Study of ionic surfactants binding to humic acid and fulvic acid by potentiometric titration and dynamic light scattering

Synergy between surface adsorption and photocatalysis during degradation of humic acid on TiO2/activated carbon composites

“…According to the literature [37][38][39], HAs, initially set to pH 10 and then adjusted to pH between 3 and 5, present somehow different characteristics from samples directly set to the required pH. The differences observed may also be associated with the possibility that humic acids may aggregate to the extent of forming micelle-like structures [36,37]. The results in Fig.…”

“…The results from dynamic light scattering and voltammetry show that humic matter present in solution is aggregated in relatively large particles (>30 nm) and some irreversible disaggregation (120 nm diameter) is promoted by pH increase up to 10 [35][36][37][38][39]. The aggregates present in solution seem to be of a dynamic nature being influenced by changes of concentration, pH and/or ionic strength, although not always in the same way for samples of different origins and/or with different preparation procedures [2][3][4].…”

Evaluation of Efficacy of Anionic Surfactant Degradation in the Presence of Concomitant Impurities of Natural Waters

“…The major organic impurities in surface waters-humic and fulvic acids (HA and FA) can fix organic xenobiotics (e.g., pesticides, petroleum products, surfactants, etc.) through different mechanisms, through formation of strong chemical bonds (such as ionic, hydrogen, and covalent), charge transfer or weak interactions (such as van der Waals forces, ligand exchange, hydrophobic links) [8][9][10][11]; therefore, they may significantly affect the properties and behavior of xenobiotics in the processes of natural water or sewage treatment [12,13]. In particular, HA are able to bind anionic surfactants (ASAS) through hydrophobic interactions, significantly distorting their quantification by standard extractionphotometric method with methylene blue [8,14].…”

Effect of adsorption site potential on adsorption of sodium dodecylbenzenesulfonate in highly humic volcanic ash soil

“…Adsorption studies of cationic surfactant on humic acids have been recently conducted (Koopal et al 2004;Yee et al 2006;Ishiguro et al 2007;Ishiguro and Koopal 2011). Yee et al (2009) found that an anionic surfactant adsorbed only slightly on humic acids. Nonionic and cationic surfactants have much higher sorption with soil and sediment than anionic surfactants do (Urano et al 1984;Rodríguez-Cruz et al 2005;Ying 2006).…”