为探明饮用水处理中ClO2预氧化高藻水过程DOM三维荧光特征的变化规律, 采用三维荧光光谱研究了ClO2预氧化过程藻类胞内外溶解性有机物组分变化, 并通过荧光体积积分法定量分析了DOM组分变化规律。 结果表明, 高含铜绿微囊藻原水的IOM荧光特征光谱有4个较为明显的荧光峰, 主要为类酪氨酸类物质与类色氨酸类等代表的蛋白类荧光峰、 腐殖酸类荧光峰、 富里酸类荧光峰及可溶性微生物代谢产物峰, 占比分别为14.52%, 48.27%, 16.22%和20.99%; 而EOM荧光特征光谱只有1个较为明显的荧光峰, 主要为可溶性微生物代谢产物, 占比为63.14%, 藻类有机物主要含在IOM中。 在经过0.5 mg·L-1的ClO2预氧化后, 3 min内叶绿素a的去除率达到73.58%, IOM中以氨基酸、 蛋白质及富里酸为代表的Ⅰ区、 Ⅱ区及Ⅲ区物质释放至胞外并被ClO2氧化为类腐殖质。 随着ClO2预氧化的进行, 藻细胞不断破裂, IOM释放到水中, 造成胞外EOM总响应值的提高, 即EOM总响应值增加了54.89%, 而IOM总响应值降低了51.50%。 因此, 饮用水处理高藻水时应该特别注意藻细胞IOM的释放, 应选用合适氧化时间, 在保证除藻效果良好的情况下, 尽可能减少IOM的释放; 该研究将为饮用水预氧化除藻及藻类消毒副产物的控制提供一定的理论基础和科学依据。

In order to explore the three-dimensional fluorescence characteristics of DOM during the preoxidation process of high algae-laden water with ClO2, the three-dimensional fluorescence spectroscopy technique was used to qualitatively investigate the changes of the composition of intracellular and extracellular organic matters in algae, and the quantitative analysis of changes in DOM composition was performed by fluorescence regional integral method. The results showed that the IOM fluorescence spectrum of the raw water containing high concentration of Microcystis aeruginosa had four distinct fluorescence peaks, which were protein fluorescence peaks, humic acid fluorescence peaks, fulvic acid fluorescence peaks, and soluble microbial metabolites peaks that were represented mainly by tyrosine-like substances and tryptophan-like proteins with 14.52%, 48.27%, 16.22% and 20.99%, respectively. While the EOM fluorescence spectrum had only one significant fluorescence peak with 63.14% that was mainly behalf of soluble microbial metabolites, and algae organics were mainly contained in IOM. The removal rate of chlorophyll a reached to 73.58% within 3 minafter preoxidation process with 0.5 mg·L-1 ClO2. During this process, substances in the regions Ⅰ, Ⅱ, and Ⅲ represented by amino acids, proteins, and fulvic acid respectively were released to outside of the algal cell membrane, and then were oxidized to non-biological humus by ClO2. Owing to algal cells burst constantly, IOM was released into the water during the ClO2 preoxidation process, leading to the results that the total response value of EOM increased by 54.89% within 3 min and the total response value of IOM decreased by 51.50%. Therefore, the drinking water treatment of high algae-laden water should pay close attention to the release of IOM from the algae cells. The appropriate preoxidation time and dosage should be properly selected, and the release of IOM should be reduced as much as possible under the premise of effective algae removal.This study will provide further theoretical and scientific basis for the removal of algae by pre-oxidation in drinking water and the control of algae disinfection by-products.