Sorption Of Anthracene Research Articles

Sorption of anthracene (C14H10) and 9-anthroic acid (C15H10O2) onto biochar-amended soils as affected by field aging treatments

There is a lack of information on how aging affects the sorption of ionizable organic compounds on biochar-amended soils. To that end, this study investigates the sorption of two hydrophobic solutes (anthracene (ANT) and 9-anthroic acid (9-ANCA)) onto biochar-amended (5%, w/w) soils as a function of aging period (0, 6, and 12 months), electrolyte (5 mM CaCl2 and 10 mM KCl), and aqueous pH. The isotherm plot of both solutes was fairly linear (r2 > 0.998) and the linear sorption coefficient (Kd, L kg−1) was obtained from this. In CaCl2 solution at pH 5, the log Kd of ANT tended to decrease (from 3.90 to 3.72) with an increasing aging period, which was attributed to clogged pore surface, whereas the differences in 9-ANCA sorption (from 2.56 to 2.51) were not significant (α = 0.05). The increased ANT sorption at acidic pH (<4) could be attributed to π-π interaction. Aqueous Ca2+ ions played an important role in 9-ANCA sorption by forming a Ca-bridge between anionic solute and negatively charged adsorbent surface, thus accounting for up to 35% of its sorption at alkaline pH (>8). The spectroscopic data and isoelectric point measurement results indicated that the number of oxygen-containing functional groups and the content of elemental oxygen were both higher in aged samples, resulting in a more polar (negatively charged) surface. The formation of surface polar groups and the associated deformation altered the adsorbent nature of the tested biochar, thereby fortifying the hydrophilic retention propensity for ionizable organic solutes.

Microbial transformation and sorption of anthracene in liquid culture

Armillaria sp. F022, a white-rot fungus isolated from decayed wood in tropical rain forest was used to biodegrade anthracene in cultured medium. The percentage of anthracene removal by Armillaria sp. F022 reached 13% after 7days and at the end of the experiment, anthracene removal level was at 87%. The anthracene removal through sorption and transformation was investigated. 69% of eliminated anthracene was transformed by Armillaria sp. F022 to form other organic structure, while only 18% was absorbed in the mycelia. In the kinetic experiment, anthracene dissipation will not stop even though the biomass had stopped growing. Anthracene removal by Armillaria sp. F022 was correlated with protein concentration (whole biomass) in the culture. The production of enzyme was affected by biomass production. Anthracene was transformed to two stable metabolic products. The metabolites were extracted in ethyl-acetate, isolated by column chromatography, and then identified using gas chromatography-mass spectrometry (GC-MS).

Adsorption kinetics of anthracene and phenanthrene in different soils of Attock Refinery Limited (ARL) Rawalpindi, Pakistan

The present study was envisaged to examine the adsorption kinetics of two polycyclic aromatic hydrocarbons anthracene and phenanthrene on soil from different areas of Attock Refinery Limited (ARL), Rawalpindi, Pakistan. Surface soil samples were characterized for their physicochemical properties. Batch experiments were designed to study adsorption capacities of selected PAHs to investigate the effect of variation in pH, initial concentration and contact time. The results revealed the high initial concentration, acidic pH and high organic matter contributes to higher adsorption capacities. The maximum adsorption exhibited for anthracene and phenanthrene under optimum conditions of pH and initial concentrations was 95.2% for anthracene and 95.4% for phenanthrene, respectively. The experimental results are described by Freundlich and Langmuir isotherms. Sorption of anthracene and phenanthrene displayed a linear isotherm. Experimental result shows that high organic matter soil may be used to control the mobil...

Long-Lived Radical Cation−Electron Pairs Generated by Anthracene Sorption in Non Brønsted Acidic Zeolites

The sorption of anthracene (ANT) in non Brønsted acidic ZSM-5 zeolite through the mere exposure at room temperature of solid ANT and dehydrated zeolite crystals with Li(3.4)(AlO2)n(SiO2)(96-n) chemical formulas per unit cell generates spontaneous ionization of ANT (IP 7.44 eV in the gas phase). In contrast, ANT was found to be sorbed as an intact molecule in M(3.4)ZSM-5 with M = Na+, K+, Rb+, and Cs+. The radical cation (ANT*+) of the long-lived ANT*+@Li(3.4)ZSM-5*- pair was characterized by conventional diffuse reflectance UV-visible and resonance Raman spectrometry. In contrast, the X-band continuous wave (CW) EPR signal was found to be typical of a weakly coupled spin correlated ion pair. The two-dimension hyperfine sublevel correlation (2D-HYSCORE) spectra provide a detailed description of the microenvironment of the trapped electron of the ANT*+@Li(n)ZSM-5*- pair. The trapped electron appears localized in close proximity of occluded ANT*+, Li+, and the Si-O-Al nearest group of the zeolite framework.

