We demonstrate that NO2 can be quantitatively analysed in the presence of CO using a single tungsten oxide based resistive gas sensor. The working temperature of the sensor was modulated between 190 and 380 degrees C and its dynamic response to different concentrations of CO, NO2, and CO + NO2 mixtures was monitored. Either the fast Fourier transform (FFT) or the discrete wavelet transform (DWT) was used to extract important features from the sensor response. These features were then input to different (statistical and neural) pattern recognition methods. The species considered can be discriminated with a success rate higher than 90% using a Fuzzy ARTMAP or a radial basis function neural network. The concentrations of the gases studied can be accurately predicted, by using the DWT coupled to partial least squares (PLS) models. The correlation coefficients of the predicted versus real concentrations were 0.923, 0.870 and 0.866 for CO, NO2, and NO2 in CO + NO2 mixtures, respectively.
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Nanoscale
January 2025
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424 Depok, West Java, Indonesia.
This study reports on the development of a highly sensitive non-enzymatic electrochemical sensor based on a two-dimensional TiCT/MWCNT-OH nanocomposite for the detection of paraoxon-based pesticide. The synergistic effect between the TiCT nanosheet and the functionalized multi-walled carbon nanotubes enhanced the sensor's conductivity and catalytic activity. The nanocomposite demonstrates superior electrochemical and electroanalytical performance compared to the pristine TiCT and MWCNT-OH in detecting paraoxon-ethyl in fruit samples (green and red grapes), with a linear response range from 0.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Civil and Environmental Engineering, Amirkabir University of Technology (Tehran Polytechnic), 350 Hafez Avenue, Tehran, 159163-4311, Iran.
Oxidant (OX), the sum of ozone (O) and nitrogen dioxide (NO), is used to determine nitrogen oxides (NO)-independent regional contribution and NO-dependent local contribution. This study investigates OX trends and its local and regional levels in Tehran, Iran using the data from 21 monitoring stations from 2012 to 2022 and satellite remote sensing data (TROPOMI) for 2022. The spatiotemporal trends of O, NO, and OX are first examined using ground-based and remote sensing data, and then the polar plots are employed to identify the dominant directions of OX transport and its sources.
View Article and Find Full Text PDFEnviron Res
January 2025
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, P. R. China. Electronic address:
The anammox dynamic membrane bioreactor (DMBR) exhibits potential for efficient nitrogen removal via anammox processes. The functional membrane biofilm in the anammox DMBR significantly enhances nitrogen removal, ensuring robust operation. Nevertheless, ecological mechanisms underpinning the nitrogen removal function of the membrane biofilm remain unclear.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
School of Metallurgical Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, PR China.
The presence of PbO in the flue gas can poison FeCe catalyst, reducing its denitrification efficiency. In this work, the mechanism of PbO poisoning of FeCe catalyst, along with the effects of W and Co co-doping on the NO oxidation performance and PbO resistance of FeCe catalyst were investigated. The S of FeCe catalyst decreased and the crystallinity increased obviously after PbO poisoning.
View Article and Find Full Text PDFACS Omega
January 2025
H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
The rising level of toxic gases in the environment poses a high demand for efficient gas sensing materials. MXenes, an emerging class of two-dimensional (2D) materials, have gained significant interest in this area for having an active-site rich structure, tunable surface properties, and remarkable stability. Herein, an extensive density functional theory (DFT) study is conducted to investigate the sensing properties of pristine and Au-functionalized TiC MXene for five toxic gas molecules: CO, COCl, HS, NH, and NO.
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