VOC Degradation Research Articles

Delta doping and positioning effects of type II GaSb quantum dots in GaAs solar cell

GaSb quantum dot (QD) solar cell structures were grown by molecular beam epitaxy on GaAs substrates. We investigate the reduction in open-circuit voltage and study the influence of the location of QD layers and their delta doping within the solar cell. Devices with 5 layers of delta-doped QDs placed in the intrinsic, n- and p-regions of a GaAs solar cell are experimentally investigated, and the deduced values of Jsc, Voc, fill factor, efficiency (η) are compared. A trade-off is needed to minimize the Voc degradation while maximizing the short circuit current density (Jsc) enhancement due to sub-bandgap absorption. The voltage recovery is attributed to the removal of the QDs from the high-field region which reduces SRH recombination. The devices with p- or n-doped QDs placed in the flat band potential (p- or n-region) show a recovery in Jsc and Voc compared to devices with delta-doped QDs placed in the depletion region. However, there is less photocurrent arising from the absorption of sub-band gap photons. Furthermore, the long wavelength photoresponse of the n-doped QDs placed in the n-region shows a slight improvement compared to the control cell. The approach of placing QDs in the n-region of the solar cell instead of the depletion region is a possible route towards increasing the conversion efficiency of QD solar cells.

Photovoltaic Platform for Investigating PV Module Degradation

Photovoltaic research is oriented more and further towards study on PV modules degradation. The objective is to understand the different degradation modes of PV modules and associated factors. This paper presents a platform for measures dedicated to do a study related to degradation of electrical characteristics of the photovoltaic modules. It is installed on the site at University of Dakar in Senegal. This work proposes a method for standardization of the direct measures of the short-circuit current (Isc) and the open-circuit voltage (Voc) of PV modules. The approach used for the assessment of degradation of Isc and Voc involves a comparison between baseline values given by manufacturer and those measured in real operating conditions brought back in the standard test conditions (STC). Findings presented on degradation of Isc and Voc photovoltaic modules cover the first ten months of measurements from Mars to January. Degradation of short-circuit current is about 13% for the three days. The degradation of open-circuit voltage measured during the three days is 8%.

Investigating the photo-oxidation of model indoor air pollutants using field asymmetric ion mobility spectrometry

We have developed a versatile measurement system utilising field asymmetric ion mobility spectrometry (FAIMS) to study the photocatalytic degradation of VOCs at concentrations comparable to indoor air. FAIMS allows continuous monitoring of chemical species in the gas phase, whilst having a high separation selectivity and sensitivity, so can be used to identify multiple species concurrently at ppb concentrations, which are clear advantages over traditional characterization techniques used in photocatalytic air purification such as gas chromatography. Here we demonstrate the methodology with the photo-oxidation of 2-propanol, ethanol and acetone using a commercial titanium dioxide felt. To the best of our knowledge, this is the first time FAIMS has been used in photocatalytic air purification applications.

Modelling and experimental investigation of activated sludge VOCs adsorption and degradation

This article deals with role and importance of adsorption in the activated sludge substrate degradation. This process is typically described according to the Monod–Michaelis–Menten (M–MM) kinetics, which is based on the assumption that the substrate has been pre-adsorbed on flocs in order for the biochemical reaction to take place. However, the simple and generalised use of M–MM equation in wastewater treatment modelling could be misleading in describing some specific scenarios, where substrate in the liquid phase is not in equilibrium with substrate inside the flocs and, in general, when adsorption and kinetic rates are not comparable. This can occur in numerous process configurations, during plant start-up, when substrate peaks or significant fluctuations are met, in batch processes. An experimental test has been carried out with the aim to investigate the characteristics of the adsorption mechanism and its relationship with the stored mass degradation. Direct application of M–MM kinetics failed in fitting the experimental data. External transport and Glueckauf and Coates particle-phase diffusion relations have been adopted to study substrate transfer to active sites. Andrews and Busby model has then been applied and an excellent accordance with the experimental data has been found. As a final aim of the work, transition from adsorption-to-kinetics has been modelled, which has shown to be very effective for a full understanding of phenomena.

