Surface speciation of Eu3+ adsorbed on kaolinite by time-resolved laser fluorescence spectroscopy (TRLFS) and parallel factor analysis (PARAFAC)

Time-resolved laser fluorescence spectroscopy (TRLFS) is an effective speciation technique for fluorescent metal ions and can be further extended by the parallel factor analysis (PARAFAC). The adsorption of Eu(3+) on kaolinite as well as gibbsite as a reference mineral was investigated by TRLFS together with batch adsorption measurements. The PAFAFAC modeling provided the fluorescence spectra, decay lifetimes, and relative intensity profiles of three Eu(3+) surface complexes with kaolinite; an outer-sphere (factor A) complex and two inner-sphere (factors B and C) complexes. Their intensity profiles qualitatively explained the measured adsorption of Eu(3+). Based on the TRLFS results in varied H(2)O/D(2)O media, it was shown that the outer-sphere complex exhibited more rapid fluorescence decay than Eu(3+) aquo ion, because of the energy transfer to the surface. Factor B was an inner-sphere complex, which became dominant at relatively high pH, high salt concentration and low Eu(3+) concentration. Its spectrum and lifetime were similar to those of Eu(3+) adsorbed on gibbsite, suggesting its occurrence on the edge face of the gibbsite layer of kaolinite. From the comparison with the spectra and lifetimes of crystalline or aqueous Eu(OH)(3), factor C was considered as a poly-nuclear surface complex of Eu(3+) formed at relatively high Eu(3+) concentration.     

Modeling Anion Adsorption on Kaolinite

Anion adsorption onto kaolinite was quantified using the triple layer surface complexation model. Fluoride adsorption data were described by both anion exchange and H-bonded complexation mechanisms. The outer-sphere complexation mechanism was used to describe the weak adsorption of Cl-, Br-, and I- on kaolinite. The F- adsorption in the presence of Br- or I- was decreased over a range of pH 4-5 whereas Cl- showed a negligible effect. Competition for binding sites appeared to be an important factor in determining the adsorptive behavior of F- in Br- or I- mediated systems. Copyright 1999 Academic Press.     

Modeling the adsorption of citric acid onto Muloorina illite and related clay minerals

The adsorption of citric acid onto goethite, kaolinite, and illite was measured as a function of pH (adsorption edges) and concentration (adsorption isotherms) at 25 degrees C. The greatest adsorption was onto goethite and the least onto illite. Adsorption onto goethite was at a maximum below pH 5 and decreased as the pH was increased to pH 9. For kaolinite, maximum adsorption occurred between pH 4.5 and pH 7, decreasing below and above this pH region, while for illite maximum adsorption occurred between about pH 5 and pH 7, decreasing at both lower and higher pH. ATR-FTIR spectra of citrate adsorbed to goethite at pH 4.6, pH 7.0, and pH 8.8 were compared with those of citrate solutions between pH 3.5 and pH 9.1. While the spectra of adsorbed citrate resembled those of the fully deprotonated solution species, there were significant differences. In particular the C[bond]O symmetric stretching band of the adsorbed species at pH 4.6 and 7.0 changed shape and was shifted to higher wave number. Further spectral analysis suggested that citrate adsorbed as an inner-sphere complex at pH 4.6 and pH 7.0 with coordination to the surface most probably via one or more carboxyl groups. At pH 8.8 the intensity of the adsorbed bands was much smaller but their shape was similar to those from the deprotonated citrate solution species, suggesting outer-sphere adsorption. Insufficient citric acid adsorbed onto illite or kaolinite to provide spectroscopic information about the mode of adsorption onto these minerals. Data from adsorption experiments, and from potentiometric titrations of suspensions of the minerals in the presence of citric acid, were fitted by extended constant-capacitance surface complexation models. On the goethite surface a monodentate inner-sphere complex dominated adsorption below pH 7.9, with a bidentate outer-sphere complex required at higher pH values. On kaolinite, citric acid adsorption was modeled with a bidentate outer-sphere complex at low pH and a monodentate outer-sphere complex at higher pH. There is evidence of dissolution of kaolinite in the presence of citric acid. For illite two bidentate outer-sphere complexes provided a good fit to all data.     

