scholarly journals Dynamics of dissolved organic matter in a wastewater effluent-impacted Japanese urban stream: characteristics, occurrence and photoreactivity of fluorescent components

2018 ◽  
Vol 78 (10) ◽  
pp. 2036-2045
Author(s):  
Kenshi Sankoda ◽  
Chieko Yamamoto ◽  
Kazuhiko Sekiguchi ◽  
Jun Kobayashi ◽  
Qingyue Wang
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Treatment Plant ◽  
Urban Stream ◽  
Aquatic Environments ◽  
Fluorescent Intensity ◽  
Parafac Model ◽  
Wwtp Effluent ◽  
Release Area ◽  
Parallel Factor

Abstract We report the results of using the excitation–emission matrix (EEM) method combined with parallel factor analysis (PARAFAC) to investigate the characteristics and occurrence of dissolved organic matter (DOM) in an urban stream impacted by effluent from a wastewater treatment plant (WWTP). The PARAFAC model divides the bulk EEM spectra into six individual fluorescent components with three humic-like components (C1–C3), two protein-like components (C4 and C5) and a wastewater-derived component (C6). In general, intensities of fluorescent components are abundant in WWTP effluent impacted samples, thus showing that such an effluent is a major source of DOM in urban rivers, but C5 is considered to have autochthonous sources within the stream. In areas where the effluent is released, the fluorescent intensity from components (except C5) gradually decreases as these components are transported downstream. However, concentrations of dissolved organic carbon remain almost constant downstream of the release area. These results would be attributed to degradation and/or modification of fluorophore. Photolysis experiments confirmed that fluorescent intensities can decrease with increase of irradiation times. C6 particularly showed a rapid photodegradation, remaining only 24.1% after 48 h photolysis. These findings would be important when assessing DOM source and water quality in aquatic environments by EEM-PARAFAC.

scholarly journals Technical note: Effects of iron(II) on fluorescence properties of dissolved organic matter at circumneutral pH

2020 ◽  
Author(s):  
Kun Jia ◽  
Cara C. Manning ◽  
Ashlee Jollymore ◽  
Roger D. Beckie
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Redox Status ◽  
Technical Note ◽  
Component Distribution ◽  
Quenching Effect ◽  
Parafac Model ◽  
Groundwater Samples ◽  
Non Linear ◽  
Parallel Factor

Abstract. Modern fluorescence spectroscopy methods, including excitation-emission matrix (EEMs) spectra parsed using parallel factor analysis (PARAFAC) statistical approaches, are widely used to characterize dissolved organic matter (DOM) pools. The effect of soluble reduced iron, Fe(II), on EEM spectra can be significant, but is difficult to quantitatively assign. In this study, we examine the effects of Fe(II) on the EEM spectra of groundwater samples from an anaerobic deltaic aquifer containing up to 300 mg/L Fe(II), located a few kilometers from the ocean, adjacent to the Fraser River in Richmond, British Columbia, Canada. We added varying quantities of Fe(II) into groundwater samples to evaluate Fe(II)-DOM interactions. Both the overall fluorescence intensity and the intensity of the primary peak, a humic-like substance at excitation/emission wavelengths 239/441–450 nm (Peak A), decreased by approximately 60 % as Fe(II) concentration increased from 1 to 306 mg/L. Furthermore, the quenching effect was non-linear and proportionally stronger at Fe(II) concentrations below 100 mg/L. This non-linear relationship suggests a static quenching mechanism. In addition, DOM fluorescence indices are substantially influenced by the Fe(II) concentration. With increasing Fe(II), the fluorescence index (FI) tends to shift to a more microbial-derived origin, and both the humidification index (HIX) and freshness index (FrI) indicate more freshly produced DOM. Nevertheless, the 13-component PARAFAC model showed that the component distribution was relatively insensitive to Fe(II) concentration, and thus, PARAFAC may be a reliable method for obtaining information about the DOM composition and its redox status in Fe(II)-rich waters. By characterizing the impacts of up to 300 mg/L Fe(II) on EEMs using groundwater from an aquifer which contains similar Fe(II) concentrations, we advance previous works which characterized impacts of lower Fe(II) concentrations (less than 2 mg/L) on EEMs.

Long-term effect of a simple storage protocol on fluorescence fingerprint of dissolved organic matter

2015 ◽  
Vol 16 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Xuechun Wang ◽  
Hao Chen ◽  
Kun Lei ◽  
Zhong Sun
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Model Development ◽  
Term Effect ◽  
Parafac Model ◽  
Long Term Effect ◽  
Simple Protocol ◽  
Long Time ◽  
Parallel Factor

Fitting a pre-established region-specific Parallel Factor Analysis (PARAFAC) model to new dissolved organic matter (DOM) samples has become a popular approach in DOM studies. A key step during the development of the pre-established model is to identify the fluorescence fingerprint, i.e. the number of fluorescent DOM (FDOM) components as well as their excitation and emission spectral features. In practice the samples to use for model development may not be measured immediately after sampling and will instead be stored for a relatively long time, thus raising the question whether the storage would change the intrinsic fingerprints. In this study, two PARAFAC models were separately developed and validated for the same set of surface water DOM samples from an estuary and its river, immediately after sampling and after 9-month storage respectively. The fingerprint did not change after storage, regardless of the change of the intensity of some components. The findings in this study highlighted that DOM samples stored using a simple protocol (i.e. filtration to 0.45 μm pore size without any preservatives and placed at 4 °C in the dark under airtight conditions) for a few months would not change fluorescence fingerprints for PARAFAC and broaden our understanding of the application of PARAFAC to DOM studies.

