改性活性炭去除水中的二甲基亚硝胺  

Removal of N-nitrosodimethylamine from water by modified activated carbons

作　　者：代晓东[1] 鲍旭晨[1] 朱勇军[2] 静国光[2] 张坤[2] Linda Zou 

机构地区：[1]中国石油管道研究中心,河北廊坊065000 [2]中国人民武装警察部队学院,河北廊坊065000 [3]澳大利亚南澳大学

出　　处：《炭素技术》2010年第2期11-15,共5页Carbon Techniques

摘　　要：针对日益严重的水污染,以饮用水中所含的致癌污染物二甲基亚硝胺(NDMA)为对象,选用木质素和椰壳两种商用活性炭作为吸附剂去除水中的NDMA,探索其吸附原理。通过低温氮气吸脱附技术、红外光谱、Boehm滴定和NDMA吸附等温线测绘,研究了惰性条件下高温改性过程中温度对活性炭孔结构、表面性能以及NDMA吸附性能的影响。结果表明:活性炭对水溶液中NDMA吸附性能远远高于分子筛,微孔有利于NDMA吸附;其吸附性能不但与孔结构相关,还受表面化学性质所制约。未改性处理时,由于水分子的竞争吸附,大多吸附位被水分子占据,同时NDMA以亚硝胺极性端被吸附,吸附量较小;改性处理后由于极性官能团的减少,活性炭疏水性增强,水分子吸附减少,NDMA多以甲基非极性端被吸附于微孔内,吸附量成倍增加。此外表面的醛或者酮结构也有利于NDMA吸附量的提高。In order to eliminate water pollution, the adsorption and relative mechanism of toxic N- nitrosodimethylamine（NDMA） from water by commercially wood and coconut shell activated carbons was studied. The N2 adsorption/desorption, infrared spectra, Boehm titration and DNMA adsorption isotherms were utilized to investigated the influences of modification on the porous structures, surface properties and NDMA adsorption. It was observed that NDMA was preferentially adsorbed in micropores, and activated carbons possessed better adsorption capacity than zeolites. The adsorption behavior is not only correlated with porous structures, but also significantly influenced by surface properties. Water molecules would take most adsorption sites on unmodified activated carbon due to selective adsorption. Simultaneously, NDMA is adsorbed with polar nitrosamine end. After modification, hydrophobic surface of activated carbon would be more likely adsorb NDMA with nonpolar methyl ends, presenting great improvement of capacity due to the less adsorption of water. By the way, the ketone and aldehyde structures on surface would also prefer to get more NDMA adsorption.

关 键 词：表面处理 微孔 表面官能团 疏水性 

分 类 号：X52[环境科学与工程—环境工程] TQ424.1[化学工程]