Sorption of components from a mixture of essential oils by cryotextured cornstarches

Sorption by cryotextured cornstarches of components of the aqueous phase of a mixture of essential oils was studied by capillary gas chromatography. The amount of cryotexture-sorbed substances depended linearly on their concentration in the initial gel. The sorption of components from the mixture by starch polysaccharides was mainly associated with hydrophobic cooperative interactions, which resulted in the formation of supramolecular structures and inclusion complexes. The structure of the compounds was a major factor determining the degree of sorption. Sorption of monoterpene carbohydrates was the most pronounced. We revealed a synergistic increase in the degree of sorption from the mixture as compared to binding of individual compounds.     

Sorption of Monoterpenoids and Sesquiterpenoids by Natural Polysaccharides

Sorption of terpenoids (essential oil components) from aqueous solutions by six types of native food starches was studied by capillary gas chromatography. Sorption of volatile substances did not depend on amylose content in starch and specific surface of its granules. The degree of sorption was maximum (86%) for corn starch containing 25–28% amylose and decreased in the following order: tapioca starch (77%) > potato starch (74%) > wheat starch (70%) > high-amylose corn starch (58%) > amylopectin corn starch (57%). Amylopectin corn starch differed from other starches in the mechanism of sorption and selectivity to compounds with various functional groups.     

Sorption of mono- and sesquiterpenes by natural polysaccharides

Sorption of terpenoids (essential oil components) from aqueous solutions by six types of native food starches was studied by capillary gas chromatography. Sorption of volatile substances did not depend on amylose content in starch and specific surface of its granules. The degree of sorption was maximum (86%) for corn starch containing 25-28% amylose and decreased in the following order: tapioca starch (77%) > potato starch (74%) > wheat starch (70%) > high-amylose corn starch (58%) > amylopectin corn starch (57%). Amylopectin corn starch differed from other starches in the mechanism of sorption and selectivity to compounds with various functional groups.     

Sorption by cornstarch of components of a mixture of volatile organic substances from aqueous solutions

Effects of the composition of a mixture of organic substances on the binding of individual components in aqueous dispersions of native and gelatinized cornstarches with different contents of amylose was studied by capillary gas chromatography. Sorption was more active when alcohols were exposed to cornstarch as mixtures rather than individual compounds. In a multiple-component mixture, compounds belonging to distinct classes competed with each other for binding sites. Odorant sorption by aqueous starch dispersions was more sensitive to the composition of the mixture and the nature of starch when studied in aqueous dispersions of native starches (compared to those of gelatinized starches).     

Sorption of penicillium-cellulase on cellulose and lignin

Sorption of Penicillium cellulase onto cotton linters samples differing in physical structure and onto KLASON - lignin from spruce has been investigated by determining cellobiase, CMCL- and ‘linters-activity’ as well as protein content of a cellulase culture filtrate before and after contact with the sorbent at different temperature for different time intervals. CMCL- and cellobiase-activity were found to be reduced much less by the sorption process onto the cellulose samples than ‘linters-activity’ and protein content. Sorption increased in the order: untreated linters < mercerized linters < wet fibrillated (‘colloidal milled’) linters. With the KLASON -lignin also a considerable sorption of the cellulase system was observed. Results are discussed with respect to preferential sorption of enzyme components.     

Sorption of components from a mixture of odorants by polysaccharides of starch, chitosan, and carrageenan

Sorption of components from a mixture of odorants in aqueous suspensions of native cornstarch, chitosan, and carrageenan was studied by the method of capillary gas-liquid chromatography. Binding was primarily effected via hydrophobic cooperative interactions. The amount of sorbed odorants depended linearly on their initial concentration in the suspension. The differences in sorption characteristics of starch and chitosan were related to the presence of amino groups in the latter polysaccharide, which contributed to an increased binding of aldehydes via polar interactions. Sorption of odorants by the sulfated polysaccharide carrageenan largely depended on the structure of odorants and properties of their functional groups. Carrageenan was potent in binding aldehydes, ketones, and esters. Alcohols were less strongly bound to this polysaccharide. Sorption of lactones and guaiacol by carrageenan was the least significant.     

Sorption of components from a mixture of odorants by polysaccharides of starch, chitosan, and carrageenan

Sorption of components from a mixture of odorants in aqueous suspensions of native cornstarch, chitosan, and carrageenan was studied by the method of capillary gas-liquid chromatography. Binding was primarily effected via hydrophobic cooperative interactions. The amount of sorbed odorants depended linearly on their initial concentration in the suspension. The differences in sorption characteristics of starch and chitosan were related to the presence of amino groups in the latter compound, which contributed to increased binding of aldehydes via polar interactions. Sorption of odorants by the sulfated polysaccharide carrageenan largely depended on the structure of odorants and properties of their functional groups. Carrageenan was potent in binding aldehydes, ketones, and esters. Alcohols were less strongly bound to this compound. Sorption of lactones and guaiacol by carrageenan was the least significant.     

