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Biography
Prof Lee grew up in Hong Kong and obtained his BSc, MSc and PhD degrees in Civil Engineering from the Massachusetts Institute of Technology (1969-1977). He joined The University of Hong Kong (HKU) in 1980, where he rose to Redmond Chair Professor of Civil Engineering in 1995. At HKU, he was Dean of Engineering from 2000 to 2003, and Pro-Vice-Chancellor and Vice-President (Staffing) from 2004-2010.  Prof Lee has been Vice-President for Research and Graduate Studies at the Hong Kong University of Science and Technology (HKUST) since November 2010.
Prof Lee is the Chief Editor of the Journal of Hydro-environment Research and past Vice-President of the International Association for Hydro-environment Engineering and Research - IAHR (2007-2011). He is the recipient of the 2013 Karl Emil Hilgard Hydraulic Prize of ASCE, and also the first Asia-based academic to receive the ASCE Hunter Rouse Hydraulic Engineering Award (2009). In 2010 he was bestowed a State Scientific and Technological Progress Award (Second Class) by the Chinese State Council. Prof Lee has served as expert consultant on numerous hydro-environmental projects and on many international advisory bodies. He is a Fellow of the Royal Academy of Engineering, United Kingdom and the Hong Kong Academy of Engineering Sciences. Prof Lee is a member of the Shanghai Committee of the Chinese People’s Political Consultative Conference (CPPCC). 
 
 
Field Experiments on the Mixing of a Dense Chlorine Jet for
Disinfection of Primary Treated Sewage
 
 
Abstract:  The Hong Kong Harbour Area Treatment Scheme (HATS) consists of a 24 km long deep tunnel sewerage system that collects and conveys sewage from the urban areas of Hong Kong to a centralized sewage treatment plant at Stonecutters Island.  In the recently commissioned Stage 2A scheme, a sewage flow of 1.8 million m3/d receives Chemically Enhanced Primary Treatment (CEPT) followed by discharge through a 1.2 km outfall in the western Victoria Harbour.  In order to protect the nearby marine beaches, chlorination facilities have been put into operation to provide disinfection to the treated sewage.  Sodium hypochlorite solution is injected at high concentrations in the form of multiple dense jets (relative density 1.2) into the sewage cross flow.  The disinfection performance and the sewage effluent quality are closely related to the mixing of the chlorine jet with the sewage and the complex chemical consumption of chlorine.  
This paper presents recent experiments on the discharge of a chlorine jet into CEPT treated sewage in a 1:2 schematic sectional physical scale model of the chlorine dosing unit and flow distribution chamber. The model is constructed in situ at the treatment works.  Experiments are performed with treated sewage directly drawn from the sedimentation tanks. The distribution of total residual chlorine, nutrient and E.coli concentrations at key locations downstream of the jet are compared with numerical predictions and discussed in relation to the predicted impact on beach water quality.