QSAR modeling of VOCs degradation by ferrous-activated persulfate oxidation

The objective of the study is to evaluate the degradability of volatile organic compounds (VOCs, in mixture) by sodium persulfate (SPS) with Fe(II) activation. Degradation of 51 VOCs by SPS alone and with 3 Fe(II)-based activators (i.e. ferrous ion, citric acid-chelated Fe(II), and EDTA-chelated Fe(II)) was investigated in batch experiments. In 48 h, 16 VOCs degraded over 90% with non-activated SPS, and 31 VOCs degraded over 90% with Fe(II) activation. The reaction rate constants of VOC degradation were also analyzed by quantitative structure-activity relationship (QSAR) model. Genetic algorithm and multiple linear regression analysis were applied to select the descriptors to build QSAR model. The main contribution to the degradation rate was given by energy level of highest occupied molecular orbital (EHOMO), double bond equivalent, and the largest negative partial net charge on a carbon atom (Qc-). Based on cluster analysis of degradation rates and main descriptors, the degradability of target VOCs were classified into three classes—rapid, moderate, and slow. The obtained statistically robust QSAR model can be used to estimate the removal efficiency of VOCs by persulfate radicals.

Challenges of TiO2-Based Photooxidation of Volatile Organic Compounds: Designing, Coating, and Regenerating Catalyst

A TiO2-based photocatalytic oxidation study of volatile organic compounds (VOCs: benzene, toluene, ethylbenzene, and xylenes) requiring close monitoring of the catalyst coating, its deactivation, and regeneration was undertaken. For all experiments, the effectiveness of sol–gel coating of nanosized TiO2 particles (on a glass cylindrical reactor) in terms of the surface morphology, film thickness, and band-gap energy was ensured for obtaining a consistent reactor performance. The estimated VOC degradation rate constants (range of 1.16 ± 0.06–1.79 ± 0.05 min–1 m–2) were comparable or higher than those reported in the literature. Reduction of the degradation rates [48% (o-xylene) and 59% (toluene) over a 13 h operation period] with successive deterioration of the catalyst surface appeared to be a major challenge both for design of the reactor and for its long-term operation. A set of definite suggestions has been made for design criteria (degradation rate) and the frequency and method of catalyst regeneratio...

Comparison of kinetics of acetone, heptane and toluene photocatalytic mineralization over TiO2 microfibers and Quartzel® mats

The kinetic parameters for VOCs (acetone, toluene, heptane) mineralization of lab-extruded pure TiO2 fibers prepared under easily scalable conditions were compared with those of a commercial photocatalytic media from Saint-Gobain, Quartzel®, under identical conditions. A flow-through recirculating reactor loop with variable LEDs irradiation at 365nm was specially designed. All the experiments were carried out in a continuous recycle mode. Both types of fibers were very efficient for acetone and heptane mineralization. At 20% relative humidity (RH), the reaction rates were higher with the commercial media, whereas at 60% RH the catalysts displayed equal activity for acetone conversion. Toluene mineralization was much faster on these lab-made fibers than on Quarztel®, which was more sensitive to poisoning by reaction by-products. At 20% relative humidity, with the lab-made TiO2 fibers, typical quantum efficiencies were, respectively, 0.0106 and 0.0027 for acetone and heptane (100ppmV initial concentration) and 0.0024 for toluene (200ppmV initial concentration) while these quantum efficiencies were 0.0358, 0.0133 and 0.0011 with expanded Quartzel fibers under the same conditions. These results evidence a clear difference in the VOCs, water and polar by-products adsorption between these two kinds of fibers.These newly developed fibers can be produced at an industrial scale with a proven efficiency for VOCs degradation and mineralization. Since they are less sensitive to humidity than the commercial fibers, they could be most useful under actual ambient air conditions. These fibers present a good alternative to other commercially available photocatalytic media for gas phase purification.

