Preparation And Properties Of Novel Composite Adsorption Materials

Dye wastewater has the characteristics of complex structure,toxic and hard to degrade.If it is discharged without treatment,it will cause serious pollution to the water system.Current wastewater treatment methods include adsorption,membrane separation,aerobic,and aerobic/anaerobic methods.The commonly used adsorbent materials can be divided into organic materials,inorganic materials and composite materials.The composite adsorbent materials have a wide range of applications in wastewater treatment due to their characteristics such as good selectivity and easy separation.In this thesis,N-Hexadecylmaleic acid radical and lanthanum(HL)/PVC,melamine formaldehyde resin(MF)-PVC and urea-melamine-formaldehyde resin(MF/MU)three composite adsorbents were synthesized,respectively.The elemental analysis,FT-IR,SEM and zero charge were used to characterize and analyze the composite adsorbent.The factors affecting the adsorption were investigated and the thermodynamics and kinetics of the adsorption process were studied.(1)The HL/PVC composite adsorbent was used for the adsorption study of methyl orange solution.The experimental results show that ratio of complexes and PVC,ionic strength,baking temperature and baking time have great influence on adsorption of methyl orange.Electrostatic effect plays a leading role on the adsorption between HL/PVC and methyl orange molecules.The thermodynamic analysis shows that the adsorption process of methyl orange solution by HL/PVC conforms to Langmuir model,and belongs to monolayer adsorption.0<RL<1 and 0<1/n<0.5 indicate that this adsorption process is an easy type of adsorption.The thermodynamic behavior shows that this adsorption process is an endothermic and spontaneous physical adsorption process.The kinetics analysis shows that the adsorption process of HL/PVC adsorbed methyl orange solution conforms to the pseudo second-order kinetics model and the liquid membrane diffusion is the main rate control step for the entire adsorption process.(2)The MF-PVC composite adsorbent was used for the adsorption study of congo red solution.The experimental results show that the adsorption between MF-PVC and congo red molecules is mainly caused by the ?-? effect of aromatic groups.The thermodynamics analysis shows that the adsorption process of MF-PVC for congo red solution fits well with the Freundlich model and belongs to multi-layer adsorption.0<RL<1 and 0<1/n<0.5 indicate that the adsorption process is an easy type of adsorption.The thermodynamic behavior indicates that the adsorption process of congo red on MF-PVC is an endothermic and spontaneous physical adsorption process.The kinetics analysis shows that the adsorption process of the MF-PVC for the congo red solution conforms to the pseudo-second-order kinetic model,and the intraparticle diffusion is the main rate control steps of the whole adsorption process.(3)The MF/MU composite adsorbent was used for the adsorption study of congo red solution.The experimental results show that the adsorption between MF/MU and congo red molecules is mainly caused by the ?-? effect of aromatic groups.The thermodynamics analysis indicates that the adsorption process of congo red solution by MF/MU conformed to the Freundlich model and was a multi-layer adsorption.0<RL<1 and 0<1/n<0.5 indicate that this adsorption process is an easy type of adsorption.The thermodynamic behavior indicates that the adsorption process of congo red by MF/MU is an endothermic and spontaneous physical adsorption process.The kinetics analysis indicates that the adsorption process of MF/MU adsorbed congo red solution conforms to the pseudo second-order kinetics model,and the liquid film diffusion is the main rate control step of the entire adsorption process.