杭州市水源中藻类衍生嗅味污染及其释放特征

Odorous contaminants in drinking water source of Hangzhou and releasing characters from algae

分别采用显微镜鉴别、计数法和固相微萃取-气质联用(SPME-GC/MS)分析方法对杭州市区饮水水源中藻类构成和部分藻类衍生嗅味污染物的分布特征进行调查,并展开主要嗅味污染物的藻源性分析.结果表明,水源水中藻类以硅藻和绿藻为构成主体,伴有季节性变化特征.β-环柠檬醛(β-cyclocitral)是最易检出嗅味污染物,最高检出质量浓度51.4ng/L,其他嗅味污染物2-甲基异茨醇(2-MIB),二甲基三硫醚(DMTS)和土臭素(GSM)等检出质量浓度较低,但峰值浓度已超出嗅阈值.β-cyclocitral的藻源性研究结果表明,铜绿微囊藻释放的嗅味污染物以β-cyclocitral为主,另含有少量的DMTS和β-紫罗兰酮(β-ionone).藻细胞质量浓度为106 L-1时,水中β-cyclocitral质量浓度最高可达44.0ng/L,通过细胞破碎测定胞内质量浓度表征释放潜能,最高可达174.8ng/L.

Identification and counting by microscope together with solid phase miroextration-gas chromatography （SPME-GC/MS） were employed to investigate distribution characteristic of algae, odorous contaminants probably derived by algae in water source of Hangzhou district followed by origin identification of primary odorous contaminant. Results show that bacillariophyta and chlorophyta account for the dominant algae and vary along with seasons during the investigation period. β-Cyclocitral is the most frequently detected chemical than others with peak value of 51.4ng/L. Other odorous chemicals such as 2-methylisoborneol（2-MIB）, dimethyl trisulfide and gesomin are detected occasionally, however peak values are beyond their odor threshold. Algae origin research for β-cyclocitral was carried out and results show that Microcystis aeruginosa can produce several odorous contaminants including a large quantity of β-cyclocitral, while a small of β-ionone and dimethyl trisulfide. When algal concentration fixed at 10^6 L^-1 , highest released concentration of β-cyclocitral is 44.0 ng/L in continuous ten-days detection, and the release potential is 174.8 ng/L through the intracellular β-cyclocitral transferring into water from break algal cells.