Preferential adsorption of extracellular polymeric substances from bacteria on clay minerals and iron oxide

The adsorption of extracellular polymeric substances (EPS) from Bacillus subtilis on montmorillonite, kaolinite and goethite was investigated as a function of pH and ionic strength using batch studies coupled with Fourier transform infrared (FTIR) spectroscopy. The adsorption isotherms of EPS on minerals conformed to the Langmuir equation. The amount of EPS-C and -N adsorbed followed the sequence of montmorillonite>goethite>kaolinite. However, EPS-P adsorption was in the order of goethite>montmorillonite>kaolinite. A marked decrease in the mass fraction of EPS adsorption on minerals was observed with the increase of final pH from 3.1 to 8.3. Calcium ion was more efficient than sodium ion in promoting EPS adsorption on minerals. At various pH values and ionic strength, the mass fraction of EPS-N was higher than those of EPS-C and -P on montmorillonite and kaolinite, while the mass fraction of EPS-P was the highest on goethite. These results suggest that proteinaceous constituents were adsorbed preferentially on montmorillonite and kaolinite, and phosphorylated macromolecules were absorbed preferentially on goethite. Adsorption of EPS on clay minerals resulted in obvious shifts of infrared absorption bands of adsorbed water molecules, showing the importance of hydrogen bonding in EPS adsorption. The highest K values in equilibrium adsorption and FTIR are consistent with ligand exchange of EPS phosphate groups for goethite surface. The information obtained is of fundamental significance for understanding interfacial reactions between microorganisms and minerals.     

蒙脱土和高岭土对Pb2+的吸附

选择带结构负电荷的蒙脱土和带微量结构负电荷的高岭土,研究了其对Pb2+的吸附性能,并探讨了吸附机理。 研究表明,蒙脱土和高岭土吸附Pb2+的动力学曲线符合准二级动力学方程,吸附等温线符合Langmuir方程。 Pb2+同时以内层络合和外层配合形式吸附,其相对量与pH值有关。 在pH值小于4和大于8的范围内,以内层配合物为主;而pH值在4～8范围内外层配合物比例增大。 Pb2+能进入蒙脱土的层间,而不能进入高岭土的层间;部分Pb2+可进入黏土颗粒的微孔中被固定。 蒙脱土对Pb2+的吸附能力和饱和吸附量明显高于高岭土。     

Surface complexes of phthalic acid at the hematite/water interface

The adsorption of o-phthalic acid at the hematite/water interface was investigated experimentally using batch adsorption experiments and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy over a wide range of solution pH, surface loading, and ionic strength conditions. Molecular orbital calculations for several possible surface complexes were also performed to assign atomistic structures to the features observed in the ATR-FTIR spectra. The results of the batch adsorption experiments exhibit typical anionic characteristics with high adsorption at low pH and low adsorption at high pH. The adsorption of phthalic acid also exhibits a strong dependence on ionic strength, which suggests the presence of outer-sphere complexes. ATR-FTIR spectra provide evidence of three fully deprotonated phthalate surface complexes (an outer-sphere complex and two inner-sphere complexes) under variable chemical conditions. A fully deprotonated outer-sphere complex appears to dominate adsorption in the circumneutral pH region, while two fully deprotonated inner-sphere complexes that shift in relative importance with surface coverage increase in importance at low pH. Comparison of experimental and theoretical calculations suggests the two inner-sphere complexes are best described as a mononuclear bidentate (chelating) complex and a binuclear bidentate (bridging) complex. The mononuclear bidentate inner-sphere complex was favored at relatively low surface coverage. With increasing surface coverage, the relative contribution of the binuclear bidentate inner-sphere complex increased in importance.     

Effects of low-molecular-weight organic ligands and phosphate on DNA adsorption by soil colloids and minerals

Adsorption of DNA on montmorillonite, kaolinite, goethite and soil clays from an Alfisol in the presence of citrate, tartrate and phosphate was studied. A marked decrease in DNA adsorption was observed on montmorillonite and kaolinite with increasing anion concentrations from 0 to 5 mM. However, the amount of DNA adsorbed by montmorillonite and kaolinite was enhanced when ligand concentration was higher than 5 mM. In the system of soil colloids and goethite, with the increase of anion concentrations, a steady decrease was found and the ability of ligands in depressing DNA adsorption followed the sequence: phosphate > citrate > tartrate. Compared to H2O2-treated clays (inorganic clays), a sharp decrease in DNA adsorption was observed on goethite and organo-mineral complexes (organic clays) with increasing ligand concentrations. The results suggest that the influence of anions on DNA adsorption varies with the type and concentration of anion as well as the surface properties of soil components. Introduction of DNA into the system before the addition of ligands had the greatest amount of DNA adsorption on soil colloids and goethite. Organic and inorganic ligands promoted DNA adsorption on montmorillonite and kaolinite when ligands were introduced into the system before the addition of DNA. The results obtained in this study have important implications for the understanding of the persistence and fate of DNA in soil environments especially rhizosphere soil where various organic and inorganic ligands are active.     

