Affiliations: School of Environmental Science and Technology, Dalian
University of Technology, Dalian 116012, China. E-mail:
xiequan@mail.dlptt.ln
Note: [] Corresponding author
Abstract: A chemical sequential separation procedure for sediment bas been
developed for the adsorptive investigation of hydrophobic organic
compounds(HOCs) including four fractions: carbonate, hydrous metallic
oxide(ferric oxide, manganese oxide and alumina), clay and organic matter.
Adsorption isotherms of these hydrophobic solute probes, such as
hexachloroethane, lindane and 1,2,4,5-tetrachlorobenzene were measured for
model sorbents, model and natural sediment, and the latter of which was
pretreated with the simplified sequential separation method. The linear and
Langmuir models are applied to correlate the experimental data of humic
substance and other model sorbents respectively. Multi-component Adsorptive
Model (MCAM) was used to simulate adsorption isotherms of model and natural
sediment. The results reveal that( 1 ) the separation efficiencies of
carbonate, organic matter, ferric oxide, manganese oxide and alumina are 98.1 %
, 72.5% ,82.6%, 93.5% and 83.3%, respectively; (2) except for removing metallic
oxide, the external structure of sediment is not changed greatly after
separation; (3) the MCAM correlates the data of adsorption isotherm rather well
with the maximal relative deviations of 9.76 % , 6.78 %and 9.53% for
hexachloroethane, lindane and 1,2,4,5-tetrachlorobenaze in model sediment,
respectively. The MCAM can clearly give expression to the different adsorptive
mechanisms for HOCs in organic and inorganic matter, though the experimental
data in each component are not very accurate due to the sequential separation
efficiency.
Keywords: hydrophobic organic compounds, sediment, adsorption, model
