Christos Eliopoulos, and Nikolaos S. Thomaidis
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0106 biological sciences ,Chemistry ,010501 environmental sciences ,Sterilization (microbiology) ,01 natural sciences ,Anaerobic digestion ,chemistry.chemical_compound ,Biogas ,Struvite ,010608 biotechnology ,Phycocyanin ,media_common.cataloged_instance ,Single-cell protein ,Food science ,European union ,Agronomy and Crop Science ,Effluent ,0105 earth and related environmental sciences ,media_common - Abstract
In this study, the cyanobacterium Arthrospira platensis, commonly known as Spirulina, was cultivated utilizing phosphorus in the form of struvite recovered from effluents of a biogas plant treating municipal and agro-industrial wastes. Under the specific experimental conditions, providing sterilized struvite at about 120 mg/L (or 15 mg-P/L) gave the same results in terms of biomass production and biochemical composition as the control cultures (with KH2PO4 as a P source). Struvite sterilization was found to be an important step because its original microbial load had a negative effect on the biomass production and resulted in biomass with lower value (lower protein and phycocyanin content). P from struvite was almost complete released upon adding it in the cultivation medium after 90 min, where parameters, such as medium pH, struvite particle size and medium reusing cycles had no effect on the kinetics of P release, indicating that P is almost immediately available for cell uptake. Since struvite was generated from effluents of a biogas plant treating municipal and agro-industrial wastes, the potential of its contamination with hazardous compounds was examined in order to assess the safety of the produced biomass. Unwanted compounds like heavy metals, bisphenol A (BPA), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) were calculated to be at levels significantly lower than those of the maximum levels allowed in the European Union regulation for feedstuff safety, while neither veterinary drugs nor Escherichia coli were detected in the struvite. Results suggest that struvite recovered from biogas plants could be used as P source for the cultivation of A. platensis for feed or food quality.
- Published
- 2019
44. Sorption and biodegradation of selected benzotriazoles and hydroxybenzothiazole in activated sludge and estimation of their fate during wastewater treatment
- Author
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Athanasios S. Stasinakis, Nikolaos S. Thomaidis, Georgia Gatidou, Henrik Rasmus Andersen, and Aikaterini A. Mazioti
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Waste Disposal, Fluid ,Environmental Chemistry ,Benzothiazoles ,Chromatography ,Sewage ,Chemistry ,Public Health, Environmental and Occupational Health ,Sorption ,General Medicine ,General Chemistry ,Models, Theoretical ,Triazoles ,Biodegradation ,Pollution ,Anoxic waters ,Kinetics ,Waste treatment ,Biodegradation, Environmental ,Activated sludge ,Wastewater ,Environmental chemistry ,Sewage treatment ,Water treatment ,Adsorption ,Water Pollutants, Chemical ,Half-Life - Abstract
Biodegradation of benzotriazole (BTR), 5-chlorobenzotriazole (CBTR), xylytriazole (XTR), 4-methyl-1H-benzotriazole (4TTR), 5-methy-1H-lbenzotriazole (5TTR) and 2-hydroxybenzothiazole (OHBTH) was studied in activated sludge batch experiments under aerobic and anoxic conditions, presence of organic substrate and different sludge residence times (SRTs). Their sludge-water distribution coefficients were also calculated in sorption experiments and ranged between 87 and 220 L kg(-1). Significant biodegradation of BTR, CBTR, XTR and OHBTH was observed in all biotic experiments. Half-life values ranged between 23 and 45 h (BTR), 18 and 47 h (CBTR), 14 and 26 h (XTR), 6.5 and 24 h (OHBTH). The addition of substrate did not suppress biodegradation kinetics; whereas in some cases accelerated biodegradation of microcontaminants. Except for CBTR, no effect of SRT on biodegradation constants was observed. Prediction of micropollutants removal in Sewage Treatment Plants (STPs) indicated that they will be partially removed, mainly due to aerobic biodegradation. Higher removal is expected at STPs operating at higher SRT and higher suspended solids concentrations.
