Sorption of Very Hydrophobic Organic Compounds (VHOCs) on Dissolved Humic Organic Matter (DOM). 2. Measurement of Sorption and Application of a Flory−Huggins Concept To Interpret the Data

Abstract

Sorption phenomena of very hydrophobic compounds (VHOCs, log K(OW) > 5) on dissolved humic organic matter (DOM) are overwhelmingly based on partitioning processes. In this respect, DOM is very similar to "rubbery" soil/sediment OM. To exclude system adsorption effects, the DOM sorption coefficients (K(DOM)) of VHOCs were determined using a dynamic approach based on the VHOCs' aqueous solubility enhancement in the presence of DOM. Partition coefficients are strongly correlated to the analytes' Kow across the alkane, PAH, and PCB groups under study. These three "families" are regarded to be good models of hydrophobic partitioning. On the basis of a uniform one-parameter concept characterizing sorption on amorphous polymers, Hildebrand solubility parameters of amorphous polymeric sorbents, including DOM, and of sorbates can be calculated on the basis of partition coefficients. Likewise, partition coefficients can be estimated using Hildebrand solubility parameters. Literature-based partition coefficients on DOM fit very well in this universal one-parameter concept. On using our own sorption data of PAHs, PCBs, and alkanes on DOM, an almost identical solubility parameter for the DOM polymer under study is obtained. The concept is also very useful in understanding both waterborne and airborne bioconcentration processes, which are considered to be partitioning phenomena.

Air–Seawater Exchange of Organochlorine Pesticides along the Sediment Plume of a Large Contaminated River

“…As a first approximation, we adopted in this study the one proposed by Poerschmann and Kopinke. 36 DOC concentration data for the ECS were taken from Hung et al 37 3. RESULTS AND DISCUSSION 3.1.…”

Solid Phase Microextraction for Sensing Freely Dissolved Analytes in Complex Water Sample

“…Biomimetic SPME has been widely applied to study the bioconcentration toxicity effect and uptake kinetics of OCs in aquatic biota [5,20,29,30,38,39,61]. Leslie et al [61] used an 85 μm polyacrylate (PA) coating to mimic the uptake of 2,4,5-trichloroaniline and 1,2,3,4-tetrachlorobenzene by midge larvae.…”

“…Several studies have showed that the DOM increases the solubility [4], decreases the volatilization [5], and also affects the bioavailability and toxicity of the OCs [6,7], as well as controls the leaching of pesticides in soil [8][9][10][11]. In addition, the presence of DOM enhances the photodegradation of pollutants through the production of reactive species such as hydroxyl radical or singlet oxygen [12], and inhibits the degradation of pesticides [13,14].…”

Determination of total and available fractions of PAHs by SPME in oily wastewaters: overcoming interference from NAPL and NOM

“…1. This method is suitable for the measurement of the freely available PAH and consequently also for the bioavailable PAH fraction in water samples (Poerschmann and Kopinke 2001;Ramos et al 1998). HS-SPME kinetics were modeled and fitted to experimental data obtained by performing extractions at different exposure times.…”

“…These binding interactions can be partitioning or adsorption phenomena, depending on the nature of the organic matter (Poerschmann and Kopinke 2001). The distribution or partitioning of non-ionic hydrophobic organic compounds like PAH between water and soil or sediment has been shown to depend primarily on the hydrophobicity of the compounds and on the fraction of organic carbon in the sorbent (Schlautman and Morgan 1993).…”