The Study Of Photocatalytic Degradation Of Organic Pollutant Phenol In Groundwater Of A Paper Mill In Fujian Province

Nowadays,groundwater is an important part of human freshwater resources and plays an important role in daily production and life.However,with the rapid development of the economy,the pollution of groundwater has been caused because of the discharge of industrial wastes,the infiltration of surface sewage and the residual problems of soil pesticides.But it is difficult for groundwater pollution to find out,and also difficult to deal with.It has become a major problem to find a solution method of groundwater pollution.Among these water treatment methods,photocatalytic technology has become a hot issue in water pollution control because of its advantages such as high efficiency,simple operation,no pollution,and environmental protection.In this paper,a paper mill in Fujian province was selected as the groundwater pollution survey area,and 8 sampling points were selected for field water detection and survey.It was found that the area of phenol was over the standard and the concentration was 18.8 mg/L.Therefore,in this paper,phenol was used as a target pollutant to conduct series experiments in the laboratory for photocatalytic degradation,which provided a scientific and effective experimental support for the investigation area to control phenol pollution.This dissertation mainly focuses on the preparation of three different metal sulfur indium salt nanomaterials,and use of these three different metal sulfur indium salt as substrate,loading different ratios of carbon nitride binary composite nanomaterials.The study compared the effects of degradation of metal sulfur indium salt and composite photocatalytic nanomaterials on the degradation of phenol in organic pollutants in groundwater.Based on the degradation results,the binary photocatalyst with the best catalytic activity was selected for further modification to prepare a ternary composite photocatalyst,and further this kind of ternary composite photocatalytic nanomaterials had been studied for the degradation of phenol,and the photocatalytic degradation mechanism had also been analyzed.First of all,metal sulfur indium salt MIn₂S₄?M=Zn,Ni,Co?and g-C₃N₄/MIn₂S₄?M=Zn,Ni,Co?composite photocatalysts,respectively,having a ratio of 10%to 50%ratio of carbon nitride were prepared by a simple hydrothermal method and an ultrasonic method.And various of characterizations of these series of photocatalysts including X-ray diffraction?XRD?,transmission electron microscopy?TEM?,and ultraviolet-visible diffuse reflectance?DRS?and photoluminescence spectroscopy?PL?had made in-depth studies on the structure and optical properties of photocatalysts.Then,xenon lamp was used as the simulation light source to degrade organic pollutants phenol by photocatalyst.By comparing the degradation results,30%g-C₃N₄/ZnIn₂S₄ nanomaterials with good photocatalytic effect can be obtained,and the efficiency of phenol degradation can reach72%.Then,the binary composite photocatalyst was further modified to obtain the ternary composite nanomaterial AgI/30%g-C₃N₄/ZnIn₂S₄.Finally,the photocatalytic activity of the ternary photocatalyst and the stability experiment of the photocatalyst were tested.The results showed that the efficiency of phenol degradation was improved by Ag I/30%g-C₃N₄/ZnIn₂S₄on the basis of loading AgI,which reached 86%.Moreover,after 6 repeated experiments,the photocatalytic activity of the ternary nanocomposite was still very good and the degradation rate can reach 76%.Therefore,the AgI/30%g-C₃N₄/ZnIn₂S₄ ternary composite photocatalytic nanomaterial prepared in this paper can be applied to the treatment of phenol contamination in the investigation area.