Drinking water aromaticity and treatability is predicted by dissolved organic matter fluorescence

Climatic and cave settings influence on drip water fluorescent organic matter with implications for fluorescent laminations in stalagmites

“…Yet, the C5 emission peak wavelength from our model (Ex/Em = 256/455 nm and Ex/Em = 370/455 nm) is slightly lower than expected for this peak in the literature (Ex/Em = 250/470–504 nm and Ex/Em = 320–365/470–504 nm), coined as Humic C+ (Coble et al, 2014). Our C5 peak might contain some Humic C+, but overall, because it is much weaker than expected (based on studies investigating active carbon adsorption [Philibert et al, 2022]), we hypothesize that a significant fraction of the Humic C + component has been preferentially adsorbed on the bedrock and is subsequently absent in the drip water PARAFAC model presented here. Component C3, shifted towards shorter peak wavelengths, aligns well with the peak Humic M (Coble et al, 2014).…”

“…Prior studies of fluorescence in groundwater and cave drip waters have indicated dominant peaks in humic-like components, with seasonally variable peak wavelengths (Baker and Genty, 1999). Compared to overlying soil-water fluorescence, spectra of drip water are likely to be blue-shifted (i.e., fluorescent peaks are shifted towards shorter wavelengths) because of the preferential adsorption of some humic-like DOM onto the bedrock (Jin and Zimmerman, 2010; Philibert et al, 2022) and continued microbial degradation. Microbial (“protein-like”) fluorescence that is produced in the soil or karst (Xia et al, 2022) or related to livestock above the cave (Mudarra et al, 2011) also has been suggested to be present in cave waters (Birdwell and Engel, 2010).…”

Substances released during the decomposition of Vallisneria natans and Thalia dealbata

“…According to the 4-component model, PARAFAC analysis was performed to distinguish fluorescence EEMs into their underlying chemical components (Figure S5), and the component spectra were interpreted using the existing literature from the OpenFluor database ( Murphy et al., 2013 ), with a minimum similarity score (congruence coefficient) of 0.90 ( Stedmon and Bro, 2008 ). Component C1 corresponds to amino-acid-like ( Kim et al., 2020 ), and C3 corresponds to microbially derived humics ( Philibert et al., 2022 ).…”

Direct Measurement of Organic Micropollutants in Water and Wastewater Using Fluorescence Spectroscopy

“…In the current study, a novel approach was used to capture interfering DOM fluorescence in natural samples compared to wastewater samples. Recent studies suggest that the underlying fluorescence components in natural river and lake sources around the world are highly similar ,, suggesting an opportunity to use a pre-existing PARAFAC model to capture natural DOM signals. An a priori model (“NW model”) was chosen with spectra matching the Swedish “Kungalv5” model of Moona et al which itself closely matches the global SUEZ8 model of Philibert et al Reusing a model with broad applicability circumvents one of the main drawbacks of the traditional PARAFAC approach, i.e., building a reliable PARAFAC model.…”

“…A novel way to surmount this challenge is by leveraging recent advances in the field of DOM fluorescence spectroscopy. Specifically, recent studies show that fluorescent components determined by parallel factor analysis (PARAFAC) are highly conserved across diverse aquatic environments. − This means that after a sample is collected and analyzed by fluorescence EEM spectroscopy, the data can be passed through automatic or semiautomatic postprocessing algorithms to subtract DOM fluorescence and quantitatively recover the concentration of fluorescent OMPs despite varying background water matrices.…”