- Published
- 2015
45. Targeted and non-targeted liquid chromatography-mass spectrometric workflows for identification of transformation products of emerging pollutants in the aquatic environment
- Author
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Junho Jeon, Eleni Archontaki, Nikolaos S. Thomaidis, Anna A. Bletsou, and Juliane Hollender
- Subjects
Background information ,Pollutant ,Identification (information) ,Non targeted ,Workflow ,Chromatography ,Chemistry ,Aquatic environment ,Mass spectrometry ,Mass spectrometric ,Spectroscopy ,Analytical Chemistry - Abstract
Identification of transformation products (TPs) of emerging pollutants is challenging, due to the vast number of compounds, mostly unknown, the complexity of the matrices and their often low concentrations, requiring highly selective, highly sensitive techniques. We compile background information on biotic and abiotic formation of TPs and analytical developments over the past five years. We present a database of biotic or abiotic TPs compiled from those identified in recent years. We discuss mass spectrometric (MS) techniques and workflows for target, suspect and non-target screening of TPs with emphasis on liquid chromatography coupled to MS (LC-MS). Both low- and high-resolution (HR) mass analyzers have been applied, but HR-MS is the technique of choice, due to its high confirmatory capabilities, derived from the high resolving power and the mass accuracy in MS and MS/MS modes, and the sophisticated software developed.
- Published
- 2015
46. Reductive degradation of perfluorinated compounds in water using Mg-aminoclay coated nanoscale zero valent iron
- Author
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Athanasios S. Stasinakis, Olga S. Arvaniti, Nikolaos S. Thomaidis, Yuhoon Hwang, Henrik Rasmus Andersen, and Maria Aloupi
- Subjects
Zerovalent iron ,Chemistry ,General Chemical Engineering ,Sorption ,General Chemistry ,Industrial and Manufacturing Engineering ,Perfluorononanoic acid ,chemistry.chemical_compound ,Perfluorooctane ,Sulfonate ,Environmental chemistry ,Environmental Chemistry ,Perfluorooctanoic acid ,Degradation (geology) ,Fluoride - Abstract
Perfluorinated Compounds (PFCs) are extremely persistent micropollutants that are detected worldwide. We studied the removal of PFCs (perfluorooctanoic acid; PFOA, perfluorononanoic acid; PFNA, perfluorodecanoic acid; PFDA and perfluorooctane sulfonate; PFOS) from water by different types of nanoscale zero-valent iron (nZVI). Batch experiments showed that an iron dose of 1 g•L-1 in the form of Mg-aminoclay (MgAC) coated nZVI, at an initial pH of 3.0 effectively removed 38 % to 96 % of individual PFCs. An increasing order of removal efficiency was observed of PFOA < PFNA < PFOS ≈ PFDA. Compared to this, PFCs removal was less than 27 % using a commercial air stabilized nZVI or freshly synthesized uncoated nZVI, under the same experimental conditions. The effectiveness of PFCs removal by MgAC coated nZVI was further investigated at various initial pH, nZVI dosage, temperature and age of the nZVI. A maximum removal was observed for all PFCs with high nZVI concentration, freshly synthesized nZVI, low pH and low temperature. A mass balance experiment with PFOS in a higher concentration of nZVI revealed that the removal was due to both sorption and degradation. Fluoride production partially matched the observed degradation, while no organic byproducts were detected using LC-QTOF-MS.
