| Endocrine-disrupting chemicals(EDCs),one sort of theemerging environmental contaminants,have attracted increasingconcern among public in recent years because of they can disrupt the natural balance of hormones in both wildlife and humans.Phthalic acid esters(PAEs)is a kind of important industrial chemicals and intermediate,among them,dibutyl phthalate(DBP)and dioctyl phthalate(DOP)are the two most widely used PAEs,which is widely used with the rapid development of industry.As typical contaminant among EDCs,the chemicals are extensively detected in the worldwide.Therefore,this study applied PAEs as the target contaminants.In this study,a novel adsorbent(PP-g-GMA-(n-OA))was designed and prepared via grafting polymerization of glycidyl methacrylate(GMA),and subsequent amination modification of 4-n-Octylaniline(n-OA)on the surface of polypropylene nonwoven.The morphological structure,composition and wettability of the PP-g-GMA-(n-OA)were thoroughly characterized by SEM,FT-IR,XPS,water contact angle.To elucidate the superiorities of the adsorbent,one specific structure were constructed as comparison(PP-g-GMA-DA).Theadsorption properties of DOP and DBPonto PP-g-GMA-(n-OA)were investigated based on the adsorption behaviors including adsorption isotherms,kinetics and thermodynamics studies,and the adsorption mechanism was also investigated in detail.The effects of temperature,PH,ionic strength and humic acid(HA)have been discussed by batch adsorption experiments.The reusability and stability of the adsorbent was also studied.According to the characterization of adsorbent and the experimental data of adsorption,the following conclusions were obtained:(1)The pseudo-second-order kinetic and Freundlich isotherm models were more applicable to simulate the adsorption behavior,which indicated thatthe surface multilayer heterogeneous adsorption occurred on PAEs(DBP and DOP)adsorption process.The saturation adsorption capacity ofDBP and DOPon PP-g-GMA-(n-OA)could reach 184.9 mg/g and 272.4 mg/g,respectively.The thermodynamic parameters confirmed the adsorption was spontaneous and exothermic process.(2)The presence of NaCl in the solution could facilitate the adsorption process,whereas the strong acid or strong alkaliconditions and higher temperature of the solution were unfavorable.Moreover,the humic acidin the solution could obvious fcilitatethe adsorption process,resulting in higher adsorption capacity.(3)Adsorption mechanism was also investigated using the results of adsorption behavior and spectrum analyses after adsorption,which demonstrated thatsynergistic effect of π-π interaction,hydrophobic interaction and hydrogen bonds,especially π-πinteraction played a dominated role in PAEs(DBP and DOP)adsorption.(4)In additional,the obtained adsorbents could be easilyregeneratedthrough methanol/water washing and the adsorptioncapacity of PP-g-GMA-(n-OA)was well maintained at 91%even forfive regeneration cycles. |
