根据2014年112月东湖3个湖区（水果湖、郭郑湖及汤菱湖）中9种溶解态异味物质（DMS、DMDS、DMTS、β-cyclocitral、β-ionone、MIB、GEO、IBMP 和 IPMP）的月间采样结果，对异味化合物浓度之间的相关性及其与东湖水体中主要环境因子的相关关系进行了分析.研究发现9种异味物质浓度整体水平在夏、秋季相对冬、春季较高，其中 DMS、DMTS、β-cyclocitral、β-ionone 的月平均浓度较高，且在夏季均超出嗅味阈值，其他几种异味物质浓度检出较低，对东湖的异味强度影响较小.低浓度β-cyclocitral 及β-ionone 具有烟草或芳香味，DMS 与 DMTS 具有腐臭味，因此 DMS 及 DMTS 为东湖异味的主要致嗅物质.从异味物质空间分布来看，郭郑湖区的 DMS、DMDS、β-cyclocitral 及β-ionone 年平均浓度均低于其他两个湖区，综合该湖区中相对较低的年平均总氮（TN）和叶绿素 a（Chl.a）浓度以及受人类活动影响程度较低的情况，该湖区的异味问题要轻于水果湖及汤菱湖区.此外，研究发现 DMTS、β-cyclocitral 和β-ionone 浓度与 Chl.a 浓度均呈显著正相关，DMDS 及 DMTS 浓度与 TN 浓度呈显著正相关，DMS 及β-cyclocitral 浓度与溶解氧浓度呈显著负相关，表明由于大量藻类快速腐败导致的水体含氧量下降可能会对水体异味产生重要影响.为防止东湖水体恶臭的发生，对藻类进行控制尤为重要.%Nine dissolved taste and odor compounds ( T & O), namely DMS, DMDS, DMTS, β-cyclocitral, β-ionone, MIB, GEO, IBMP and IPMP were investigated in three water areas (Lake Shuiguo, Lake Guozheng and Lake Tangling) of Lake Donghu monthly in 2014. According to the changes of the nine T & O compounds and related environmental factors of each month, relation-ships of these compounds as well as the relationships with environmental factors were analyzed in this study. It was found that the concentrations of the nine T & O compounds were higher in the summer and fall than in the winter and spring. The seasonal concen-trations of DMS, DMDS, DMTS, β-cyclocitral and β-ionone were high and their concentrations all surpassed OTC ( Over The Count) in the summer, while other T & O compounds made little contributions to the odor problems of Lake Donghu because of their relative low concentrations. Low concentrations of β-cyclocitral and β-ionone can make water smell flavoury while DMS and DMTS contribute fusty smelling, making the main odors that led Lake Donghu smelly. As for the distributions of odors, the yearly concentrations of DMS, DMDS, β-cyclocitral and β-ionone in Lake Guozheng were all lower than that of the other two areas in Lake Donghu. Based on the relative low concentrations of total nitrogen and chlorophyll-a(Chl.a) and the relative low influence of human activities on Lake Guozheng, odor problem in this area is lighter than that of Lake Shuiguo and Lake Tangling. Meanwhile, there were significantly positive correlations between concentrations of Chl.a and the three taste and odor compounds (DMTS, β-cy-clocitral and β-ionone), as well as between concentrations of total nitrogen and the two odors (DMDS and DMTS) in the study. Besides, negative correlations were presented in concentration of dissolved oxygen ( DO ) with DMS and β-cyclocitral, respectively, indicating that low DO concentration induced by decayed algae could aggravate odor problems. To manage the occur-rences of taste and odor events in Lake Donghu, it is critical to control the growth of algae.
展开▼
