Studies On The Removal Of Environmental Estrogen-Genistein And Tricyclazole By MWCNT

In this paper,a fast and efficient method for separation and enrichment genistein/tricyclazole was developed in water samples.MWCNT did as solid phase extraction(SPE)sorbents and HPLC detection.This experiment determined the optimal conditions for the removal and recovery of genistein/tricyclazole,and also systematically studied the optimum conditions and mechanism of MWCNT adsorpting genistein/tricyclazole.1.By studying six kinds of carbon nanotubes(MWCNT,MWCNT-OH,MWCNT-COOH,Short-MWCNT,Short-MWCNT-OH Short—MWCNT-COOH)for the removal of genistein/Tricyclazole.MWCNT without modified has shown the great potential as a kind of effective adsorbents for genistein/tricyclazole in water samples treatment.The optimum conditions of MWCNT adsorpting and desorpting genistein/trieyclazole listed as follow:the removal percentages of genistein/tricyclazole could reach up to 97.3%/98.4%with 10mg/20mg MWCNT,ethanol-NaOH(V:V=7:3)/ethanol as resolution agent could get the best desorption rate 90%.2.The influence of pH?ionic strength?interfering ions and the mechanism of adsorption:When the pH value is between 4-9,pH and ionic strength had no influence on adsorption process,the Impact of most of interfering ions on adsorption process almost can be ignored.the adsorption mechanism of MWCNT adsorpting genistein/tricyclazole mainly due to the Joint action of,?-? stacking interactions,hydrogen bonds and hydrophobic.3.The adsorption dynamics behavior of genistein/tricyclazole on MWCNT:the equilibrium was attained within 6.0 min following the pseudo-second-order model.At three temperatures(283K?298K?313K),the rate constants(k):genistein 0.0224?0.0404 and 2.932 g mg-1min?1,and tricyclazole 0.116?0.0558 and 0.0349 g mg-1min-1.Kinetic data and diffusion model fitting results indicate:the overall rate process mainly governed by the external mass transfer.4.The sorption machanism could be well interpreted by the Langmuir model with the maximum adsorption capacity of genistein 113.379%100.200 and 88.417 mg·g-1 and tricyelazole 229.358?194.932 and 164.474 mg*g-1 latthe mentioned temperatures.The thermodynamics constants of genistein/tricyclazole ?H0?0,?G0<0 showed that the adsorption process was spontaneous exothermic reaction.The average free energy of genistein/tricyclazole calculated from Dubinin-Radushkevich adsorption isotherm werel.886 kJ·moF-1 and 1.361 kJ·mol-1(298 K),which showed that the adsorption process is physical.5.Reuse and the actual sample analysis:MWCNT showed high stability in the recycling experiments and keep high effective in six times removal-regeneration recycles.The content of genistein/tricyclazole were detected in environmental water samples/soybean samples,environmental water/rice samples and made spiked analysis,the recoveries were reached(90.14%-112.52%),and 94.5%-109.90%respectively.This method can be used as actual sample handling of genistein/Tricyclazole.