残留性有機汚染化合物の水環境中への溶解挙動の測定および計算予測

学術(環

Predictions of flavonoid solubility in ionic liquids by COSMO-RS: experimental verification, structural elucidation, and solvation characterization

Predictions of the solubility of flavonoids in a large variety of ionic liquids (ILs) with over 1800 available structures were examined based on COSMO-RS computation. The results show that the solubilities of flavonoids are strongly anion-dependent. Experimental measurement of the solubilities of esculin and rutin in 12 ILs with varying anions and cations show that predicted and experimental results generally have a good agreement. Based on the sound physical basis of COSMO-RS, the solubility changes of flavonoids were quantitatively associated with solvation interactions and structural characteristics of ILs. COSMO-RS derived parameters, i.e. misfit, H-bonding and van der Waals interaction energy, are shown to be capable of characterizing the complicated multiple interactions in the IL system effectively. H-bonding interaction is the most dominant interaction for ILs (followed by misfit and van der Waals interactions) to determine the solubility of flavonoids, and the anionic part has greater effect on the overall H-bonding capability of the IL. Based on basicity of anions, ILs were categorized into 3 groups, corresponding to the classification of the solubility of flavonoid. COSMO sigma-moment descriptors, which roughly denote the characteristic properties of the ILs, might be of general value to have a fast estimation for the solubilities of flavonoids as well as those compounds with massive moieties as H-bonding donors. The results obtained in this work may be important for achieving an improved understanding of IL solvations and the tailoring of the desired structures of ILs used as the media for efficient enzymatic esterification of flavonoids

Dioksyny w komunalnych osadach sciekowych w zaleznosci od etapu ich przerobki

Do grupy toksycznych związków organicznych obecnych w komunalnych osadach ściekowych należą dioksyny. W niniejszej pracy określono stopień kumulacji dioksyn: PCDD i PCDF (z wyszczególnieniem 17 kongenerów) w komunalnym osadzie ściekowym na kolejnych etapach jego przeróbki, tj. w osadzie nadmiernym, po fermentacji i odwodnionym po fermentacji. Uzyskane wartości porównano z danymi dostępnymi w literaturze. We wszystkich próbkach osadów ściekowych dominującym kongenerem był OCDD (od 75,0% do 78,3% sumarycznej zawartości). Następnie w sekwencji malejącej: 1,2,3,4,6,7,8-HpCDD, OCDF i 1,2,3,4,6,7,8-HpCDF (udział każdego z nich nie przekraczał 10% sumarycznej zawartości). Średnia wartość poziomu toksyczności próbki - TEQ wynosiła od 12,18 ng I-TEQ·kg⁻¹ s.m. dla osadu nadmiernego do 16,84 ng I-TEQ·kg⁻¹ s. m. dla osadu przefermentowanego odwodnionego.Dioxins are the toxic organic compounds existing in municipal sewage sludge. In presented work the concentration of dioxins: PCDD and PCDF (17 congeners) in municipal sewage sludge at particular treatment stages i.e. in excess sludge, after digestion and in dewatered sludge, were investigated. Determined contents were compared with the data available in literature. OCDD was a dominated congener (from 75.0 to 78.3% of total content) in all samples of sewage sludge. Next, there were in decreasing sequence: 1,2,3,4,6,7,8-HpCDD, OCDF and 1,2,3,4,6,7,8-HpCDF (the content of each was below 10% of total content). Average toxic equivalent ranged from 12.18 ng I-TEQ·kg⁻¹ DM in excess sludge to 16.84 ng I-TEQ·kg⁻¹ DM in dewatered sludge

Predicting Physico-Chemical Properties of Alkylated Naphthalenes with COSMO-RS

COSMO-RS, the Conductor-like Screening Model for Real Solvents, has been used to predict a set of basic partition coefficients of 22 (alkylated) naphthalenes. To validate the approach, methyl-, dimethyl-, and ethylnaphthalenes have been chosen, according to the availability of experimental data. Then, predictions have been extended to diisopropylnaphthalenes. Given the model's expected uncertainty intervals, COSMO-RS predictions of aqueous solubilities, (subcooled) vapor pressures, Henry's law constants, as well as octanol-water partition coefficients, are in agreement with available literature data. Simultaneous overestimation of aqueous solubilities and vapor pressures of comparable magnitude leads to partial error cancellation in the Henry's law constants. Based on physico-chemical property data obtained with COSMO-RS, the Mackay Level III fugacity model, a steady-state, non equilibrium, and regional-scale model, has been applied to exemplary evaluate the tendency of 2,6-diisopropylnaphthalene to migrate between media by modelling emissions to each individual medium and calculating the amount present at steady state