黄浦江水中卤乙酸前体物的荧光光谱分析

Fluorescence Exciationemission Matrix Analysis of HAAs Precursor in Huangpu River Water

摘要:

使用三维荧光光谱(3DEEMs)分析黄浦江水中的有机物特性.结果表明,黄浦江水3DEEMs包含2个类蛋白峰(T峰)和1个类腐植酸峰(A峰),其中类蛋白质峰较高,说明污染较为严重.类腐植酸峰沿着水厂工艺流程的变化与传统指标高锰酸钾指数ρCODMn、紫外吸收AUV 254和溶解性有机碳ρDOC的变化一致.卤乙酸生成潜能实验表明,随着氯化反应程度的增加(增加反应时间、从氯胺转到自由氯消毒以及增大自由氯的投加量),三维荧光光谱特征值减少,相对应的卤乙酸(HAAs)生成量增加.投加溴离子后,氧化能力随自由氯含量降低而降低,而取代能力随次溴酸增加而增加,所以反应后水体中残余有机物的三维荧光光谱特征值增加,而HAAs先升后降.三维荧光光谱可作为水中溶解性有机物的补充指标,更全面反映水中有机物的变化.

Abstract:

Three dimesional excitationemission matrix fluroscence spectroscopy (3DEEMs) was used to analyze natural organic matters in raw water from Huangpu River.The 3DEEMs of raw water contain two proteinlike peaks (T)and one humiclike peak(A).The relative high intensity of peak T indicates a heavy pollution.The variation of peak A along with the treatment processes is similar with traditional indexes,such as CODMn,UV254 and total organic carbon (TOC).All measures,which enhanced chlorination such as increasing chlorination reaction time,replacing monochloramine with free chlorine and increasing chlorine dosage,decreased fluorescence characteristic values and consequently increased HAAs amount.By adding bromide ions,oxidation capacity lowered as free chlorine concentration decreased,but halogenation capacity increased because free bromine concentration increased,which led to a buildup of fluorescence characteristic values,as well as a first going up followed by a decline of HAAs amount.3DEEMs is a promising supplement index to better characterize the variation of dissolved organic matters in water.