Hydrophilic and hydrophobic sorption of organic acids by variable charge soils: effect of chemical acidity and acidic functional group

Sorption of organic acids by variable-charge soil occurs through both hydrophilic and hydrophobic sorption. In this study, the effect of chemical acidity and the type of acidic functional group on the relative contribution of hydrophilic and hydrophobic processes to sorption by a gibbsite-dominated and a kaolinite-dominated variable-charge soils was quantified by measuring sorption isotherms from different electrolytes (CaCl2, Ca(H2PO4)2, and KCl). The A1 soil is dominated by gibbsite whereas the DRC soil is primarily kaolinite. The organic acids investigated include five chlorinated phenols (pentachlorophenol, 2,3,4,6-tetrachlorophenol, 2,4,6-trichlorophenol, 2,4,5-trichlorophenol, and 2,4-dichlorophenol) with pKa values ranging from 4.69 to 7.85 and two acidic herbicides (2,4-D (pKa = 2.8) and prosulfuron (pKa = 3.76)) that contain carboxyl and urea functional groups, respectively. Anion exchange of chlorinated phenols and prosulfuron on both variable-charge soils as well as 2,4-D sorption on the A1 soil was linearly correlated to chemical acidity. The effective positive surface charge [AEC/(AEC + CEC)] and the anionic fraction of the organic acid in solution, which are both pH-dependent, were sufficient to estimate the contribution of anion exchange to organic acid sorption except for 2,4-D sorption by DRC soil. The latter was much greater than would be predicted from the pKa of 2,4-D. Calcium bridging between silanol edge group and 2,4-D was hypothesized and corroborated by differences in sorption measured from KCl and CaCl2 solutions. For predicting contributions from hydrophobic processes, a log-log linear relationship between pH-dependent octanol-water (Kow(pH)) and organic carbon-normalized sorption coefficients (Koc(pH)) appeared adequate.     

Geochemical modulation of pesticide sorption on smectite clay

Pesticide adsorption by soil clays can be dramatically influenced by the exchangeable cations present. Among the common exchangeable base cations in soils (Ca2+, Mg2+, K+, and Na+), K+-saturated clays frequently demonstrate the strongest affinity for pesticides. In the presence of multiple exchangeable cations in the system, we hypothesize that the magnitude of pesticide sorption to soil minerals is proportional to the fraction of clay interlayers saturated with K+ ions. To test this hypothesis, we measured sorption of three pesticides with different polarities (dichlobenil, monuron, and biphenyl) by homoionic K- and Ca-smectite (SWy-2) in KCl/CaCl2 aqueous solutions. The presence of different amounts of KCl and CaCl2 resulted in varying populations of K+ and Ca2+ on the clay exchange sites. The sorption of dichlobenil and, to a lesser extent monuron, increased with the fraction of K+ on clay mineral exchange sites. Ca- and K-SWy-2 displayed the same sorption capacities for nonpolar biphenyl. X-ray diffraction patterns indicated that at lower fractions of K+-saturation, exchangeable K+ ions were randomly distributed in clay interlayers and did not enhance pesticide sorption. At higher populations of K+ (vs Ca2+), demixing occurred causing some clay interlayers, regions, or tactoids to become fully saturated by K+, manifesting greatly enhanced pesticide sorption. The forward and reverse cation exchange reactions influenced not only K+ and Ca2+ populations on clays but also the nanostructures of clay quasicrystals in aqueous solution which plays an important, if not dominant, role in controlling the extent of pesticide sorption. Modulating the cation type and composition on clay mineral surfaces through cation exchange processes provides an environmental-safe protocol to manipulate the mobility and availability of polar pesticides, which could have applications for pesticide formulation and in environmental remediation.     

Sorption of tetracycline and chlortetracycline on K- and Ca-saturated soil clays, humic substances, and clay-humic complexes

Tetracycline (TC) and chlortetracycline (CTC) are used extensively for growth promotion and therapeutic purposes in livestock production. The sorption of TC and CTC on clays, humic substances (HS), and clay-humic complexes (clay-HC) derived from two agricultural soils was quantified using dilute CaCl2 (Ca) and KCI (K) as background solutions. In all systems, the soil components sorbed > 96% of added tetracyclines. Strongest sorption was observed for clays, followed by HS, and then clay-HC. Greater sorption by the Ca systems than the K systems and decreased sorption with increasing pH suggests that cation bridging and cation exchange contribute to sorption. X-ray diffraction analysis showed that TC and CTC were sorbed in the interlayers of smectites and that the presence of HS reduced interlayer sorption of tetracyclines by smectites in clay-HC. The results indicate that tetracyclines are dominantly sorbed on soil clays and that HS in clay-HC either mask sorption sites on clay surfaces or inhibit interlayer diffusion of tetracyclines.     

