Application Of Solar Energy And Induction Heating Driven Interfacial Evaporation Technology In Pharmaceutical Wastewater Treatment

Solar thermal conversion is mainly used in the direction of interface evaporation,including seawater desalination,sterilization and disinfection.At present,the photothermal conversion technology has made great progress,but there are still many problems.First of all,although the photothermal conversion efficiency has reached a very high level,there is still room for further improvement.Secondly,at this stage,solar-driven interface evaporation technology is mainly used in seawater desalination,and there are few applications in wastewater purification and power generation.Based on the research status and existing problems of solar-driven interface evaporation technology,this article aims to improve the composition material and the design of the microstructure of the absorber,aiming at the low photothermal conversion efficiency of traditional absorbers,and constructed a structured ordered AgNPs@C3N4/GO membrane improves the photothermal conversion efficiency and wastewater purification performance.On this basis,the microstructure of the absorber was further controlled,and a black TiO2@AuNPs membrane with a large number of micro channels was designed.There is a network structure in the micro channels,which further improves the photothermal conversion efficiency and wastewater purification performance.In addition,we also proposed a new idea of combining solar-driven interface evaporation technology with the principle of electromagnetic conversion,using absorbers to generate electricity,converting electrical energy into magnetic field energy,for wastewater purification,and further improving wastewater purification capacity and efficiency.The specific research content is as follows:(1)AgNPs@C3N4/GO was dispersed in PVA solution and freeze-dried to prepare AgNPs@C3N4/GO(SCG)membrane.The morphological characteristics of AgNPs@C3N4 and GO were determined by Transmission Electron Microscope(TEM)and Atomic Force Microscopy(AFM).The vertical channels and layered nanostructures inside the SCG film were determined by Scanning Electron Microscopy(SEM).By measuring the absorbance,thermal conductivity,thermal diffusivity and heating curve of the SCG membrane,it proves its superior photothermal conversion performance.It also shows that the SCG membrane can concentrate heat on the surface of the membrane and quickly heat the water,thereby realize the rapid evaporation of water.Through the treatment of pollutants in simulated pharmaceutical wastewater,high performance liquid chromatography(HPLC)and ICP can prove that both dyes and metal ions can be removed efficiently by SCG membrane,which makes the water quality meet the WHO standard.In addition,SCG membrane also showed high-efficiency and durable desalination ability.(2)In order to further improve the photothermal conversion efficiency and wastewater purification performance of the membrane,we changed the composition of the membrane and the production process of the membrane on the basis of the first part.We prepared anatase TiO2 by hydrothermal method,and then modified by NaBH4 to prepare defective black TiO2.Finally,black TiO2 and Au-DCDA microspheres were calcined together to prepare the TiO2@AuNPs composite.The TiO2@AuNPs composite was dispersed in the PVA solution.After multiple freezing and thawing,a multi-channel TiO2@AuNPs(TDG)film was prepared by vacuum drying.The microstructure of the defective TiO2@AuNPs composite and the formation of the network structure in the TDG membrane channel were determined through the TEM and SEM.Compared the absorbance of the composite and TDG membrane,the SPR effect of AuNPs and the network structure of micro channels enhance the photothermal conversion performance of the membrane.The temperature rise curve confirms that the TDG membrane can concentrate heat on the surface of the film,resulting in a higher temperature and higher photothermal conversion efficiency.The results of the HPLC and ICP prove that TDG membrane has more efficient wastewater purification performance and longer lasting and effective desalination performance(3)We use the principle of electromagnetic induction to design a water treatment model(WTM)for wastewater purification and seawater desalination.The high-frequency alternating magnetic field formed by the energized coil generates eddy currents on the cylinder.The eddy current heats the cylinder through the Joule effect and converts the energy of the magnetic field into heat,which is used for the rapid temperature rise of water,which in turn realizes the evaporation of water and produces sterilization and disinfection.By simulating the volume loss density of the cylinder in the WTM model,we have obtained the electromagnetic input power at different relative distances.When the relative distance is 1.1cm,we obtain the maximum energy conversion efficiency.When the WTM model is used to treat wastewater,the dyes,heavy metals and pathogens(bacteria,viruses)in the wastewater can be almost completely removed.When applied to seawater desalination,the salt ion removal rate is as high as 99.99%,and it also shows excellent stability.