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Pietraru RN, Nicolae M, Mocanu Ș, Merezeanu DM. Easy-to-Use MOX-Based VOC Sensors for Efficient Indoor Air Quality Monitoring. SENSORS (BASEL, SWITZERLAND) 2024; 24:2501. [PMID: 38676118 PMCID: PMC11054856 DOI: 10.3390/s24082501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 03/25/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024]
Abstract
This research paper presents a case study on the application of Metal Oxide Semiconductor (MOX)-based VOC/TVOC sensors for indoor air quality (IAQ) monitoring. This study focuses on the ease of use and the practical benefits of these sensors, drawing insights from measurements conducted in a university laboratory setting. The investigation showcases the straightforward integration of MOX-based sensors into existing IAQ monitoring systems, highlighting their user-friendly features and the ability to provide precise and real-time information on volatile organic compound concentrations. Emphasizing ease of installation, minimal maintenance, and immediate data accessibility, this paper demonstrates the practicality of incorporating MOX-based sensors for efficient IAQ management. The findings contribute to the broader understanding of MOX sensor capabilities, providing valuable insights for those seeking straightforward and effective solutions for indoor air quality monitoring. This case study outlines the feasibility and benefits of utilizing MOX-based sensors in various environments, offering a promising avenue for the widespread adoption of user-friendly technologies in IAQ management.
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Affiliation(s)
- Radu Nicolae Pietraru
- Faculty of Automatic Control and Computers, National University of Science and Technology Politehnica Bucharest, 060042 București, Romania
| | - Maximilian Nicolae
- Faculty of Automatic Control and Computers, National University of Science and Technology Politehnica Bucharest, 060042 București, Romania
| | - Ștefan Mocanu
- Faculty of Automatic Control and Computers, National University of Science and Technology Politehnica Bucharest, 060042 București, Romania
| | - Daniel-Marian Merezeanu
- Faculty of Automatic Control and Computers, National University of Science and Technology Politehnica Bucharest, 060042 București, Romania
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Czerwinska N, Giosuè C, Matos I, Sabbatini S, Ruello ML, Bernardo M. Development of activated carbons derived from wastes: coffee grounds and olive stones as potential porous materials for air depollution. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169898. [PMID: 38184266 DOI: 10.1016/j.scitotenv.2024.169898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/20/2023] [Accepted: 01/02/2024] [Indexed: 01/08/2024]
Abstract
Agro-industrial byproducts and food waste necessitate an environmentally friendly way of reducing issues related to their disposal; it is also necessary to recover as much new raw material from these resources as possible, especially when we consider their potential usage as a precursor for preparing depolluting materials, such as activated carbon. In this work, coffee grounds and olive stones were chosen as precursors and the adsorption capacity of the obtained porous carbons for volatile organic compounds (VOCs) was studied. Microporous activated carbons (ACs) were prepared using chemical (K2CO3) and physical (CO2) activation. The influence of the activation process, type, and time of activation was also investigated. Measurements of VOCs adsorption were performed, and methyl-ethyl-ketone (MEK) and toluene were chosen as the model pollutants. The surface areas and total pore volumes of 1487 m2/g and 0.53 cm3/g and 870 m2/g and 0.22 cm3/g for coffee ground carbons and olive stone carbons, respectively, were obtained via chemical activation, whereas physical activation yielded values of 716 m2/g and 0.184 cm3/g and 778 cm2 g-1 and 0.205 cm3/g, respectively. As expected, carbons without activation (biochars) showed the smallest surface area, equal to 331 m2/g and 251 m2/g, and, hence, the lowest adsorption capacity. The highest adsorption capacity of MEK (3210 mg/g) and toluene (2618 mg/g) was recorded for chemically activated coffee grounds. Additionally, from the CO2 isotherms recorded at a low pressure (0.03 bar) and 0 °C, the maximum CO2 adsorption capacity was equal to 253 mg/g.
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Affiliation(s)
- Natalia Czerwinska
- Department of Science and Engineering of Matter, Environment and Urban Planning (SIMAU), Università Politecnica delle Marche, UdR INSTM Ancona, Italy.
| | - Chiara Giosuè
- Department of Science and Engineering of Matter, Environment and Urban Planning (SIMAU), Università Politecnica delle Marche, UdR INSTM Ancona, Italy.