Carbonate adsorption on goethite in competition with phosphate

Competitive interaction of carbonate and phosphate on goethite has been studied quantitatively. Both anions are omnipresent in soils, sediments, and other natural systems. The PO4-CO3 interaction has been studied in binary goethite systems containing 0-0.5 M (bi)carbonate, showing the change in the phosphate concentration as a function of pH, goethite concentration, and carbonate loading. In addition, single ion systems have been used to study carbonate adsorption as a function of pH and initial (H)CO3 concentration. The experimental data have been described with the charge distribution (CD) model. The charge distributions of the inner-sphere surface complexes of phosphate and carbonate have been calculated separately using the equilibrium geometries of the surface complexes, which have been optimized with molecular orbital calculations applying density functional theory (MO/DFT). In the CD modeling, we rely for phosphate on recent parameters from the literature. For carbonate, the surface speciation and affinity constants have been found by modeling the competitive effect of CO3 on the phosphate concentration in CO3-PO4 systems. The CO3 constants obtained can also predict the carbonate adsorption in the absence of phosphate very well. A combination of inner- and outer-sphere CO3 complexation is found. The carbonate adsorption is dominated by a bidentate inner-sphere complex, (FeO)2CO. This binuclear bidentate complex can be present in two different geometries that may have a different IR behavior. At a high PO(4) and CO3 loading and a high Na+ concentration, the inner-sphere carbonate complex interacts with a Na+ ion, probably in an outer-sphere fashion. The Na+ binding constant obtained is representative of Na-carbonate complexation in solution. Outer-sphere complex formation is found to be unimportant. The binding constant is comparable with the outer-sphere complexation constants of, e.g., SO(2-)4 and SeO(2-)4.     

Surface complexation of mellitic acid to goethite: an attenuated total reflection Fourier transform infrared study

The nature of the interaction between mellitic acid (benzene hexacarboxylic acid) and the common soil mineral goethite (alpha-FeOOH) has been investigated as a function of pH and ionic strength by use of attenuated total reflection Fourier transform infrared spectroscopy. Molecular orbital calculations of the theoretical vibrational frequencies of the mellitate ion (L6-) and dihydrogen mellitate (H2L4-) have allowed the measured absorption frequencies to be accurately assigned. At pH values above 6, adsorption involves outer-sphere complexation of the deprotonated L6- ion. At lower pH values, there is evidence of a second outer-sphere surface complex involving a partially protonated species, although the extent of protonation of the surface species is significantly less than that found for the solution species at the same pH. While there is no evidence of inner-sphere complexation, increasing the ionic strength to 2.0 M does not displace the adsorbed species but does increase the fraction present on the surface as the fully deprotonated L6-. The small effect of ionic strength suggests that the adsorptive interaction, although outer-sphere in character, is still relatively strong, which indicates that hydrogen bonds may play a significant role. Hydrogen bonding may also help to account for the observed outer-sphere complexation at pH values above the pHiep of goethite.     

Effects of low-molecular-weight organic ligands and phosphate on adsorption of Pseudomonas putida by clay minerals and iron oxide

Adsorption of Pseudomonas putida on kaolinite, montmorillonite and goethite was studied in the presence of organic ligands and phosphate. Citrate, tartrate, oxalate and phosphate showed inhibitive effect on P. putida adsorption by three minerals in a broad range of anion concentrations. The highest efficiencies of the four ligands in blocking the adsorption of P. putida on goethite, kaolinite and montmorillonite were 58–90%, 35–76% and 20–48%, respectively. The ability of organic ligands in prohibiting the binding of P. putida cells to the minerals followed the sequence of citrate > tartrate > oxalate > acetate. The significant suppressive effects on P. putida adsorption were ascribed to the increased negative charges by adsorbed ligands and the competition of ligands with bacterial surface groups for binding sites. The inhibitive effects on P. putida adsorption by organic ligands were also dependent on the steric hindrance of the molecules. Acetate presented promotive effect on P. putida adsorption by kaolinite and goethite at low anion concentrations. The results obtained in this study suggested that the adsorption of bacteria in soils especially in the rhizosphere can significantly be impacted by various organic and inorganic anions.     

