Professor, Mechanical and Mechatronics Engineering

Research interests: airborne nanoparticles, measurement, separation, capture; environmental protection


Professor Zhongchao Tan received his B.Sc. and M.Sc. degrees, both in Thermal Engineering, in 1996 and 1999, respectively, from Tsinghua University, Beijing, China and Ph.D. degree in Bioenvironmental Engineering in 2004 from the University of Illinois at Urbana-Champaign (UIUC), Illinois, USA. He is now a Full Professor appointed in multiple engineering departments and institutes at the University of Waterloo, Waterloo, Ontario, Canada. Prior to this position, he was an Assistant Professor and later on promoted to Associate Professor at the University of Calgary from July 2004 to August 2010. Tan’s research interests include air pollution control, indoor air quality, nanosafety, and bioproducts.

As Director of the Air Pollution Research and Innovation Laboratory (APRIL) at the University of Waterloo, Tan’s research interests involve air pollution, indoor air quality, nanosafety, and biofuels. He has developed a novel cyclone for multiphase particulate matter emission control for sulfur processing industry; his group is now working on granular filtration aiming at fine particles in the air. He and his graduate students are also developing a novel absorbent for simultaneous NOx and SO2 emission controls. Recently, nanotechnology has become a revolutionary field due to its unique applications across a wide range of industries, from medicine to alternative energy. However, increased production of these technologies has led to increased amounts of airborne nanoparticles (sub-100 nm particles) and, consequently, growing environmental and health concerns. Submicron particles can penetrate deeply into the respiratory system, and smaller (<100 nm) particles can enter the circulation system. Nanosized particles may become more toxic than the micron ones made from the same material.

Tan is an expertise in instrumentation for airborne nanoparticle measurement. He has been developing a cost-effective technology to directly measure the number distribution of airborne nanoparticles by diffusive charging and aerodynamic focusing. The newly improved prototype could reach down to 40 nm. The lower size limit and accuracy of this technology could be further improved with a better understanding of nanoparticle focusing. Theoretically, a properly designed focusing orifice could separate particles down to 3±1 nm. Tan’s group is also investigating the mechanisms of separation of nanoparticles from air.

Conventional filtration theory states that diffusion dominates the behaviour of submicron particles, and the filtration efficiency increases inversely with the particle size. In reality, there should be a critical size from which filtration efficiency drops with the decrease of particle diameter; otherwise, gas molecules (extremely small particles) should have been captured by filters with no separation of gas and particles.

Theoretical analyses showed that the critical size is between 1 and 10 nm, due to the thermal rebound effect. Tan’s basic research in filtration is critical to the development of technologies for effective capture of airborne nanoparticles that are smaller than 10 nanometers. Availability of these technologies will enable the protection of atmospheric environmental and occupation health from nanoparticles, and the corresponding environment protection policies and standards.

Tan’s group also has expertise in catalytic hydrothermal conversion of biomass to biofuels & valuable chemicals. A new process based on aqueous-phase dehydration/hydrogenation (APD/H) has been developed aiming at liquid alkanes (C7-9), which are the main components of fossil gasoline, from cellulose in one single batch reactor without the consumption of external hydrogen (H2). In the liquid water phase, cellulose can be converted to an alkane precursor, such as 5-(hydroxymethyl)furfural (HMF), by hydrothermal decomposition. 5-HMF itself is a valuable pharmaceutical product, and it can be extracted from the liquid products or converted into alkanes by reacting with in situ H2 through APD/H.

In 2004, his PhD research work was awarded First Place Graduate Student Research Award in PhD Category from ASAE. In 2009, he was presented with the Schulich School of Engineering Eearly Research Award.

Tan has been teaching both undergraduate and graduate courses. He has been presented with Teaching Excellence twice at the University of Calgary: SSE's Departmental Teaching Award (Jan 2010) and The UofC Student Union's Teaching Excellence Award Honorable Mention (2007). In 2003, he was honored in the "Incomplete Lists of Teachers Ranked as Excellent", from the Centre for Teaching Excellence, University of Illinois at Urbana-Champaign (USA).


  • PhD, Bioenvironmental Engineering, University of Illinois, 2004
  • MSc, Thermal Engineering, Tsinghua University, 1999
  • BSc, Thermal Engineering, Tsinghua University, 1996

Zhongchao Tan

    University of Waterloo