| Chlortetracycline hydrochloride（CTC）,one of the tetracycline,is widely used as an infection treatment drug for human and livestock and as a growth promoter for crops.It has good solubility,pseudo persistence and hard-to-degrade property.Currently,many countries have reported that antibiotics have been detected in effluent from sewage plants,groundwater and rivers.Typically,the concentrations of antibiotics in the water can be increased due to the over-uses of antibiotics,high-concentration discharges of industries and emergency leaks.The accumulated antibiotics will do harm to the health of human and environmental ecosystem.However,considering the incomplete degradations of antibiotic by using common wastewater treatment technologies,adsorption has been regarded as one of the alternative technologies with the characteristics of highly adaptations and conveniences.Therefore,various Fe-based metal-organic gels（MOGs）are prepared by a solvothermal method for solving the above problems,which possess large specific surface areas,various pore structures,abundant active sites and large adsorption capacities.After determining the significant influenced parameters and relevant ranges by batch experiments,the optimal operating conditions of powder-like MOG adsorbents could be obtained by response surface methodology（RSM）.However,there are still problems such as agglomeration and precipitation during the adsorption processes.Constructing the loaded adsorbents on the carriers can solve these shortcomings,however,it is not suitable for the actual applications due to the disadvantages of common carbon carriers including complex fabrication procedures and high energy consumptions.Based on that,granular cellulose-based MOG adsorbents were constructed by in-situ fabrication for adsorptive removal of antibiotics in a continuously operated adsorption bed.Besides,introducing the lanthanide metals into the fabrication procedures endows adsorbents with fluorescence property accompanying with broadened potential application prospects,which can act for detecting antibiotics and judging the life-span of adsorbents.Through above-mentioned discussions,JLUE-MOG-1 and JLUE-MOG-2 had been successfully prepared for the adsorption removal of CTC based on the single metal specie(Fe3+or Al3+).Specifically,the maximum adsorption amounts for CTC were 1259.45 mg·g-1 and 625.00 mg·g-1,respectively.Moreover,three novel（Fe-Al）JLUE-MOG-3,JLUE-MOG-4 and JLUE-MOG-5 with stronger adsorption capacities were successfully synthesized with the relevant adsorption amounts of1841.62 mg·g-1,1600.00 mg·g-1 and 1396.65 mg·g-1,respectively.Simultaneously,the granular JLUE-MOG-4@cellulose adsorbent was constructed and used for adsorptive removal of CTC in the continuously operated adsorption bed,which achieved 94.00%CTC adsorption removal with inlet CTC concentration of 10.0mg·L-1 during the operation of 24.0 h.These adsorbents not only facilitate subsequent separations and recoveries,but also maintain strong CTC adsorption removal capacities and excellent availabilities.The fluorescent adsorbents can detect the concentrations of pollutants and reflect the conditions of adsorbents.Thus,the fluorescent（Fe-Eu）JLUE-MOG-6,JLUE-MOG-7 and JLUE-MOG-8 and fluorescent（Fe-Tb）JLUE-MOG-9,JLUE-MOG-10 and JLUE-MOG-11 were successfully prepared.Through monitoring the adsorptive performances under various conditions,the maximum CTC adsorption amounts of JLUE-MOG-6,JLUE-MOG-7 and JLUE-MOG-8 were227.76 mg·g-1,346.61 mg·g-1 and 479.05 mg·g-1,respectively.In addition,the maximum CTC adsorption amounts of JLUE-MOG-9,JLUE-MOG-10 and JLUE-MOG-11 were 911.99 mg·g-1,1518.62 mg·g-1 and 1520.79 mg·g-1,respectively.Moreover,the fluorescence quenches of both adsorbents kept linear relationships with various CTC concentrations.The detection limit of JLUE-MOG-7towards CTC was 0.52μM,while JLUE-MOG-9 had a higher sensitivity than JLUE-MOG-7 with CTC detection limit of 0.079μM（about one-tenth of the latter）.To be accurate,ligand to metal charge transfer and antenna effect were the main mechanisms for fluorescence emission,while inner filter effect（IFE）was the main mechanism for the fluorescence quenching of JLUE-MOG-9.Further,the different applications were established according to the various fluorescence sensitivities of adsorbents.For one hand,the granular fluorescent JLUE-MOG-7@cellulose aerogels were constructed and used in the continuously operated adsorption bed.The penetration curve was consistent with the Thomas and Bohart-Adams models with breakthrough point of 10.0 h.During the adsorption processes,the fluorescence colors of adsorbent can straightforwardly correspond to various different stages and then reflect the life-span of adsorbents.For the other hand,the concentrations of CTC in wastewater could be obtained by fluorescent changes of JLUE-MOG-9assisted by a smartphone.Apart from that,the fluorescent JLUE-MOG-9@paper and analytical device were constructed for reflecting the CTC concentrations towards the actual water samples.In this thesis,a series of high-performance adsorbents have been successfully prepared for the antibiotics removals and fluorescence responses in wastewater,which not only have higher CTC adsorption capacities,but also can determine the life-span of adsorbents and detect the concentrations of antibiotics in wastewater.This study has practical significances on the applications of MOG adsorbents for antibiotic wastewater treatments. |
