| Antibiotic wastewater is a kind of untreatable wastewater, which was discharged intowater environment will cause harm to the ecological balance and human health.Semiconductor photocatalytic oxidation process is deemed as an ideal treatment technologyfor antibiotic wastewater because it exhibits outstanding superiority such as mild reactionconditions, thorough purification, environmental protection, high economic efficieney, and etc.ZnO has great potential applications in the field of environmental pollution control due to itshigh photocatalytic activity and low cost. In this article, transition metal doped ZnOphotocatalysts; ZnO nanoparticles coated on carbon nanotubes photocatalysts; ZnOnanosphere coated on halloysite nanotubes photocatalysts; ZnO nanoparticles coated on PVCalloy ultrafiltration membrane photocatalytic materials were prepared via different methods.The as-obtained products were characterized by X-ray diffraction (XRD), scanning electronmicroscopy (SEM), transmission electron microscope (TEM) and ultraviolet and visiblediffuse reflectance spectra (UV–Vis DRS). Their main physical properties, chemicalproperties and photocatalytic activity were discussed.(1) Fe doped, Co doped, Ni doped and Fe–Co codoped, Fe–Ni codoped ZnOphotocatalysts were prepared via a hydrothermal synthesis method. Fe doped ZnO samples,Fe–Co codoped and Fe–Ni codoped ZnO samples have shown greater photocatalyticperformance than pure ZnO photocatalysts. The characterization results showed thatabsorbance spectra of ZnO had a red shift with doping of doping of transition metal, whichgive ZnO ability of using visible light. And photocatalytic activity of3%Fe–1%Ni/ZnO ishighest. The photocatalytic degradation of tetracycline hydrochloride reached87.95%in2hours under the irradiation of xenon lamp light (λ=250nm~800nm).(2) ZnO/CNTs composite photocatalysts were prepared by a sol method. Thecharacterization results showed that a dense layer of ZnO nanoparticles cover on carbonnanotubes. Attributed to the excellent adsorption ability, photocatalytic activity of ZnO/CNTswas higher than that of pure ZnO. The photocatalytic degradation of tetracyclinehydrochloride reached82.38%in2hours under the irradiation of xenon lamp light(λ=250nm~800nm). The ZnO/CNTs samples showed higher stability in extreme pH values solution, photocorrosion suppression of ZnO was also be suppressed. It benefited from theexcellent chemical stabilities, electrical properties, and adsorption abilities of CNTs.(3) ZnO/HNTs composite photocatalysts were prepared via a sol method. Thecharacterization results showed that ZnO crystal grown into nanoparticles without HNTs.The photocatalytic degradation of tetracycline hydrochloride reached77.07%in2hours underthe irradiation of xenon lamp light (λ=250nm~800nm). Attributed to the excellent adsorptionability, photocatalytic activity of ZnO/HNTs was higher than that of pure ZnO. ZnO/HNTsalso showed a great photocatalytic activity after reused for multiple times.(4) ZnO nanoparticles coated on PVC UF membrane composite materials were preparedwith silane coupling agents via ultrasonic methods. SEM images showed that a layer of ZnOnanoparticles cover on PVC membrane. After that，the composite photocatalytic materialshave ability to photocatalytic degradation by using ultra violet. The degradation oftetracycline hydrochloride reached54.35%in2hours under the irradiation of xenon lamplight (λ=250nm~800nm), which was lower than that of pure ZnO nanoparticles. ButZnO/PVC composite materials showed great ability in photocorrosion suppression. Afterreused for several times, the photocatalytic performance of ZnO/PVC is better than that ofpure ZnO photocatalysts.Four different kinds of modified ZnO photocatalysts were obtained in this article, it wasfound that the as-prepared materials exhibited high photocatalytic efficiency in the treatmentof antibiotic wastewater, which was a good prospect in the field of actual antibioticwastewater treatment. |
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