Analyses on cause for odor and potential problems in water source during odor episode event in Wuxi
无锡市饮用水嗅味突发事件致嗅原因及潜在问题分析

An odor episode event, occurring in Wuxi city from the end of May to early June, 2007, were investigated. Using flavor profile analysis (FPA) and sensory GC, the odorous compounds of polluted black agglomeration, raw water and finished water were identified. Meanwhile, main odorous compounds were quantified using GC/MS, and microcystins content and biological genotoxicity were also determined. It showed that the main odorous compounds were some sulfide compounds such as dimethyl trisulfide, coming from organisms decomposition, and concentration of dimethyl trisulfide were 11399 ng·L-1 high in the black agglomeration sampled in 4 June. Some cyanobacterial metabolites like MIB were also detected but not the main odorous compound, which was covered by fishy and septic odor caused by sulfide compounds like dimethyl trisulfide. Microcystins content in raw water sampled in 4 June and 8 June was much lower than the standard that was recently implemented in Standards for Drinking Water Quality, and the biological genotoxicity determined by umu test was very low.