TY - JOUR

T1 - Characterisation of dissolved organic matter fluorescence properties by PARAFAC analysis and thermal quenching

AU - Carstea, Elfrida M.

AU - Baker, Andy

AU - Bieroza, Magdalena

AU - Reynolds, Darren M.

AU - Bridgeman, John

PY - 2014/9/15

Y1 - 2014/9/15

N2 - The fluorescence intensity of dissolved organic matter (DOM) in aqueous samples is known to be highly influenced by temperature. Although several studies have demonstrated the effect of thermal quenching on the fluorescence of DOM, no research has been undertaken to assess the effects of temperature by combining fluorescence excitation – emission matrices (EEM) and parallel factor analysis (PARAFAC) modelling. This study further extends previous research on thermal quenching by evaluating the impact of temperature on the fluorescence of DOM from a wide range of environmental samples, in the range 20 °C – 0 °C. Fluorescence intensity increased linearly with respect to temperature decrease at all temperatures down to 0 °C. Results showed that temperature affected the PARAFAC components associated with humic-like and tryptophan-like components of DOM differently, depending on the water type. The terrestrial humic-like components, C1 and C2 presented the highest thermal quenching in rural water samples and the lowest in urban water samples, while C3, the tryptophan-like component, and C4, a reprocessed humic-like component, showed opposite results. These results were attributed to the availability and abundance of the components or to the degree of exposure to the heat source. The variable thermal quenching of the humic-like components also indicated that although the PARAFAC model generated the same components across sites, the DOM composition of each component differed between them. This study has shown that thermal quenching can provide additional information on the characteristics and composition of DOM and highlighted the importance of correcting fluorescence data collected in situ.

AB - The fluorescence intensity of dissolved organic matter (DOM) in aqueous samples is known to be highly influenced by temperature. Although several studies have demonstrated the effect of thermal quenching on the fluorescence of DOM, no research has been undertaken to assess the effects of temperature by combining fluorescence excitation – emission matrices (EEM) and parallel factor analysis (PARAFAC) modelling. This study further extends previous research on thermal quenching by evaluating the impact of temperature on the fluorescence of DOM from a wide range of environmental samples, in the range 20 °C – 0 °C. Fluorescence intensity increased linearly with respect to temperature decrease at all temperatures down to 0 °C. Results showed that temperature affected the PARAFAC components associated with humic-like and tryptophan-like components of DOM differently, depending on the water type. The terrestrial humic-like components, C1 and C2 presented the highest thermal quenching in rural water samples and the lowest in urban water samples, while C3, the tryptophan-like component, and C4, a reprocessed humic-like component, showed opposite results. These results were attributed to the availability and abundance of the components or to the degree of exposure to the heat source. The variable thermal quenching of the humic-like components also indicated that although the PARAFAC model generated the same components across sites, the DOM composition of each component differed between them. This study has shown that thermal quenching can provide additional information on the characteristics and composition of DOM and highlighted the importance of correcting fluorescence data collected in situ.

KW - Fluorescence spectroscopy

KW - Thermal quenching

KW - Dissolved organic matter

KW - Parallel factor analysis

KW - Temperature correction

KW - EXCITATION-EMISSION MATRIX

KW - DRINKING-WATER TREATMENT

KW - PARALLEL FACTOR-ANALYSIS

KW - OXYGEN-DEMAND BOD

KW - WASTE-WATER

KW - FRESH-WATER

KW - IN-SITU

KW - RECYCLED WATER

KW - SPECTROSCOPY

KW - COMPONENTS

U2 - 10.1016/j.watres.2014.05.013

DO - 10.1016/j.watres.2014.05.013

M3 - Journal article

VL - 61

SP - 152

EP - 161

JO - Water Research

JF - Water Research

SN - 0043-1354

ER -