Optical Properties of Dissolved Organic Matter in Urban Fountains

World Multidisciplinary Earth Sciences Symposium

Parszuto, Katarzyna^1 ; Tandyrak, Renata^1 ; Augustyniak, Renata^1 ; Grochowska, Jolanta^1 ; Lopata, Michal^1 ; Plachta, Anna^1 ; Neugebauer, MacIej^2

University of Warmia and Mazury, Faculty of Environmental Sciences, Prawocheñskiego 1, Olsztyn

10-720, Poland^1

University of Warmia and Mazury, Faculty of Technical Sciences, Oczapowskiego 11, Olsztyn

10-736, Poland^2

关键词: Allochthonous organic matter;    Anthropogenic pressures;    Dissolved organic carbon;    Dissolved organic matters;    High molecular weight;    Kruskal-Wallis tests;    Primary production;    UV spectrophotometry;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/221/1/012112/pdf
DOI  :  10.1088/1755-1315/221/1/012112

来源: IOP

【 摘 要 】

Optical properties of dissolved organic carbon compounds (DOC) in selected fountains in Olsztyn (Poland) were investigated. The DOC fraction was isolated by using a membrane filter (Sartorius, pore size 0.45 μm). The amount of absorption for the DOC fraction was determined using the UV spectrophotometry method (UV range) at wavelength: 203 nm (A203), 250 nm (A250), 254 nm (A254) and 365 nm (A365). Then the absorption ratios were determined: A250/A365 and A254/A203. The aim of the study was to determine the contribution of macromolecules (hardly biodegradable, having an aromatic character) in the fraction of DOC. The variability of DOC compounds in the water of fountains was investigated depending on the water supply method (also subjected to disinfection) and depending on the period of research (season of the year) or the impact of the environment. It was shown that the average A250/A365 values were three times lower in fountains not subjected to disinfection than in artificial fountains. The A254/A203 parameter was on average several times lower in artificial fountains where the water was chlorinated. The Kruskal-Wallis test confirmed that the differences between the artificial objects and the other two in the average values of A250/A365 and A254/A203 ratios are significant. The values of these quotients indicate that natural and semi-natural fountains are characterized by a high share of aromatic compounds with high molecular weight. For artificial objects, the effect of the study period on differences in average values of A250/A365 and A254/A203 was not confirmed. The U Mann-Whitney test showed that there are differences in the mean values of A254/A203 between the semi-natural and natural fountain, and the changes of A250/A365 in these fountains are related to the date of sampling. After examining the influence of the catchment and anthropogenic pressure, it was found that in the semi-natural fountain, the quality of the DOC fraction changed due to the supply of allochthonous organic matter (leaves, waterfowl and its feeding by resting people). In the case of a fountain on a natural reservoir, the relatively high primary production and allochthonous inflow of DOC had significant influence on the DOC character (leaching from slopes with rainfall, groundbaits using by anglers).