Optimal enhancement in conversion efficiency of crystalline Si solar cells using inverse opal photonic crystals as back reflectors

The effect of using inverse opal photonic crystals as back reflectors on the power conversion efficiency of c-Si solar cells is investigated. The reflection spectra of inverse opal photonic crystals with different diameters of air spheres are simulated using the finite difference time domain (FDTD) method. The reflection peaks are correlated with photonic band gaps present in the photonic band gap diagram. Significant improvement in the optical absorption of the crystalline silicon layer is recorded when inverse opal photonic crystals are considered. Physical mechanisms which may contribute to the enhancement of the light absorption are underlined. With higher short-circuit current enhancement possible, and with no corresponding degradation in open-circuit voltage Voc or the fill factor, the power conversion efficiency is increased significantly when inverse opal photonic crystals are used as back reflectors with optimized diameter of air spheres.

Characteristics of flow and reactive pollutant dispersion in urban street canyons

In this study, the effects of aspect ratio defined as the ratio of building height to street width on the dispersion of reactive pollutants in street canyons were investigated using a coupled CFD-chemistry model. Flow characteristics for different aspect ratios were analyzed first. For each aspect ratio, six emission scenarios with different VOC–NOX ratios were considered. One vortex was generated when the aspect ratio was less than 1.6 (shallow street canyon). When the aspect ratio was greater than 1.6 (deep street canyon), two vortices were formed in the street canyons. Comparing to previous studies on two-dimensional street canyons, the vortex center is slanted toward the upwind building and reverse and downward flows are dominant in street canyons. Near the street bottom, there is a marked difference in flow pattern between in shallow and deep street canyons. Near the street bottom, reverse and downward flows are dominant in shallow street canyon and flow convergence exists near the center of the deep street canyons, which induces a large difference in the NOX and O3 dispersion patterns in the street canyons. NOX concentrations are high near the street bottom and decreases with height. The O3 concentrations are low at high NO concentrations near the street bottom because of NO titration. At a low VOC–NOX ratio, the NO concentrations are sufficiently high to destroy large amount of O3 by titration, resulting in an O3 concentration in the street canyon much lower than the background concentration. At high VOC–NOX ratios, a small amount of O3 is destroyed by NO titration in the lower layer of the street canyons. However, in the upper layer, O3 is formed through the photolysis of NO2 by VOC degradation reactions. As the aspect ratio increases, NOX (O3) concentrations averaged over the street canyons decrease (increase) in the shallow street canyons. This is because outward flow becomes strong and NOX flux toward the outsides of the street canyons increases, resulting in less NO titration. In the deep street canyons, outward flow becomes weak and outward NOX flux decreases, resulting in an increase (decrease) in NOX (O3) concentration.

Degradation of VOCs and NOx over Mg(Cu)–AlFe mixed oxides derived from hydrotalcite-like compounds

A series of Mg(Cu)–AlFe mixed oxides derived from hydrotalcite-like compounds has been prepared. These solids were characterized by various physicochemical methods and their catalytic performances were tested towards the catalytic oxidation of propene and the simultaneous elimination of propene and NO x . X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the formation of the hydrotalcite structure for all the solids, except for Cu 4 AlFe HT, for which a mixture of the hydrotalcite and the malachite phases is observed. The XRD study of the calcined samples revealed the existence of metal oxides and spinels of types MgO, CuO, -Fe 2 O 3 or/and Fe 3 O 4 , MgFe 2 O 4 and CuFe 2 O 4 . During propene oxidation, it was shown that the increase in the copper content enhanced the activity of the solids. However, Cu 2 Mg 2 AlFe 500, with the highest amount of surface copper species, exhibited the best activity towards the simultaneous elimination of propene and NO. Indeed surface Cu species are the active sites, while bulk Cu species could provide the adsorption sites for nitrogen species. Une série d’oxydes mixtes Mg(Cu)–AlFe dérivée de composés hydrotalcites a été préparée. Ces solides ont été caractérisés par différentes techniques physicochimiques, puis leur performance catalytique a été testée vis-à-vis de l’oxydation catalytique du propène et de l’élimination simultanée du propène et des NO x . L’étude par diffraction de rayons X (DRX) et la microscopie électronique à balayage (MEB) ont confirmé l’obtention de la structure hydrotalcite pour tous les solides, à l’exception du solide Cu 4 AlFe HT, pour lequel les phases hydrotalcite et malachite sont observées. L’étude par DRX des échantillons calcinés a révélé l’existence d’oxydes métalliques et de spinelles des types MgO, CuO, -Fe 2 O 3 ou/et Fe 3 O 4 , MgFe 2 O 4 et CuFe 2 O 4 . Lors de l’oxydation du propène, il est montré que l’augmentation de la quantité de cuivre améliore l’activité des solides. Cependant, le solide Cu 2 Mg 2 AlFe 500 ayant le plus grand nombre d’espèces de cuivre en surface a présenté la meilleure activité vis-à-vis de l’élimination simultanée du propène et du NO. En effet, les espèces cuivriques présentes en surface sont les sites actifs, alors que les espèces cuivre dans la masse du solide semblent être des sites d’adsorption pour les espèces d’azote.

