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Polyacrylamides are polymers used in many fields and represent the main source of release of the highly toxic acrylamide in the environment. In this work, a simple, rapid, and sensitive analytical method was developed with HPLC/MS/MS and direct injection for acrylamide analysis in water and adsorption samples. AFNOR standards NF T90-210 and NF T90-220 were used for the analytical method validation and uncertainty estimation. Limit of quantification (LOQ) for acrylamide was 1 μg/L, and accuracy was checked at three acrylamide levels (1, 6, and 10 μg/L). Uncertainties were estimated at 34.2, 22, and 12.4 % for acrylamide concentrations at LOQ, 6 μg/L, and 10 μg/L, respectively. Acrylamide adsorption on clays (kaolinite, illite) and sludge was then studied as a function of pH, time, and acrylamide concentrations. Acrylamide adsorption on kaolinite, illite, and sludge was found to be very weak since adsorption percentages were inferior to 10 %, whatever the pH value and the initial acrylamide concentration. The low affinity of acrylamide for clays and sludge is likely due to its hydrophilic property, small size, and charge neutrality.

The management of dredged sediments is an important issue in coastal regions where the marine sediments are highly polluted by metals and organic pollutants. In this paper, mineral-based amendments (hematite, zero-valent iron and zeolite) were used to stabilize metallic pollutants (As, Cd, Cu, Mo, Ni, Pb, and Zn) in a contaminated marine sediment sample. Mineral-based amendments were tested at three application rates (5 %, 10 %, and 15 %) in batch experiments in order to select the best amendment to perform column experiments. Batch tests have shown that hematite was the most efficient amendment to stabilize inorganic pollutants (As, Cd, Cu, Mo, Ni, Pb, and Zn) in the studied sediment. Based on batch tests, hematite was used at one application rate equal to 5 % to conduct column experiments. Column tests confirmed that hematite was able to decrease metal concentrations in leachates from stabilized sediment. The stabilization rates were particularly high for Cd (67 %), Mo (80 %), and Pb (90 %). The Microtox solid phase test showed that hematite could decrease significantly the toxicity of stabilized sediment. Based on batch and column experiments, it emerged that hematite could be a suitable adsorbent to stabilize metals in dredged marine sediment.