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(56-08) Behaviour of selected endocrine modulators with the adsorption at activated charcoal. Fürhacker, Maria*,1, Staubmann, Klaus1, Vospernik, Paul1, 1 Institute for Water Provision, Water Ecology and Wastemanagement, Wien, Austria ABSTRACT- In the context of an Austrian research project on endocrine modulators (ARCEM) it is examined to what extent the concentration of endocrine modulators is influenced by conventional drinking water technologies.In this study laboratory experiments were conducted to find out if activated charcoal (AC)adsorption is a suitable procedure for the elimination of 17 Key words: endocrine modulators, adsorption, 17 |
-estradiol, 17
-ethinylestradiol and estron from drinking water and where the limitations of this system with regards to these substances have to be drawn. The studied concentrations are in the range between 1 and 100 ng/l. Equilibrium between residual concentration in the solution and corresponding loading of the AC are described. The single substance adsorption isotherm experiments at AC of the type "Chemviron F200" were performed following the "DVGW paper W 240". In addition to the batch tests continuos experiments through a filter bed of 10 cm height with constant filter rate (5 m/h) were carried out. The effluent concentration was determined over the time. Adsorption isotherms were drawn for batch and continuous-flow (short fixed bed) experiments using radio-labelled compounds. All three examined steroids showed regarding the equilibrium very similar adsorptive properties (Kf=0,3 to 4.5, n=0.9 to 1.0). Although in the literature no data in the examined, very low concentration range (0.5 to 25 ng/l) are available the results indicate that the equilibrium for the steroids is situated substantially more unfavourably, as for other substances, which are usually removed by means of AC adsorption. If one extrapolates the isotherms, for the same requested residual concentrations the resulting equilibrium loadings for the steroids are two to three powers of magnitudes under that of other substances like trichloroethene, tetrachloroethene or benzene. With the continuous experiments however a substential higher loading of the AC was achieved, than is derived from the adsorption isotherm (q = 1.10-4 mol/kg instead of 1.10-7 mol/kg for c=50 ng/l). That means it that the adsorption behaviour of 17