Professor, Division of Environment and Sustainability
Director, Environmental Central Facility

Tel: (852) 3469 2207
Fax: (852) 2335 9317
Office: Room 4356 (Lift 13/15)
Link(s): Personal Home Page

Research Area
  • Environmental sensor technology and algorithm development
  • Sensor and sensor network application
  • Urban air quality and built environment
  • Combustion emission and impact on roadside air quality
  • Personal exposure and environmental health
Research Interests

Dr. Zhi Ning’s research interests cover the innovation and development of environmental monitoring technologies with a focus on low-cost sensor algorithm and its application on air quality research. Dr. Ning has active participation in the low-cost sensor related work initiated by USEPA, WHO and WMO, and has led his team to develop the air sensing technologies for use in the first marathon route sensor network, large scale urban mobile sensor network with wide recognition locally and globally. Besides the technology development, Dr. Ning’s research also aims to understand the physical and chemical process of air pollution in complex urban built environment and their impact on the air quality and public health.

Research Highlights
  • Establishment of a large-scale air sensor monitoring network with in-house designed low-cost sensor system for 2015 Standard Chartered Hong Kong Marathon.
  • Development of a miniature Personal Exposure Kit equipped with particle and gas sensors, for personal integrated exposure measurement.
  • Development of an ultralight sensor system for unmanned aerial vehicle-based ship emission measurement and the fuel sulfur content detection.
  • Implementation of the first comprehensive Mobile Air Sensor Network in Hong Kong across 14 districts spanning high population density areas, and Real-time Air Quality measurements.
  • Development of next generation air sensor operational protocol with the Hong Kong Environmental Protection Department.
  • On-road Plume Chasing and Analysis System (OPCAS) with automated data processing protocols for fast screening on on-road high emitters.
  • Winner of 2016 Hong Kong Green Innovation Awards with certificate of merits on “Internet of Things Application of environmental sensors for building energy saving and sustainable environment.”
Recent Publications
  • Liu, Y., Ning, Z., Chen, Y., Guo, M., Liu, Y., Gali, N.K., Sun, L., Duan, Y., Cai, J., Westerdahl, D., Liu, X., Xu, K., Ho, K., Kan, H., Fu, Q. and Lan, K. (2020) Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals. Nature (
  • Jiang, S.Y., Gali, N.K., Ruan, H.D. and Ning, Z. (2020) “Photo-oxidation of particle phase iron species dominates the generation of reactive oxygen species in secondary aerosol.” Science of the Total Environment 723: 137994.
  • Ghadikolaei, M.A., L. Wei, C. Cheung, K.F. Yung and Z. Ning (2020) “Particulate emission and physical properties of particulate matter emitted from a diesel engine fuelled with ternary fuel (diesel-biodiesel-ethanol) in blended and fumigation modes.” Fuel 263: 116665.
  • Zhang, Q., Z. Shen, Y. Lei., T. Zhang, Y. Zeng, Z. Ning, J. Sun, Westerdahl, F. D., H. Xu, Q. Wang, J. Cao and R. Zhang (2019) “Optical properties and source identification of black carbon and brown carbon: comparison of winter and summer haze episodes in Xi’an, northwest China.” Environmental Science-Processes & Impacts 21: 2058-2069.
  • Li, Y., H. Xu., K. He., J. Wang., Z. Ning., Q. Wang., N. Li., Z. Shen., P. Liu., J. Sun., X. Niu., Y. Cao and J. Cao (2019). “Reactive oxygen species induced by personal exposure to fine particulate matter emitted from solid fuel combustion in rural Guanzhong Basin, northwest China.” Air Quality, Atmosphere and Health 12: 1323-1333.
  • Wei, P., Ning, Z., Westerdahl, F.D., Lam, Y. F., Louie, P. K. K., Sharpe, R. N., Williams, R. W. and Hagler, G. S. W. (2019). “Solar-powered air quality monitor applied under subtropical conditions in Hong Kong: Performance evaluation and application for pollution source tracing.” Atmospheric Environment 214: 116825.
