Surface activity of humic substances depending on their origin
DOI:
https://doi.org/10.15626/Eco-Tech.2005.058Keywords:
Surface tension; Humic substances; KineticsAbstract
Humic substances are a general category of naturally occurring, biogenic, heterogeneous
organic substances that can be characterised as being yellow to black in colour, of high
molecular weight and refractory. Surface tension measurement defined humic substances as
surface active substances. Unless micellar structural model of humic substances has been
suggested, in the same time there are only a few studies about the factors that affect the
surface activity of humic solutions. The objective of this study was to study changes in
surface activity depending on the origin and properties of humic substances.
The surface tension-pH curves of humic substances featured a minimum for all solutions,
declining steeply from higher and lower pH values. The decrease in surface tension with
decreasing pH reflects the gradual neutralization of acidic sites, which created amphiphilic
species that migrated to the surface. Surface tension of solutions of humic substances
decreased with increasing concentration, as well as in presence of metal salts. Many
industrially produced humic materials demonstrated no or insignificant impact on surface
tension of their solutions, but humic substances isolated from natural environments (water,
soil, peat, sediments) demonstrated significant impact of surface tension of their solutions.
Thus there exist direct links between origin, structure of humic substances and their ability to
influence surface tension of aquatic solutions.
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References
Kjavii;is M., 1998. Aquatic humic substances. Latvian University, Riga, 234.
Simpson M.J., Simpson A.J., Hatcher P.O., 2004. Noncovalent interactions between aromatic compounds and dissolved humic acid examined by nuclear magnetic resonance spectroscopy. Environ. Sci. Technol. 23(2), 355 - 362. https://doi.org/10.1897/03-217
Guetzloff T.F., Rice J.A., 1994. Does humic acid form a micelle? Sci. Total Environ., 152, 31 - 35. https://doi.org/10.1016/0048-9697(94)90548-7
Wershaw R.L., 1993. Model for humus in soils and sediments. Environ. Sci. Technol. 27, 814- 816. https://doi.org/10.1021/es00042a603
Engebretson R.R., von Wandruszk.a R., 1994. Microorganization in dissolved humic acids. Environ. Sci. Technol. 28, 1934 - 1941. https://doi.org/10.1021/es00060a026
Engebretson R.R., von Wandruszk.a R., 1996. Quantitative approach to humic acid associations. Environ. Sci. Technol. 30, 990 - 997.
Yates L.M., von Wandruszk.a R., 1999. Effects of pH and metals on the surface tension of aqueous humic materials. Soil Sci. Soc. Am. J. 63, 1645 - 1649. https://doi.org/10.2136/sssaj1999.6361645x
Thurman, E. M., Malcolm, R. L., 1981. Preparative isolation of aquatic humic substances. Environ. Sci. Technol. 15, 463-466. https://doi.org/10.1021/es00086a012
Rozenbaha I., Odham G. , Jamberg U., Alsberg T. , Klavins M., 2002. Characterisation of humic substances by acid catalysed transesterification. Anal. Chim.Acta 452, 105-114. https://doi.org/10.1016/S0003-2670(01)01429-5
Klavins M., Eglite L., 2002. Immobilisation of humic substances. Colloids and Surfaces A: Physicochem., Eng. Aspects 203, 47 - 54. https://doi.org/10.1016/S0927-7757(01)01066-4
Juhna T., Klavins M., Eglite L., 2003. Sorption ofthumic substances on aquifer material at artificial recharge of groundwater. Chemosphere 51 (9), 861-868. https://doi.org/10.1016/S0045-6535(03)00108-5
Eg!Ite L., Rozenbaha I., Odham G., Jamberg U., Kjavii;is M., 2003. Reductive degradation of humic substances. Latv. /f:lm.tZ. (3), 283-291.
Kjavii;is M., Jankovska L., Bumane !, Kreismanis J., 2004. Degradation of humic substances by UV irradiation, Latv. /f:fm.tZ. ( 4), 379-385.
Kawahigashi M., Fujitake N., Tsurudome T., Suzuki S., Otsuka H., 1997. Changes in configurations and surface active properties of humic acid with increasing concentration of NaCl. In: Proceedings of the 8th IHSS meeting. The role of humic substances in the ecosystems and in environmental protection, Wroclaw, Poland, pp. 127 - 133.
Anderson, M.A., Hung A., Mills D., Scott M.S., 1995. Factors affecting the surface tension of soil solutions and solutions of humic acids. Soil Sci. 160, 111 - I I 6.
Klacking, R., Miicke, D., 1969. Isolierung Waserloslicher Huminsauren (Fulvosauren) aus ihren Blei(II) chelatverbindungen. Z. Chem. 12, 453-454.
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