改性颗粒活性炭吸附低浓度甲醛的试验研究

通过试验研究了表面改性方法、焙烧气氛和气相水分对颗粒活性炭(GAC)吸附低浓度甲醛性能的影响。结果表明:3%HNO3浸泡改性可增加GAC表面的含氧官能团,显著改善GAC对甲醛的吸附性能,并延长吸附穿透时间;O2气氛下焙烧所得GAC的吸附效果优于N2气氛下焙烧的GAC;反应气体含水1.5%时,GAC对甲醛的吸附性能明显降低。另外,分别采用低温N2吸附法和傅立叶红外光谱法表征了3%NHO3浸泡改性前、后GAC的孔结构和孔表面化学性质的差别,从而揭示了GAC的吸附性能与孔结构、孔表面化学性质之间的关系。

Experimental Study on Low Concentration Formaldehyde Adsorption by Modified Granular Activated Carbons

The impacts of surface modification methods,calcination atmosphere and the addition of water vapor on the adsorption of low concentration formaldehyde by granular activated carbon(GAC) are experimentally investigated.The adsorption capacities and breakthrough time of GAC impregnated in 3% HNO3 are significantly improved,because the modifier increases oxygen functional groups.The adsorption capacity of GAC calcinated in O2 is much higher than that calcinated in N2.The adsorption capacity of GAC decreases when 1.5% water is fed into the reaction gases.The pore structure parameters and pore surface chemistry of GAC before and after 3% HNO3 modification are represented by standard nitrogen adsorption and Fourier transform infrared spectra(FTIR),respectively.The relationship between the adsorption capacity,pore structure and pore surface chemistry is revealed.