Sorption and Release of Organics by Primary,Anaerobic, and Aerobic Activated Sludge Mixed with Raw Municipal Wastewater

New activated sludge processes that utilize sorption as a major mechanism for organics removal are being developed to maximize energy recovery from wastewater organics, or as enhanced primary treatment technologies. To model and optimize sorption-based activated sludge processes, further knowledge about sorption of organics onto sludge is needed. This study compared primary-, anaerobic-, and aerobic activated sludge as sorbents, determined sorption capacity and kinetics, and investigated some characteristics of the organics being sorbed. Batch sorption assays were carried out without aeration at a mixing velocity of 200 rpm. Only aerobic activated sludge showed net sorption of organics. Sorption of dissolved organics occurred by a near-instantaneous sorption event followed by a slower process that obeyed 1^st order kinetics. Sorption of particulates also followed 1^st order kinetics but there was no instantaneous sorption event; instead there was a release of particles upon mixing. The 5-min sorption capacity of activated sludge was 6.5±10.8 mg total organic carbon (TOC) per g volatile suspend solids (VSS) for particulate organics and 5.0±4.7 mgTOC/gVSS for dissolved organics. The observed instantaneous sorption appeared to be mainly due to organics larger than 20 kDa in size being sorbed, although molecules with a size of about 200 Da with strong UV absorbance at 215–230 nm were also rapidly removed.     

Studies on Octylphenoxy Surfactants : III. Sorption of Triton X-100 by Isolated Tomato Fruit Cuticles

Sorption characteristics of a polyethoxy (EO) derivative of octylphenol (OP) were determined for enzymically isolated mature tomato (Lycopersicon esculentum Mill. cv Sprinter) fruit cuticles at 25°C. Sorption was followed using ¹⁴C-labeled OP + 9.5EO (Triton X-100). Solution pH (2.2-6.2) did not affect surfactant sorption by tomato fruit cuticular membranes (CM). Surfactant concentration (0.001-1.0%, w/v) had a marked impact on sorption. Sorption equilibrium was reached in 24 hours for OP + 9.5EO concentrations below the critical micelle concentration (CMC), whereas 72 to 120 hours were required to reach equilibrium with concentrations greater than the CMC. Regardless of when equilibrium was attained, initial sorption of OP + 9.5EO occurred rapidly. Partition coefficients (K) of approximately 300 were obtained at pre-CMC concentrations, whereas at the highest concentration (1.0%), K values were approximately 15- to 20-fold lower. Sorption was higher for dewaxed CM (DCM) than for CM. At OP + 9.5EO concentrations below the CMC, the amount (millimoles per kilogram) sorbed by CM and DCM increased sharply as the CMC was reached. After an apparent plateau in the amount sorbed at concentrations immediately below and above the CMC, sorption by CM and DCM increased dramatically with OP + 9.5EO concentrations greater than the CMC (0.5 and 1.0%). In contrast, sorption of OP + 5EO (Triton X-45) by CM and DCM differed from one another at relatively high (0.5 and 1.0%) concentrations, where sorption by DCM increased with increasing concentration, but plateaued for the CM. Sorption of OP + 9.5EO was also related to CM concentration, with an inverse relationship existing between sorption and CM at concentrations less than 3.33 milligrams per milliliter.     

Binding of Lactones by Polysaccharides of Corn and Potato Starches

Sorption of - and -lactones from aqueous solutions by cryotropic gels of corn and potato starches was studied using capillary gas–liquid chromatography and Fourier transform infrared spectroscopy. The sorption patterns were similar for both types of starch. However, the sorption of lactones by potato starch was 5–10% lower than their sorption by corn starch. The amount of substances bound by cryotextures of the starches depended linearly on their initial concentrations in the gel. An increase in the length of the alkyl substituent improved sorption of lactones. It was shown that six-membered rings play a greater role in total lactone sorption than five-membered rings. The apparent constants and numbers of binding sites were estimated for compounds that reached the stage of saturation. The interaction between lactones and polysaccharides was accompanied by a decrease in their conformational mobility and changes in the rheological characteristics of thermotropic and cryotropic starch gels.     

