Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 19
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Cyanobacterials (Cyanophyta) belong to phytoplancton. In normal stale concentration of cyanobacterial cells in water rangs between a few hundreds to a few thousands in I drn' of water but while blooming may be increased even to one million in I dm3. At this time water has characteristic color, depending on dominated species. Also characteristic smell is the results of the presence ofcyanobacterial and phytoplankton cells producing odour substances. The cyanobacterial blooms are very important hygienic problem for both human and animal health. While blooming they form foams and head coating on water surface. Also cyanobacterial toxins are huge problem. Cyanobacteria may produce acute toxins such as hepatotoxic peptides (microcystins, nodularins and cylindrospermopsin) and neurotoxic alkaloids (anatoxin-a, anatoxin-a(s), homoanatoxin and aphanotoxins). Cyanobacterial toxins are very dangerous substances which can intoxicate hepatocytes and the nervous system in humans and animals. In this situation it is very important to remove them effectively in water pretreatment processes. In the present paper have been presented for the first time in Poland data on removing cyanobacterial toxins from water in pretreatment process with application of chlorine dioxide and ozone on the example of Sulejów - Łódź water pipe system. In period I 998-200 I the effectiveness rnicrocystin-LR removal ranged between 74--92% while for other izoforms they were between 45-94%.
Go to article

Authors and Affiliations

Andrzej K.M. Kabziński
Helena Grabowska
Jerzy Cyran
Renata Juszczak
Józef Dziegieć
Alicja Zawadzka
Dominik Szczukocki
Konrad Szczytowski
Download PDF Download RIS Download Bibtex

Abstract

The decomposition of hydrocarbons using combined advanced oxidation methods is largely considered owing to abundant production of OH radicals and the potential economic advantages. In this study, the synergetic effect of ozonation on photocatalytic oxidation of chloroform and chlorobenzene over expanded graphite-TiO2&ZnO Nano composite was investigated. The effect of introduced ozone concentration and residence time was also examined on removal efficiency. The results showed that the removal efficiency was significantly enhanced by the combined system resulting from the additional oxidation process causing active species to be increased. Increasing the introduced ozone concentration which generates more reactive compounds had a greater effect on the removal efficiency than that of residence time. However, from the mineralization point of view, the residence time had a dominant effect, and the selectivity towards CO2 was dramatically declined when the flow rate increased. Based on these results, the combined system is preferred due to higher removal efficiency and complete mineralization.

Go to article

Authors and Affiliations

Hossein Ebrahimi
Farshid Ghorbani Shahna
Abdulrahman Bahrami
Babak Jaleh
Kamal ad-Din Abedi
Download PDF Download RIS Download Bibtex

Abstract

Almost all matter in our Universe exists in the form of plasma. Although it’s not easy to generate on Earth, it has a vast range of applications in medicine, biotechnology, farming and industry.

Go to article

Authors and Affiliations

Joanna Pawłat
Download PDF Download RIS Download Bibtex

Abstract

The paper focuses on the modelling of bromate formation. An axial dispersion model was proposed to integrate the non-ideal mixing, mass-transfer and a kinetic model that links ozone decomposition reactions fromthe Tomiyasu, Fukutomi and Gordon (TFG) ozone decaymodelwith direct and indirect bromide oxidation reactions, oxidation of natural organicmatter and its reactionswith aqueous bromine. To elucidate the role of ammonia an additional set of reactions leading to bromamine formation, oxidation and disproportionation was incorporated in the kinetic model. Sensitivity analysis was conducted to obtain information on reliability of the reaction rate constants used and to simplify the model.

