Influence of colloids on sediment-water partition coefficients of polychlorobiphenyl congeners in natural waters

The factors controlling the partitioning of polybrominated diphenyl ethers and polychlorinated biphenyls in the water-column of the Pearl River Estuary in South China

“…These results are consistent with those of Butcher et al (1998), which suggests that less than 10% of PCBs containing three or more chlorines are sorbed to colloids in the Hudson River (USA) under normal conditions (4.79 mg/L DOC and 1.40 mg/L POC). These values conflict with the findings of Baker et al (2002) and Totten et al (2001), who have suggested that at commonly encountered DOC and SPM concentrations, substantial fractions of moderately hydrophobic compounds were sorbed to the colloidal phase. It should be noted that the PCB congeners detected in the present study were di-to tetra-chlorobiphenyls, which are less hydrophobic compounds compared to higher chlorinated congeners.…”

“…The colloidal-associated contaminants may be the dominant species in some surface waters. Therefore, colloidal associations significantly impact the geochemistry of HOCs (Totten et al, 2001;Baker et al, 2002). In the particulate phase, carbonaceous materials, such as black carbon (BC), have been shown to be the principal particulate component responsible for the adsorption of HOCs such as pesticides and PAHs (Zhou et al, 1996;Orecchio, 2010).…”

The effect of protozoan grazers on the cycling of polychlorinated biphenyls (PCBs) in marine systems

“…Consequently, it is clear that the two-phase equilibrium model does not fully explain the partitioning behavior of hydrophobic organic contaminants observed in aquatic systems (Wijayaratne and Means, 1984;Gschwend and Wu, 1985;Baker et al, 1986;Brownawell and Farrington, 1986). The reason for this lies in the difficulty of determining analytically the true aqueous concentration, C, due to interferences by macromolecular or colloidal material within the aqueous phase.…”

“…Subsequent investigations noted enhanced aqueous concentrations over that expected from aqueous solubility calculations (Carter and Suffet, 1982;Chiou et al, 1986). These enhanced aqueous concentrations have since been attributed to interactions between hydrophobic contaminants and colloidal or dissolved organic matter (Gschwend and Wu, 1985;Baker et al, 1986;Brownawell and Farrington, 1986;Gunnarsson and Rosenberg, 1996). Since the recognition of the role of colloidal/dissolved organic matter in contaminant speciation, numerous studies have attempted to collect and characterize this material and its sorptive qualities (Schlautman and Morgan, 1993;Chin et al, 1997;.…”

Biogeochemical Processes Governing Exposure and Uptake of Organic Pollutant Compounds in Aquatic Organisms

“…Field and laboratory evidence from several studies with PCBs has established that partitioning of hydrophobic compounds to colloids or very small particles must be considered in many natural water systems to account for the observed distributions of hydrophobic compounds in the dissolved and particulate fractions of water samples (43,44,54,55). Nomographs similar to those ofFigure 2 (32) have been presented (46,55,56) and are useful in providing first order assessments of the physical chemical state of a given hydrophobic pollutant in coastal, estuarine, riverine, lacustrine, and interstitial waters.…”