Impacts of Soil Organic Matter and Temperature on Sorption of Acetazolamide on Four Soils

Batch sorptions of acetazolamide (AZ) were conducted using four soils from China. Sorption of AZ was found to be impacted by OC, clay content, and soil pH, with higher k_d values for soils with higher clay content. The k_d values of SOM-removed soils are much lower than those of bulk soils. Sorption data were well fitted with a Freundlich model (r² > 0.99). Chelating with the metal ions on the surfaces of soil particles was probably involved. With pH increase, the electrostatic attraction between anionic AZ and positively charged soil surface may increase. The sorption capacity decreased when the temperature increased from 20 to 40°C, and the calculated thermodynamics parameters of ΔG₀, ΔH₀, and ΔS₀ indicated that the sorption was a non-spontaneous, physisorption, and exothermic process. Sorption coefficients (k_d) for the compound in soil were low (ranging from 0.42 to 1.19 L·kg^?1) and indicated that low level sorption of AZ with appreciable risk of ground water contamination.     

Binding of lactones by polysaccharides of corn and potato starches

Sorption of gamma- and delta-lactones from aqueous solutions by cryotropic gels of corn and potato starches was studied using capillary gas-liquid chromatography and Fourier transform infrared spectroscopy. The sorption patterns were similar for both types of starch. However, the sorption of lactones by potato starch was 5-10% lower than their sorption by cornstarch. The amount of substances bound by cryotextures of the starches depended linearly on their initial concentrations in gel. Increase in the length of the alkyl substituent improved sorption of lactones. It was shown that six-membered rings play a greater role in total lactone sorption than five-membered rings. The apparent constants and numbers of binding sites were estimated for compounds that reached the stage of saturation. The interaction between lactones and polysaccharides was accompanied by a decrease in their conformational lability and changes in the rheological characteristics of thermotropic and cryotropic starch gels.     

Supramolecular interactions of solid human serum albumin with binary mixtures of solvent vapors.

Sorption isotherms of organic compounds on solid human serum albumin (HSA) from binary vapor mixtures were determined by gas chromatographic headspace analysis. The shape of sorption isotherms depends on molecular structure of studied sorbates. The 'active' compounds capable to sorb effectively on dry HSA increase the sorption of 'passive' compounds unable to be sorbed by dry HSA in absence of the third component. The critical hydration of HSA is required for sorption activation of 'passive' sorbates if water is taken as 'active' component. Ethanol and acetonitrile exhibit such activation effect without threshold. 'Passive' sorbates are able to produce cooperative activation effect on the sorption of 'active' component. Hydration history effect is observed for sorption on prehydrated HSA and HSA hydrated in situ. Obtained results were interpreted in terms of clathrate formation by 'passive' sorbate (substrate) and 'active' component inside the HSA (receptor) binding centers.     

Norfloxacin Sorption to Different Fractions in Sediments from Typical Water Systems in China

Sorption isotherms of Norfloxacin (NOF) to different fractions from six typical sediments in China were determined to compare the NOF sorption behavior and contribution of different fractions to total sorption. All sorption isotherms were nonlinear and fitted well with the Freundlich model. Sorption coefficients (K _f) by original sediments changed in larger magnitude, from 114 (mg/g)/(mg/L)ⁿ to 5271 (mg/g)/(mg/L)ⁿ, and black carbon with more aromatic carbon has more sorption capacity and nonlinearity. The sorption capacity K _f values were found to significantly correlate with SSA (specific surface area), OC (organic carbon), BC (black carbon), and TON (total organic nitrogen) (p < 0.05), but had no obvious relation with pH, CEC (cation exchange capacity), TOC/TON, and BC/TOC. The DOC removed, NaOH extracted, and 375°C heated fractions showed more nonlinear sorption than the original sediments, suggesting more heterogeneous sorption sites in these fractions. Among different sediment fractions, the 375°C heating fractions were responsible for >50% of the total NOF sorption over the whole concentration range. The contribution of DOC removed fractions to the total sorption was the highest at higher NOF concentration.     

Preliminary media screening for application in the removal of clofibric acid,carbamazepine and ibuprofen by SSF-constructed wetlands

The aim of the present work was to evaluate the sorption capacity of light expanded clay aggregates (LECA) to remove mixtures of ibuprofen, carbamazepine and clofibric acid in water and wastewater. High removal efficiencies were attained for carbamazepine and ibuprofen while a less satisfactory performance was observed for clofibric acid. In a mixture of the three compounds in water a slight decrease in the sorbed amounts is observed in comparison with solutions of the single compounds, indicating some competitive sorption. In wastewater, the pharmaceuticals mixture also undergoes a slight reduction in the sorbed amounts of carbamazepine and ibuprofen, probably due to the presence of dissolved organic matter which increases their solubility. These compounds were removed in the following order of efficiencies in all the tested conditions: carbamazepine > ibuprofen > clofibric acid. Two other clay materials – sepiolite and vermiculite – were tested for the removal of the more recalcitrant clofibric acid, and vermiculite exhibited higher removal efficiency than LECA. The sorption is characterized by an initial fast step, with most pharmaceuticals being removed within the first 24 h. The results of this study are a first step in the process of selecting an appropriate material or combination of materials to be used as media in SSF-CWs designed for the removal of pharmaceuticals from wastewaters.     