| | - Ines Matos
- LAQV/REQUIMTE, NOVA School of Science and Technology, NOVA University of Lisbon, 2829-516 Caparica, Portugal
| | - Simona Sabbatini
- Department of Science and Engineering of Matter, Environment and Urban Planning (SIMAU), Università Politecnica delle Marche, UdR INSTM Ancona, Italy
| | - Maria Letizia Ruello
- Department of Science and Engineering of Matter, Environment and Urban Planning (SIMAU), Università Politecnica delle Marche, UdR INSTM Ancona, Italy
| | - Maria Bernardo
- LAQV/REQUIMTE, NOVA School of Science and Technology, NOVA University of Lisbon, 2829-516 Caparica, Portugal
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Brabo-Catala L, Cernic A, Collins E, Barton B. The heat goes on: Simplifying the identification of energy hardship. Heliyon 2023; 9:e19087. [PMID: 37636461 PMCID: PMC10450965 DOI: 10.1016/j.heliyon.2023.e19087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/04/2023] [Accepted: 08/10/2023] [Indexed: 08/29/2023] Open
Abstract
Energy hardship affects over 6% of households in New Zealand, defined as the inability to afford and obtain energy services. In late 2021, the Ministry of Business, Innovation and Employment proposed 26 indicators to identify energy hardship. However, this study aimed to explore the leading causes and consequences of energy hardship in the following year, including relevant variables not included in the proposed indicators. A survey of 1278 Kiwi respondents was conducted to understand their demographic and energy consumption patterns. Using 17 of the proposed indicators, the severity of energy hardship was measured and related to other important variables. Results showed that energy unaffordability, poor housing quality, and choosing between food expenses or energy bills were the main drivers of energy hardship. Consequences included feeling cold due to restricted energy consumption and accumulating energy debt. This study provides valuable insights to simplify the identification of households experiencing energy hardship and highlights the main areas of focus for policy development aimed at eradicating this problem.
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Affiliation(s)
| | | | - Eva Collins
- Waikato Management School, University of Waikato, Hamilton, New Zealand
| | - Barry Barton
- Te Piringa Faculty of Law, University of Waikato, Hamilton, New Zealand
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Yang S, Muthalagu A, Serrano VG, Licina D. Human personal air pollution clouds in a naturally ventilated office during the COVID-19 pandemic. BUILDING AND ENVIRONMENT 2023; 236:110280. [PMID: 37064616 PMCID: PMC10080864 DOI: 10.1016/j.buildenv.2023.110280] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 03/31/2023] [Accepted: 04/05/2023] [Indexed: 05/03/2023]
Abstract
Personal cloud, termed as the difference in air pollutant concentrations between breathing zone and room sites, represents the bias in approximating personal inhalation exposure that is linked to accuracy of health risk assessment. This study performed a two-week field experiment in a naturally ventilated office during the COVID-19 pandemic to assess occupants' exposure to common air pollutants and to determine factors contributing to the personal cloud effect. During occupied periods, indoor average concentrations of endotoxin (0.09 EU/m3), TVOC (231 μg/m3), CO2 (630 ppm), and PM10 (14 μg/m3) were below the recommended limits, except for formaldehyde (58 μg/m3). Personal exposure concentrations, however, were significantly different from, and mostly higher than, concentrations measured at room stationary sampling sites. Although three participants shared the same office, their personal air pollution clouds were mutually distinct. The mean personal cloud magnitude ranged within 0-0.05 EU/m3, 35-192 μg/m3, 32-120 ppm, and 4-9 μg/m3 for endotoxin, TVOC, CO2, and PM10, respectively, and was independent from room concentrations. The use of hand sanitizer was strongly associated with an elevated personal cloud of endotoxin and alcohol-based VOCs. Reduced occupancy density in the office resulted in more pronounced personal CO2 clouds. The representativeness of room stationary sampling for capturing dynamic personal exposures was as low as 28% and 5% for CO2 and PM10, respectively. The findings of our study highlight the necessity of considering the personal cloud effect when assessing personal exposure in offices.
