The Preparation Of Catalyst Load Iron On Modificated Palygorskite And Primaryapplications In Paper Wastewater Deep Treatment

This paper analyzed the thermal modification, acid modification of natural palygorskiteand acid modified palygorskite load iron source preparing catalyst, researched deep treatmentto papermaking wastewater with heterogeneous UV/Fenton system, to reach standard ofwastewater discharge.By analysising the thermal modification structure of natural palygorskite with DSC, TG,XRD and IR, the results showed that as the temperature increased, moisture in thepalygorskite was removed quickly, obvious endothermic peak appeared at temperature of109.3℃, this loss water is mainly surface adsorbed water and channel adsorbed water; boundwater began to lose when temperature reached171.6℃, the endothermic peak appeared attemperature of216.9℃, within300℃, natural palygorskite is endothermic reaction. No morethan600℃, the basic structure of palygorskite won’t change much.By researching acid modification of purified natural palygorskite, the results showed that,acid modification of purified natural palygorskite was taken under the experimentalconditions of6mol/L HCL, modification temperature of50℃for2hours, the SiO2contentwas increased by2.86%, the Al2O3content declined about3%, specific surface area increasedby about40m2/g; in addition, the adsorption equilibrium constant of methyl orange tohydrochloric acid modified palygorskitecan well satisfied the Langmuir adsorption isothermequation, the adsorption enthalpy of methyl orange into palygorskite was23.12kJ/mol, whichindicated that it was an endothermal process with the entropy increasing.With acid modified palygorskite as the carrier, load iron source to prepare heterogeneouscatalysts. Through XRF, XRD, IR, SEM etc. characterization methods, catalysts wascharacterized, at the same time, using chlorine phenol as organic pollutants to research thedegradation effect of catalysts, the experimental results showed that the Fe2O3content incatalysts increased from4.53%to19.38%, but the surface area decreased about22m2/g.In thechlorine phenol degradation experiment, for100mg/L chlorine phenol, the optimumdegradation conditions were: dosage of hydrogen peroxide was half of the theory dosage, pHwas3, dosage of catalyst was400mg/L, when processing30min the degradation rate canreach more than98%. Heterogeneous UV/Fenton system degradation process of chlorinephenol were first-order reaction kinetics. Catalysts used for repeated five times, thedegradation rate still remained above94%, at the same time, soluble iron content in the wastewater measured by atomic absorption was less than0.1mg/L, which indicated that catalystshad good repeatable practicability and good stability. Studying the papermaking wastewater degradation reaction with heterogeneousUV/Fenton system, the results showed that UV254and CODcr of papermaking wastewater hadgood linear relationship, in the condition of pH=3, dosage of hydrogen peroxide and catalystwas28ml/L (H2O21mol/L) and1000mg/L respectively, after treating120min the CODcr canmeet the national discharge standard.