Photocatalytic Degradation of Aqueous VOCs Using N Doped TiO2: Comparison of Photocatalytic Degradation under Visible and Sunlight Irradiation

Photocatalytic Degradation of Aqueous VOCs Using N Doped TiO2: Comparison of Photocatalytic Degradation under Visible and Sunlight Irradiation

Treatment of volatile organic compounds in pharmaceutical wastewater using submerged aerated biological filter

Performance of an up-flow submerged aerated biological filter (SABF), treating mixture of VOCs in pharmaceutical wastewater was evaluated. Methanol, acetone, dichloromethane, benzene and toluene were chosen as target pollutants. The effects of airflow rate, hydraulic retention time and organic loading rate on VOC emission were evaluated. During the start-up phase, SABF removed over 92% of COD, up to an organic loading rate (OLR) of 3.09±0.05kg/m3/d at 12h HRT. It was observed that the limited mass transfer of VOC to the gas phase at low air flow rate (0.4L/min, with an empty bed residence time of 114s) reduced its emission from the reactor. Performance of SABF varied with hydraulic retention time (HRT) and maximum COD removal (93%) was achieved at 10h. Reduced contact time (less than 10h) between pollutant and biomass affected the degradation of dichloromethane, benzene and toluene in the liquid phase. SABF exhibited effective degradation (95%) of VOCs up to an OLR of 17.45±0.01kg/m3/d. Enzyme inactivation reduced the efficiency (72%) of the SABF for increased OLR of 20.85±0.03kg/m3/d. Irrespective of organic loading rate, competition for the active site between the pollutants mainly affected the degradation of benzene and toluene in the liquid phase. Presence of high biomass and reduced mass transfer of VOCs to gas phase due to low air flow rate reduced VOC stripping even at higher organic loading rate. Average gas phase emission reduced to 0.075% for DCM, benzene, toluene whereas methanol and acetone was completely removed from the gas phase.

Gaseous chemistry and aerosol mechanism developments for version 3.5.1 of the online regional model, WRF-Chem

Abstract. We have made a number of developments to the Weather, Research and Forecasting model coupled with Chemistry (WRF-Chem), with the aim of improving model prediction of trace atmospheric gas-phase chemical and aerosol composition, and of interactions between air quality and weather. A reduced form of the Common Reactive Intermediates gas-phase chemical mechanism (CRIv2-R5) has been added, using the Kinetic Pre-Processor (KPP) interface, to enable more explicit simulation of VOC degradation. N2O5 heterogeneous chemistry has been added to the existing sectional MOSAIC aerosol module, and coupled to both the CRIv2-R5 and existing CBM-Z gas-phase schemes. Modifications have also been made to the sea-spray aerosol emission representation, allowing the inclusion of primary organic material in sea-spray aerosol. We have worked on the European domain, with a particular focus on making the model suitable for the study of nighttime chemistry and oxidation by the nitrate radical in the UK atmosphere. Driven by appropriate emissions, wind fields and chemical boundary conditions, implementation of the different developments are illustrated, using a modified version of WRF-Chem 3.4.1, in order to demonstrate the impact that these changes have in the Northwest European domain. These developments are publicly available in WRF-Chem from version 3.5.1 onwards.

