Negative values of ∆G0 of the three estrogens indicated spontaneous adsorption and the degree of spontaneity of the reaction decrease with increasing temperature. Because the physical sorption energies are in the range of 0 to −20 kJ/mol and the chemisorption energies in the range of −80 to −400 kJ/mol . The interaction between the three estrogens and Nylon 6 nanofibers mat can be considered as a physical adsorption rather than chemisorption. The negative PF-6463922 price values of ∆H0 indicated that the adsorption process of estrogens on Nylon 6 nanofiber mat was exothermic process. The negative values of ∆S0 indicated the decreased randomness at the solid/solution interface during the adsorption of three estrogens in aqueous solution on the nanofibrous membrane. Dynamic disk mode studies Continuous adsorption trials in dynamic flow mode were performed in a home-made disk filter device for the removal of three model estrogens in 100 mL solution. Since the adsorption performance of adsorbents usually depends on available sorbent amount for adsorption, the effect of the Nylon 6 nanofibers mat amount was examined in the range of 1.0 to 5.0 mg (the initial concentration
was 5.0 mg/L and NF-��B inhibitor flow rate was 1.0 mL/min). The results indicated that the amount of AZD8931 purchase adsorbent strongly influenced estrogens adsorption yield. The removal yields of DES, DS, and HEX increased from 70.15 ± 1.93% to 97.59 ± 2.26%, 62.47 ± 1.96% to 96.72 ± 1.81%, and 60.32 ± 2.23% to 96.26 ± 1.68%, respectively, with an increase in the adsorbent amount from 1.0 to 4.0 mg, and the variations of removal for target contaminants using 5.0 mg nanofibers were not remarkable. The higher adsorption yields for higher adsorbent amount are due to the increase of more available binding sites for the adsorption. And then, after a certain point (4.0 mg), the adsorption yield stayed
nearly constant may be due to the saturation of binding sites on the adsorbent surface. Therefore, 4.0 mg of the Nylon 6 nanofibers mat was found to be optimum of the further dynamic flow mode adsorption. The effect of the flow rate on the estrogen adsorption in continuous mode was also investigated. Cepharanthine The flow rate of estrogens solution was varied from 0.5 to 4.0 mL/min while the initial concentration (5.0 mg/L) and adsorbent amount (4.0 mg) were kept constant. It was found that the flow rate strongly influenced estrogen uptake capacity, and lower flow rates favored estrogen adsorption. The maximum removal yields were obtained at flow rates of 0.5 and 1.0 mL/min (p > 0.05). The adsorption capacity significantly decreased with increased flow rate from 2.0 to 4.0 mL/min (p < 0.05). This was due to a decrease in the residence time of estrogens within the Nylon 6 nanofibers mat at higher flow rates. This caused a weak distribution of the liquid inside the mat, which leaded to a lower diffusivity of the adsorbates to the binding sites for the adsorption. Therefore, removal yields of DES, DS, and HEX decreased from 97.