Sorption interaction of phenanthrene with soil and sediment of different particle sizes and in various CaCl2 solutions

Abstract

The objective of this investigation is to evaluate the influences of natural sorbent particle size and system Ca 2+ concentration on sorption of low-polarity organic chemicals. The physicochemical properties of the different particle size soil and sediment subsamples and the surface characters of the soil and sediment samples in various CaCl 2 concentrations were determined. The sorption behavior of phenanthrene (PHN) on the subsamples of different particle size and to the samples in various CaCl 2 solutions was examined. Batch experiments demonstrate that the sorption capacities increase with decreased particle size for both soil and sediment. It is presumably due to the higher total organic carbon (TOC) content for the finer particles. But the enhancements in sorption coefficients are not met with the equal increases in TOC contents. The effect of Ca 2+ on PHN uptake is strong in short contact time but slight in long contact time. With increasing Ca 2+ concentration, the sorption capacities for Beizhai soil increase first in the low Ca 2+ concentration range, and then decline. Nevertheless, the increase of Ca 2+ concentration greatly reduces the uptake of phenanthrene on Guanting sediment over the overall measured range. The different physicochemical properties, such as dissolved organic carbon (DOC) content, mineral and element composition, and surface characters, between soil and sediment may result in this discrepancy.

Effects of particle size, organic matter and ionic strength on the phosphate sorption in different trophic lake sediments

“…The tubes were capped and placed at 25 ± 1 • C in an orbital shaker at 250 rpm for various time intervals between 0 and 60 h (0.5, 1, 1.5, 2.5, 5,9,13,18,24,36,48 and 60 h). The supernatant was immediately centrifuged at 5000 rpm for 10 min and was then filtered through 0.45 m GF/C filter membranes.…”

“…For the three studied sediments, TOC, TN, TP, Al and Fe contents and CEC increased as particle size decreased. This is probably due to the increase of clay mineral concentration in the clay fraction and the larger specific area for the fine fractions [36,37]. As fractions with different sizes had different specific surface areas and weight, they had different effects on the exchange of phosphate between sediments and the overlying water.…”

Facilitating Effects of Metal Cations on Phenanthrene Sorption in Soils

“…Coagulation of OC has been demonstrated to decrease the sorption of PAHs (12)(13)(14). However, several studies have also claimed that condensed OC exhibits greater sorption capacity and nonlinearity for PAHs (9,10,15).…”

Effect of salinity and sediment characteristics on the sorption and desorption of perfluorooctane sulfonate at sediment-water interface

“…The calculated n both decreased at pH 7.0 and 8.0 as the CaCl 2 concentration increased. Electrolyte CaCl 2 , in the concentration of 0.005 mol L À1 was often used as mineral background to simulate freshwater (Higgins and Luthy, 2006;Zhou et al, 2004). In order to evaluate the effect of salinity on the sorption and desorption, 0.05 and 0.5 mol L À1 CaCl 2 were used as the background electrolyte for this study.…”