Elution of Pyrene from Activated Carbon into an Aqueous System Containing Humic Acid

Abstract

The elution of pyrene (Pyr) into an aqueous solution containing humic acids (HAs) was investigated using activated carbon (AC) as an adsorbent of Pyr. The apparent water solubility of Pyr that adsorbed to the AC was increased by the presence of HAs. To quantitatively interpret the water solubility enhancement of Pyr in the presence of HAs, the partition coefficient of Pyr was evaluated using a micellelike partition model that took into account the partition of Pyr between water and the HA phase. The relationship between the apparent water solubility of Pyr and the concentration of HA was not linear, as expected by that model. To explain this result, we introduced a Langmuir isotherm that assumed the re-adsorption of Pyr on the AC in a micelle-like partition model. The experimental data set fitted well to the derived equation, and the partition and adsorption coefficients were evaluated based on this model. The elution of trace amounts of Pyr from the adsorbent as affected by the presence of dissolved organic carbon was simulated using the derived coefficients.

Complex formation of water-soluble iron(III)-porphyrin with humic acids and their effects on the catalytic oxidation of pentachlorophenol

“…Such biomimetic catalysts have the potential to serve as clean remedial processes for the removal of organic pollutants in soils. In soil environments, humic acids (HAs) are ubiquitous and play important roles in the remediation of organic pollutants via a variety of interactions, including solubilization [5] and electron transfer [6]. However, HAs are heterogeneous compounds and their physicochemical properties vary with the type of soil.…”

Study of the Water Solubility and Sorption on Particulate Matters of Phthalate in the Presence of Humic Acid Using 14C Labelled Di-(2-Ethylhexyl)Phthalate

“…This experiment was conducted based on method reported in literature (Fukushima et al, 1997). The mixture of each PM (activated carbon, kaolinite, and ferrihydride) 1.0 g and 1.81 × 10 −3 mM DEHP in ethanol (100 mL) was stirred for 24 h. Subsequently, this mixture was filtered through a silica fiber filter (Advantec QR100), which can filtrate 99.9% of 0.3 μm particles (dioctyl phthalate).…”

“…However, since the DEHP molecule is much smaller than the HA macromolecule, we can assume on the first approximation that the sorption behaviour of HA-DEHP on PM is similar to that of HA (Fukushima et al, 1997) …”

Adsorption of pentachlorophenol to a humin-like substance–bentonite complex prepared by polycondensation reactions of humic precursors

“…On the one hand, humic substances are naturally occurring, surface active materials that have amphiphilic characteristics, thus giving them both hydrophilic and hydrophobic properties. Such functions of humic substances can serve as media for the sorption of hydrophobic organic contaminants, such as polycyclic aromatic hydrocarbons (Fukushima et al, 1997;Wang and Xing, 2005), polychlorinated dibenzo-p-dioxins (Yabuta et al, 2004;Tanaka et al, 2005;Fukushima et al, 2006) and chlorophenols (Robinson and Novak, 1994;Paolis and Kukkonen, 1997). In addition, it has been reported that the affinity of hydrophobic organic contaminants for clay minerals can be enhanced by complexation with humic substances (Terashima et al, 2003;He et al, 2006).…”