Photochemical Alterations of Natural and Anthropogenic Dissolved Organic Nitrogen in the York River

Mesfioui, Rajaa; Abdulla, Hussain; Hatcher, Patrick G.

doi:10.1021/es504095c

Cited by 47 publications

(30 citation statements)

References 57 publications

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“…The CHNO components ( Figures S3 and S4), which were produced (red dots) are related to lignin-like components. N-containing photo products were also reported by [79,83]. The degraded components (black dots) included more condensed aromatics components.…”

Section: Average Photo-chemical Dom Quality Changementioning

confidence: 74%

Photochemically Induced Changes of Dissolved Organic Matter in a Humic-Rich and Forested Stream

Wilske

Herzsprung

Lechtenfeld

et al. 2020

Water

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Photochemical processing is an important way to transform terrestrial dissolved organic matter (DOM) but was rarely investigated by ultra-high resolution mass spectrometry. We performed an irradiation experiment with water from a shaded forest stream flowing into a lit reservoir. Bacterial activity explained only 1% of dissolved organic carbon (DOC) decline in a combined bacterial and photodegradation approach. Photodegradation decreased the DOC concentration by 30%, the specific ultraviolet (UV) absorption by 40%–50%, and fluorescence intensity by 80% during six days. The humification index (HIX) decreased whereas the fluorescence index (FI) did not change. Two humic-like components identified by parallel factor analysis (PARAFAC) of excitation–emission matrices followed the decrease of fluorescent DOM. Changes of relative peak intensities of Fourier transform-ion cyclotron resonance mass spectroscopy (FT-ICR MS) elemental formula components as a function of cumulated radiation were evaluated both by Spearman’s rank correlation and linear regression. The FT-ICR MS intensity changes indicate that high aromatic material was photochemically converted into smaller non-fluorescent molecules or degraded by the release of CO2. This study shows the molecular change of terrestrial DOM before the preparation of drinking water from reservoirs.

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Section: Average Photo-chemical Dom Quality Changementioning

confidence: 74%

Photochemically Induced Changes of Dissolved Organic Matter in a Humic-Rich and Forested Stream

Wilske

Herzsprung

Lechtenfeld

et al. 2020

Water

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“…For CHON formulas, the correlation peaks intensity is greatest at H/C ratios of ca. 1.25-1.62, indicating that most of the changes occur in these regions during biotreatment (Mesfioui et al, 2014). The white space implies that these CHON formulas do not display significant changes in number of formulas during biotreatment.…”

Section: Molecular Compositional Pattern Of Donmentioning

confidence: 99%

“…S3 in the SI). This is because the ESI-FTICR-MS is not a quantitative technique and the observed point on the van Krevelen diagram is based on numbers of formulas (Mesfioui et al, 2014).…”

Section: Molecular Compositional Pattern Of Donmentioning

confidence: 99%

“…Therefore, measurement of DON fractions can enable a better understanding of the relationship between DON and NDMA precursors and the biotoxicity of DOM. In recent years, electrospray ionization coupled to Fourier transform ion cyclotron resonance ultrahigh resolution mass spectrometry (ESI-FTICR-MS) has been used to determine the molecular composition of wastewater-derived DON (Mesfioui et al, 2014). ESI-FTICR-MS allows for an unprecedented resolution of thousands of molecular formulas from organic matter mixture, which provides detailed molecular transformations information on DON (Yekta et al, 2012;Lusk and Toor, 2016).…”

Section: Introductionmentioning

confidence: 99%

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Removal characteristics of DON in pharmaceutical wastewater and its influence on the N-nitrosodimethylamine formation potential and acute toxicity of DOM

Jiang

et al. 2017

Water Research

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Previous research has focused on dissolved organic carbon (DOC) as a surrogate for dissolved organic matter (DOM) in pharmaceutical wastewater. Dissolved organic nitrogen (DON) as a part of DOM has received little attention. This study investigated the removal characteristics of DON and its influence on the N-nitrosodimethylamine formation potential (NDMA FP) and acute toxicity of DOM in a full-scale hydrolysis/acidification + anaerobic/anoxic/aerobic + moving bed biofilm reactor (MBBR) process treating pharmaceutical wastewater. Results showed that maximum removal of DON (68 ± 12%) was present in the anaerobic process. The removal of DON by anoxic and aerobic processes was negligible as a result of the production of new N-containing compounds that are characteristic of proteins/amino sugars and lipids. DON concentration decreased significantly in the MBBR process (p < 0.05, t-test), indicating that manipulation of the solids retention times (SRTs) could be a solution to minimize DON. Based on the Pearson correlation analysis, the behavior of NDMA FP and DOM acute toxicity was significantly associated with the 3 kDa < MW < 10 kDa (r = 0.709, p < 0.05) and MW < 3 kDa DON (r = 0.659, p < 0.05), respectively, and are not identical to that of DOC fractions (r = 0.037-0.466, p = 0.051-0.886). Moreover, the removal and molecular changes of DON are not coupled with that of DOC during biotreatment. Thus, testing the performance indicator of DON in pharmaceutical wastewater was recommended, as it provides important information for DOM removal characteristics.

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“…Ultrahigh-resolution mass spectrometry (FT-ICR or Orbitrap MS) provides chemical information about DOM molecules, thus providing a direct link to microbial, photochemical, or geochemical reactivity. − Experimental approaches with isolated transformation processes provide the direction and strength of the molecular changes of DOM. However, the transferability to natural environments with coupled transformation processes can be limited and needs to be combined with field observations. ,,− …”

Section: Introductionmentioning

confidence: 99%

Improved Understanding of Dissolved Organic Matter Processing in Freshwater Using Complementary Experimental and Machine Learning Approaches

Herzsprung

Wentzky

Kamjunke

et al. 2020

Environ. Sci. Technol.

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Dissolved organic matter plays an important role in aquatic ecosystems and poses a major problem for drinking water production. However, our understanding of DOM reactivity in natural systems is hampered by its complex molecular composition. Here, we used Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and data from two independent studies to disentangle DOM reactivity based on photochemical and microbial-induced transformations. Robust correlations of FT-ICR-MS peak intensities with chlorophyll a and solar irradiation were used to define 9 reactivity classes for 1277 common molecular formulas. Germany’s largest drinking water reservoir was sampled for 1 year, and DOM processing in stratified surface waters could be attributed to photochemical transformations during summer months. Microbial DOM alterations could be distinguished based on correlation coefficients with chlorophyll a and often shared molecular features (elemental ratios and mass) with photoreactive compounds. In particular, many photoproducts and some microbial products were identified as potential precursors of disinfection byproducts. Molecular DOM features were used to further predict molecular reactivity for the remaining compounds in the data set based on a random forest model. Our method offers an expandable classification approach to integrate the reactivity of DOM from specific environments and link it to molecular properties and chemistry.

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Photochemical Alterations of Natural and Anthropogenic Dissolved Organic Nitrogen in the York River

Cited by 47 publications

References 57 publications

Photochemically Induced Changes of Dissolved Organic Matter in a Humic-Rich and Forested Stream

Photochemically Induced Changes of Dissolved Organic Matter in a Humic-Rich and Forested Stream

Removal characteristics of DON in pharmaceutical wastewater and its influence on the N-nitrosodimethylamine formation potential and acute toxicity of DOM

Improved Understanding of Dissolved Organic Matter Processing in Freshwater Using Complementary Experimental and Machine Learning Approaches

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