Go to article

Authors and Affiliations

Urszula Olsińska
Download PDF Download RIS Download Bibtex

Abstract

The results of experimental investigations on the removal of NOx from gases applying ozone as the oxidizing agent and the absorption of higher nitrogen oxides in the sodium hydroxide solutions are presented. The experiment was conducted using a pilot plant installation with the air flow rate 200 m3/h, being a prototype of a boiler flue gas duct and a FGD scrubber. It was shown that in the range of [NOref] = 50 ÷ 250 ppm the mechanism of NO ozonation depends on the molar ratio X = O3/NOref: for X ≤ 1.0 oxidation of NO to NO2 predominates and NO2 is poorly absorbed, for X >> 1.0 NO2 undergoes further oxidation to N2O5, which is efficiently absorbed in the scrubber. The stoichiometric molar ratio of complete conversion of NO into N2O5 is X = 1.5, in these studies to reach the effectiveness η ≥ 90% the molar ratio X was much higher (2.75).

Go to article

Authors and Affiliations

Włodzimierz Kordylewski
Maciej Jakubiak
Tomasz Hardy
Download PDF Download RIS Download Bibtex

Abstract

The paper presents results of experimental studies on removal of NOx from flue gas via NO ozonation and wet scrubbing of products of NO oxidation in NaOH solutions. The experiment was conducted in a pilot plant installation supplied with flue gas from a coal-fired boiler at the flow rate 200 m3/h. The initial mole fraction of NOx,ref in flue gas was approx. 220 ppm, the molar ratio X = O3/NOref varied between 0 and 2.5. Ozone (O3 content 1÷5% in oxygen) was injected into the flue gas channel before the wet scrubber. The effect of the mole ratio X, the NaOH concentration in the absorbent, the liquid-to-gas ratio (L/G) and the initial NOx concentration on the efficiency of NOx removal was examined. Two domains of the molar ratio X were distinguished in which denitrification was governed by different mechanisms: for X ≤ 1.0 oxidation of NO to NO2 predominates with slow absorption of NO2, for X >> 1.0 NO2 undergoes further oxidation to higher oxides being efficiently absorbed in the scrubber. At the stoichiometric conditions (X = 1) the effectiveness of NO oxidation was better than 90%. However, the effectiveness of NOx removal reached only 25%. When ozonation was intensified (X ≥ 2.25) about 95% of NOx was removed from flue gas. The concentration of sodium hydroxide in the aqueous solution and the liquid-to-gas ratio in the absorber had little effect on the effectiveness of NOx removal for X > 2.

Go to article

Authors and Affiliations

Maciej P. Jakubiak
Włodzimierz K. Kordylewski
Download PDF Download RIS Download Bibtex

Abstract

Ozonation is a heterogeneous process of chemical absorption often controlled by a gas-liquid mass transfer rate. This paper presents the results of kinetics in a reaction between phenylphenol isomers and ozone. The degradation of phenylphenol isomers during ozonation proceeds quite fast. In order to avoid the influence of mass transfer limitation the kinetics experiments were conducted in a homogenous liquid-liquid system. The second-order rate constants were determined using classical and competition methods, which are especially recommended for fast reactions. The determined rate constants at pH 2 using the two different methods are almost the same. The increase of pH causes an increase of rate constants for the reaction of phenylphenol isomers with ozone.

Go to article

Authors and Affiliations

Magdalena Olak-Kucharczyk
Stanisław Ledakowicz
Download PDF Download RIS Download Bibtex

Abstract

Validation results of a theoretical model that describes the formation of bromate during ozonation of bromide-containing natural waters are presented. An axial dispersion model integrating the nonideal mixing, mass-transfer and a kinetic model that links ozone decomposition reactions from the Tomiyasu, Fukutomi and Gordon ozone decay model with direct and indirect bromide oxidation reactions, oxidation of natural organicmatter and reactions of dissolved organics and aqueous bromine was verified. Themodel was successfully validated with results obtained both at a laboratory and a full scale. Its applicability to different water supply systems was approved.