Bio-separation, speciation and determination of chromium in water using partially pyrolyzed olive pomace sorbent

Speciation of Cr(III)/Cr(VI) from water using olive pomace (OP) was improved by partial pyrolysis of OP. The sorbents were characterized by physicochemical techniques. Sorption of Cr(III) on raw and partially pyrolyzed OP sorbents followed Freundlich isotherm and second-order rate kinetics. OP pyrolyzed at 150 °C (sorbent OP-150) exhibited maximum sorption capacity, favorability and the lowest sorption energy. Sorption was exothermic and spontaneous for the raw-OP and OP pyrolyzed at 100 or 150 °C; but endothermic and non-spontaneous for OP pyrolyzed at 200, 250, 300 or 400 °C. A speciation method of chromium was proposed, in which Cr(III) was selectively retained at pH 3 on sorbent OP-150; while total Cr was determined after reduction of Cr(VI). The method was selective with a detection limit for Cr(III) of 1.58 μg L⁻¹. The method was applied on natural and industrial waters (recoveries >97.7%, RSD’s <9%) and on tobacco leaves certified reference material (INCT-PVTL-6).     

Effect of Acid treatment of plant cuticles on sorption of selected auxins

Sorption characteristics of 2-(1-naphthyl)acetic acid (NAA), 2-(1-naphthyl)acetamide (NAAm), and 2,4-dichlorophenoxyacetic acid (2,4-D) were determined for cuticles enzymically isolated from mature tomato (Lycopersicon esculentum Mill. cv Sprinter) and pepper (Capsicum annuum L.) fruit. Sorption equilibrium for NAA and 2,4-D by tomato cuticular membranes (CM) and dewaxed cuticular membranes (DCM) was achieved within 24 hours at 25°C. The average K (partition coefficient) values for NAA in tomato CM and DCM were 166 and 204, respectively, whereas the corresponding K values for 2,4-D were 292 and 383, respectively. Sorption equilibrium for 2,4-D and NAA in pepper cuticles was not achieved after 18 and 63 days, respectively. Sorption equilibrium for NAAm in tomato and pepper CM and DCM was attained within 48 hours. Acid pretreatment (2.0 n HCl, 10 minutes) had no effect on NAA, 2,4-D, or NAAm sorption by tomato CM and DCM, or on NAAm sorption by pepper CM and DCM. Acid pretreatment of pepper CM and DCM led to slightly lower K^pH (apparent partition coefficient) values for both NAA and 2,4-D. More significantly, sorption equilibrium for NAA and 2,4-D in pepper CM and DCM was achieved within 24 hours after acid treatment.     

Effect of the Composition of Polysaccharides in Gelatinized Cornstarch on Alcohol Absorption

Sorption of alcohols in aqueous suspensions of gelatinized cornstarches with various contents of amylose was studied by capillary gas chromatography. Alcohol sorption depended primarily on the structure of alcohols, rather than on the composition of polysaccharides. No correlation was found between the efficiency of sorption and amylose content in starch. The amount of substances sorbed by starches depended linearly on their initial concentration in the gel. Normal and high-amylose starches sorbed alcohols to a similar degree. However, increasing the length of alkyl substituents improved sorption of alcohols. Amylopectin starch differed in high affinity for small molecules and low sensitivity to the structure and hydrophobicity of alcohols.     

Nitrate sorption in the profile of an acid soil

Sorption of NO _inf3 ^sup– by different horizons of a highly weathered, acid tropical soil was measured in laboratory batch experiments. Sorption was found to increase with depth, ranging from small amounts in the 0–15 cm layer to amounts that would be roughly equivalent to 25 to 50% of the NO _inf3 ^sup– in the 90–120 cm layer at water and NO _inf3 ^sup– contents commonly found under field conditions. Calculations, based on sorption isotherms, demonstrated how sorption may be important for managing N in a tropical acid soil. Sorption of Cl^– was also found in the range of 0.1 and 2.0 mol m^–3. In this range of concentrations sorption of NO _inf3 ^sup– and chloride were found to be independent, suggesting that anion exchange sites were far from saturated.Contribution from the Department of Soil, Crop and Atmospheric Sciences, New York State College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853. SCAS paper No. 1726. This research is part of the TropSoils program.Contribution from the Department of Soil, Crop and Atmospheric Sciences, New York State College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853. SCAS paper No. 1726. This research is part of the TropSoils program.