| Environmental Endocrine Disruptors(EEDs), a typical pollutant of humus, is formed from a series of chemical and biological reactions of plant and animal biomass. The presence of EEDs in natural waters may cause harmful effects on human health. Therefore, how to effectively remove HA has become a hot research field of water treatment.The biggest advantage of adsorption method is the good removal rate of metal ions and biological refractory organics which are difficult to treat with bio-method, which make it widespread concern on the field in environmental functional materials. In this paper, three kinds of adsorbents different degrees of oxidation, GO-Ti O2 and GO-CTAB were synthesized and characterized in the laboratory. The experiment of removing Tetracycline(TC) and Bisphenol A(BPA) with this three kinds of adsorbents which to study the factors on the adsorption process such as temperature, initial concentration, adsorption time, p H and cation were researched in this paper. Binding characterization results and adsorption data, the conclusions are as follows:Adsorption of TC on GO-1,GO-2 and GO-3:(1) GO-1, GO-2 and GO-3 surface contained different degrees of carboxyl and hydroxyl functional groups after oxidation from the graphite,and the crystalline structure had a corresponding change, the oxygen content increased with the degree of oxidation increasing.(2) GO-1,GO-2 and GO-3 has a good adsorption capacity on TC and the maximum adsorption amount at 25 ℃ were 74.63 mg/g,55.25mg/g and 47.26 mg/g. And adsorption equilibrium was achieved with 150 min. Frendlich equation could be well fitted on the adsorption isotherm and the adsorption was a non-homogeneous adsorption process.Adsorption kinetics can be fitted with a pseudo- second kinetic equation.(3) The TC adsorption on GO-1, GO-2 and GO-3 decreased with increasing p H of the solution. The presence of cations in solution wouldreduce the amount of adsorption, the order of cations effects on adsorption is Ca2+>K+≈Na+.(4) TC adsorbed on GO-1 could be effectively desorbed in alkaline solution. Adsorption amount of TC had no apparent decrease after desorption,it had a good desorption and recucling property.Adsorption of TC on GO-Ti O2:(1) Ti O2 was polymerized on the surface of GO by hydrothermal reaction, the grain type and structure of GO had changed, and the composites contained Ti element, which indicated successful synthesis of GO-Ti O2 adsorbent.(2) The GO-Ti O2 adsorbent showed high adsorption capcity for TC,In this studay, the maximum adsorption amount was 117.98 mg/g at 25℃.Adsorption equilibrium was achieved with in 300 min. Adsorption isotherms at different temperature obeyed Frendlich model, the adsorption was an endothermic process and physical adsorption mainly. The adsorption kinetics followed pseudo-second-order equation, the adsorption was a non-homogeneous adsorption process and would be affected by boundary layer diffusion.(3) TC adsorption on GO-Ti O2 was highly dependent onsolution p H.The TC adsorption on GO-Ti O2 decreased with increasing p H. And Ca2+ion could evidently reduce the adsorption.(4) TC adsorbed on GO-Ti O2 could be effectively regenerated under UV irradiation, and the photodegradation-regeneration rate was 81.20%.The adsorption amount was 87.96mg/g after forth photodegradation-regenetation cycles, it had a good recucling propertyAdsorption of BPA on GO-CTAB:(1)Based on the analysis of TEM, XRD and FTIR, the CTAB had effectively covered on the surface of GO. And the crystal structure of GO changed.(2) GO-CTAB had a higher adsorption capacity on BPA compared with G and MWCNT, and the maximum adsorption amount of BPA on GO-CTAB, G and MWCNT at 25℃ was 236.18mg/g, 12.42 mg/g and81.76 mg/g. Langmuir equation is well fit on the adsorption isotherm and the adsorption was an exothermic and entropy reduction adsorptionprocess. Adsorption kinetics could be fitted with the pseudo-second kinetic equation, BPA are adsorbed in the form of homogenous coverafe on the adsorbents’ surface. And the adsorption process reaches equilibrium within 150 min.(3) In the p H of acidic and neutral range, the adsorption amount of BPA on GO-CTAB, G and MWCNT had little change, while the adsorption amount reduced significantly under basic conditions. The presence of cations in solution would increase the amount of adsorption,and Ca2+ could significantly promote the adsorption capacity of the adsorbent.(4) TC adsorbed on GO-CTAB can be effectively desorbed in 0.1M Na OH solution. Adsorption amount of BPA had no apparent decrease after forth desorption-regenetation cycles, which indicated the regenerated GO-CTAB could be used repeatedly. |