Go to article

Authors and Affiliations

Urszula Olsińska
Download PDF Download RIS Download Bibtex

Abstract

The paper describes the effectiveness of mycoestrogen removal in an integrated ozonation - nanofiltration system for water treatment. The results were compared to those obtained for ozonation and nanofiltration carried out as single processes. It has been found that the effectiveness of mycoestrogen removal in the integrated system was higher than that observed for single ozonation. During ozonation, the removal of micropollutants was affected by the dose of an oxidizing agent and type of treated water. As far as nanofiltration is concerned, its effectiveness both in the integrated system and as a single process was similar. Nevertheless, it is advisable to precede nanofiltration with ozonation because of membrane efficiency.

Go to article

Authors and Affiliations

M. Dudziak
Download PDF Download RIS Download Bibtex

Abstract

A process capable of NOx control by ozone injection gained wide attention as a possible alternative to proven post combustion technologies such as selective catalytic (and non-catalytic) reduction. The purpose of the work was to develop a numerical model of NO oxidation with O3 that would be capable of providing guidelines for process optimisation during different design stages. A Computational Fluid Dynamics code was used to simulate turbulent reacting flow. In order to reduce computation expense a 11-step global NO - O3 reaction mechanism was implemented into the code. Model performance was verified by the experiment in a tubular flow reactor for two injection nozzle configurations and for two O3/NO ratios of molar fluxe. The objective of this work was to estimate the applicability of a simplified homogeneous reaction mechanism in reactive turbulent flow simulation. Quantitative conformity was not completely satisfying for all examined cases, but the final effect of NO oxidation was predicted correctly at the reactor outlet.

Go to article

Authors and Affiliations

Norbert J. Modliński
Włodzimierz K. Kordylewski
Maciej P. Jakubiak
Download PDF Download RIS Download Bibtex

Abstract

Nowadays, in addition to the thermodynamic properties of refrigerants, their impact on the environment is of high significance. Hence, it is important to use refrigerants with the lowest possible values of ozone depletion potential and global warming potential indices in refrigeration, organic Rankine cycle (ORC), air conditioning, and heat pump systems. Natural refrigerants are the most environmentally friendly; unfortunately, they have less favourable thermodynamic properties. Currently, low-pressure refrigerants from the FC (fluorocarbons, fluorine liquids) and HFE (hydrofluoroether) groups are increasingly used. This paper presents the most important properties and applications of selected refrigerants from these groups and also reviews the literature on their use.
Go to article

Authors and Affiliations

Małgorzata Sikora
1
Tadeusz Bohdal
1

  1. Koszalin University of Technology, Śniadeckich 2, 75-453 Koszalin, Poland
Download PDF Download RIS Download Bibtex

Abstract

In the article, results of the air-quality experiment in a Nowy Sącz area have been presented. The experiment combining both calculations and measurements was done in July 1993. Its goal was to assess the capability of the ,,box-model" method for simulation time-series of ozone and other pollutants in the lowest layer of the atmosphere. The numeric calculations' results were verified by the measurements from the airquality monitoring network. The model's prognostic capacity was assessed by the qualitative and quantitative data analysis. For analyzed episode, the error of calculated maximum ozone concentrations did not exceed ±22% of measured maximum values. The calculated daily-average ozone concentrations were 29% lower comparing to measured values. TI1c errors of calculations were most probably due to the errors in distribution of depth of the mixing layer, assumed for the calculations.
Go to article