  • Stevanovic, S., Gali, N.K., Salimi, F., Brown, R.A., Ning, Z., Cravigan, L., Brimblecombe, P., Bottle, S. and Ristovski, Z.D. (2019) “Diurnal profiles of particle-bound ROS of PM2.5 in urban environment of Hong Kong and their association with PM2.5, black carbon, ozone and PAHs.” Atmospheric Environment 219:117023
  • Li, M.Y., Liu, L.Z., Li, W., Ng, S.H.C., Liu, Y., Kong, W.Y.A., Zhao, Z., Wang, S., Qi, H., Jia, H., Yang, S., Du, J., Long, X., Ho, L.K.R., Chak, C.W.E., Wan, Y.P.I., Mok, S.K.T., Underwood, J.M., Gali, N.K., Ning, Z. and Chen, G. (2019) “Ambient fine particulate matter inhibits 15-lipoxygenases to promote lung carcinogenesis.” J Experimental & Clinical Cancer Research 38:359
  • Gali, N. K., G. Li, Z. Ning and P. Brimblecombe (2019). “Diurnal trends in redox characteristics of water-soluble and -insoluble PM components.” Environmental Pollution (Accepted Manuscript - in Press) Doi: 10.1016/j.envpol.2019.07.009
  • ​Li, Y, H. Xu, J. Wang, S. S. H. Ho, K. He, Z. Shen, Z. Ning, J. Sun, L. Li, R. Lei, T. Zhang, Y. Lei, L. Yang, Y. Cao and J. Cao (2019). “Personal exposure to PM2.5-bound organic species from domestic solid fuel combustion in rural Guanzhong Basin, China: characteristics and health implication.” Chemosphere 227: 53-62.
  • Qi, X., A. Ding, W. Nie, X. Chi, X. Huang, Z. Xu, T. Wang, Z. Wang, J. Wang, P. Sun, Q. Zhang, J. Huo, D. Wang, Q. Bian, L. Zhou, Q. Zhang, Z. Ning, D. Fei, G. Xiu and Q. Fu (2019). “Direct measurement of new particle formation based on tethered airship around the top of the planetary boundary layer in eastern China.” Atmospheric Environment 209: 92-101.
  • Williams, R., R. Duvall, V. Kilaru, G. Hagler, L. Hassinger, K. Benedict, J. Rice, A. Kaufman, R. Judge, G. Pierce, G. Allen, M. Bergin, R. C. Cohen, P. Fransioli, M. Gerboles, R. Habre, M. Hannigan, D. Jack, P. Louie, N. A. Martin, M. Penza, A. Polidori, R. Subramanian, K. Ray, J. Schauer, E. Seto, G. Thurston, J. Turner, A. S. Wexler and Z. Ning (2019). “Deliberating performance targets workshop: Potential paths for emerging PM2.5 and O3 air sensor progress.” Atmospheric Environment:X 2:100031
  • Yang, X., P. Brimblecombe and Z. Ning (2019). “Fine-scale spatial structure of air pollutant concentrations along bus routes.” Science of the Total Environment 628: 1-7
  • Yang, F., C. F. Lau, V. W. T. Tong, K. Zhang, D. F. Westerdahl, S. Ng and Z. Ning (2019). “Assessment of personal integrated exposure to fine particulate matter of urban residents in Hong Kong.” Journal of the Air & Waste Management Association 69(1): 47-57.
  • Zhang, Q., Z. Shen, Z. Ning, Q. Wang, J. Cao, Y. Lei, J. Sun, Y. Zeng, D. Westerdahl, X. Wang, L. Wang and H. Xu (2018). "Characteristics and source apportionment of winter black carbon aerosols in two Chinese megacities of Xi’an and Hong Kong." Environmental Science and Pollution Research 25(33): 33783-33793.