Effect of iron oxide coatings on zinc sorption mechanisms at the clay-mineral/water interface

Oxide surface coatings are ubiquitous in the environment, but their effect on the intrinsic metal uptake mechanism by the underlying mineral surface is poorly understood. In this study, the zinc (Zn) sorption complexes formed at the kaolinite, goethite, and goethite-coated kaolinite surfaces, were systematically studied as a function of pH, aging time, surface loading, and the extent of goethite coating, using extended X-ray absorption fine structure (EXAFS) spectroscopy. At pH 5.0, Zn partitioned to all sorbents by specific chemical binding to hydroxyl surface sites. At pH 7.0, the dominant sorption mechanism changed with reaction time. At the kaolinite surface, Zn was incorporated into a mixed metal Zn-Al layered double hydroxide (LDH). At the goethite surface, Zn initially formed a monodentate inner-sphere adsorption complex, with typical Zn-Fe distances of 3.18 A. However, with increasing reaction time, the major Zn sorption mechanism shifted to the formation of a zinc hydroxide surface precipitate, with characteristic Zn-Zn bond distances of 3.07 A. At the goethite-coated kaolinite surface, Zn initially bonded to FeOH groups of the goethite coating. With increasing aging time however, the inclusion of Zn into a mixed Zn-Al LDH took over as the dominant sorption mechanism. These results suggest that the formation of a precipitate phase at the kaolinite surface is thermodynamically favored over adsorption to the goethite coating. These findings show that the formation of Zn precipitates, similar in structure to brucite, at the pristine kaolinite, goethite, and goethite-coated kaolinite surfaces at near neutral pH and over extended reaction times is an important attenuation mechanism of metal contaminants in the environment.     

Adsorption of dicarboxylic acids by clay minerals as examined by in situ ATR-FTIR and ex situ DRIFT

The adsorption of dicarboxylic acids by kaolinite and montmorillonite at different pH conditions was investigated using in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) and ex situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The sorption capacity of montmorillonite was greater than that of kaolinite. Adsorption of dicarboxylic acids (succinic acid, glutaric acid, adipic acid, and azelaic acid) was the highest at pH 4 as compared with those at pH 7 and 9. These results indicate that sorption is highly pH-dependent and related to the surface characteristics of minerals. The aliphatic chain length of the dicarboxylic acids highly influenced the sorption amount at acidic pH, regardless of the clay mineral species: succinic acid [HOOC(CH2)2COOH] < glutaric acid [HOOC(CH2)3COOH] < adipic acid [HOOC(CH2)4COOH] < azelaic acid [HOOC(CH2)7COOH]. With in situ ATR-FTIR analysis, most samples tend to have outer-sphere adsorption with the mineral surfaces at all tested pHs. However, inner-sphere coordination between the carboxyl groups and mineral surfaces at pH 4 was dominant from DRIFT analysis with freeze-dried complex samples. The complexation types, inner- or outer-sphere, depended on dicarboxylic acid species, pH, mineral surfaces, and solvent conditions. From the experimental data, we suggest that organic acids in an aqueous environment prefer to adsorb onto the test minerals by outer-sphere complexation, but inner-sphere complexation is favored under dry conditions. Thus, organic acid binding onto clay minerals under dry conditions is stronger than that under wet conditions, and we expect different conformations and aggregations of sorbed organic acids as influenced by complexation types. In the environment, natural organic material (NOM) may adsorb predominantly on positively charged mineral surfaces at the aqueous interface, which can convert into inner-sphere coordination during dehydration. The stable NOM/mineral complexes formed by frequent wetting-drying cycles in nature may resist chemical/microbial degradation of the NOM, which will affect carbon storage in the environment and influence the sorption of organic contaminants.     