Authors and Affiliations

Marek Bogacki
Download PDF Download RIS Download Bibtex

Abstract

Sulphonamides (SAs) are one of the most frequently detected anthropogenic micropollutants in the aquatic environment and their presence in it may pose a threat to living organisms. The aim of the study was to determine susceptibility of selected sulphonamides, i.e. sulfadiazine (SDZ) and sulfamethazine (SMZ), to degradation in the ozonation process and in enzymatic oxidation by unspecific peroxygenase extracted from Agrocybe aegerita mushroom ( AaeUPO). Moreover, the acute toxicity of the aqueous solution of the selected sulphonamides (SMZ and SDZ) before and after mentioned treatment processes were studied on the freshwater crustacean Daphnia magna. Initial concentrations were equal to 2×10-5 M for sulfadiazine and 1.8×10-5 M for sulfamethazine. The percentage of transformation for the O3 process was at the level 95% for both SDZ and SMZ (after 10 s of the process), whilst enzymatic oxidation of SDZ and SMZ by AaeUPO caused transformation efficiencies at the levels of 97% and 94% (after 1 minute of the process), respectively. The second order rate constants of selected sulfonamides with molecular ozone and fungal peroxidase were also determined in the research. EC50 (median effective concentration) values from toxicity test on D. magna were found in the range from 14.6% to 37.2%, depending on the type of the process. The conducted oxidation processes were efficient in degradation of selected sulphonamides. The toxicity of the mixtures before and after treatment was comparable and did not change significantly. The research have shown that biological processes are not always safer for living organisms compared to the chemical processes.
Go to article

