Prof. X. Z. Li has been a full-time staff in the CSE Department of The Hong Kong Polytechnic University since 1993.  Before joining PolyU, he spent seven years in research and consulting engineering in water and wastewater treatment and odour pollution control fields in the University of New South Wales, Australia.  His major research and consultancy interests include physico-chemical and biological treatment of trade and industrial wastewaters with outstanding achievement in the area of the photocatalytic oxidation techniques. His works have resulted in the publication of over 100 articles in reputable journals and international conference proceedings. He is the editorial board member of China Water and Wastewater and also Urban Environment and Urban Ecology, and the regular reviewer for a number of renowned international journals.  Prof. Li is also specialized in the field of odour sampling, measurement and control techniques. In 1995, he established the first odour research laboratory in HK to lead the odour research activities in this region as a local expert and also has been the advisor for China National Laboratory for Odour Pollution Control since 1999.