The Sorption of Anthracene onto Goethite and Kaolinite in the Presence of Some Benzene Carboxylic Acids

The uptake of anthracene from dilute aqueous solutions onto goethite and kaolinite was investigated at 25°C, first in the absence and then in the presence of three benzene carboxylic acids: phthalic acid (benzene-1,2-dicarboxylic acid), trimesic acid (–1,3,5–), and mellitic acid (–1,2,3,4,5,6–). Carboxylic acid concentrations were 0.20, 0.10, and 0.05 mM. Anthracene (0.20 μM) did not adsorb strongly onto the pure mineral surfaces, but in the presence of phthalic acid a substantial increase in anthracene uptake was observed, particularly for the goethite systems. Trimesic and mellitic acids did not enhance anthracene uptake. Phthalate and proton adsorption data have been used to model phthalate adsorption onto the mineral surfaces using an extended constant capacitance surface complexation model. This model was then successfully adapted to account for the observed increase in anthracene uptake, where anthracene molecules were assumed to interact with adsorbed phthalate. We propose that the enhancement of anthracene adsorption in the presence of phthalic acid is due to an increase in the hydrophobicity of the mineral surface once phthalic acid molecules adsorb. The same effect was not observed for the other benzene carboxylates because of their greater polarity.

Sorption of anthracene, phenanthrene and 9,10-dimethylanthracene on activated acid HZSM-5 zeolite. Effect of sorbate size on spontaneous ionization yield

In situ diffuse reflectance UV visible and Raman scattering spectroscopies were used to monitor the spontaneous ionization of anthracene, phenanthrene and 9,10-dimethylanthracene by direct exposure to thermally activated acid HZSM-5 zeolite. Calcination of the zeolite under oxygen is a prerequisite for the spontaneous ionization through the formation of Lewis acid sites. The framework structure of ZSM-5 zeolites contains two types of intersecting channels sufficiently wide to allow rod-shaped molecules like anthracene to pass through and to diffuse into the void space. As expected, molecular modeling calculations suggest that anthracene is able to penetrate into the void space of zeolite and that phenanthrene and dimethylanthracene cannot pass through due to steric constraints. The anthracene radical cation is found to be generated in high yield and to be stable over several months. The tight fit between the shape of anthracene and the pore size of the straight channels of the zeolite is considered to be the main factor responsible for the stabilization of the anthracene radical ion. Dimethylanthracene is found to generate dimethylanthracene radical cation in very low yield. Dimethylanthracene radical cation is probably located at the pore openings and is not stabilized in the void space. Ionization of phenanthrene occurs in low yield. However the resulting stable radical cation is identified as anthracene radical cation. The assumption is made that phenanthrene isomerizes readily at the openings of pores via its radical cation.

The Sorption of Pyrene and Anthracene to Humic Acid‐Mineral Complexes: Effect of Fractional Organic Carbon Content

AbstractCarbon‐normalized distribution coefficients (Koc) of organic solutes appear to increase as the amount of organic C in a system decreases. This study was conducted to determine the effect of fractional organic C content (foc) on the sorption of anthracene and pyrene. Batch‐sorption experiments were conducted on reagent CaCO3, a geologic calcite, and a montmorillonite to measure anthracene and pyrene sorption. An organic C‐free mineral surface and two surface loadings of humic acid (HA) were evaluated. The Koc of anthracene and pyrene varied with foc as well as with the underlying mineral surface. The sorption of anthracene and pyrene to all HA‐mineral complexes increased with increases in foc, while Koc for the compounds decreased. In higher foc systems (&gt;3 × 10−5), isotherms were C‐type curves indicative of partitioning. In lower foc systems (&lt;3 × 10−5), isotherms were commonly L and S‐type curves indicative of adsorption and condensation. Sources of potential experimental artifact examined were loss of HA from the mineral surface to solution, dissolution of CaCO3 during the experiment, and loss of NOS to experimental glassware or volatilization. None were found to contribute to the observations made. Our results suggest that adsorption‐condensation of pyrene and anthracene created more surface excess than predicted by partitioning alone as evidenced by the large experimental Koc values obtained.

Graft copolymers of methacrylic acid and SBS and K-resin by the anthracene photosensitized formation of hydroperoxides

The sorption of anthracene from a methanolic solution into SBS and K-resin has been studied. More anthracene may be sorbed into K-resin than into SBS; this is surprising since the free volume will be in the butadiene phase and SBS contains substantially more butadiene than does K-resin. For both polymers, photolysis generates singlet oxygen and hydroperoxides in the butadiene region. The effects of anthracene and methacrylic acid concentration, time and temperature have been investigated.

Influence of organic cosolvents on sorption of hydrophobic organic chemicals by soils

Sorption of anthracene and two herbicides (diuron and atrazine) by soils from aqueous solutions and binary solvent mixtures consisting of methanol-water and acetone-water was measured. These data were used to evaluate recently proposed solvophobic theory for describing sorption of hydrophobic molecules from mixed solvents. As predicted by the theory, the sorption coefficient (K/sup m/) decreased exponentially with increasing fraction of the organic cosolvent (f/sup c/) in the binary solvent mixtures. The slope of the ln K/sup m/ vs. f/sup c/ plot, designated as sigma/sup c/, was unique to each sorbate-solvent combination and was independent of the soil (sorbent). Thus, the organic cosolvent effects on sorption could be specified by a single parameter that combines the coefficients characterizing solvent and sorbate properties. The sigma/sup c/ value was shown to be directly proportional to the solvent-sorbate interfacial free energy( ..delta gamma../sup c/) and the hydrocarbonaceous molecular surface area (HSA) of the sorbate.