Bibliography

Anh D.H., Ullrich R., Benndorf D., Svatos A., Muck A. & Hofrichter M. (2007). The coprophilous mushroom Coprinus radians secretes a haloperoxidase that catalyzesaromatic peroxygenation, Appl Environ Microbiol, 73, 17, pp. 5477-5485, DOI: 10.1128/AEM.00026-07.
Anskjær G.G., Rendal C. & Kusk K.O. (2013). Effect of pH on the toxcity and bioconcentration of sulfadiazine on Daphnia magna, Chemosphere, 91, pp. 1183-1188, DOI: 10.1016/j.chemosphere.2013.01.029.
Aracagök D., Göker H. & Cihangir N. (2018): Biodegradation of diclofenac with fungal strains, Archives of Environmental Protection, 44 (1), pp. 55–62, DOI: 10.24425/118181.
Bader H., Hoigné J. (1982). Determination of ozone by the indigo method: a submitted standard method, Ozone: Sci. Eng, 4, pp. 169-176, DOI: 10.1080/01919518208550955.
Bertanza G., Pedrazzani R., Grande M.D., Papa M., Zambarda V., Montani C., Steimberg N., Mazzoleni G., Lorenzo D.D. (2011): Effect of biological and chemical oxidation on the removal of estrogenic compounds (NP and BPA) from wastewater: an integrated assessment procedure, Water Res, 45(8), pp. 2473-2484, DOI: 10.1016/j.watres.2011.01.026.
Bílková Z., Malá J. & Hrich K. (2019). Fate and behaviour of veterinary sulphonamides under denitrifying conditions, Science of The Total Environment, 695, pp. 133824, DOI: 10.1016/j.scitotenv.2019.133824.
Bourgin M., Beck B., Boehler M., Borowska E., Fleiner J., Salhi E., Teichler R., von Gunten U., Siegrist H. & McArdell C. (2018). Evaluation of a full-scale wastewater treatment plant upgraded with ozonation and biological post-treatments: Abatement of micropollutants, formation of transformation products and oxidation by-products, Water Res, 129, pp. 486-498, DOI: 10.1016/j.watres.2017.10.036.
Bourgin M., Borowska E., Helbing J., Hollender J., Kaiser H.-P., Kienle C., McArdell C.S., Simon E. & von Gunten U. (2017). Effect of operational and water quality parameters on conventional ozonation and the advanced oxidation process O3/H2O2: Kinetics of micropollutants abatement, transformation product and bromate formation in a surface water, Water Res, 122, pp 234–245, DOI: 10.1016/j.watres.2017.05.018.
Cruz-Moratóa C., Lucas D., Llorca M., Rodriguez-Mozaz S., Gorga M., Petrovic M., Barceló D., Vicenta T., Sarràa M. & Marco-Urrea E. (2014). Hospital wastewater treatment by fungal bioreactor: Removal efficiency for pharmaceuticals and endocrine disruptor compounds, Science of The Total Environment, 493, pp. 365–376, DOI: 10.1016/j.scitotenv.2014.05.117.
Dalla Bona M., Di Leva V. & De Liguoro M. (2014). The sensitivity of Daphnia magna and Daphnia curvirostris to 10 veterinary antibacterials and to some of their binary mixtures, Chemosphere 115, pp. 67-74, DOI: 10.1016/j.chemosphere.2014.02.003.
De Liguoroa M., Fioretto B., Poltronieri C. & Gallina G. (2009).The toxicity of sulfamethazine to Daphnia magna and its additivity to other veterinary sulfonamides and trimethoprim, Chemosphere, 75 (11), pp. 1519–1524, DOI: 10.1016/j.chemosphere.2009.02.002.
Fang X., Wu S., Wu Y., Yang W., Lia Y., He J., Hong P., Nie M., Xie C., Wu Z., Zang K., Kong L. & Liu J. (2020). High-efficiency adsorption of norfloxacin using octahedral UIO-66-NH2 nanomaterials: Dynamics, thermodynamics, and mechanisms, Applied Surface Science, 518, pp. 146226, DOI: 10.1016/j.apsusc.2020.146226.
Felis E., Kalka J., Sochacki A., Kowalska K., Bajkacz S., Harnisz M. & Korzeniewska E. (2020). Antimicrobial pharmaceuticals in the aquatic environment - occurrence and environmental implications, European Journal of Pharmacology, 866, pp. 172813, DOI: 10.1016/j.ejphar.2019.172813.
Fletcher S. (2015). Understanding the contribution of environmental factors in the spread of antimicrobial resistance, Environ. Health Prevent. Med., 20, pp. 243–252, DOI: 10.1007/s12199-015-0468-0.
Garoma T., Umamaheshwar S. K. & Mumper A. (2010). Removal of sulfadiazine, sulfamethizole, sulfamethoxazole, and sulfathiazole from aqueous solution by ozonation, Chemosphere, 79, pp. 814–820, DOI: 10.1016/ j.chemosphere.2010.02.060.
Hernandez A. & Ruiz M. T. (1998). An EXCEL template for calculation of enzyme kinetic parameters by non-linear regression, Bioinformatics, 14, pp. 227-28, DOI: 10.1093/bioinformatics/14.2.227.
Hester R. E. & Harrison R. M. (2015). Pharmaceuticals in the Environment, Issues in Environmental Science and Technology. Royal Society of Chemistry Publishing, DOI: 10.1039/9781782622345.
Hofrichter M., Ullrich R., Pecyna M.J., Liers C. & Lundell T. (2010). New and classic families of secreted fungal peroxidases, Appl Microbiol Biotechol, 87, pp. 871-897, DOI: 10.1007/s00253-010-2633-0.
Huber M., Göbel A., Joss A., Hermann N., Löffler D., McArdel C.S., Siegrist H., Ried A., Ternes T.A. & von Gunten U. (2005). Oxidation of pharmaceuticals during ozonation of municipal wastewater effluents: a pilot study, Environmental Science and Technology, 39 (11), pp. 4290-4299, DOI: 10.1021/es048396s.
Kinne M., Poraj-Kobielska M., Aranda E., Ullrich R., Hammel K.E., Scheibner K. & Hofrichter M. (2009). Regioselective preparation of 5-hydroxypropranolol and 4'-hydroxydiclofenac with a fungal peroxygenase, Bioorganic & Medicinal Chemistry Letters, 9 (11), pp. 3085-7, DOI: 10.1016/j.bmcl.2009.04.015.
