QSAR Models To Predict Effect of Ionic Strength on Sorption of Chlorinated Benzenes and Phenols at Sediment–Water Interface

Abstract

Abstract}It is hypothesised that the experimental sorption coefficient normalised to the organic carbon fraction of sediment (K exp oc ) for non-ionic, hydrophobic, organic pollutant depends upon the molecular properties as well as background ionic strength of the aquatic system. The utility of this concept has been demonstrated by incorporating ionic strength as a parameter in the three quantitative structure activity relationships (QSARs) namely octanol-water partitioning coefficient model (Kow model), the linear solvation energy model (LSE model), and molecular connectivity indices theory (MCI model). Four chlorinated benzenes and two chlorinated phenols were employed in the present study. Sorption experiments using sediment from the Patalganga River were conducted in laboratory (bottle point method) at different ionic strengths (viz. 0.01, 0.05, and 0.10 M). The K cal oc values predicted using Kow model incorporating ionic strength compare reasonably well with the K exp oc values (r 2 ¼ 0:60 and standard error of estimator i.e. SEE=0.35). The LSE model incorporating ionic strength too, was found to be equally good (r 2 ¼ 0:67, SEE=0.33). An attempt has also been made to validate the QSARs developed in the present study utilising the sorption parameters experimentally measured by Dewulf et al. (1996)

Impacts of environmental conditions on the sorption of volatile organic compounds onto tire powder

“…Similar observations have been reported by Zhao et al [23]. Rao and Asolekar [24] studied that the effect of ionic strength on sorption of chlorinated benzenes and phenols at the sediment-water interface. They found that ionic strength had a strong effect for ionizable chemicals such as phenol as compared to that of either polarisable chemicals such as chlorobenzene or non-polar chemicals such as benzene.…”

Electrochemical incineration of cresols: A comparative study between PbO2 and boron-doped diamond anodes

“…Phenol and its derivatives are the major constituents of industrial wastewater produced by oil refineries, petrochemicals, polymeric resins, pharmaceuticals, coal conversion plants and chemical industries (Rajkumar and Palanivelu, 2003;Ródenas-Torralva et al, 2005;Wu et al, 2006). Their high aqueous solubility and weak adsorption to most soils result in a quick entry into groundwater due to leaching (Rao and Asolekar, 2001). The concentration of these compounds in agro-industrial wastewaters can vary from 0.05 to 10 g L À1 depending on the type and origin of the effluent.…”

Chemical Introductions to Estuarine and Coastal Systems

“…A few studies have examined the effect of high salinity (ionic strength) on the sorption of organics (Sullivan et al, 1982;Rao and Asolekar, 2001;Turner, 2003), generally finding increased adsorption for nonpolar (i.e., more hydrophobic) organic compounds. A high K d indicates that the organic compound is likely to partition strongly onto the particular sediment.…”