The effects of various variables in process such as adsorbent amount (1.0 to 5.0 mg, depended on the thickness of the Nylon 6 nanofiber mat) and flow rate (0.5 to 4.0 mL/min) on removal yields were assessed and optimized at the constant initial concentration (5.0 mg/L). The maximum dynamic check details adsorption capacities of estrogens on Nylon 6 nanofiber mat were evaluated
under the optimum dynamic flow conditions via breakthrough initial concentration (1.0 to 20.0 mg/L). Figure 1 Home-made disk filter device for dynamic disk mode adsorption studies. Desorption experiment For desorption studies, 1.5 mg Nylon 6 nanofibers mat was first contacted with 50 mL 2 mg/L estrogens for 6 h at 298 K. Then the adsorbent was eluted by 0.5 mL click here methanol/water (80:20, v/v, i.e., mobile phase for HPLC separation) for 20 min. Before the second adsorption, Nylon 6 nanofibers mat was washed with 0.5 mL water on a magnetic stirrer at 200 rpm. The above procedure was repeated for seven times to test the reusability of the adsorbent. Results and discussion Morphology of the nanofibers mat The morphology YH25448 cell line of Nylon 6 nanofibers mat was studied by SEM; the results are shown in Figure 1. We can see that the surface of Nylon 6 nanofibers was smooth, the average diameter is about 200 nm, and the average specific surface of Nylon 6 fibers was 23.90 m2/g. Adsorption kinetics The effect of adsorption time on the adsorption capacity at different initial
solution concentration is shown in Figure 2. The results indicated Cyclooxygenase (COX) that the adsorption capacity of the three estrogens increased with an increase in adsorption time until equilibrium was reached between the adsorbents and estrogens solution. The equilibrium time of the three estrogens increased from 120 to 180 min as the initial solution concentration increased from 0.1 to 2.0 mg/L. And the equilibrium capacity DES, DE and HEX increased from 2.98 to 68.88 mg/g, 3.21 to 66.66 mg/g, 3.01 to 64.22 mg/g, respectively,
with the initial concentrations of estrogens solution increase from 0.1 to 2.0 mg/L. Figure 2 Time and concentration to the adsorption of DES (a), DE (b), and HEX (c). In order to better understand the adsorption behaviors, parameters from two commonly used kinetic models, namely, the pseudo-first-order and the pseudo-second-order, were fit to experimental data to examine the adsorption kinetics of three estrogens uptake by Nylon 6 nanofibers mat. These two kinetic models are used to describe the adsorption of solid/liquid systems, which can be expressed in the linear forms as Eqs. (4) and (5), respectively : (4) (5) where K1 and K2 are the pseudo-first-order and second-order rate constants, respectively. The adsorption kinetic plots for the adsorption of three estrogens are shown in Figure 3, and the obtained kinetic parameters are summarized in Table 1. Figure 3 The adsorption kinetic plots for the adsorption of three estrogens.