Kümmerer K. (2010). Pharmaceuticals in the environment, Annual Review of Environment and Resources 35, pp. 57-75, DOI: 10.1146/annurev-environ-052809-161223
Lee C.O., Howe K.J. & Thomson B.M. (2012). Ozone and biofiltration as an alternative to reverse osomosis for removing PPCPs and micropollutants from treated wastewater, Water Research, 46, pp. 1005-1014, DOI: 10.1016/j.watres.2011.11.069.
Lemańska-Malinowska N. & Bjerkelund V.A. (2014). Removal of selected sulphonamides during the ozonation process in the presence and absence of bicarbonates. The Globaqua-Cytothreat-Endetech-Scarce Workshop, Barcelona, Spain, 2014.
Lemańska-Malinowska N., Felis E. & Surmacz-Górska J. (2013). Photochemical degradation of sulfadiazine, Archives of Environmental Protection, 39 (3),pp. 79-91, DOI: 10.2478/aep-2013-0027.
Loos R., Marinov D., Sanseverino I., Napierska D. & Lettieri T. (2018). Review of the 1st Watch List under the Water Framework Directive and recommendations for the 2nd Watch List, Publications Office of the European Union, Luxembourg, DOI: 10.2760/614367.
Nanaboina V. & Korshin G. V. (2010). Evolution of absorbance spectra of ozonated wastewater and its relationship with the degradation of trace-level organic species. Environ Sci Technol, 44, pp. 6130-6137, DOI: 10.1021/es1005175.
OECD, 2004. Test No. 202: Daphnia sp. Acute Immobilisation Test OECD Guidelines for the Testing of Chemicals, Section 2 Effects on Biotic Systems 202.
Paździor K., Bilińska L. & Ledakowicz S. (2019). A review of the existing and emerging technologies in the combination of AOPs and biological processes in industrial textile wastewater treatment, Chemical Engineering Journal, 376, pp. 120597, DOI: 10.1016/j.cej.2018.12.057.
Pecyna M. J. (2010). Fungal peroxygenases and methods of application, United States, Patent publication: US 2010/0279366 A1, Pub. Date: 04.11.
Pelalak R., Alizadeh R., Ghareshabani E. & Heidari Z. (2020). Degradation of sulfonamide antibiotics using ozone-based advanced oxidation process: Experimental, modeling, transformation mechanism and DFT study, Science of the Total Environment, 734, pp. 139446, DOI: 10.1016/j.scitotenv.2020.139446.
Poraj-Kobielska M., Kinne M., Ullrich R., Scheibner K., Kayser G., Hammel K.E. & Hofrichter M. (2011). Preparation of human drug metabolites using fungal peroxygenases, Biochemical Pharmacology, 82(7), pp. 789-789, DOI: 10.1016/j.bcp.2011.06.020.
Rakness K., Gordon G., Langlais B., Masschelein W., Matsumoto N., Richard Y., Robson M. & Somiya I. (1996). Guideline for measurements of ozone concentration in the process gas from an ozone generator, Ozone Sci Eng, 18, pp. 209-229, DOI: 10.1080/01919519608547327.
Reungoat J., Escher B.I., Macova M., Argaud F.X., Gerjak W. & Keller J. (2012). Ozonation and biological activated carbon filtration of wastewater treatment plant effluents, Water Research, 46, pp. 863-872, DOI: 10.1016/j.watres.2011.11.064.
Rodríguez-Rodríguez C. E., García-Galán J., Blánquez P., Díaz-Cruz M. S., Barceló D., Caminal G. & Vicent T. (2012). Continuous degradation of a mixture of sulfonamides by Trametes versicolor and identification of metabolites from sulfapyridine and sulfathiazole, Journal of Hazardous Materials, 213–214, pp. 347–354, DOI: 10.1016/j.jhazmat.2012.02.008.
Santos L.M, Araújo A.N., Fachini A., Pena A., Delerue-Matos C. & Montenegro M. (2010). Ecotoxicological aspects related to the presence of pharmaceutical in the aquatic environment, Journal of Hazardous Materials, 175,pp. 45-95, DOI: 10.1016/j.jhazmat.2009.10.100.
Schwarz J., Aust M.-O. & Thiele-Bruhn S. (2010). Metabolites from fungal laccase-catalysed transformation of sulfonamides, Chemosphere, 81 (11), pp. 1469–1476, DOI: 10.1016/j.chemosphere.2010.08.053. Tahergorabi M., Esrafili A., Kermani M., Gholami M., Farzadkia M. (2019). Degradation of four antibiotics from aqueous solution by ozonation: intermediates identification and reaction pathways, Desalination and Water Treatment, 139, pp. 277-287, DOI: 10.5004/dwt.2019.23307.
Ullrich R., Nüske J., Scheibner K., Spantzel J. & Hofrichter M. (2004). Novel haloperoxidase from the agaric basidiomycete Agrocybe aegerita oxidizes aryl alcohols and aldehydes, Appl Environ Microbiol, 70, pp. 4575–4581, DOI: 10.1128/AEM.70.8.4575-4581.2004.
von Sonntag C. & von Gunten U. (2012). Chemistry of ozone in water and wastewater treatment: from basic principles to applications. IWA Publishing.
Voulvoulis N. (2014). The need for catchment management of pharmaceuticals: the role of STPs, The Globaqua-Cytothreat-Endetech-Scarce Workshop, Barcelona, Spain, 2014.
Yang Y., Ok Y.S., Kim K.-H., Kwon E.E. & Tsang Y.F. (2017). Occurrences and removal of pharmaceuticals and personal care products (PPCPs) in drinking water and water/sewage treatment plants: A review, Science of The Total Environment, 596-597, pp. 303-320.
Zhang C., Wang L., Gao X. & He X. (2016): Antibiotics in WWTP discharge into the Chaobai River, Beijing, Archives of Environmental Protection, 42(4), pp. 48–57, DOI: 10.1515/aep-2016-0036.