Solubility and sorption by soils of 8:2 fluorotelomer alcohol in water and cosolvent systems

The solubility and sorption by five soils of 8:2 fluorotelomer alcohol (FTOH) were measured from water and cosolvent/ water solutions. Aqueous solubility and soil-water distribution coefficients (Kd,w, L kg(-1)) were extrapolated from cosolvent data using a log-linear cosolvency model and compared to direct aqueous measurements. Liquid chromatography tandem mass spectrometry with electrospray ionization was employed to analyze the 8:2 FTOH in solutions and soil extracts. The cosolvent-extrapolated water solubility is 0.224 mg L(-1), in good agreement with the measured value of 0.194 mg L(-1). All sorption isotherms were generally linear regardless of cosolvent composition or soil organic carbon (OC) content. Kd,w values extrapolated from cosolvent data were similar but consistently higher than those measured in aqueous solutions. The latter was hypothesized to be due to dissolved OC (DOC) in the aqueous slurries. An average log KDOC of 5.30 was estimated and supported by DOC and Kd,w measurements at two soil-water ratios. Sorption appeared to be driven by hydrophobic partitioning with a log KOC value of 4.13 +/- 0.16. Irreversible sorption was also observed and appeared to be related to OC content, with the extraction efficiency reduced from 85% to 45% with increasing contact time from 3 to 72 h for the highest OC soil.     

Influence of smectite hydration and swelling on atrazine sorption behavior

Smectites, clay minerals commonly found in soils and sediments, vary widely in their ability to adsorb organic chemicals. Recent research has demonstrated the importance of surface charge density and properties of exchangeable cations in controlling the affinity of smectites for organic molecules. In this study, we induced hysteresis in the crystalline swelling of smectites to test the hypothesis that the extent of crystalline swelling (or interlayer hydration status) has a large influence on the ability of smectites to adsorb atrazine from aqueous systems. Air-dried K-saturated Panther Creek (PC) smectite swelled less (d(001) = 1.38 nm) than never-dried K-PC (d(001) = 1.7 nm) when rehydrated in 20 mM KCl. Correspondingly, the air-dried-rehydrated K-PC had an order of magnitude greater affinity for atrazine relative to the never-dried K-PC. Both air-dried-rehydrated and never-dried Ca-PC expanded to approximately 2.0 nm in 10 mM CaCl2 and both samples had similar affinities for atrazine that were slightly lower than that of never-dried K-PC. The importance of interlayer hydration status in controlling sorption affinity was confirmed by molecular modeling, which revealed much greater interaction between interlayer water molecules and atrazine in a three-layer hydrate relative to a one-layer hydrate. The entropy change on moving atrazine from a fully hydrated state in the bulk solution to a partially hydrated state in the smectite interlayers is believed to be a major factor influencing sorption affinity. In an application test, choice of background solution (20 mM KCl versus 10 mM CaCl2) and air-drying treatments significantly affected atrazine sorption affinities for three-smectitic soils; however, the trends were not consistent with those observed for the reference smectite. Further, extending the initial rehydration time from 24 to 240 h (prior to adding atrazine) significantly decreased the soil's sorption affinity for atrazine. We conclude that interlayer hydration status has a large influence on the affinity of smectites for atrazine and that air-drying treatments have the potential to modify the sorption affinity of smectitic soils for organic molecules such as atrazine.     

Ionic strength-induced formation of smectite quasicrystals enhances nitroaromatic compound sorption

Sorption of organic contaminants by soils is a determinant controlling their transport and fate in the environment. The influence of ionic strength on nitroaromatic compound sorption by K+- and Ca2+ -saturated smectite was examined. Sorption of 1,3-dinitrobenzene by K-smectite increased as KCl ionic strength increased from 0.01 to 0.30 M. In contrast, sorption by Ca-smectite at CaCl2 ionic strengths of 0.015 and 0.15 M remained essentially the same. The "salting-out" effect on the decrease of 1,3-dinitrobenzene aqueous solubility within this ionic strength range was <1.5% relative to the solubility in pure water. This decrease of solubility is insufficient to account for the observed increase of sorption by K-smectite with increasing KCl ionic strength. X-ray diffraction patterns and light absorbance of K-clay suspensions indicated the aggregation of clay particles and the formation of quasicrystal structures as KCI ionic strength increased. Sorption enhancement is attributed to the formation of better-ordered K-clay quasicrystals with reduced interlayer distances rather than to the salting-out effect. Dehydration of 1,3-dinitrobenzene is apparently a significant driving force for sorption, and we show for the first time that sorption of small, planar, neutral organic molecules, namely, 1,3-dinitrobenzene, causes previously expanded clay interlayers to dehydrate and collapse in aqueous suspension.     

