改性颗粒活性炭吸附低浓度甲醛的试验研究

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

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。

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 experi- mentally 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 capaci- ty of GAC calcinated in O2 is much higher than that caleinated in N2. The adsorption capacity of GAC de- creases 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 ca- pacity, pore structure and pore surface chemistry is revealed.