High-rise buildings form deep urban street canyons and restrict the dispersion of vehicle emissions,posing severe health risks to the public by aggravating roadside air quality.Field measurements are important for und...High-rise buildings form deep urban street canyons and restrict the dispersion of vehicle emissions,posing severe health risks to the public by aggravating roadside air quality.Field measurements are important for understanding the dispersion process of tailpipe emissions in street canyons,while a major challenge is the lack of a suitable tracer gas.Carbon dioxide(CO_(2)),which is safe to the public and inexpensive to obtain,can be reliably measured by existing gas analysers.This study investigated the suitability of using CO_(2)as a tracer gas for characterising vehicle emission dispersion in a real-world street canyon.The tracer gas was released via a line or point source,whose dispersion was characterised by a sensors network comprising low-cost air quality sensors.The results showed that the CO_(2)contained in the exhaust gas of a test vehicle itself had unmeasurable effect at roadsides.Both the line and point sources produced obvious CO_(2)level elevations at approximately 30 s after the test vehicle passed by.In addition,for both line and point sources,the CO_(2)elevations were much more distinct at the roadside next to tailpipe exit than the opposite side,and were higher at 0.8 m than 1.6 m above the ground.The present study demonstrated that using CO_(2)as a tracer gas is feasible for investigating vehicle emission dispersion in real-world street canyons.Future studies are needed to improve the gas release rate of the developed tracer gas systems for more reliable measurements and larger street canyons.展开更多
Carbon Capture,Utilization,and Storage(CCUS)technology has gained widespread attention in recent years as a critical strategy to combat global climate change,particularly in achieving carbon neutrality goals.The Guang...Carbon Capture,Utilization,and Storage(CCUS)technology has gained widespread attention in recent years as a critical strategy to combat global climate change,particularly in achieving carbon neutrality goals.The Guangdong-Hong Kong-Macao Greater Bay Area(GBA),as one of China's most economically active regions,serves as a key engine for economic growth while also facing considerable carbon emission challenges.This study analyzes the industrial emission volume and geographical distribution of key emitting enterprises in the GBA,summarizes their technological processes and main carbonemitting equipment,and provides scientific support for precise mitigation policies and low-carbon development.Based on data from 176 key emitting enterprises,the study reveals that Guangzhou and Dongguan host the largest number of such enterprises.Carbon emissions are primarily concentrated in the power sector,dominated by coal-and gas-fired power units,characterized by significant spatial dispersion and uneven distribution.Beyond the power sector,the paper industry has a high number of enterprises but lower emissions.Key facilities such as boilers,cogeneration systems,and production lines are predominantly located near tributaries rivers in Dongguan and Jiangmen.The building materials sector,primarily cement production,ranks as the second-largest emitter,with hightemperature kilns and grinding equipment,particularly rotary kilns and glass furnaces,as the main sources.The petrochemical and chemical sectors have fewer enterprises and lower emissions in the GBA,mainly located in suburban industrial clusters.Carbon emissions in the GBA exhibit distinct industry concentration and geographical distribution disparities.This study provides crucial data and theoretical insights for the development of targeted emission reduction strategies,optimization of source-sink matching,and the advancement of CCUS technologies in the region,particularly from the GBA to the northern South China Sea.展开更多
基金supported by the Environment and Conservation Fund(No.ECF 14/2018)of the Hong Kong SAR Government,China.
文摘High-rise buildings form deep urban street canyons and restrict the dispersion of vehicle emissions,posing severe health risks to the public by aggravating roadside air quality.Field measurements are important for understanding the dispersion process of tailpipe emissions in street canyons,while a major challenge is the lack of a suitable tracer gas.Carbon dioxide(CO_(2)),which is safe to the public and inexpensive to obtain,can be reliably measured by existing gas analysers.This study investigated the suitability of using CO_(2)as a tracer gas for characterising vehicle emission dispersion in a real-world street canyon.The tracer gas was released via a line or point source,whose dispersion was characterised by a sensors network comprising low-cost air quality sensors.The results showed that the CO_(2)contained in the exhaust gas of a test vehicle itself had unmeasurable effect at roadsides.Both the line and point sources produced obvious CO_(2)level elevations at approximately 30 s after the test vehicle passed by.In addition,for both line and point sources,the CO_(2)elevations were much more distinct at the roadside next to tailpipe exit than the opposite side,and were higher at 0.8 m than 1.6 m above the ground.The present study demonstrated that using CO_(2)as a tracer gas is feasible for investigating vehicle emission dispersion in real-world street canyons.Future studies are needed to improve the gas release rate of the developed tracer gas systems for more reliable measurements and larger street canyons.
基金supported by the National Natural Science Foundation of China(52304098,52106092,42376215,52474105)Shenzhen Science and Technology Program(JCYJ20220818095605012,JCYJ20220530113011027)+5 种基金Guangdong Basic and Applied Basic Research Foundation(2022A1515110338,2023A1515012316,2023A1515012761,2025A1515010748)Research Team Cultivation Program of Shenzhen University(2023QNT004)Shenzhen Key Laboratory of Natural Gas Hydrates(ZDSYS20200421111201738)the General Research Fund(No.12616222)Early Career Scheme(No.22611624)of Hong Kong Research Grants CouncilMajor Science and Technology Infrastructure Project of Material Genome Big–science Facilities Platform supported by the Municipal Development and Reform Commission of Shenzhen。
文摘Carbon Capture,Utilization,and Storage(CCUS)technology has gained widespread attention in recent years as a critical strategy to combat global climate change,particularly in achieving carbon neutrality goals.The Guangdong-Hong Kong-Macao Greater Bay Area(GBA),as one of China's most economically active regions,serves as a key engine for economic growth while also facing considerable carbon emission challenges.This study analyzes the industrial emission volume and geographical distribution of key emitting enterprises in the GBA,summarizes their technological processes and main carbonemitting equipment,and provides scientific support for precise mitigation policies and low-carbon development.Based on data from 176 key emitting enterprises,the study reveals that Guangzhou and Dongguan host the largest number of such enterprises.Carbon emissions are primarily concentrated in the power sector,dominated by coal-and gas-fired power units,characterized by significant spatial dispersion and uneven distribution.Beyond the power sector,the paper industry has a high number of enterprises but lower emissions.Key facilities such as boilers,cogeneration systems,and production lines are predominantly located near tributaries rivers in Dongguan and Jiangmen.The building materials sector,primarily cement production,ranks as the second-largest emitter,with hightemperature kilns and grinding equipment,particularly rotary kilns and glass furnaces,as the main sources.The petrochemical and chemical sectors have fewer enterprises and lower emissions in the GBA,mainly located in suburban industrial clusters.Carbon emissions in the GBA exhibit distinct industry concentration and geographical distribution disparities.This study provides crucial data and theoretical insights for the development of targeted emission reduction strategies,optimization of source-sink matching,and the advancement of CCUS technologies in the region,particularly from the GBA to the northern South China Sea.
