Optical measurements like fluorescence spectroscopy and photometry have proven to be a reliable, inexpensive and fast technique for monitoring of contaminated urban waters both from industrial and domestic wastewater. The changes of absorbance and fluorescence intensity of river water samples during different storage conditions were studied. The present research was carried out in the region of Saint Petersburg (Russia), in particular Kapralijev stream was investigated, a tributary of Okhta river, which is the largest right tributary of Neva river and one of the most polluted river in Saint Petersburg region. Furthermore, Kapralijev is polluted by untreated municipal wastewater discharge from residential buildings of the Novoye Devyatkino neighborhood. Moreover, this fact was confirmed by the results of the analysis performed in laboratory. The water quality was obtained by measuring the concentration of total organic carbon (TOC), total inorganic carbon (IC), total nitrogen (TN), ammonium NH4+, specific electrical conductivity, and by obtaining fluorescence and absorbance spectra, in the UV-Vis range. Finally it was established how these parameters change when storing water at room temperature (20°C) and in the fridge (8°C). It is shown in the work that in the spectra of absorbance of water there were no strong qualitative differences between polluted and unpolluted water. During storage, the absorbance of all samples decreased (up to 40% in 12 days, up to 60% in 48 days). Fluorescence spectra showed qualitative differences between polluted and unpolluted water. Polluted water is characterized by increased values of fluorescence intensity (I) both in the protein-like (up to 200%) and in the humic-like region (up to 50%). In particular, high values of fluorescence intensity of tryptophan-like peak compared to a background situation is proof of municipal water contamination. When stored in contaminated samples, I decreased in the protein region and I increased in the humic-like region, more pronounced at 20°C. The best parameters for qualitative detection of water pollution were I230,350, I230,370, I267, 350. In addition, the data showed no significant changes between corrected and uncorrected sample due to Inner filter effect (IFE). Since there is a lack of studies in Russia regarding the monitoring of urban river waters, this study can be an example to do further investigations on Russian urban rivers using optical methods to detect rapidly the pollution.
Metodi ottici come la spettroscopia a fluorescenza e la fotometria si sono dimostrati tecniche affidabili, economiche e veloci per il monitoraggio delle acque urbane contaminate sia da acque reflue industriali che domestiche. Sono stati studiati i cambiamenti di assorbanza e intensità di fluorescenza dei campioni di acqua di fiume durante le diverse condizioni di conservazione. La presente ricerca è stata condotta nella regione di San Pietroburgo (Russia), in particolare è stato studiato il torrente Kapralijev, un affluente del fiume Okhta, il più grande affluente di destra del fiume Neva. Kapralijev è inquinato dallo scarico di acque reflue domestiche non trattate degli edifici residenziali del quartiere Novoye Devyatkino. Questo fatto è stato confermato dai risultati delle analisi eseguite in laboratorio. Le caratteristiche di qualità dell’acqua sono state ottenute misurando la concentrazione di carbonio organico totale (TOC), carbonio inorganico totale (IC), azoto totale (TN), ammonio NH4+, conducibilità elettrica specifica e ottenendo spettri di fluorescenza e assorbanza, nell'intervallo UV-Vis. Si è studiato come questi parametri cambiano quando si conserva l'acqua a temperatura ambiente (20°C) e in frigorifero (8°C). È stato dimostrato che negli spettri di assorbanza dell'acqua non c'erano forti differenze qualitative tra acqua inquinata e non inquinata. Durante la conservazione, l'assorbanza di tutti i campioni è diminuita (fino al 40% in 12 giorni, fino al 60% in 48 giorni). Gli spettri di fluorescenza, invece, hanno mostrato differenze qualitative tra acqua inquinata e non inquinata. L'acqua inquinata è caratterizzata da un aumento dei valori di intensità della fluorescenza (I) sia nella banda proteica (fino al 200%) che nella banda umica (fino al 50%). In particolare, valori elevati di intensità di fluorescenza al picco del triptofano rispetto a una situazione di fondo sono la prova di contaminazione da refluo domestico. Se conservato in campioni contaminati, I diminuisce nella banda proteica e aumenta nella banda umica. Tale diminuzione è più pronunciata a 20°C. I migliori parametri per il rilevamento qualitativo dell'inquinamento idrico risultano I230,350, I230,370, I267, 350. In aggiunta, i dati non hanno mostrato cambiamenti significativi tra campione corretto e non corretto per “Inner filter effect” (IFE). Poiché in Russia scarseggiano studi sul monitoraggio delle acque fluviali urbane, questo studio può essere un esempio per fare ulteriori indagini sui fiumi urbani russi utilizzando metodi ottici per rilevare rapidamente l'inquinamento.
Analisi della qualità delle acque superficiali attraverso la misura della variazione dei parametri fluorimetrici e fotometrici : analisi di caso di studio in Russia
Marveggio, Pietro
2020/2021
Abstract
Optical measurements like fluorescence spectroscopy and photometry have proven to be a reliable, inexpensive and fast technique for monitoring of contaminated urban waters both from industrial and domestic wastewater. The changes of absorbance and fluorescence intensity of river water samples during different storage conditions were studied. The present research was carried out in the region of Saint Petersburg (Russia), in particular Kapralijev stream was investigated, a tributary of Okhta river, which is the largest right tributary of Neva river and one of the most polluted river in Saint Petersburg region. Furthermore, Kapralijev is polluted by untreated municipal wastewater discharge from residential buildings of the Novoye Devyatkino neighborhood. Moreover, this fact was confirmed by the results of the analysis performed in laboratory. The water quality was obtained by measuring the concentration of total organic carbon (TOC), total inorganic carbon (IC), total nitrogen (TN), ammonium NH4+, specific electrical conductivity, and by obtaining fluorescence and absorbance spectra, in the UV-Vis range. Finally it was established how these parameters change when storing water at room temperature (20°C) and in the fridge (8°C). It is shown in the work that in the spectra of absorbance of water there were no strong qualitative differences between polluted and unpolluted water. During storage, the absorbance of all samples decreased (up to 40% in 12 days, up to 60% in 48 days). Fluorescence spectra showed qualitative differences between polluted and unpolluted water. Polluted water is characterized by increased values of fluorescence intensity (I) both in the protein-like (up to 200%) and in the humic-like region (up to 50%). In particular, high values of fluorescence intensity of tryptophan-like peak compared to a background situation is proof of municipal water contamination. When stored in contaminated samples, I decreased in the protein region and I increased in the humic-like region, more pronounced at 20°C. The best parameters for qualitative detection of water pollution were I230,350, I230,370, I267, 350. In addition, the data showed no significant changes between corrected and uncorrected sample due to Inner filter effect (IFE). Since there is a lack of studies in Russia regarding the monitoring of urban river waters, this study can be an example to do further investigations on Russian urban rivers using optical methods to detect rapidly the pollution.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/177368