Go to article

Authors and Affiliations

Natalia Lemańska
1
Ewa Felis
2
Marzena Poraj-Kobielska
3
Zuzanna Gajda-Meissner
4
Martin Hofrichter
3

  1. EkoNorm Sp. z o.o., Katowice, Poland
  2. The Silesian University of Technology, Gliwice, Poland
  3. Technische Universität Dresden, Germany
  4. School of Life Sciences, Heriot-Watt University, Edinburgh, United Kingdom
Download PDF Download RIS Download Bibtex

Abstract

Landfilling is the main method of waste disposal in Poland as well as in most countries all over the world. Leachate originating during waste deposition may be a source of ground water pollution. The aim of the paper was to characterize and compare the composition of leachate originating from three landfills in Lublin Province (Poland) and differing in their methods of waste pre-treatment. Ozonation was used in the initial trials to treat landfill leachate. Experiments were carried out to determine whether ozonation using a single dose of 1.8 gO,lm3 has the same effect on the efficiency of organic removal from leachates characterized by different ages and degrees of solid waste pretreatment. From analyses (BOD5, COD, N-NH,, heavy metals) it was concluded, that excluding some fractions (glass, paper, plastics, aluminum, fine organic fraction) from the waste mass affects the leachate quality. The studied oxidizing method was found to influence the BOD5 and COD levels
Go to article

Authors and Affiliations

Magdalena Lebiocka
Agnieszka Montusiewicz
Małgorzata Pawłowska
Janusz Ozonek
Ewa Szkutnik
Marcin Rosłan
Download PDF Download RIS Download Bibtex

