活性炭对卤代苯甲醚类嗅味物质的吸附特性

Adsorption of Odorous Compound Haloanisoles by Activated Carbon

摘要:

探究了椰壳酸洗活性炭、椰壳水洗活性炭、煤质活性炭、果壳活性炭、木质活性炭等对2，4，6-三氯苯甲醚（2，4，6-trichloroanisole， 2，4，6-TCA）和2，4，6-三溴苯甲醚（2，4，6-tribromoanisole， 2，4，6-TBA）的吸附等温线和吸附动力学。研究发现5种活性炭均可有效吸附卤代苯甲醚，吸附等温线都能较好拟合Freundlich模型（R²>0.97）。其中果壳活性炭和椰壳活性炭吸附效果较好，果壳活性炭对2，4，6-TCA的吸附常数（K_F）最大，为11.90，椰壳酸洗活性炭对2，4，6-TBA的吸附常数（K_F）最大，为9.47。五种活性炭的吸附过程均符合拟二级动力学模型（R²>0.97），椰壳水洗活性炭对2，4，6-TCA的吸附最快，椰壳酸洗活性炭对2，4，6-TBA的吸附最快。以椰壳酸洗活性炭为研究对象，探究其吸附机制和主要影响因素，结果表明内扩散是主要限速步骤，化学吸附是主要吸附机制，初始底物浓度和溶解有机物对吸附效果影响较大。

Abstract:

Five types of commonly used granular activated carbon （coconut shell pickling， coconut shell water washing， coal， fruit shell， wood activated carbon） were selected to study the adsorption isotherm and adsorption kinetics of 2，4，6-trichloroanisole （2，4，6-TCA ） and 2，4，6-tribromoanisole（2，4，6-TBA ）.Results show that all the used activated carbon can effectively adsorb halogenated anisole and the adsorption isotherms are well fitted to Freundlich model （R²>0.97）. The fruit shell activated carbon and coconut shell activated carbon performe better. Fruit shell activated carbon has the maximum adsorption capacity（K_F） for 2，4，6-TCA， while coconut shell pickling activated carbon possesses the maximum K_F for 2，4，6-TBA . The adsorption processes are consistent with the pseudo-second-order kinetics model （R²>0.97）. The adsorption rate of 2，4，6-TCA on coconut shell washing activated carbon is the fastest， and the adsorption rate of 2，4，6-TBA on pickled coconut shell activated carbon is the fastest. The adsorption mechanism and main influencing factors of coconut shell pickling activated carbon are studied. The results show that the internal diffusion is the main rate-limiting step， chemical adsorption is the main adsorption mechanism， and the concentration of initial substrate and dissolved organic matter have a great influence on the adsorption efficiency.