| Humic acid,widely existing in the water bodies has become one dominant factor for the continual water quality deterioration.Since the 1970 s,the technologies used for humic acid removal in the natural water body research method gradually developed from traditional chemical oxidation method such as biological processing,chemical processing,heat treatment,catalytic oxidation and the phase transfer to the advanced oxidation technology like photocatalytic oxidation.Photocatalyst titanium dioxide has become the most ptomising catalysts because of its non-toxic,non-corrosive,strong catalytic ability,good chemical stability,low cost ect.But Ti O2 still could not be widely used because of its low pollutants molecular,high electronic-hole recombination rate and low molecular collision probability.In this paper,using sol-gel method and ultrasonic assisted solvent evaporation from the group to prepare the Ti O2/AC load type photocatalytic.Studied the modification of Ti O2/AC load type photocatalyst adsorption and photocatalytic activity of humic acid.Through a series of experiment research and analysis,this topic has achieved the following results:(1)Using sol-gel method and ultrasonic assisted solvent evaporation from the group to prepare the Ti O2/AC load type photocatalyst.Using X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscope(SEM)to characterize catalyst composition,structure and size.The results show that the actived carbon(AC)can improve the dispersion performance of titanium dioxide(Ti O2),reduce the reunion size,contact interface between Ti O2 and AC have Ti-O-C key generation.Besides,adding surfactant modified catalyst has more porous,cause it has bigger specific surface area,which is beneficial to improve its photocatalytic performance.(2)The change of UV254 value and spectral characteristic value of humic acid was found to follow a pseudo-first-order rate law,the kinetic behavior could be described in terms of a modified Langmuir–Hinshelwood model.Characteristics of humic acid spectrum analysis showed that the supported Ti O2/AC can reduce the molecular weight of humic acid content is 97.8% in 8 hours under 1g/L concentration of Ti O2/AC and for add surfactant modification of catalyst,the value can reach 98.1%.Also,the modified catalyst decreases the aromaticity of humic acid content is 1.9 times higher than unmodified catalyst and adding surface active agent modified catalysts are compared with the unmodified Ti O2 increased 2.4 times.(3)Cationic surfactant CTAB showed inhibitory effect on the light catalytic degradation of humic acid,when the surfactant CTAB concentration is lower than the critical colloid concentration,with the increase of concentration,the efficiency is more obvious and also the photocatalytic efficiency is lower,but when the surfactant concentration is higher than critical colloid concentration,the inhibition effect will be weakened,but it still has the inhibition effect.(4)Under rhe condition of different initial concentration of humic acid itself photolysis rate equation could be expressed by (?).In adsorption experiment,humic acid removal efficiency decreases with the increase of solution concentration,but two kinds of catalyst adsorption of humic acid is gradually increasing.Humic acid on the surface of two kinds of composite catalyst to adsorb the Langmuir and Freundlich adsorption equation can be used in the process of fitting. |
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