  • Candice, L., R. Jones, C. Zellweger, A. Karppinen, M. Penza, T. Dye, C. Huglin, Z. Ning, R. Leigh, D. Hagan, O. Laurent and G. Carmichael (2018). “Low-cost sensors for the measurement of atmospheric composition: overview of topic and future applications.” Lewis, A., Peltier, W. R. and von Schneidemesser, E. (Eds). Research Report. World Meteorological Organization (WMO).  
  • Zhang, Q., Z. Shen, Y. Lei, Y. Wang, Y. Zeng, Q. Wang, Z. Ning, J. Cao, L. Wang and H. Xu (2018). "Variations of particle size distribution, black carbon, and brown carbon during a severe winter pollution event over Xi’an, China." Aerosol and Air Quality Research 18(6): 1419-1430.
  • Wei, P., Z. Ning, S. Ye, L. Sun, F. Yang, K. C. Wong, D. Westerdahl and P. K. K. Louie (2018). "Impact analysis of temperature and humidity conditions on electrochemical sensor response in ambient air quality monitoring." Sensors (Switzerland) 18(2).
  • Wei, L., C. S. Cheung and Z. Ning (2018). "Effects of biodiesel-ethanol and biodiesel-butanol blends on the combustion, performance and emissions of a diesel engine." Energy 155: 957-970.
  • Morawska, L., P. K. Thai, X. Liu, A. Asumadu-Sakyi, G. Ayoko, A. Bartonova, A. Bedini, F. Chai, B. Christensen, M. Dunbabin, J. Gao, G. S. W. Hagler, R. Jayaratne, P. Kumar, A. K. H. Lau, P. K. K. Louie, M. Mazaheri, Z. Ning, N. Motta, B. Mullins, M. M. Rahman, Z. Ristovski, M. Shafiei, D. Tjondronegoro, D. Westerdahl and R. Williams (2018). "Applications of low-cost sensing technologies for air quality monitoring and exposure assessment: How far have they gone?" Environment International 116: 286-299.
  • Li, G. L., L. Sun, K. F. Ho, K. C. Wong and Z. Ning (2018). "Implication of light absorption enhancement and mixing state of black carbon (BC) by coatings in Hong Kong." Aerosol and Air Quality Research 18(11): 2753-2763.
  • Farid, M. U., S. Jeong, D. H. Seo, R. Ahmed, C. Lau, N. K. Gali, Z. Ning and A. K. An (2018). "Mechanistic insight into the in vitro toxicity of graphene oxide against biofilm forming bacteria using laser-induced breakdown spectroscopy." Nanoscale 10(9): 4475-4487.
  • Fan, W., K. Y. Chan, C. Zhang, K. Zhang, Z. Ning and M. K. H. Leung (2018). "Solar photocatalytic asphalt for removal of vehicular NOx: A feasibility study." Applied Energy 225: 535-541.
  • Zhang, Q., Z. Ning, Z. Shen, G. Li, J. Zhang, Y. Lei, H. Xu, J. Sun, L. Zhang, D. Westerdahl, N. K. Gali and X. Gong (2017). "Variations of aerosol size distribution, chemical composition and optical properties from roadside to ambient environment: A case study in Hong Kong, China." Atmospheric Environment 166: 234-243.
  • Wei, L., C. S. Cheung and Z. Ning (2017). "Influence of waste cooking oil biodiesel on combustion, unregulated gaseous emissions and particulate emissions of a direct-injection diesel engine." Energy 127: 175-185.
  • Sun, L., D. Westerdahl and Z. Ning (2017). "Development and evaluation of a novel and cost-effective approach for low-cost NO2 sensor drift correction." Sensors (Switzerland) 17(8).
