Study On The Preparation Of Biomass/ZIFs Three-dimensional Material And Its Adsorption/photocatalysis For Wastewater

With the development of nuclear power industry,electroplating industry and dyeing industry,it is inevitable that a large number of radionuclide wastewater,dye wastewater and heavy metal wastewater flow into natural environment,which has caused great damage to the ecology.Meanwhile,as the continuous consumption of non-renewable energy,humans will face the dual challenge of environmental pollution and energy shortage.Therefore,it is very meaningful to explore a strategy of treating wasteweter with waste.The subject centered on renewable waste biomass materials and multifunctional zeolitic imidazolate framework compounds(ZIFs),and carried on the following research:(1)For recycling waste biomass,self-assembly approach and coupling agent approach were respectively used to prepare one-dimensional palygorskite(Pal)and three-dimensional pomelo peel(PP)composite PP/Pal and PP/KPal for removing uranium(U(VI))from aqueous solution.Moreover,the mass ratio(PP:Pal),temperature,contact time,adsorbent dosage,p H and ionic strength are investigated.The adsorption behavior was analyzed by kinetic model,and the maximum adsorption capacity was evaluated by isotherm model.The results shown that the maximum adsorption capacities for U(VI)were 370.5 mg·g-1 on PP/Pal and 357.3 mg·g-1 on PP/KPal at temperature 25 o C,contact time 150 min and p H 6.0.Furthermore,thermodynamic studies indicate that adsorption is spontaneous accompanied by endothermic.And the adsorption involved electrostatic attraction,ion exchange and surface complexation.Meanwhile,due to water-insoluble properties of pomelo peel,the separatation of composite from water is easy via a simple filtering.Therefore,PP/Pal composite with the advantage of high efficiency,low-cost and green has a further application in treatment of wastewater containing U(VI).(2)In this work,to realize the simple recovery of metal ions in metal electroplating wastewater and solve the problems of sludge symbiosis and difficult recovery of metal ions in traditional treatment process,3D LC/ heterogeneous ZIFs(h-ZIF-8)composite LC/h-ZIF-8 prepared via luffa cylindrical(LC)as carrier and metal plating wastewater containing Zn(?)as material for removal of organic pollutants(Nitrofurazone(NFZ),Methylene Blue(MB),Rhodamine B(Rh B)and Congo Red(CR))and mixed-dye wastewater.Furthermore,the preparation temperature and LC pretreatment were optimized to increase the catalyst loading.The experimental results show that the removal capacity of LC/h-ZIF-8 on MB,CR,Rh B and NFZ are 95%,90%,85% and 80%,respectively,after adsorption 240 min and photocatalytic 300 min.Moreover,the spectroscopy and electrochemical are employed to elaborate possible degradation mechanisms,expounding the LC/h-ZIF-8 possess lower recombination rates of carriers and transfer resistance of electron compared with ZIF-8.Furthermore,investigations of cycling performance indicated the photocatalytic stability and easy separation from water.Therefore,the 3D LC/h-ZIF-8 prepared by wastewater realizes the combination of resource recovery and wastewater treatment,and provides a new avenue for the treatment of metal wastewater.(3)In this work,to explore the influence factors on the morphology of during the transition from electroplating wastewater to catalyst,various morphologies Zn/Co Zeolite imidazolate framewor(ZIF-Zn Co)was fabricated using different proportions of binary metal ions.Spectral test results show that the prepared three-dimensional cross-shaped Zn/Co bimetallic zifs materials(ZIF-Zn Co-8:1)have lower recombination rate of electron and hole pairs compared with ZIF-8,thus promoting the photocatalytic ability.In photocatalytic reduction Cr(VI),the ability of ZIF-Zn Co-8:1 is 22% higher than that of ZIF-8.Moreover,the photocatalytic ability of 3D cross-like ZIF-Zn Co-8:1 was investigated for removing mixed solution of dye(Cong Red(CR))and metal(Cr(VI)).As a result,CR was altogether removed at adsorption process and Cr(VI)was removed 70% after adsorption process 120 min and photocatalytic 240 min.Therefore,the high adsorption and photocatalytic capacity denote the potential application of 3D cross-like ZIF-Zn Co-8:1.Simultaneously,it provides theoretical support for the preparation ZIFs via polymetallic waste liquid.