Characterization and seasonal variations of surface active substances in the natural sea surface micro-layers of the coastal Middle Adriatic stations

Frka, Sanja; Kozarac, Zlatica; Ćosović, Božena

doi:10.1016/j.ecss.2009.09.023

Cited by 29 publications

(41 citation statements)

References 41 publications

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“…On the other site, bacteria were well and active (Rahlff et al, 2017;Engel et al, 2018). Therefore, the measured surfactant concentrations were in a typical range (300-1000 µgL −1 ) for natural seawater (Frka et al, 2009;Wurl et al, 2011), and probably also in its composition. Nevertheless, the biological production of surfactants by phytoplankton has been known for decades (Ẑutić et al, 1981) and also by bacteria (Satpute et al, 2010) as they were more abundant in the Aeolotron.…”

Section: Biogenic Production Of Surfactantsmentioning

confidence: 73%

Air-Sea CO2-Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants

et al. 2018

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Wind, chemical enhancement, phytoplankton activity, and surfactants are potential factors driving the air-sea gas exchange of carbon dioxide (CO 2). We investigated their effects on the gas transfer velocity of CO 2 in a large annular wind-wave tank filled with natural seawater from the North Atlantic Ocean. Experiments were run under 11 different wind speed conditions (ranging from 1.5 ms −1 to 22.8 ms −1), and we increased the water pCO 2 concentration twice by more than 950 µatm for two of the seven experimental days. We develop a conceptual box model that incorporated the thermodynamics of the marine CO 2 system. Surfactant concentrations in the sea surface microlayer (SML) ranged from 301 to 1015 µgL −1 (as Triton X-100 equivalents) with enrichments ranged from 1.0 to 5.7 in comparison to the samples from the underlying bulk water. With wind speeds up to 8.5 ms −1 , surfactants in the SML can reduce the gas transfer velocity by 54%. Wind-wave tank experiments in combination with modeling are useful tools for obtaining a better understanding of the gas transfer velocities of CO 2 across the air-sea boundary. The tank allowed for measuring the gas exchange velocity under extreme low and high wind speeds; in contrast, most previous parametrizations have fallen short because measurements of gas exchange velocities in the field are challenging, especially at low wind conditions. High variability in the CO 2 transfer velocities suggests that gas exchange is a complex process not solely controlled by wind forces, especially in low wind conditions.

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Section: Biogenic Production Of Surfactantsmentioning

confidence: 73%

Air-Sea CO2-Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants

et al. 2018

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“…Distribution of surface active substances depends on seasonal periodicity as well. Frka et al [4] showed that in the summer time period the surfactant activities were more intense with respect to winter time. A similar result was achieved by Wurl et al [8], who showed that in the surface micro layer of the Santa Barbara Basin surface active substances were enriched with respect to bulk during the late summer.…”

Section: Introductionmentioning

confidence: 98%

Surfactant induced complex formation and their effects on the interfacial properties of seawater

Guzmán¹,

Santini²,

Benedetti³

et al. 2014

Colloids and Surfaces B: Biointerfaces

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“…Although organic surface-active substances are usually electroinactive, that is, those chemical species do not undergo electroreduction or electrooxidation within the available potential window, they can be analyzed by electrochemical methods on the basis of their influence upon the electrode double-layer structure when they get adsorbed at the electrode surface. Surface-active substances were most extensively investigated by electrochemical methods in the sea [3][4][5][6][7], particularly in the thin layer at the sea surface [8][9][10], in estuarine [11], and river water systems [12,13], and recently in the atmospheric precipitation samples [14]. Adsorption study at the electrode-solution interface may allow quantification of surface-active substances by measuring the extent of adsorption.…”

Section: Introductionmentioning

confidence: 99%

Simple Electrochemical Determination of Surface-Active Substances in Natural Waters

Cvrković-Karloci

Krznarić

Šeruga

et al. 2011

International Journal of Electrochemistry

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A simple electrochemical determination of surface-active substances by using time-dependent variation of the capacitive current in a.c. voltammetry at the HMDE is described. Surface-active substances were accumulated by stirring solution at the deposition potential of −0.6 V versus Ag/AgCl (sat. NaCl). The capacitive current was recorded for different deposition times in the range 0–120 s, wherefrom the linear calibration plot is constructed. The proposed method was verified for model surfactant TritonX-100 in the concentration range 0.02–0.25 mg/L and for humic acid in the concentration range 1.65–20 mg/L. The application of the method was demonstrated for freshwater samples of the Drava river, Danube river, and the wetland Kopački Rit, Croatia. The shape of theiac-Ecurves as well as the obtained concentrations of surface-active substances by using humic acid as the calibration substance are quite well describing the type and the nature of organic matter in the freshwater samples.

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Characterization and seasonal variations of surface active substances in the natural sea surface micro-layers of the coastal Middle Adriatic stations

Cited by 29 publications

References 41 publications

Air-Sea CO2-Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants

Air-Sea CO2-Exchange in a Large Annular Wind-Wave Tank and the Effects of Surfactants

Surfactant induced complex formation and their effects on the interfacial properties of seawater

Simple Electrochemical Determination of Surface-Active Substances in Natural Waters

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