Removal of endocrine disruptors by sorption method using PDMS membranes

A study was carried out to investigate the concentration and removal of endocrine disrupting chemicals, e.g., DDT, biphenyl, polychlorinated biphenyls (PCB), and dibenzo-p-dioxins, from foodstuffs including breast milk, cow's milk, etc, performed by sorption method using hydrophobic polydimethylsiloxane (PDMS) membranes. The concentration of 1,2-dibromo-3-chloropropane (DBCP) in the solution dramatically decreased by the sorption using the PDMS membranes with the increase of time and the concentration of DBCP in the solution became almost constant after 30 min run. The optimal time to reach the equilibrium time of sorption was 3 hr. The removal ratio of DBCP in water or cow's milk increased with increasing weight of membranes used, although higher amount of membranes was necessary for the removal of DBCP in cow's milk compared to that in water. Thus, there was an equilibrium of DBCP concentration between the hydrophobic PDMS membrane, the micelles in cow's milk, and free water. Concentration of dioxin solution in aqueous solution decreased from 1.168 to 0.037 ppm in the sorption experiments due to the absorption of dioxin to PDMS membranes. On the other hand, in the desorption experiments, the concentration of dioxin in 2-propanol desorbed from PDMS membranes varied from 0 to 1.119 ppm, indicating 95% of removal ratio of dioxin. The removal ratio of endocrine disrupting chemicals in aqueous solution using PDMS membranes was high for the endocrine disrupting chemicals having high water-octanol distribution coefficients.