Mohammad Reza Samarghandi1, Seyed Alireza Babaee1, Mohammad Ahmadian2, Ghorban Asgari1, Farshid Ghorbani Shahna3, Ali Poormohammadi4. 1. Research Center for Health Sciences and Department of Environmental Engineering, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran. 2. School of Public Health, Kermanshah University of Medical Sciences, Kermanshah, Iran. 3. Department of Occupational Health Engineering, School of Public Health and Research Center for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran. 4. Social Development & Health Promotion Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran. apoormohammadi000@yahoo.com.
Abstract
BACKGROUND: Toluene is a volatile organic compound, one of 189 hazardous air pollutants (HAPs) and the most important pollutant found in most industries and indoor environments; owing to its adverse health, toluene must be treated before being released into the environment. METHODS: In this research study, a continuous-flow system (including an air compressor, silica gel filters and activated charcoal, impinger, an ozone generation and a fixed bed reactor packed with the carbosieve in size 1.8-2.3 mm, specific surface: 972 m2/g,) was used. This glass reactor was 0.7 m in height; at a distance of 0.2 m from its bottom, a mesh plane was installed so as to hold the adsorbent. Moreover, 3 l/min oxygen passed through this system, 0.43 g/h ozone was prepared. The flow rate of waste airstream was 300 ml/min. The efficiency of this system for removal of toluene was compared under the same experimental conditions. RESULTS: Under similar conditions, performance of catalytic ozonation was better in toluene removal than that of ozonation and carbosieve alone. On average, increasing the removal efficiency was 45% at all concentrations. When carbosieve and ozone come together, their synergistic effects increased on toluene degradation. CONCLUSIONS: Catalytic ozonation is a suitable, high-efficient and available method for removing toluene from various concentrations of waste air stream. This process due to the short contact time, low energy consuming and making use of cheap catalysts can be used as a novel process for removing various concentrations of volatile organic compounds.
BACKGROUND:Toluene is a volatile organic compound, one of 189 hazardous air pollutants (HAPs) and the most important pollutant found in most industries and indoor environments; owing to its adverse health, toluene must be treated before being released into the environment. METHODS: In this research study, a continuous-flow system (including an air compressor, silica gel filters and activated charcoal, impinger, an ozone generation and a fixed bed reactor packed with the carbosieve in size 1.8-2.3 mm, specific surface: 972 m2/g,) was used. This glass reactor was 0.7 m in height; at a distance of 0.2 m from its bottom, a mesh plane was installed so as to hold the adsorbent. Moreover, 3 l/min oxygen passed through this system, 0.43 g/h ozone was prepared. The flow rate of waste airstream was 300 ml/min. The efficiency of this system for removal of toluene was compared under the same experimental conditions. RESULTS: Under similar conditions, performance of catalytic ozonation was better in toluene removal than that of ozonation and carbosieve alone. On average, increasing the removal efficiency was 45% at all concentrations. When carbosieve and ozone come together, their synergistic effects increased on toluene degradation. CONCLUSIONS: Catalytic ozonation is a suitable, high-efficient and available method for removing toluene from various concentrations of waste air stream. This process due to the short contact time, low energy consuming and making use of cheap catalysts can be used as a novel process for removing various concentrations of volatile organic compounds.
Authors: Ali Poormohammadi; Abdulrahman Bahrami; Alireza Ghiasvand; Farshid Ghorbani Shahna; Maryam Farhadian Journal: J Environ Health Sci Eng Date: 2019-12-05
Authors: Ali Poormohammadi; Saeid Bashirian; Ali Reza Rahmani; Ghasem Azarian; Freshteh Mehri Journal: Environ Sci Pollut Res Int Date: 2021-06-14 Impact factor: 4.223