  • Lui, K. H., B. A. M. Bandowe, L. Tian, C. S. Chan, J. J. Cao, Z. Ning, S. C. Lee and K. F. Ho (2017). "Cancer risk from polycyclic aromatic compounds in fine particulate matter generated from household coal combustion in Xuanwei, China." Chemosphere 169: 660-668.
  • Jiang, S. Y., N. K. Gali, F. Yang, J. Zhang and Z. Ning (2017). "Chemical characterization of size-segregated PM from different public transport modes and implications of source specific contribution to public exposure." Environmental Science and Pollution Research 24(24): 20029-20040.
  • Guan, C., C. S. Cheung, Z. Ning, P. K. Wong and Z. Huang (2017). "Comparison on the effect of using diesel fuel and waste cooking oil biodiesel as pilot fuels on the combustion, performance and emissions of a LPG-fumigated compression-ignition engine." Applied Thermal Engineering 125: 1260-1271.
  • Gali, N. K., F. Yang, C. S. Cheung and Z. Ning (2017). "A comparative analysis of chemical components and cell toxicity properties of solid and semi-volatile PM from diesel and biodiesel blend." Journal of Aerosol Science 111: 51-64.
  • Gali, N. K., S. Y. Jiang, F. Yang, L. Sun and Z. Ning (2017). "Redox characteristics of size-segregated PM from different public transport microenvironments in Hong Kong." Air Quality, Atmosphere and Health 10(7): 833-844.
  • Wei, L., C. S. Cheung and Z. Ning (2016). "Influence of waste cooking oil biodiesel on the nanostructure and volatility of particles emitted by a direct-injection diesel engine." Aerosol Science and Technology 50(9): 893-905.
  • Sun, L., K. C. Wong, P. Wei, S. Ye, H. Huang, F. Yang, D. Westerdahl, P. K. K. Louie, C. W. Y. Luk and Z. Ning (2016). "Development and application of a next generation air sensor network for the Hong Kong marathon 2015 air quality monitoring." Sensors (Switzerland) 16(2).
  • Man, X. J., C. S. Cheung, Z. Ning, L. Wei and Z. H. Huang (2016). "Influence of engine load and speed on regulated and unregulated emissions of a diesel engine fueled with diesel fuel blended with waste cooking oil biodiesel." Fuel 180: 41-49.
  • Kaul, D. S., Z. Ning, D. Westerdahl, X. Yin and R. A. Cary (2016). "A novel tandem of thermal desorption carbon analyzer and off-axis integrated cavity output spectroscopy for aerosol stable carbon isotope ratio measurement." Aerosol and Air Quality Research 16(6): 1345-1355.
  • Ho, K. F., S. S. H. Ho, R. J. Huang, H. C. Chuang, J. J. Cao, Y. Han, K. H. Lui, Z. Ning, K. J. Chuang, T. J. Cheng, S. C. Lee, D. Hu, B. Wang and R. Zhang (2016). "Chemical composition and bioreactivity of PM2.5 during 2013 haze events in China." Atmospheric Environment 126: 162-170.
  • Ho, K. F., C. C. Chang, L. Tian, C. S. Chan, B. A. Musa Bandowe, K. H. Lui, K. Y. Lee, K. J. Chuang, C. Y. Liu, Z. Ning and H. C. Chuang (2016). "Effects of polycyclic aromatic compounds in fine particulate matter generated from household coal combustion on response to EGFR mutations in vitro." Environmental Pollution 218: 1262-1269.
  • Hagler, G., Z. Ning, N. Y. F. Lam, R. Sharpe, R. Williams and P. Louie (2016). Performance assessment of a solar-powered air quality and weather station placed on a school rooftop in Hong Kong. Air and Waste Management Association - Air Quality Measurement Methods and Technology Conference 2016.
  • Gali, N. K., Z. Ning, W. Daoud and P. Brimblecombe (2016). "Investigation on the mechanism of non-photocatalytically TiO2-induced reactive oxygen species and its significance on cell cycle and morphology." Journal of Applied Toxicology 36(10): 1355-1363.
