[Aqueous Fingerprint of Printing and Dyeing Wastewater]

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.