Effects of pH and ionic strength on the adsorption of phosphate and arsenate at the goethite-water interface

The surface properties of a well-crystallized synthetic goethite have been studied by acid-base potentiometric titrations, electrophoresis, and phosphate and arsenate adsorption isotherms at different pH and electrolyte concentrations. The PZC and IEP of the studied goethite were 9.3+/-0.1 and 9.3+/-0.2, respectively. Phosphate and arsenate adsorption decrease as the pH increases in either 0.1 or 0.01 M KNO(3) solutions. Phosphate adsorption is more sensitive to changes in pH and ionic strength than that of arsenate. The combined effects of pH and ionic strength result in higher phosphate adsorption in acidic media at most ionic strengths, but result in lower phosphate adsorption in basic media and low ionic strengths. The CD-MUSIC model yields rather good fit of the experimental data. For phosphate it was necessary to postulate the presence of three inner-sphere surface complexes (monodentate nonprotonated, bidentate nonprotonated, and bidentate protonated). In contrast, arsenate could be well described by postulating only the presence of the two bidenate species. A small improvement of the arsenate adsorption data could be achieved by assuming the presence of a monodentate protonated species. Model predictions are in agreement with spectroscopic evidence, which suggest, especially for the case of arsenate, that mainly bidentate inner-sphere complexes are formed at the goethite-water interface.     

Mechanistic modeling of arsenic retention on natural red earth in simulated environmental systems

Arsenic retention on natural red earth (hereafter NRE) was examined as a function of pH, ionic strength, and initial arsenic loading using both macroscopic and spectroscopic methods. Proton binding sites on NRE were characterized by potentiometric titrations yielding an average pH(zpc) around 8.5. Both As(III)- and As(V)-NRE surface configurations were postulated by vibration spectroscopy. Spectroscopically, it is shown that arsenite forms monodentate complexes whereas arsenate forms bidendate complexes with NRE. When 4相似文献   

Adsorption of humic acids onto goethite: effects of molar mass, pH and ionic strength

In this paper, the LCD (ligand charge distribution) model is applied to describe the adsorption of (Tongbersven) humic acid (HA) to goethite. The model considers both electrostatic interactions and chemical binding between HA and goethite. The large size of HA particles limits their close access to the surface. Part of the adsorbed HA particles is located in the compact part at the goethite surface (Stern layers) and the rest in the less structured diffuse double layer (DDL). The model can describe the effects of pH, ionic strength, and loading on the adsorption. Compared to fulvic acid (FA), adsorption of HA is stronger and more pH- and ionic-strength-dependent. The larger number of reactive groups on each HA particle than on a FA particle results in the stronger HA adsorption observed. The stronger pH dependency in HA adsorption is related to the larger number of protons that are coadsorbed with HA due to the higher charge carried by a HA particle than by a FA particle. The positive ionic-strength dependency of HA adsorption can be explained by the conformational change of HA particles with ionic strength. At a higher ionic strength, the decrease of the particle size favors closer contact between the particles and the surface, leading to stronger competition with electrolyte ions for surface charge neutralization and therefore leading to more HA adsorption.     

Adsorption of organic matter at mineral/water interfaces: 5. Effects of adsorbed natural organic matter analogues on mineral dissolution

The effects of the adsorption of pyromellitate, an analogue for natural organic matter, on the dissolution behavior of corundum (alpha-Al2O3) have been examined over a wide range of pyromellitate concentrations (0-2.5 mM) and pH conditions (2-10). The adsorption modes of pyromellitate on corundum have first been examined using in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and are shown to be dominated by a fully deprotonated, outer-sphere pyromellitate species ([triple bond]AlOH2+. . .Pyr4-) at pH >/= 5.0. At lower pH conditions, however, an additional protonated outer-sphere species ([triple bond]AlOH2+. . .H2Pyr2-) and an inner-sphere species are also evident. In accordance with the ATR-FTIR findings, modeling of macroscopic pyromellitate adsorption data using an extended constant capacitance treatment was possible using two outer-sphere ([triple bond]AlOH2+. . .Pyr4- and [triple bond]AlOH2+. . .H2Pyr2-) and one inner-sphere ([triple bond]AlPyr3-) adsorbed pyromellitate species. The presence of adsorbed pyromellitate strongly inhibited the dissolution of corundum under acidic (pH < 5) conditions, consistent with a mechanism previously proposed by Johnson et al. whereby outer-spherically adsorbed Pyr4- species sterically protect dissolution-active surface sites from attack by dissolution-promoting species such as protons. A reduction in the protolytic dissolution rate of corundum results. A reference Suwannee River fulvic acid, which also adsorbs to aluminum (oxyhydr)oxide surfaces in a predominantly outer-sphere manner, was similarly shown to strongly inhibit the dissolution of corundum at pH = 3.     