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Affiliation(s)
- Shen Yang
- Human-Oriented Built Environment Lab, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Akila Muthalagu
- Human-Oriented Built Environment Lab, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Environmental Systems Group, Department of Civil Engineering, Indian Institute of Technology Hyderabad, Kandi, India
| | - Viviana González Serrano
- Human-Oriented Built Environment Lab, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Dusan Licina
- Human-Oriented Built Environment Lab, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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Yen YC, Ku CH, Hsiao TC, Chi KH, Peng CY, Chen YC. Impacts of COVID-19's restriction measures on personal exposure to VOCs and aldehydes in Taipei City. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163275. [PMID: 37028680 PMCID: PMC10074730 DOI: 10.1016/j.scitotenv.2023.163275] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 02/21/2023] [Accepted: 03/31/2023] [Indexed: 05/23/2023]
Abstract
The Coronavirus Disease 2019 (COVID-19) pandemic provided an unprecedented natural experiment, that allowed us to investigate the impacts of different restrictive measures on personal exposure to specific volatile organic compounds (VOCs) and aldehydes and resulting health risks in the city. Ambient concentrations of the criteria air pollutants were also evaluated. Passive sampling for VOCs and aldehydes was conducted for graduate students and ambient air in Taipei, Taiwan, during the Level 3 warning (strict control measures) and Level 2 alert (loosened control measures) of the COVID-19 pandemic in 2021-2022. Information on the daily activities of participants and on-road vehicle counts nearby the stationary sampling site during the sampling campaigns were recorded. Generalized estimating equations (GEE) with adjusted meteorological and seasonal variables were used to estimate the effects of control measures on average personal exposures to the selected air pollutants. Our results showed that ambient CO and NO2 concentrations in relation to on-road transportation emissions were significantly reduced, which led to an increase in ambient O3 concentrations. Exposure to specific VOCs (benzene, methyl tert-butyl ether (MTBE), xylene, ethylbenzene, and 1,3-butadiene) associated with automobile emissions were remarkably decreased by ~40-80 % during the Level 3 warning, resulting in 42 % and 50 % reductions of total incremental lifetime cancer risk (ILCR) and hazard index (HI), respectively, compared with the Level 2 alert. In contrast, the exposure concentration and calculated health risks in the selected population for formaldehyde increased by ~25 % on average during the Level 3 warning. Our study improves knowledge of the influence of a series of anti-COVID-19 measures on personal exposure to specific VOCs and aldehydes and its mitigations.
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Affiliation(s)
- Yu-Chuan Yen
- National Institute of Environmental Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan Town, Miaoli, Taiwan
| | - Chun-Hung Ku
- National Institute of Environmental Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan Town, Miaoli, Taiwan
| | - Ta-Chih Hsiao
- Graduate Institute of Environmental Engineering, National Taiwan University, Taiwan
| | - Kai Hsien Chi
- Institute of Environmental and Occupational Health Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
| | - Chiung-Yu Peng
- Department of Public Health, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Yu-Cheng Chen
- National Institute of Environmental Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan Town, Miaoli, Taiwan; Department of Occupational Safety and Health, China Medical University, 91 Hsueh-Shih Road, Taichung, Taiwan; Department of Safety, Health and Environmental Engineering, National United University, No. 2, Lienda, Miaoli 360302, Taiwan; Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
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Ding E, Zhang D, Hamida A, García-Sánchez C, Jonker L, de Boer AR, Bruijning PCJL, Linde KJ, Wouters IM, Bluyssen PM. Ventilation and thermal conditions in secondary schools in the Netherlands: Effects of COVID-19 pandemic control and prevention measures. BUILDING AND ENVIRONMENT 2023; 229:109922. [PMID: 36575741 PMCID: PMC9779948 DOI: 10.1016/j.buildenv.2022.109922] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
During the COVID-19 pandemic, the importance of ventilation was widely stressed and new protocols of ventilation were implemented in school buildings worldwide. In the Netherlands, schools were recommended to keep the windows and doors open, and after a national lockdown more stringent measures such as reduction of occupancy were introduced. In this study, the actual effects of such measures on ventilation and thermal conditions were investigated in 31 classrooms of 11 Dutch secondary schools, by monitoring the indoor and outdoor CO2 concentration and air temperature, both before and after the lockdown. Ventilation rates were calculated using the steady-state method. Pre-lockdown, with an average occupancy of 17 students, in 42% of the classrooms the CO2 concentration exceeded the upper limit of the Dutch national guidelines (800 ppm above outdoors), while 13% had a ventilation rate per person (VRp) lower than the minimum requirement (6 l/s/p). Post-lockdown, the indoor CO2 concentration decreased significantly while for ventilation rates significant increase was only found in VRp, mainly caused by the decrease in occupancy (average 10 students). The total ventilation rate per classrooms, mainly induced by opening windows and doors, did not change significantly. Meanwhile, according to the Dutch national guidelines, thermal conditions in the classrooms were not satisfying, both pre- and post-lockdown. While opening windows and doors cannot achieve the required indoor environmental quality at all times, reducing occupancy might not be feasible for immediate implementation. Hence, more controllable and flexible ways for improving indoor air quality and thermal comfort in classrooms are needed.
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Affiliation(s)
- Er Ding
- Chair Indoor Environment, Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, the Netherlands
| | - Dadi Zhang
- Chair Indoor Environment, Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, the Netherlands
| | - Amneh Hamida
- Chair Indoor Environment, Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, the Netherlands
| | - Clara García-Sánchez
- 3D Geoinformation Research Group, Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, the Netherlands
| | - Lotte Jonker
- Julius Center for Health Sciences and Primary Care, UMC Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Annemarijn R de Boer
- Julius Center for Health Sciences and Primary Care, UMC Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Patricia C J L Bruijning
- Julius Center for Health Sciences and Primary Care, UMC Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Kimberly J Linde
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Inge M Wouters
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Philomena M Bluyssen
- Chair Indoor Environment, Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, the Netherlands
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