The Limited Relevance of SWE Dangling Bonds to Degradation in High-Quality a-Si:H Solar Cells

Contributions of different light-induced defect states to degradation of solar cells have been established for high-quality p-i-n solar cells with i layers of protocrystalline a-Si:H deposited at very low rates, whose nanostructure is dominated by hydrogen-passivated divacancies. Nature of the different light-induced gap states and their respective roles as electron and hole recombination centers were characterized in the thin films from their photocurrents, and in corresponding solar cells from their Shockley-Reed-Hall carrier recombination currents. The results were directly related to three light-induced states, with “A” and “B” within 0.2 eV and “C” 0.4 eV below midgap, identified from subgap absorption. The A and B states are efficient electron, while the C states are very efficient hole recombination centers. Under 1-sun illumination, the former dominate the electron lifetimes, while the latter are key to solar cell operation as is confirmed by the direct correlation of their creation with the degradation of VOC and 1-sun fill factor (FF). It is also shown that the apparent correlation found earlier between the cell FF and electron lifetimes is due to the same long-term degradation kinetics of the light-induced changes in the B t and C states.

Quantitative measurements and modeling of industrial formaldehyde emissions in the Greater Houston area during campaigns in 2009 and 2011

AbstractA sensitive Mobile differential optical absorption spectroscopy (DOAS) system with real‐time evaluation capability and HCHO detection limit of 3 ppb over 100 m has been developed. The system was operated together with a Solar Occultation Flux system for large‐scale vertical flux measurements of HCHO, NO2, SO2, and VOCs in the Houston‐Galveston‐Brazoria area during two studies, in 2009 (Study of Houston Atmospheric Radical Precursors campaign) and in 2011 (Air Quality Research Program study). Both in 2009 and 2011, HCHO plumes from five separate local sources in Texas City, Mont Belvieu, and Houston Ship Channel (HSC) were repeatedly detected using Mobile DOAS with emissions varying between 6 and 40 kg/h. In many cases significant alkene emissions were detected simultaneously with the HCHO plumes. Furthermore, in 2011 two additional sources were observed in Texas City and in HSC, with 10 kg/h and 31 kg/h HCHO, respectively. A plume chemistry model was applied to 13 cases to investigate whether the detected HCHO was emitted directly from the industries or was produced by photochemical degradation of VOCs. The model results showed that on average 90% of the detected HCHO was of primary origin and the photochemical production contributed more than 10% in only three cases. Based on the repeatability, it is likely that the most significant HCHO sources in the area are included in this study with an overall emission of 120 kg/h. On a regional scale, this emission is small compared to the secondary HCHO formed from oxidation of reactive VOCs emitted from the same industries, estimated to be an order of magnitude higher.

Strain Effects on Radiation Tolerance of Triple-Junction Solar Cells With InAs Quantum Dots in the GaAs Junction

A comparison of quantum dot (QD) triple-junction solar cells (TJSCs) with the QD superlattice under tensile strain are compared with those under compressive strain and baseline devices to examine the effects of strain induced by the InAs QD layers in the middle junction. Theoretical results show samples with tensile-strained InAs QDs have lower defect formation energy while compressive-strained QDs have the greatest. Experimentally, it is found that tensile strain leads to degradation of i-region material at values of -706 ppm. Irradiating with 1-MeV electrons, TJSCs with tensile strain exhibit a faster degradation in Isc of the QD samples and slower degradation in Voc but overall faster degradation in efficiency compared with baseline TJSCs, regardless of the magnitude of tensile strain. Compressively strained QD TJSCs have similar degradation in Isc and slower degradation in Voc compared with baseline TJSCs. From this study, it is determined that a slightly compressive strain in the QD superlattice allows for the best performance pre- and postirradiation for QD TJSCs based upon AM0 IV and quantum efficiency measurements and analysis. Fabricating devices with improvements determined from samples with varying strain leads to QD TJSCs with better radiation tolerance in terms of power output for 5, 10, 15, and 20 layers of QDs.

