活性炭的硝酸表面改性及其吸附性能

用硝酸对粒状活性炭进行了表面改性,考察了硝酸浓度及氧化时间对活性炭表面官能团的影响.采用傅里叶变换红外光谱仪(FT-TR)、Boehm滴定、X射线衍射仪(XRD)、物理吸附以及颗粒强度分析仪等对氧化前后样品进行了表征分析.以改性活性炭为载体,浸渍活性组分后制备了浸渍炭催化剂,考察了其对氯化氰防护性能.研究发现,低浓度硝酸氧化改性可增加活性炭表面酸性基团的含量,减少碱性基团的含量,从而提高活性炭的表面亲水性,而对活性炭的结构没有明显影响;制备的浸渍炭催化剂对氯化氰防护时间明显增长.当硝酸浓度为8%,氧化时间为8 h时防护效果最好.

SURFACE MODIFICATION AND ADSORPTION PROPERTY OF ACTIVATED CARBON BY HNO_3

Granular activated carbon was modified with HNO_3. The influences of the HNO_3 concentration and treatment time on the activated carbon surface functional groups were investigated. The original and oxidized samples were characterized by Boehm's titration , FT - IR , BET , XRD and particle strength analyzer. Carbon supported catalysts were prepared by using the modified activated carbon as a carrier through impregnating the active component. The cyanogen chloride protection times were determined. The results show that modifying activated carbon with diluted HNO_3 can increase the content of acidic groups, reduce the content of alkaline groups , improve the surface hydrophilic, and do not change the textural properties. Compared with the original carbon supported catalysts, the modified carbon supported catalysts show longer cyanogen chloride protection time. The protective effect is the best at the concentration of 8% hydrogen peroxide and oxidation time of 8 h.