Abstract

In some areas of the United States (US), asthma prevalence has reached historically unprecedented highs. Three peer-reviewed studies in New York City found prevalence rates among children from 25% to 39%. That is not true in all places. For example, prevalence in Miami, Florida, was estimated to be only 6-10%. A recent study in major cities in Georgia found only 8.5%. One study in California found asthma prevalence was unrelated to local concentrations of criterion pollutants. In the US, all criterion pollutants, including PM2.5, show a downward trend over the last two decades. These facts argue against any significant influence of criterion pollutants in this crisis.These facts suggest that an unrecognized ambient pollutant may be the cause. One important study in southern California in mid-summer measured pulmonary function in children as it was related to outdoor ozone pollution. They found a negative association; higher levels of ozone were associated with improved respiratory function. We call this a "Paradoxical Ozone Association" (POA). Further evidence for a POA appears in seven other studies in Los Angeles, London, Scotland, and southeastern Canada.One plausible explanation for these observations would be the production of methyl nitrite (MN) as an exhaust product of MTB E in gasoline. Unlike ozone, MN is rapidly destroyed by sunlight. All of the POA studies were done in regions with significant methyl ether in gasoline. This explanation is strengthened by the observation that a POA has not been seen in regions without ether in gasoline.A previous A WMA paper proposed a plausible chemical model predicting that MTBE in gasoline will create MN in the exhaust. MN is highly toxic and closely related alkyl nitrites are known to induce respiratory sensitivity in humans. Funding to measure MN has not been available
Go to article

Authors and Affiliations

Peter M. Joseph
Download PDF Download RIS Download Bibtex

Abstract

Tungsten diselenide (WSe2) is one of the promising transition metal dichalcogenides (TMDs) for nanoelectronics and optoelectronics. To enhance and tune the electronic performance of TMDs, chemical functionalization via covalent and van der Waals approaches has been suggested. In the present report, the electric and structural transition of WSe2 oxidized by exposure to O3 is investigated using scanning tunneling microscopy. It is demonstrated that the exposure of WSe2/high-ordered pyrolytic graphite sample to O3 induces the formation of molecular adsorbates on the surface, which enables to increase in the density of states near the valence band edge, resulting from electric structural modification of domain boundaries via exposure of atomic O. According to the work function extracted by Kelvin probe force microscopy, monolayer WSe2 with the O3 exposure results in a gradual increase in work function as the exposure to O3. Therefore, the present report demonstrates the potential pathway for the chemical functionalization of TMDs to enhance the electric performance of TMDs devices.
Go to article

Authors and Affiliations

Eunjeong Kim
1
Sangyoeb Lee
2
ORCID: ORCID
Yeonjin Je
3
Dong Park Lee
3
Sang Jun Park
3
Sanghyun Jeong
2
Joon Sik Park
2
Byungmin Ahn
4
ORCID: ORCID
Jun Hong Park
1 3
ORCID: ORCID

  1. Gyeongsang National University, Department of Materials Engineering and Convergence Technology, Jinju, Korea
  2. Hanbat National University, Department of Materials Science and Engineering and Department of Materials and Manufacturing Engineering, Daejeon, Korea
  3. Gyeongsang National University, School of Materials Science and Engineering, Jinju, Korea
  4. Ajou University, Department of Materials Science and Engineering and Department of Energy Systems Research, Suwon, Korea
Download PDF Download RIS Download Bibtex

Abstract

Low-cost sensor arrays are an economical and efficient solution for large-scale networked monitoring of atmospheric pollutants. These sensors need to be calibrated in situ before use, and existing data-driven calibration models have been widely used, but require large amounts of co-location data with reference stations for training, while performing poorly across domains. To address this problem, a meta-learningbased calibration network for air sensors is proposed, which has been tested on ozone datasets. The tests have proved that it outperforms five other conventional methods in important metrics such as mean absolute error, root mean square error and correlation coefficient. Taking Manlleu and Tona as the source domain and Vic as the target domain, the proposed method reduces MAE and RMSE by 17.06% and 6.71% on average, and improves R2 by an average of 4.21%, compared with the suboptimal pre-trained multi-source transfer calibration. The method can provide a new idea and direction to solve the problem of cross-domain and reliance on a large amount of co-location data in the calibration of sensors.
Go to article

Authors and Affiliations

Feng Tianliang
1
Xiong Xingchuang
2
Jin Shangzhong
1

  1. College of Optical and Electronic Technology, China Jiliang University, Hangzhou, Zhejiang 310018, China
  2. National Institute of Metrology, Beijing 100029, China

This page uses 'cookies'. Learn more