Sorption of three tetracyclines by several soils: assessing the role of pH and cation exchange

Tetracyclines (TCs) are widely used in veterinary medicine for treatment and prevention of disease and are present in animal waste products. Detection of TCs in soil, sediments, and water, and the growing concern of their potentially adverse effect on natural ecosystems have resulted in a need to understand their behavior in aqueous soil systems. TCs have multiple ionizable functional groups such that at environmentally relevant pH values, they may exist as a cation (+ 0 0), zwitterion (+ - 0), or a net negatively charged ion (+ - -), which complicates predicting their sorption, availability, and transport. We investigated the sorption of oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) by several soils varying in pH, clay amount and type, cation exchange capacity (CEC), anion exchange capacity (AEC), and soil organic carbon in 0.01 N CaCl2, 0.001 N CaCl2, and 0.01 N KCI. All three TCs are highly sorbed, especially in acidic and high clay soils. When normalized to CEC, sorption tends to decrease with increasing pH. A sorption model in which species-specific sorption coefficients normalized to pH-dependent CEC (Kd+00, kd+-0, and kd+--) and weighted by the pH-dependent fraction of each species fit the data well across all soils except for a soil rich in gibbsite and high in AEC. Resulting kd+00 values were more than an order of magnitude larger than values for either kd+0 and kd+--values such that kd+00 alone described most of the sorption observed as a function of pH for eight soils that varied in their mineralogy and pH (pH ranged from 4 to 8).     

Sorption of veterinary pharmaceuticals in soils: a review

Veterinary pharmaceuticals (VPs) are used in large amounts in modern husbandry. Due to their use pattern, they possess a potential for reaching the soil environment. To assess their mobility in soil, the literature on sorption of chemicals used as VPs is reviewed and put into perspective of their physicochemical properties. The compilation of sorption coefficients to soil solids (Kd,solid) demonstrates that these chemicals display a wide range of mobility (0.2 < Kd,solid < 6,000 L/kg). Partition coefficients for association of tetracycline and quinolone carboxylic acid VPs to dissolved organic matter (Kd,DOM) vary between 100 and 50,000 L/kg. The variation in Kd,solid for a given compound in different soils can be significant. For most of the compounds, the variation is not considerably lower for the organic carbon-normalized sorption coefficient Koc. In addition, prediction of log Koc by log Kow leads to significant underestimation of log Koc and log Kd,DOM values. This suggests that mechanisms other than hydrophobic partitioning play a significant role in sorption of VPs. A number of hydrophobicity-independent mechanisms such as cation exchange, cation bridging at clay surfaces, surface complexation, and hydrogen bonding appear to be involved. These processes are not accounted for by organic carbon normalization, suggesting that this data treatment is conceptually inappropriate and fails to describe the sorption behavior. Moreover, prediction of log Koc based on the hydrophobicity parameter log Kow is not successful.     

Enhanced sorption of trichloroethene by smectite clay exchanged with Cs+

Trichloroethene (TCE) is one of the most common pollutants in groundwater, and Cs+ can be a cocontaminant at nuclear facilities. Smectite clays have large surface areas, are common in soils, have high affinities for some organic contaminants, and hence can potentially influence the transport of organic pollutants entering soils and sediments. The exchangeable cations present near smectite clay surfaces can radically influence the sorption of organic pollutants by soil clays. This research was undertaken to determine the effect of Cs+, and other common interlayer cations, such as K+ and Ca2+, on the sorption of TCE by a reference smectite clay saponite. Cs-saturated clay sorbed the most TCE, up to 3500 mg/kg, while Ca-saturated smectite sorbed the least. We hypothesize that the stronger sorption of TCE by the Cs-smectite can be attributed to the lower hydration energy and hence smaller hydrated radius of Cs+, which expands the lateral clay surface domains available for sorption. Also, Cs-smectite interlayers are only one or two water layers thick, which may drive capillary condensation of TCE. Our results implicate enhanced retention of TCE in aquifer materials containing smectites accompanied by Cs+ cocontamination.     

