| Bagasse is one of the most productive solid wastes in sugar industry,with an annual output of more than 15 million tons.The existing conventional treatment methods,such as combustion,power generation,pulp and paper making,cannot meet the demand for its"resource and high value"environmental protection treatment.Solid-liquid heterogeneous photocatalytic advanced oxidation technology,as a relatively efficient treatment technology for water pollutants in recent years,has great development potential in studying the migration and transformation process of pollutants in different phase states and treating pollutants that are difficult to remove in water.Especially heavy metals in water body by antibiotics,such as multiple pollution increasingly serious today,to develop a kind of efficient in the combined system of pollution treatment containing antibiotics and heavy metals of solid-liquid heterogeneous photocatalytic materials,for the early realization of a harmonious coexistence between man and nature"beautiful China"target has extremely important significance.On this basis,using bagasse as solid-liquid heterogeneous photocatalytic solid catalyst in the main raw material,Ti O2 particles on the surface of bagasse in situ nucleation,again used the means of in situ synchronization"one-step"hydrogenated,let bagasse/Ti O2 synchronization by hydrogen reduction,the design has a kind of under the condition of visible light photocatalytic degradation of the water phase,and the refractory antibiotics Meanwhile,bagasse biochar supported modified Ti O2photocatalytic/adsorption multifunctional material（HSCB/H2-Ti O2）,which can adsorb heavy metal ions in water.Compared with the traditional"two-step"multi-functional materials,it has higher photocatalytic degradation efficiency and better reusability.Then examines the HSCB/H2-Ti O2 degradation mechanism and the mechanism of antibiotic in water of heavy metal ions in the process of adsorption of heavy metal migration transformation process,and it exists in the simulation of aquaculture wastewater pollution of heavy metals-antibiotics combined system of treatment effect was studied,for bagasse"resource,high value"provides a new idea.The main research contents and conclusions are as follows:（1）Research on modification method and mechanism of titanium dioxide with visible light responseThree kinds of conventional modification methods which can make Ti O2 produce visible light response were studied,and their effects on the visible light catalytic degradation efficiency of Ti O2 were compared.The change of visible light response of Ti O2 by different means was qualitatively analyzed by a series of characterization methods.Combined with energy band analysis,the influence of different means on Ti O2 photocatalytic degradation efficiency and the mechanism of Ti O2 photocatalytic degradation of organic matter under visible light were explained.The results showed that among the three different modification methods,hydrogen modified sample（H2-Ti O2）had the best methylene blue degradation efficiency,which could degrade about 95%methylene blue within 180 minutes.The degradation effect of hydrogen and fluorine doped modified sample（H2-F-Ti O2）is the next,and the degradation effect of fluorine doped modified sample（F-Ti O2）is the worst.The reason for the above results lies in their different band structures.Although the band gap width of F-Ti O2 decreases from 3.22 e V to 3.14 e V,it still fails to reach the band gap width（less than 3.11 e V）for the response to visible light,so it cannot respond to visible light.The band gap width of H2-F-Ti O2 is 2.91 e V.Although it can be excited by visible light,it is located at-0.37 V at the lower edge of its conduction band,so the electron energy is not enough to oxidize O2 to generate superoxide radicals,resulting in the decrease of its photocatalytic efficiency.However,the band gap of H2-Ti O2 is suitable（2.89e V）,and the energy of electrons and holes located in the conduction band and valence band is enough to react to generate superoxide radical and hydroxyl radical,so it has a very high degradation efficiency under visible light.（2）Preparation of HSCB/H2-Ti O2 multifunctional materials by in-situ simultaneous hydrogenation of bagasse supported Ti O2Firstly,the Ti precursor was loaded on the surface of bagasse by hydrothermal method,and then the bagasse/Ti O2was simultaneously reduced by hydrogen by one-step in-situ synchronous hydrogenation,and a bagasse biochar-based multifunctional material HSCB/H2-Ti O2 with the original macromorphology of bagasse was prepared.The differences of photocatalytic effect and reusability between HSCB/H2-Ti O2 and traditional"two-step"HSCB@H2-Ti O2 were investigated,and the reasons for the performance improvement of HSCB/H2-Ti O2 were explained by means of characterization.The effects of p H,dosage and modification temperature on the photocatalytic efficiency of HSCB/H2-Ti O2 were investigated.The surface morphology and internal structure of HSCB/H2-Ti O2 were further characterized,and the mechanism of improving the photocatalytic efficiency of HSCB/H2-Ti O2 was explained by combining band structure analysis and free radical capture experiment.The study shows that HSCB/H2-Ti O2 has a higher visible light catalytic degradation efficiency compared with HSCB@H2-Ti O2 prepared by"two-step"method,and 95%methylene blue can be degraded within 180 minutes under visible light irradiation.After 12times of repeated degradation of methylene blue,the degradation efficiency can still remain at55.1%.HSCB/H2-Ti O2 also had better reusability,and the catalyst recovery was up to 70%after12 repetitions.The"one-step method"can simultaneously introduce a large number of defect structures into the interior of skeleton material HSCB and supported H2-Ti O2.These defect structures not only reduce the recombination probability of electron-hole pair,but also reduce the band gap from 3.2 e V to 2.8 e V,enabling HSCB/H2-Ti O2 to respond to visible light.The introduction of bagasse biochar framework material reduced the agglomeration of supported particles,induced the crystallization process of Ti O2,inhibited the formation of rutile crystal in the high-temperature modification process,improved hydrophilicity,and increased the probability of contact between water molecules and organic matter.In addition,the addition of bagasse biochar framework material also provides more·O2-in the system.