水质指纹携带了水样的发光有机物组成的信息, 可以作为一种新方法来弥补COD和TOC等传统理化参数只能给出有机物总量信息的不足。 印染废水是我国水量最大的工业废水之一, 其特点是水量大、 污染重, 含有大量发光有机物质, 且难降解, 其对自然水体的危害尤为明显。 对我国某印染废水处理厂废水进行了连续采样, 对水样的水质指纹特征进行了研究。 结果表明, 该厂印染废水水质指纹特征比较明显, 水质指纹上主要有激发波长/发射波长分别为230/340和280/310 nm左右的两个峰, 其中230/340 nm处的强度最强, 280/310 nm处的强度次之, 各峰波长和强度比较稳定。 该印染废水的两个水纹峰的峰强呈正相关关系, 线性相关系数为0.910 8, 斜率为1.506。 激发波长/发射波长为280/310 nm的强度与230/340 nm强度比值的平均值为0.777, 范围为0.712～0.829。 对该印染污水水质指纹的可能荧光物质进行分析, 结果表明生活污水和苯胺类物质的水质指纹与该印染污水的水质指纹不同, 而几种大量使用的染料的水质指纹与该印染污水的水质指纹大致相同, 所以染料的大量使用可能是导致印染废水产生上述典型水质指纹特征的主要原因。 水质指纹可以用于水体水质预警。

Aqueous fingerprint has an advantage to represent the organic components of water samples as compared to traditional parameters such as chemical oxygen demand (COD) and total organic carbon (TOC). Printing and dyeing wastewater is one of the major types of industrial wastewater in China. It is of huge volume and heavy pollution, containing large numbers of luminescent components and being difficult to be degraded. In this study the aqueous fingerprint of printing and dyeing wastewater was investigated with the fluorescent spectrometry. The experimental results showed that there existed two peaks in the aqueous fingerprint of the printing and dyeing wastewater, locating at the excitation/emission wavelength around 230/340 nm and 280/310 nm respectively. The intensity of the excitation/emission wavelength at 230/340 nm was higher than that of 280/310 nm. The locations and intensities of peaks varied within small range. The intensities of the two peaks linearly correlated with coefficient of 0.910 8 and slope of 1.506. The intensity ratio of Peak at 280/310 nm to Peak at 230/340 nm averagely was 0.777, ranging between 0.712 and 0.829. It was found that the aqueous fingerprints of sewage and aniline compounds were significantly different from that of the printing and dyeing wastewater, but the aqueous fingerprints of several types of widely-used dye were similar to that of the printing and dyeing wastewater. Thus dye may be the main luminescent components in the wastewater. The aqueous fingerprint can be used as a novel tool of early warning of waterbodies.