Using nitrogen and carbon dioxide molecules to probe arsenic(V) bioaccessibility in soils

Highly specialized personnel and high cost are typically required for in vivo risk assessment of arsenic (As) exposure to humans in As-contaminated soils. Arsenic bioaccessibility in soils, as determined with the aid of in vitro tests, is quite variable, and its magnitude depends upon unidentified soil properties. Use of soil chemical properties is a common practice for construction of As(V) sorption and bioaccessibility models with relative success. We propose a novel As(V) bioaccessibility model, which was tested on 17 soils. The model includes only two parameters characterizing surface properties of soils that are readily determined from N2- and CO2-based specific surface areas (SSAs), and total organic carbon (OC) content. We found that N2 and CO2 molecules act as As(V) "surrogates", probing easily accessible and relatively difficult to access soil porosity, respectively. Three interrelated linear models were constructed using two terms (CO2/N2-based SSAs and OC) that were significant (p <0.001) in explaining 51 and 95% of the variability observed in As(V) sorption and bioaccessibility, respectively. The proposed models successfully predicted bioaccessible As concentrations for 4 out of the 5 soils that were not included in the bioaccessibility models, reaching RMSE values of < or =10%.     

Slow formation and dissolution of Zn precipitates in soil: a combined column-transport and XAFS study

Recent spectroscopic studies have demonstrated the formation of layered double hydroxides (LDH) and phyllosilicates upon sorption of Zn2+, Ni2+, and Co2+ to clay minerals and aluminum oxides at neutral to alkaline pH and at relatively high initial metal concentrations (>1 mM). The intention of the present study was to investigate whether such phases also form in soil under slightly acidic conditions and at lower metal concentrations. Columns packed with a loamy soil were percolated with aqueous solutions containing 0.1 or 0.2 mM Zn, Ni, Co, and Cd in a 10 mM CaCl2 background at pH 6.5. Metal breakthrough curves indicated a rapid initial sorption step, resulting in retarded breakthrough fronts, followed by further slow metal retention during the entire loading period of 42 days (7000 pore volumes). Total metal sorption and the contribution of slow sorption processes decreased in the order Zn > Ni > Co > Cd. Leaching the reacted soil with 10 mM CaCl2 at pH 6.5 remobilized 8% of the total retained Zn, 15% of Ni, 21% of Co, and 77% of Cd. Subsequent leaching with acidified influent (pH 3.0) remobilized most of the remaining metals. X-ray absorption fine-structure (XAFS) spectroscopy revealed that slow Zn sorption was due to the formation of a Zn-Al LDH precipitate. Although Ni, Co, and Cd concentrations were too low for XAFS analysis, their leaching patterns suggest that part of Ni and Co were also incorporated in solid phases, while most sorbed Cd was still present as exchangeable sorption complex after 42 days. A small but significant percentage of the sorbed metals (2-5%) remained in the soil, even after leaching with more than 3000 pore volumes at pH 3.0, which may suggest micropore diffusion or incorporation into more stable mineral phases.     

Modeling tetracycline antibiotic sorption to clays

Sorption interactions of three high-use tetracycline antibiotics (oxytetracycline, chlortetracycline, tetracycline) with montmorillonite and kaolinite clays were investigated undervaried pH and ionic strength conditions. Sorption edges were best described with a model that included cation exchange plus surface complexation of zwitterion forms of these compounds. Zwitterion sorption was accompanied by proton uptake, was more favorable on acidic clay, and was relatively insensitive to ionic strength effects. Calcium salts promoted oxytetracycline sorption at alkaline pHs likely by a surface-bridging mechanism. Substituent effects among the compounds in the tetracycline class had only minor effects on sorption edges and isotherms under the same solution pH and ionic strength conditions. At low ionic strength, greater sorption to montmorillonite than kaolinite was observed at all pHs tested, even after normalizing for cation exchange capacity. These results indicate that soil and sediment sorption models for tetracyclines, and other pharmaceuticals with similar chemistry, must account for solution speciation and the presence of other competitor ions in soil or sediment pore waters.     