Light scattering studies on Ficoll PM70 solutions reveal two distinct diffusive modes

Enrofloxacin (ENR) occurs widely in natural waters because of its extensive use as a veterinary chemotherapeutic agent. To improve our understanding of the interaction of this emerging contaminant with soils and sediments, sorption of ENR on homoionic smectites and kaolinite was studied as a function of pH, ionic strength, exchangeable cations, and humic acid concentration. Batch experiments and in situ ATR-FTIR analysis suggested multiple sorption mechanisms. Cation exchange was a major contributor to the sorption of cationic ENR species on smectite. The decreased ENR sorption with increasing ionic strength indicated the formation of outer-sphere complexes. Exchangeable cations significantly influenced the sorption capacity, and the observed order was Cs相似文献   

Effect of Phosphate on the Adsorption of Glyphosate on Soils,Clay Minerals and Oxides

The effect of phosphate (ortho-phosphate) on the adsorption of the widely used glyphosate herbicide was evaluated with three typical Danish agricultural soils as well as pure oxides (goethite, FeOOH and gibbsite, Al(OH) 3 ) and silicates (illite and montmorillonite), which are considered the most important glyphosate and phosphate adsorbents in soils. Batch experiments where made in order to find out how phosphate affects adsorption of glyphosate and how glyphosate affects adsorbed phosphate. Solution glyphosate was quantified by liquid scintillation counting of 14 C-taggered herbicide and the concentration of phosphate by the molybdenum blue method. All experiments showed competition between phosphate and glyphosate for adsorption sites but the various adsorbents exhibited great variation in affinity for glyphosate and phosphate. Thus, gibbsite and, in particular goethite strongly prefer phosphate, whereas the competition on the silicates is more equal. The current studies showed that the competition in soils is almost equal, but still phosphate affects the sorption of glyphosate in soil. The amount of glyphosate and phosphate adsorbed by the various kinds of adsorbents was found to decrease in the order: oxides > silicates > soils. For the soils tested aluminium oxides, and to a lesser extent iron oxides seem the most important components in determining a soil's ability to adsorb phosphate and glyphosate, whereas the clay content and clay type seem of minor or little importance for adsorption of these species.     

甲基对硫磷和西维因在粘土矿物表面的吸附解吸特性

研究了甲基对硫磷和西维因在蒙脱石、高岭石和针铁矿表面的吸附 解吸特征。结果表明,Langmuir方程能较好的描述甲基对硫磷和西维因在３种矿物表面的等温吸附过程,且蒙脱石对农药的最大吸附量大于高岭石和针铁矿。用动力学方程对2种农药的吸附过程进行拟合,Elovich方程、双常数方程和一级动力学方程均得到较好的结果,其中Elovich方程为最佳模型,相关系数（R²）在0.93～0.98之间,说明该吸附为非均相扩散过程。3种矿物对甲基对硫磷和西维因的吸附强度均为蒙脱石＞高岭石＞针铁矿。     

The Hofmeister series effect in adsorption of cationic surfactants--theoretical description and experimental results

Interfacial properties of cationic surfactants show strong dependence on the type of surfactant counterion or on the type of anion of a salt added to the surfactant solution. In the paper, the models of ionic surfactant adsorption that can take into account ionic specific effects are reviewed. Model of ionic surfactant adsorption based on the assumption that the surfactant ions and counterions undergo nonequivalent adsorption within the Stern layer was selected to describe experimental surface tension isotherms of aqueous solutions of a number of cationic surfactants. The experimental isotherms for: n-alkyl trimethylammonium cationic surfactants, namely: C(16)TABr (CTABr or CTAB), C(16)TACl, C(16)TAHSO(4), C(10)TABr and C(12)TABr as well as decyl- and dodecylpyridinium salts with and without various electrolyte anions as Cl(-), Br(-), F(-), I(-), NO(3)(-), ClO(4)(-) and CH(3)COO(-) were described in terms of the model and a good agreement between the theory and experiment was obtained for a wide range of surfactants and added electrolyte concentrations. A very pronounced Hofmeister effect in dependence of surface tension of cationic surfactants on the type of anion was found. Analysing this dependence in terms of the proposed model of ionic surfactant adsorption, strong correlation between "anion surface activity" (the model parameter accounting for ion penetration into the Stern layer), and the ion polarizability was obtained. That suggests that the mechanism related to the dispersive interaction of polarized ion with electric field at interface is responsible for Hofmeister series effects in surface activity of cationic surfactants. The same mechanism was proposed recently to explain the dependence of surface tension increase with electrolyte concentration on anion and cation type.