Photooxidation of Dissolved Organic Matter: Role for Carbon Bioavailability and for the Penetration Depth of Solar UV-Radiation

Sulzberger, Barbara

doi:10.1007/978-3-662-04207-6_4

Cited by 6 publications

(4 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2) decreased slightly from 0.0146 to 0.0143 nm -1 at pH t = 0 4.0 and from 0.0138 to 0.0128 nm -1 at pH t = 0 8.0 after 24 h irradiation. The increase in the ratio of absorption a 250 nm /a 365 nm from 3.93 to 4.53 after 24 h irradiation at pH t = 0 4.0 further indicates a decrease in the average molecular weight of the DOM (Bertilsson and Bergh, 1999;Sulzberger, 2000). This result was confirmed by SEC (see below).…”

supporting

confidence: 72%

“…Here A l is the decadic absorption at the wavelength l, and d the optical pathlength in m. The absorption coefficient at a reference wavelength of l 0 = 300 nm was a 300 nm = 170 m -1 , and the parameter S, describing how rapidly the absorption decreases with increasing wavelengths, accounted for 0.014 nm -1 (regression coefficient r = 0.974). Both values are typical for brown, humic rich freshwaters (Kirk, 1994;Blough and Green, 1995;Sulzberger, 2000).…”

Section: Sample Characteristicsmentioning

confidence: 99%

See 1 more Smart Citation

Photobleaching of humic rich dissolved organic matter

Brinkmann

Sartorius

Frimmel

2003

Aquatic Sciences - Research Across Boundaries

View full text Add to dashboard Cite

Humic rich dissolved organic matter (DOM) from a bog lake in the Northern Black Forest was treated with simulated solar UV-light. The effects of irradiation time, initial pH values, and dissolved iron and copper on photobleaching were investigated. The DOC concentration and the UV/VIS absorption decreased with increasing amounts of absorbed light energy. The wavelengths of the maximum bleaching effect and of the maximum amount of absorbed energy were found to coincide. A de- Aquat. Sci. 65 (2003) 415-424 Aquatic Sciences crease in the average hydrodynamic radii of the DOM was shown by size-exclusion chromatography. Furthermore, evidence was given that hydrophilic moieties of the DOM were preferentially photodegraded while hydrophobic ones remained relatively unaffected or were even formed. Iron was an important factor of DOM photobleaching in the bog lake. However, copper, another redox active metal ion, inhibited the bleaching processes.

show abstract

supporting

confidence: 72%

Section: Sample Characteristicsmentioning

confidence: 99%

Photobleaching of humic rich dissolved organic matter

Brinkmann

Sartorius

Frimmel

2003

Aquatic Sciences - Research Across Boundaries

View full text Add to dashboard Cite

show abstract

“…It can originate from both aquatic microbial sources and terrestrial sources such as lignin that have degraded and dissolved; for purposes of this review, we refer to these materials as microbial and terrestrial, respectively. Absorption of sunlight by CDOM controls photic zone depths [1][2][3][4][5][6] and initiates a variety of photochemical reactions that convert CDOM to inorganic carbon [6][7][8][9][10][11][12][13][14] and biologicallyavailable, low molecular weight compounds, 5,[15][16][17][18] affect tracemetal redox speciation, 7,[19][20][21] inuence the fate of aquatic contaminants, [22][23][24][25][26][27][28][29] and in some instances can contribute significantly to aquatic oxygen demand. [30][31][32][33] The optical and photochemical properties of CDOM vary with season, CDOM source, and water chemistry.…”

Section: Introductionmentioning

confidence: 99%

The importance of charge-transfer interactions in determining chromophoric dissolved organic matter (CDOM) optical and photochemical properties

Sharpless

Blough

2014

Environ. Sci.: Processes Impacts

270

412

View full text Add to dashboard Cite

Absorption of sunlight by chromophoric dissolved natural organic matter (CDOM) is environmentally significant because it controls photic zone depth and causes photochemistry that affects elemental cycling and contaminant fate. Both the optics (absorbance and fluorescence) and photochemistry of CDOM display unusual properties that cannot easily be ascribed to a superposition of individual chromophores. These include (i) broad, unstructured absorbance that decreases monotonically well into the visible and near IR, (ii) fluorescence emission spectra that all fall into a single envelope regardless of the excitation wavelength, and (iii) photobleaching and photochemical quantum yields that decrease monotonically with increasing wavelength. In contrast to a simple superposition model, these phenomena and others can be reasonably well explained by a physical model in which charge-transfer interactions between electron donating and accepting chromophores within the CDOM control the optical and photophysical properties. This review summarizes current understanding of the processes underlying CDOM photophysics and photochemistry as well as their physical basis.

show abstract

“…Thus, autochthonous organic matter is considered more bio labile and, at the same time, is characterized as less chromophoric, while DOM of terrigenous origin is characterized by less bio lability, but being more chromophoric and photolabile (Benner & Kaiser, 2011; Zhu et al, 2017). An estimated 65% of the surface water organic compounds of the total DOM content can absorb solar irradiation, thereby capable of undergoing direct photolysis (Sulzberger, 2000). It is not difficult, therefore, to understand this mainly comprises the colour fraction of DOM, which includes HS.…”

Section: Influence Of Various Factors On Photochemical Degradation Of...mentioning

confidence: 99%

Photochemical processes in surface water bodies and their potential impacts on the chemical composition of water: A review

2023

View full text Add to dashboard Cite

The present study is a review of photochemical processes that occur in surface water bodies and which can affect the chemical composition of water. It is expected that water bodies with a slow rate of water exchange, including lakes, reservoirs, estuaries and ponds with significant areas of shallow water will be most vulnerable to the impacts of these processes. It involves natural organic compounds and xenobiotics of organic origin that enter water bodies from anthropogenic sources or are formed in water bodies because of the development of cyanobacteria and other algae species. Photodegradation of dissolved organic matter (DOM) occurs as a result of both direct photolysis and photosensitized cleavage involving inorganic and organic compounds, which are characterized by chromophore properties, such as humic substances. Photolysis is accompanied by the transformation of high molecular weight organic compounds into lower molecular weight compounds that can become bioavailable to, and promote the development of, microorganisms. Photodegradation results in bioavailable forms of nitrogen and phosphorus being released into the water column. Accordingly, the present study presents the results of analysis of the photochemical destruction of humic substances, such as the most widespread group of the surface water body DOM under the influence of artificial UV irradiation and solar radiation. The results provide data on the products of humic substances photolysis, as well as the influence of the latter on the destruction of a number of organic substances, including xenobiotics (herbicides, pesticides, etc.). Photolysis of algotoxins, which are mainly concentrated in the water of highly trophic reservoirs and lakes during the period of water “blooming,” is among the main concerns being addressed, noting photochemical destruction of these dangerous toxicants can be considered an important means of removing them from drinking water. Also emphasized is that photochemical processes in surface water will likely intensify in the future amid the recent climate changes, also affecting the chemical composition of water.

show abstract

Photooxidation of Dissolved Organic Matter: Role for Carbon Bioavailability and for the Penetration Depth of Solar UV-Radiation

Cited by 6 publications

References 49 publications

Photobleaching of humic rich dissolved organic matter

Photobleaching of humic rich dissolved organic matter

The importance of charge-transfer interactions in determining chromophoric dissolved organic matter (CDOM) optical and photochemical properties

Photochemical processes in surface water bodies and their potential impacts on the chemical composition of water: A review

Contact Info

Product

Resources

About