  • Chan, K. L., S. Y. N. Jiang and Z. Ning (2016). "Speciation of water soluble iron in size segregated airborne particulate matter using LED based liquid waveguide with a novel dispersive absorption spectroscopic measurement technique." Analytica Chimica Acta 914: 100-109.
  • Zhou, J. H., C. S. Cheung, W. Z. Zhao, Z. Ning and C. W. Leung (2015). "Impact of intake hydrogen enrichment on morphology, structure and oxidation reactivity of diesel particulate." Applied Energy 160: 442-455.
  • Yang, F., D. Kaul, K. C. Wong, D. Westerdahl, L. Sun, K. F. Ho, L. Tian, P. Brimblecombe and Z. Ning (2015). "Heterogeneity of passenger exposure to air pollutants in public transport microenvironments." Atmospheric Environment 109: 42-51.
  • Wubulihairen, M., Sabrina, Y. Jiang and Z. Ning (2015). "Prototype development and laboratory evaluation of an aerosol to hydrosol sampler." Aerosol and Air Quality Research 15(3): 776-785.
  • Wubulihairen, M., X. Lu, P. K. H. Lee and Z. Ning (2015). "Development and laboratory evaluation of a compact swirling aerosol sampler (SAS) for collection of atmospheric bioaerosols." Atmospheric Pollution Research 6(4): 556-561.
  • Man, X. J., C. S. Cheung, Z. Ning and K. F. Yung (2015). "Effect of waste cooking oil biodiesel on the properties of particulate from a DI diesel engine." Aerosol Science and Technology 49(4): 199-209.
  • Man, X. J., C. S. Cheung and Z. Ning (2015). “Effect of Diesel Engine Operating Conditions on the Particulate Size, Nanostructure and Oxidation Properties when Using Wasting Cooking Oil Biodiesel.” Energy Procedia.
  • Lau, C. F., A. Rakowska, T. Townsend, P. Brimblecombe, T. L. Chan, Y. S. Yam, G. Močnik and Z. Ning (2015). "Evaluation of diesel fleet emissions and control policies from plume chasing measurements of on-road vehicles." Atmospheric Environment 122: 171-182.
  • Jiang, S. Y., D. S. Kaul, F. Yang, L. Sun and Z. Ning (2015). "Source apportionment and water solubility of metals in size segregated particles in urban environments." Science of the Total Environment 533: 347-355.
  • Hu, L., X. Zhang, W. Zhu, Z. Ning and F. Tang (2015). "A global relation of fire smoke re-circulation behaviour in urban street canyons." Journal of Civil Engineering and Management 21(4): 459-469.
  • Gali, N. K., F. Yang, S. Y. Jiang, K. L. Chan, L. Sun, K. Ho and Z. Ning (2015). "Spatial and seasonal heterogeneity of atmospheric particles induced reactive oxygen species in urban areas and the role of water-soluble metals." Environmental pollution (Barking, Essex : 1987) 198: 86-96.
  • Chan, K. L., A. Hartl, Y. F. Lam, P. H. Xie, W. Q. Liu, H. M. Cheung, J. Lampel, D. Pöhler, A. Li, J. Xu, H. J. Zhou, Z. Ning and M. O. Wenig (2015). "Observations of tropospheric NO2 using ground based MAX-DOAS and OMI measurements during the Shanghai World Expo 2010." Atmospheric Environment 119: 45-58.
  • Brimblecombe, P., T. Townsend, C. F. Lau, A. Rakowska, T. L. Chan, G. Močnik and Z. Ning (2015). "Through-tunnel estimates of vehicle fleet emission factors." Atmospheric Environment 123: 180-189.
  • Brimblecombe, P. and Z. Ning (2015). "Effect of road blockages on local air pollution during the Hong Kong protests and its implications for air quality management." Science of the Total Environment 536: 443-448.