Preparation Of Modified Attapulgite Clay And Study On The Photocatalytic Degradation Of Tetracycline Hydrochloride Wastewater

Antibiotic wastewater is a kind of untreatable wastewater, which was discharged into water environment will cause harm to the human health and ecological environment. Attapulgite Clay has strong adsorption capacity and easy to get. It also has significant advantages in treatment of antibiotic wastewater. While TiO2 and ZnO are also good photocatalysts. They show the huge potential of semiconductor photocatalytic technology in the treatment of antibiotic wastewater. This paper aims to through modified Attapulgite Clay prepare new photocatalytic materials with better degradation efficiency. The new materials including Ti-ATPs、Zn/Ti-ATPs and Ni/Ti-ATPs. Among them, Zn/Ti-ATPs has the best photocatalytic performance. The new materials can not only exert strong adsorption of attapulgite clay, but also combined with the composite photocatalyst improve the efficiency of light energy, make the ability of degradation of tetracycline hydrochloride greatly increased. In addition, we used impregnation-calcination method to prepare the samples. This method is easy and simple to handle. It will provide new ideas for antibiotic wastewater treatment for further.Considering the research needs, we have characterized the structure, morphology and composition of products by means of Scanning Electron Microscopy(SEM), X-ray Diffraction(XRD) and Ultraviolet and Visible Diffusion Reflectance Spectra(UV-Vis). We monitored the degradating effect of materials under the visible light by tetracycline hydrochloride as the target pollutant.(1) Prepared Ti-ATPs. The modified attapulgite clay have good ability of degradation combine adsorption with photocatalysis. UV-Vis shows that the absorbance of Ti-ATPs increase to a certain extent in ultraviolet wavelengths, but not quite apparent in visible wavelengths. We do the photocatalytic degradation experiments with tetracycline hydrochloride as the target pollutant. The study shows that the Ti-ATPs has a good photocatalytic performance with the Ti content of 40% and the roasting temperature of 450℃. In the experiment, the degradation of tetracycline hydrochloride can be made as high as up to 75.8% in 120 min under the irradiation of xenon lamp light.(2) We prepared Zn/Ti-ATPs by further modification with Ti and Zn element. The modified attapulgite clay has better ability of degradation than Ti-ATPs combine adsorption with semiconductor composite photocatalysis. UV-Vis shows that the spectra have red shift, while the absorbance of Zn/Ti-ATPs increased significantly in both ultraviolet and visible wavelengths. We do the photocatalytic degradation experiments with tetracycline hydrochloride as the target pollutant. The study shows that the Ti-ATPs has a good photocatalytic performance with the Zn/Ti molar ratio of 3∶1and the roasting temperature of 400℃.In the experiment, the initial concentration of tetracycline hydrochloride was 20mg/L,pH was 7 and the dosage of Zn/Ti-ATPs was 20 mg. As a reslut, the degradation of tetracycline hydrochloride can be made as high as up to 94.64% in 120 min under the irradiation of xenon lamp light. Zn/Ti-ATPs composite has the best photocatalytic performance than Ti-ATPs and Zn-ATPs. In addition, it also has the good stability. The degradation rate can reach 77.42% at the third repeat test.(3)The Ni/Ti-ATPs composite has no photocatalytic efficiency at the same preparation method. We do the photocatalytic degradation experiments with tetracycline hydrochloride as the target pollutant. But the result shows that the Ni/Ti-ATPs has no photocatalytic performance neither any of the roasting temperature nor the Zn/Ti molar ratio. The reason may be there is no right temperature to make TiO2 and NiO in the best crystal.In the other temperature, the two oxides are modified by interaction with each other. So it affects the photocatalytic reaction. Degradation efficiency is also only stay on the adsorption level of attapulgite clay.In the paper, we modified a series of attapulgite clay, the Zn/Ti-ATPs on the degradation of tetracycline hydrochloride wastewater has the highest efficiency of all. The material has high photocatalytic activity, stable performance and easy recycling. It will make very important theoretical significance in the field of water treatment.