天津某水库2-MIB季节性变化规律及来源分析

Seasonal Variation Rule and Source Analysis of 2-MIB in a Reservoir of Tianjin

针对天津某水库2-甲基异莰醇(2-MIB)导致的饮用水源嗅味问题,分析了2019年3月—2020年2月2-MIB浓度的变化及优势藻的演变情况。结果表明,2-MIB在6月初、8月中旬和11月中旬出现3次峰值;2-MIB在夏季和秋初主要以结合态形式存在,而在秋末和冬季主要以溶解态形式存在;水库水中优势藻逐渐由春季的硅藻和绿藻演变为夏秋季的蓝藻,再演变为冬季的硅藻和隐藻,藻类数量呈现先升高后降低的变化趋势。相关性分析结果表明,水库水中溶解态2-MIB与假鱼腥藻的占比有极为显著的正相关性,假鱼腥藻与铜绿微囊藻具有极为显著的负相关性,由此可以推断水库水中2-MIB主要是由假鱼腥藻代谢产生的。

Aiming at the taste and odor problem in drinking water source caused by 2-methylisoborneol(2-MIB)in a reservoir of Tianjin,variation in 2-MIB concentration and evolution of dominant algae in the reservoir from March 2019 to February 2020 were analyzed.The 2-MIB had three peaks in early June,mid-August and mid-November.2-MIB mainly existed as a bound state in summer and early autumn,while it mainly existed as a dissolved state in late autumn and winter.Meanwhile,the dominant algae in the reservoir gradually evolved from Bacillariophyta and Chlorophyta in spring to Cyanophyta in summer and autumn,and then to Bacillariophyta and Cryptophyta in winter.The quantity of algae increased firstly and then decreased during these periods.The results of correlation analysis showed that there was a significant positive correlation between the concentration of dissolved 2-MIB in the reservoir and the proportion of Pseudanabaena sp.,and the latter had an extremely significant negative correlation with the proportion of Microcystis aeruginosa.It thus could be inferred that 2-MIB was mainly produced by metabolism of Pseudanabaena sp.in the reservoir.