Characterisation of complex organic matter present in contaminated sediments from water retention ponds

The aim of the present work is the study of the complex organic matter present in sediments from two retention ponds, Wissous located in an urban area and Cheviré receiving road runoff. The main questions are relative to the origins, the transformation processes and the final structure of organic matter. The sediment from Wissous contained 22.3 wt.% of organic matter, compared to 14.7 wt.% for the Cheviré sediment. FT-IR spectra did not reveal significant differences. Total organic matter (TOM) was fractionated into lipids and humic-like substances. “Humic acid” and “humin” fractions from the two samples were studied using pyrolysis techniques in presence of alkylating agents. The nature of TMAH pyrolysis products from Wissous and Cheviré “humic acids” did not differ. The presence of C7-C28 aliphatic monocarboxylic acid methyl esters with a dominant short