Applying the Method of Fluorescence Spectroscopy to Study Dissolved Organic Matter in Waters of the Moskva River

Abstract

The applicability of fluorescence spectroscopy for studying the dissolved organic matter in the Moskva River has been shown. The most typical surface water fluorophores—humic and fulvic acids and protein substances—have been revealed in the studied water samples. The fluorescence intensity depends on the sampling site and indicates the contamination rate. The dynamics of the composition and fluorescence parameters of river waters varies with respect to the sampling period. While the concentration of dissolved organic matter and chemical oxygen demand increases from October until November, specific ultraviolet absorbance, biological oxygen demand, and fluorescence of humic acids significantly decrease. The observed dynamics does not depend on the sampling site, which confirms the effect of climatic conditions. Statistically significant (p < 0.05) correlations between spectral and chemical parameters of water contamination have been revealed. Fluorescence intensity, tryptophan-containing organic substances, fulvic acids, and values of biological index correlate (r = 0.63–0.92) with the content of ammonium and phosphate ions. The fluorescent index A may be used to determine the zone of the effect of anthropogenic biological impurities on the status of waters of the Moskva River.