Progress in Laser-Crystallized Thin-Film Polycrystalline Silicon Solar Cells: Intermediate Layers, Light Trapping, and Metallization

Diode laser crystallization of thin silicon films on the glass has been used to form polycrystalline silicon layers for solar cells. Properties of an intermediate layer stack of sputtered SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> between the glass and the silicon have been improved by reactively sputtering the SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> layer, which result in enhanced optical and electrical performance. Light trapping is further enhanced by texturing the rear surface of the silicon prior to metallization. An initial efficiency of 11.7% with V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OC</sub> of 585 mV has been achieved using this technique, which are the highest values reported for poly-Si solar cells on glass substrates. Cells suffer a short term, recoverable degradation of V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OC</sub> , and fill factor. The magnitude of the degradation is reduced via the repeated thermal treatment. A selective p+ metallization scheme has been developed which eliminates the degradation altogether.

Use of Experimental Designs to Establish a Kinetic Law for a Gas Phase Photocatalytic Process

Abstract The photocatalytic degradation of three common indoor VOCs – acetone, toluene and heptane – is investigated in a dynamic photocatalytic oxidation loop using Box–Behnken designs of experiments. Thanks to the experimental results and the establishment of a kinetic rate law based on a simplified mechanism, a predictive model for the VOC degradation involving independent factors is developed. The parameters under investigation are initial concentration, light intensity and air velocity through the photocatalytic medium. The obtained model fits properly the experimental curves in the range of concentration, light intensity and air flow studied.

Missing OH source in a suburban environment near Beijing: observed and modelled OH and HO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; concentrations in summer 2006

Abstract. Measurements of ambient OH and HO2 radicals were performed by laser induced fluorescence (LIF) during CAREBeijing2006 (Campaigns of Air Quality Research in Beijing and Surrounding Region 2006) at the suburban site Yufa in the south of Beijing in summer 2006. On most days, local air chemistry was influenced by aged air pollution that was advected by a slow, almost stagnant wind from southern regions. Observed daily concentration maxima were in the range of (4–17) × 106 cm−3 for OH and (2–24) × 108 cm−3 for HO2 (including an estimated interference of 25% from RO2). During daytime, OH reactivities were generally high (10–30 s−1) and mainly contributed by observed VOCs and their calculated oxidation products. The comparison of modelled and measured HOx concentrations reveals a systematic underprediction of OH as a function of NO. A large discrepancy of a factor 2.6 is found at the lowest NO concentration encountered (0.1 ppb), whereas the discrepancy becomes insignificant above 1 ppb NO. This study extends similar observations from the Pearl-River Delta (PRD) in South China to a more urban environment. The OH discrepancy at Yufa can be resolved, if NO-independent additional OH recycling is assumed in the model. The postulated Leuven Isoprene Mechanism (LIM) has the potential to explain the gap between modelled and measured OH at Beijing taking into account conservative error estimates, but lacks experimental confirmation. This and the hereby unresolved discrepancy at PRD suggest that other VOCs besides isoprene might be involved in the required, additional OH recycling. Fast primary production of ROx radicals up to 7 ppb h−1 was determined at Beijing which was dominated by the photolysis of O3, HONO, HCHO, and dicarbonyls. For a special case, 20 August, when the plume of Beijing city was encountered, a missing primary HOx source (about 3 ppb h−1) was determined under high NOx conditions similar to other urban areas like Mexico City. CAREBeijing2006 emphasizes the important role of OVOCs as a radical source and sink, and the need for further investigation of the chemical degradation of VOCs in order to better understand radical chemistry in VOC-rich air.

Photocatalytic degradation of several VOCs (n-hexane, n-butyl acetate and toluene) on TiO2 layer in a closed-loop reactor

This paper deals with photocatalytic degradation of three VOCs differing in chemical structure (n-hexane, n-butyl acetate and toluene) in a closed-loop reactor. Degradation tests were performed on particulate layers prepared from TiO2 VLP7000 (Kronos). Concentration dependencies of VOCs were simulated and initial degradation rates calculated. Dependence of the latter on initial concentrations confirms single-site Langmuir–Hinshelwood kinetics with value of hexane adsorption constant 0.023m3mmol−1. It was shown that butyl acetate is oxidized preferably to hexane when they react in a mixture, while their individual degradation seems to be kinetically similar. Toluene deactivates the photocatalyst and its degradation is thus very slow but the catalyst can be renewed by thermal treatment. The found selectivity or inhibitive ability of investigated VOCs in mixture is important for the proper choice of a suitable purification method of industrial exhaust fumes.