- Published
- 2015
47. Removal of endocrine disruptors and non-steroidal anti-inflammatory drugs through wastewater chlorination: The effect of pH, total suspended solids and humic acids and identification of degradation by-products
- Author
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Elena Koumaki, Nikolaos S. Thomaidis, Daniel Mamais, Maria-Christina Nika, Constantinos Noutsopoulos, and Anna A. Bletsou
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,Endocrine Disruptors ,Wastewater ,Waste Disposal, Fluid ,chemistry.chemical_compound ,polycyclic compounds ,Chlorine ,Environmental Chemistry ,Humic Substances ,Total suspended solids ,Pollutant ,Anti-Inflammatory Agents, Non-Steroidal ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Hydrogen-Ion Concentration ,Pollution ,Nonylphenol ,Triclosan ,chemistry ,Environmental chemistry ,Water treatment ,Sewage treatment ,Water Pollutants, Chemical - Abstract
Endocrine disrupting chemicals (EDCs) and non-steroidal anti-inflammatory drugs (NSAIDs) are two groups of emerging pollutants the significance of which rests on their persistent detection in the aquatic environment and their possible adverse effects. Wastewater treatment plants are one of the major ways for transporting such chemicals in the aquatic environment. Chlorination is usually the last stage of treatment before wastewater being disposed to the aquatic environment. This work focuses on the evaluation of the effect of chlorine dose and specific wastewater characteristics (pH, total suspended solids and humic acids) on the removal of target EDCs and NSAIDs through chlorination. Another objective of this study is the identification of chlorination by-products of specific EDCs and NSAIDs and their dependence on contact time. Based on the results it is concluded that the effect of chlorine dose and humic acids concentration on the degradation of target compounds during chlorination is minimal. On the contrary, pH is a critical parameter which highly affects process performance. Moreover, it is concluded that not only the free available chlorine species, but also the properties of EDCs and NSAIDs under different pH conditions can affect chlorination process performance. The effect of TSS on the degradation of the target compounds during chlorination is more profound for chemicals with high Kow values and therefore higher affinity to partition to the particulate phase (i.e. nonylphenols, triclosan). Several degradation by-products were identified through chlorination of nonylphenol, bisphenol A and diclofenac. The dependence of these by-products on chlorination contact time is also demonstrated.
- Published
- 2015
48. Fate of selected emerging micropollutants during mesophilic, thermophilic and temperature co-phased anaerobic digestion of sewage sludge
- Author
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Vasilios G. Samaras, Athanasios S. Stasinakis, Themistokles D. Lekkas, Daniel Mamais, and Nikolaos S. Thomaidis
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Environmental Engineering ,Bioengineering ,Endocrine Disruptors ,Water Purification ,chemistry.chemical_compound ,Bioreactors ,Phenols ,Bioreactor ,Anaerobiosis ,Microbial biodegradation ,Waste Management and Disposal ,Chromatography ,Sewage ,Renewable Energy, Sustainability and the Environment ,Anti-Inflammatory Agents, Non-Steroidal ,Temperature ,Thermophilic digester ,General Medicine ,Triclosan ,Nonylphenol ,Anaerobic digestion ,Biodegradation, Environmental ,chemistry ,Biofuels ,Water Pollutants, Chemical ,Sludge ,Mesophile - Abstract
The removal of endocrine disrupting compounds (EDCs) and non-steroidal anti-inflammatory drugs (NSAIDs) was studied in three lab-scale anaerobic digestion (AD) systems; a single-stage mesophilic, a single-stage thermophilic and a two-stage thermophilic/mesophilic. All micropollutants underwent microbial degradation. High removal efficiency (80%) was calculated for diclofenac, ibuprofen, naproxen and ketoprofen; whereas triclosan, bisphenol A and the sum of nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate were moderately removed (40-80%). NSAIDs removal was not affected by the type of AD system used; whereas slightly higher EDCs removal was observed in two-stage system. In this system, most microcontaminants were removed in thermophilic digester. Biotransformation of NP1EO and NP was affected by the temperature applied to bioreactors. Under mesophilic conditions, higher removal of NP1EO and accumulation of NP was noticed; whereas the opposite was observed under thermophilic conditions. For most analytes, higher specific removal rates were calculated under thermophilic conditions and 20 days SRT.