Correlation between Fluorescent and UV Absorbance in Dissolved Organic Matter of the Effluent from the Pulp Mill

2013 ◽  
Vol 726-731 ◽  
pp. 1463-1467
Author(s):  
Shao Wei Liao ◽  
Jing Wen Cao ◽  
Chung Yi Chung ◽  
Hwa Sheng Gau ◽  
Chang Gai Lee ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Water Samples ◽  
Membrane Filter ◽  
Pulp Mill ◽  
Secondary Treatment ◽  
Uv Absorbance ◽  
Fluorescent Intensity ◽  
Parafac Model ◽  
Explained Variation

During the interval from Oct.2011to April.2012, water samples were collected from the effluent treated by the secondary treatment of pulp mill. The measurements of EEFM (Excitation Emission Fluorescent matrix) by the fluorescent spectrometry as well as the value of UV absorbance were analyzed for water samples filtered by 0.45μm membrane filter. The EEFM information of dissolved organic matter of filtered water samples were characterized as 8 components with 89.7% of explained variation using PARAFAC model. Four substances had high loading, including the wavelength of Excitation /Emission (Ex/Em) of 360/420 nm, 280/270-430 nm, 350/430 nm and 300/420-480 nm. The fluorescent characteristic of 270/310 nm and 270/450 nm had a high correlation with UV254 value (R=0.838); however, the fluorescent intensity of 240/410 nm had a negative correlation with the value of UV200-400.

scholarly journals Technical note: Effects of iron(II) on fluorescence properties of dissolved organic matter at circumneutral pH

2021 ◽  
Vol 25 (9) ◽  
pp. 4983-4993
Author(s):  
Kun Jia ◽  
Cara C. M. Manning ◽  
Ashlee Jollymore ◽  
Roger D. Beckie
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Redox Status ◽  
Technical Note ◽  
Quenching Mechanism ◽  
Component Distribution ◽  
Quenching Effect ◽  
Parafac Model ◽  
Groundwater Samples ◽  
Parallel Factor

Abstract. Modern fluorescence spectroscopy methods, including excitation–emission matrix (EEM) spectra parsed using parallel factor analysis (PARAFAC) statistical approaches, are widely used to characterize dissolved organic matter (DOM) pools. The effect of soluble reduced iron, Fe(II), on EEM spectra can be significant but is difficult to quantitatively assign. In this study, we examine the effects of Fe(II) on the EEM spectra of groundwater samples from an anaerobic deltaic aquifer containing up to 300 mg L−1 Fe(II), located a few kilometres from the ocean and adjacent to the Fraser River in Richmond, British Columbia, Canada. We added varying quantities of Fe(II) into groundwater samples to evaluate Fe(II)–DOM interactions. Both the overall fluorescence intensity and the intensity of the primary peak, a humic-like substance at excitation and emission wavelengths of 239 and 441–450 nm (peak A), respectively, decreased by approximately 60 % as Fe(II) concentration increased from 1 to 306 mg L−1. Furthermore, the quenching effect was nonlinear and proportionally stronger at Fe(II) concentrations below 100 mg L−1. This nonlinear relationship suggests a static quenching mechanism. In addition, DOM fluorescence indices are substantially influenced by the Fe(II) concentration. With increasing Fe(II), the fluorescence index (FI) shifts to higher values, the humidification index (HIX) shifts to lower values, and the freshness index (FrI) shifts to higher values. Nevertheless, the 13-component PARAFAC model showed that the component distribution was relatively insensitive to Fe(II) concentration; thus, PARAFAC may be a reliable method for obtaining information about the DOM composition and its redox status in Fe(II)-rich waters. By characterizing the impacts of up to 300 mg L−1 Fe(II) on EEMs using groundwater from an aquifer which contains similar Fe(II) concentrations, we advance previous work which characterized impacts of lower Fe(II) concentrations (less than 2 mg L−1) on EEMs.

Characterization and biogeochemical implications of dissolved organic matter in aquatic environments

2021 ◽  
Vol 294 ◽  
pp. 113041
Author(s):  
Hengfeng Zhang ◽  
Yucong Zheng ◽  
Xiaochang C. Wang ◽  
Yongkun Wang ◽  
Mawuli Dzakpasu
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Aquatic Environments
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