Thermodynamics of peat-, plant-, and soil-derived humic acid sorption on kaolinite

Humic acids (HAs) form coatings on clays and minerals that can play an important role in nutrient and contaminant migration in soil and water. Humic acid-clay mineral interactions are known to be affected by pH and ionic strength, but little attention has been paid to the effects of temperature. In this paper we report the stoichiometry and thermodynamics of interactions of aqueous HAs (isolated from two peats, two soils and a marine alga with a method that removes lipids) with kaolinite clay, Al2Si2O5(OH)4, at seven temperatures from 5.0 to 35.0 degrees C in 0.05 M NaCl at pH 3.5. All the sorption isotherms exhibit consecutive steps ascribed to HA monolayer and bilayer formation, respectively. Site capacity comparisons suggest different HA molecular conformations on kaolinite. Linearly correlated enthalpy and entropy changes for HA sorption point to the importance of hydration and dehydration in the sorption mechanism.     

Facilitating effects of metal cations on phenanthrone sorption in soils

Effects of metal cations (Na+, Ca2+, and Al3+) on phenanthrene sorption were investigated using two soils with contrasting organic carbon (OC) contents. The presence of the polyvalent cations (i.e., Ca2+ or Al3+) at a concentration of 0.01 mol/L significantly increased the capacity and nonlinearity of phenanthrene sorption to soils compared with the monovalent Na+. The effects were governed by the content of soil OC. Rubbery OC (i.e., soft, amorphous OC including dissolved organic carbon (DOC)) tended to become condensed on soil surfaces as evidenced by a decrease in the signals of the 1H NMR spectra of DOC and an increase in the glass transition temperature (Tg) of the soils when the polyvalent cations were present. Increasing Ca2+ concentration led initially to an effect similar to that of the polyvalent cations in the low cation concentration range, and the effect was gradually attenuated as Ca2+ concentration further increased. These findings lead us to propose that the modifications in the physical configuration and chemical characteristics of OC resulting from the presence of metal cations account for the increase in the capacity and nonlinearity of phenanthrene sorption to the soils. This study points to an important role of metal cations in the sorption and fate of phenanthrene in the soil environment.     

Sorption of the herbicide dichlobenil and the metabolite 2,6-dichlorobenzamide on soils and aquifer sediments

The worldwide used herbicide dichlobenil (2,6-dichlorobenzonitrile) has resulted in widespread presence of its metabolite 2,6-dichlorobenzamide (BAM) in pore- and groundwater. To evaluate the transport of these compounds we studied the sorption of dichlobenil and BAM in 22 sediment samples of clayey till, sand, and limestone including sediments exhibiting varying oxidation states. Dichlobenil sorbed to all investigated sediments, with a high sorption in topsoils (Kd = 7.4-17.4 L kg(-1)) and clayey till sediments (Kd = 2.7-126 L kg(-1)). The sorption of the polar metabolite BAM was much lower than the sorption of dichlobenil but followed the same tendency with the highest sorption in the topsoils (Kd = 0.24-0.66 L kg(-1)) and in the clayey till sediments (Kd = 0.10-0.93 L kg(-1)). The sorption of both compounds was significantly higher (2-47 times) in the unoxidized (reduced) clayey till than in the weathered (oxidized) clayey till. Such a difference in sorption capacity could neither be explained by a higher organic carbon content, sorption to clay minerals, differences in clay mineralogy, nor by blocking of reactive surface sites on clay minerals by iron oxides. However, by removing an average of 81% of the organic carbon from the reduced clayey till with H2O2, the sorption decreased on average 50%. Therefore, most of the sorption capacity in the reduced clayey till was related to organic carbon, which indicates that sorption processes are affected by changes in organic compound composition due to weathering.     

Sorption of oxytetracycline to iron oxides and iron oxide-rich soils

The sorption interactions of oxytetracycline with goethite, hematite, and two iron oxide-rich soils were investigated using batch sorption experiments. Oxytetracycline sorption coefficients for goethite and hematite increased with pH to maximum values at pH approximately 8. The sorption edge shape and desorption treatments were consistent with a surface complexation mechanism and could be described by the interaction of divalent anion species with the oxide surface. Oxytetracycline sorption to Georgeville and Orangeburg Ultisol soils decreased with pH. Chemical digestion treatments were used to deduce that soil sorption occurred by complexation to oxide coatings on clay and quartz grains. These results indicate that sorption models must consider the interaction of oxytetracycline, and other similar ionogenic compounds, with soil oxide components in addition to clays and organic matter when predicting sorption in whole soils.     