- Published
- 2014
49. Development, validation and accreditation of a method for the determination of Pb, Cd, Cu and As in seafood and fish feed samples
- Author
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Nikolaos S. Thomaidis, K.A. Barkonikos, Nikolaos I. Rousis, Aikaterini K. Psoma, and Ioannis N. Pasias
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Reproducibility ,Spectrophotometry, Atomic ,Fishes ,Reproducibility of Results ,General Medicine ,Repeatability ,Pulp and paper industry ,Accreditation ,Analytical Chemistry ,Commercial fish feed ,law.invention ,Seafood ,law ,Metals, Heavy ,Environmental chemistry ,Animals ,Environmental science ,%22">Fish ,Uncertainty calculation ,Atomic absorption spectroscopy ,Council directive ,Food Science - Abstract
A rapid, sensitive, accurate and precise method for the determination of Pb, Cd, As and Cu in seafood and fish feed samples by Simultaneous Electrothermal Atomic Absorption Spectrometry was developed in regard to Council Directive 333/2007EC and ISO/IEC 17025 (2005). Different approaches were investigated in order to shorten the analysis time, always taking into account the sensitivity. For method validation, precision (repeatability and reproducibility) and accuracy by addition recovery tests have been assessed as performance criteria. The expanded uncertainties based on the Eurachem/Citac Guidelines were calculated. The method was accredited by the Hellenic Accreditation System and it was applied for an 8 years study in seafood (n = 202) and fish feeds (n = 275) from the Greek market. The annual and seasonal variation of the elemental content and correlation among the elemental content in fish feeds and the respective fish samples were also accomplished.
- Published
- 2014
50. Occurrence and removal efficiencies of benzotriazoles and benzothiazoles in a wastewater treatment plant in Greece
- Author
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Kurunthachalam Kannan, Alexandros G. Asimakopoulos, Nikolaos S. Thomaidis, and Akinranti S. Ajibola
- Subjects
Environmental Engineering ,Biosolids ,Chemical Fractionation ,Wastewater ,Waste Disposal, Fluid ,Water Purification ,chemistry.chemical_compound ,Limit of Detection ,Tandem Mass Spectrometry ,Environmental Chemistry ,Benzothiazoles ,Waste Management and Disposal ,Detection limit ,Benzotriazole ,Greece ,Reproducibility of Results ,Triazoles ,Pollution ,chemistry ,Benzothiazole ,Environmental chemistry ,Sewage treatment ,Water Pollutants, Chemical ,Sludge ,Chromatography, Liquid ,Waste disposal - Abstract
Despite the widespread use of benzotriazoles and benzothiazoles and the occurrence of these compounds in wastewater treatment plants (WWTPs), no earlier study has comprehensively examined their fate in WWTPs. In this study, an integrated liquid chromatography-tandem mass spectrometry (LC-ESI(+)MS/MS) method was developed and validated for simultaneous determination of four benzotriazoles and four benzothiazoles in dissolved and particulate phases of wastewater (raw and treated), and in dewatered sewage sludge. The target benzotriazoles (BTRs) were 1H-benzotriazole, 1-hydroxy-benzotriazole, tolyltriazole, and xylyltriazole (or 5,6-dimethyl-1H-benzotriazole), and the target benzothiazoles (BTHs) were benzothiazole, 2-hydroxy-benzothiazole, 2-methylthio-benzothiazole, and 2-amino-benzothiazole. The limits of detection ranged from 0.08 (2-methylthio-benzothiazole) to 17 ng/L (benzothiazole) for dissolved phase samples, and from 0.04 (2-methylthio-benzothiazole) to 13 ng/g dry weight (dw) (benzothiazole) for particular matter and sludge samples. The method was applied in the analysis of wastewater and sludge samples from the WWTP in Athens, Greece. All target chemicals were detected in wastewater samples, and in some cases the concentrations were significant, on the order of a few μg/L. In sludge samples, benzothiazole and tolyltriazole were present at the highest concentrations (174 and 116 ng/g dw, respectively). For benzotriazole and tolyltriazole, the removal efficiency was below 68%, and for benzothiazoles, the removal efficiency was greater than 64% in the activated sludge treatment process. Both BTRs and BTHs showed low solid-liquid distribution coefficients.
- Published
- 2013
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