二价铁催化过氧化氢-过硫酸钠再生活性炭可行性研究

利用二价铁(Fe~(2+))催化过氧化氢(H_2O_2)-过硫酸钠(Na_2S_2O_8)双氧化体系(ICHP)对被三氯乙烯(TCE)吸附饱和的20~40目粒状活性炭(AC)进行再生研究.同时,结合扫描电子显微镜(SEM)、能量散射光谱仪(EDS)、X射线光电子能谱仪(XPS)及氮气吸附-解吸技术等手段对再生前后的AC进行表征,进一步探讨影响再生效率的原因.结果表明,AC对TCE的吸附符合准一级动力学模型,等温吸附符合Freundlich模型.在TCE∶Fe~(2+)∶H_2O_2∶S_2O_2-8=1∶9.20∶59.79∶77.52(物质的量比)的条件下,AC再生效率约为50%.研究表明,AC的炭损失、比表面积、孔隙体积及孔隙面积的减小,是再生AC吸附能力低于原状AC的主要原因.利用ICHP再生的AC可以实现对TCE的有效吸附并达到AC重复使用的目的,具有很好的实用价值.

Feasibility on the regeneration of activated carbon by ferrous ion catalyzed hydrogen peroxide coupled with sodium persulfate

A binary catalytic system, ferrous ion (Fe²⁺)-catalyzed hydrogen peroxide (H₂O₂) coupled with sodium persulfate (Na₂S₂O₈) (ICHP), was investigated for the regeneration of 20~40 mesh activated carbon (AC) adsorbed by trichloroethylene (TCE). The Scanning Electron Microscope(SEM), Energy Dispersive Spectrometer(EDS), X-ray Photoelectron Spectroscopy (XPS), Nitrogen Adsorption-Desorption Techniques were used to further investigate the influence of regeneration efficiency. The results indicated that the adsorption of TCE on AC followed pseudo first-order kinetic model and Freundlich model. The regeneration efficiency of AC was 50% when TCE:Fe²⁺:H₂O₂:S₂O₈^2-=1:9.20:59.79:77.52 in molar ratio was used. The carbon loss, the decrease in surface area, pore volume, and aperture area were the main factors which inhibited the efficiency of the regenerated AC. The results of this study indicate that the regeneration of AC by ICHP achieves high TCE adsorption efficiency, and therefore achieves the recycling of AC, which provides the good practical value.