Yiu Fai Tsang
The Hong Kong Institute of Education, Hong Kong
Dr. Yiu Fai (Chris) Tsang is an Assistant Professor in the Department of Science and Environmental Studies (SES) at the Hong Kong Institute of Education (HKIEd). He received his PhD from the Hong Kong Polytechnic University (PolyU). He further worked as a Visiting Scholar in the Department of Agricultural and Biological Engineering at the University of Illinois at Urbana-Champaign (UIUC). Prior to joining HKIEd, he was a Programme Coordinator of BSc (Hons) in Applied Science (Energy and Environment) at Vocational Training Council and a Research Fellow in the Department of Civil and Environmental Engineering at PolyU. He is currently an Associate Editor for RSC Advances (Royal Society of Chemistry) and serves as Advisory Committee Member/Honorary Advisor in several non-governmental organizations and green groups. He has been also appointed as Adjunct Professor in Guizhou Academy of Sciences, China.
Traditional water treatment processes cannot provide an effective removal of geosmin and MIB (Bruce et al., 2002). The application of activated carbon is one of the most commonly used treatment processes, however, the presence of natural organic materials can result in competition for adsorption sites, leading to decreases in geosmin and MIB removal (Ho et al., 2002). Larger dose of activated carbon is required for effective removal. A cost effective and practical method for the treatment of MIB and geosmin is therefore required. One of the effective processes is ozone-enhanced biofiltration (Bridget et al., 2009). Locating biofilters downstream of ozonation improves dissolved organic carbon removal and can aid in producing biologically stable water such that the potential for biofilm regrowth in water distribution systems is minimised. Field operational data suggests that ozone can oxide 10% to more than 90% of the Geosmin and MIB, and typical biofiltration can reach 50% removal only (Metz et al., 2006; Yang et al., 2007). Several factors may significantly influence geosmin and MIB removal in biofilters, including such as seasonal water temperature variations, filter media (GAC, EC, or sand), empty bed contact time (Liu et al., 2001). Some investigations demonstrated that temperature and media are the most important factors affecting drinking water biofiltration processes (Urfer, 1998) and may influence the removal of compounds such as geosmin and MIB. In this study, the major factors affecting the biological degradation of geosmin and MIB removal in biofilters, including (i) initial concentration, (ii) empty bed contact time, (iii) ozone dosage, and (iv) media, were examined.