Analysis and sorption of psychoactive drugs onto sediment

An analytical method was developed to analyze eight psychoactive pharmaceuticals--including the antiepileptic carbamazepine, the opiates morphine, codeine, dihydrocodeine, the opiode tramadol, and the tranquilizers diazepam, oxazepam, temazepam--and the antibiotic sulfamethoxazole as well as three metabolites (10,11-dihydrocarbamazepine (DHC), 10,11-dihydroxy-10, 11-dihydrocarbamazepine, and N4-acetylsulfamethoxazole) in river sediments. Relative recoveries of all analytes exceeded 97% using either deuterated or 13C15N-labeled surrogate standards. Sorption isotherms of all analytes were constructed at pH 6.5-6.6 on two natural river sediments (Burgen and Dausenau) that differed in organic carbon contents and particle size distributions. Affinities of all analytes were up to an order of magnitude higher for the Dausenau sediment in comparison to the Burgen sediment. Isotherms were well described by the Freundlich model. Sorption of all analytes was linear on the Burgen sediment except for structurally similar carbamazepine (n = 0.90) and DHC (n = 0.88). Conversely, most analytes showed pronounced nonlinear sorption to the Dausenau sediment (n = 0.77-0.92) except for positively charged codeine, dihydrocodeine, and tramadol. Linear sorption of the latter was taken to arise from concentration-independent electrostatic interactions of the organocations with negatively charged surfaces on clay minerals or in the sediment organic matter. Desorption gave rise to hysteresis in 13 out of 16 investigated analyte-sorbent systems. Hysteresis was likely due to slow desorption kinetics beyond 24 h used in the experiment.     

Use of copper shavings to remove mercury from contaminated groundwater or wastewater by amalgamation

The efficacy of copper shavings (Cu(0)) for the removal of Hg2+ from aqueous solution by amalgamation is demonstrated. Two kinds of copper shavings were investigated: (a) chemically processed shavings (Fluka) and (b) recycled shavings from scrap metal. Batch sorption experiments yielded very high retardation coefficients of 28 850-82 830 for the concentration range studied (1-10 000 microg/L Hg2+ dissolved in distilled water or in a 0.01 M CaCl2 matrix solution). Sorption data were well-described bythe Freundlich isotherm equation. Kinetic batch sorption experiments showed that 96-98% of Hg2+ was removed within 2 h. Column experiments were performed with a mercury solution containing 1000 microg/L Hg in a 0.01 M CaCl2 matrix with a flow rate of 0.5 m/d. No mercury breakthrough (c/c(0) = 0.5) could be detected after more than 2300 percolated pore volumes, and the high retardation coefficients determined in the batch studies could be confirmed. Copper was released from the shavings due to the amalgamation process and to copper corrosion by oxygen, resulting in concentrations of mobilized copper of 0.2-0.6 mg/L. Due to their high efficiency in removing Hg2+ from aqueous solution, the use of copper shavings for the removal of mercury from contaminated water is suggested, employing a sequential system of mercury amalgamation followed by the removal of mobilized copper by an ion exchanger such as zeolites. Possible applications could be in environmental technologies such as wastewater treatment or permeable reactive barriers for in situ groundwater remediation.     

Effect of fluorotelomer alcohol chain length on aqueous solubility and sorption by soils

Fluorotelomer alcohols (FTOHs) are a group of polyfluorinated alkyl chemicals that have been widely studied as precursorsto perfluorocarboxylates such as perfluorooctanoic acid and for which knowledge on their fate in soils is sparse. The solubility and sorption by soil of the homologous 4:2 to 10:2 FTOHs were measured in water or cosolvent/ water solutions. For the smaller 4:2 and 6:2 FTOHs, solubility and sorption could be measured adequately in aqueous systems although transformation was apparent even in gamma-irradiated and autoclaved systems. Sorption coefficients estimated by measuring both sorbed and solution-phase concentrations were not significantly affected by the biotransformation process. The use of cosolvents was employed for probing the behavior of the longer-chain FTOHs with limited aqueous solubility. A single log-linear correlation between aqueous solubility and modified McGowan molar volumes resulted for the n-alkanols and FTOHs. Soil organic carbon (OC) consistently appeared to be the key soil property influencing sorption of the FTOHs while the perfluorocarbon chain length was the dominant structural feature influencing solubility and sorption. Each CF2 moiety decreased the aqueous solubility by -0.78 log units (compared to 0.60 log units for each CH2 addition in hydrogenated primary alcohols), and increased OC-normalized sorption coefficients (Koc) by -0.87 log units. Good log-log linear correlations between Koc and both octanol-water partition coefficients and solubility were observed for the FTOHs.