（3）Visible light degradation of Enrofloxacin by HSCB/H2-Ti O2 multifunctional materialsThe photocatalytic degradation of enrofloxacin（ENR）,a typical fluoroquinolone veterinary antibiotic,was studied by HSCB/H2-Ti O2 under visible light irradiation,and excellent ENR degradation efficiency and mineralization results were obtained.Through a series of characterization methods,the reasons for the improvement of photocatalytic efficiency of multifunctional materials in the heterogeneous photocatalytic degradation of ENR and the main types of free radicals were explained.Combined with LC-MS,the intermediates that ENR may form in the degradation process of HSCB/H2-Ti O2 were analyzed,and the photocatalytic degradation path of ENR was speculated through the intermediates.The results show that HSCB/H2-Ti O2 can degrade ENR rapidly,effectively and thoroughly by visible light irradiation without adding any additional chemical agents.The degradation rate of ENR is up to 95%within 180 minutes,and the degradation rate of TOC is 80%within 240minutes.Meanwhile,HSCB/H2-Ti O2 has excellent reusable ability.According to ESR results,even in the dark state,there are a large number of electrons on the surface of HSCB/H2-Ti O2,which can produce abundant·O2-in water and reduce the resistance of ENR to free radical degradation.According to the results of free radical capture,·O2-was the main free radical in the photocatalytic degradation of ENR by HSCB/H2-Ti O2.Degradation by LC-MS on the ENR has the intermediates were determined,in the process of parsing out altogether 15 kinds of organic intermediate,intermediate product and free radical ESR as a result,the main process of ENR has degraded in the degradation path has three,respectively by ethyl reaction,fluorine and occur in connection with piperazine ring opening reaction to happen on the benzene ring in order to realize.（4）Adsorption of heavy metals by HSCB/H2-Ti O2 multifunctional materialsThe adsorption experiments of simulated wastewater containing Pb2+,Cu2+,Zn2+and Cd2+with different concentrations were carried out by using HSCB/H2-Ti O2.The kinetic models（pseudo-first-order adsorption model and pseudo-second-order adsorption model）and thermodynamic models（Langmuir model and Freundlich model）were used to fit the adsorption results,and the fitting parameters of the relevant models were calculated.Furthermore,XPS and FT-IR characterization were carried out on the multifunctional materials after heavy metal adsorption,and the element distribution and functional group composition on the surface of the materials after adsorption were analyzed.In addition,the adsorption effects of HSCB/H2-Ti O2on different heavy metals in binary heavy metal simulated wastewater（Pb/Cd and Cu/Zn）were also investigated.The adsorption results were fitted by kinetic model,and the surface element distribution and functional group composition of the adsorbed materials were investigated by XPS and FT-IR.The research shows that HSCB/H2-Ti O2 has excellent adsorption effect on four kinds of heavy metals when the initial concentration of heavy metals is 50 mg/L.The maximum equilibrium adsorption capacities of Pb2+,Cu2+,Cd2+and Zn2+were 69 mg/g,106 mg/g,126mg/g and 28 mg/g,respectively.In the mixed system,the competition between ions is related to the difference of hydration radius,and the smaller the difference is,the more intense the competition is.At the same time,in the mixed system,the larger the hydration radius,the easier the ions are adsorbed by the multifunctional materials.Combined with the results of adsorption site analysis,the adsorption of Pb2+mainly occurs on the carboxyl group on the surface of HSCB when single metal is adsorbed.Cu2+and Cd2+react with H2-Ti O2 particles supported on the surface of the multifunctional material to generate adsorption.The adsorption site of Zn2+was also on HSCB,and it was crosslinked with C-OR and-COOH.（5）Study on the treatment effect of HSCB/H2-Ti O2 on pollutants in the heavy metal-antibiotic combined systemThe treatment effects of HSCB/H2-Ti O2 in different heavy metal-antibiotic combined systems were investigated.By comparing the differences of treatment effects,the main factors affecting the treatment effects in the combined systems were analyzed with a series of spectral analysis techniques,and their mechanism of action was explained.Furthermore,LC-MS was used to analyze the degradation intermediates in different combined systems,and the changes of the combined systems on the degradation process were studied.The results show that the adsorption capacity of heavy metals in the coupled systems is affected to varying degrees except for the increase of Pb adsorption capacity in the Pb-ENR system,indicating that the stability of the coupled system and the difference of combined morphology are important factors affecting the adsorption capacity of heavy metals by multifunctional materials.In the four combined systems,degradation efficiency and mineralization rate are inhibited,mainly due to the stability differences of different combined systems.Using LC-MS technology,we analyzed the intermediates of Cu-,Zn-,Pb-and Zn-ENR combined systems when they were degraded by HSCB/H2-Ti O2,including 11,15,11 and15 intermediates,and analyzed their respective degradation paths and differences.It was found that the stability of the combined substance and the difference of the combined site in the combined system affected both the intermediates and the degradation path. 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