稻壳与脱硅稻壳活性炭特性及对有机物吸附

The Adsorption Properties of Rice Husk-based and Silicon-freed Rice Husk-based Activated Carbon on Organic Compounds

以稻壳为原料,同时制备脱硅稻壳,采用ZnCl2-CuCl2复合活化剂制备活性炭,并对所制备的稻壳活性炭(RAC)与脱硅稻壳活性炭(FAC)的孔结构和表面化学性质进行了分析,而后将其应用于对水中有机物的去除,同时研究了其吸附特性。结果表明:所制得的稻壳活性炭比表面积达到了1 924 m2/g,而稻壳经过脱硅处理制得的活性炭比表面积达到了2 433 m2/g。脱硅稻壳表面具有更多种类的官能团存在。稻壳与脱硅稻壳活性炭在碱性条件下有利于品红的吸附,并且适用于高盐度条件下品红的吸附;在初始pH值为7,初始质量浓度为400 mg/L,投加量为0.8 mg/g时,稻壳活性炭和脱硅稻壳活性炭对有机物的吸附量分别达到439和483 mg/g;吸附等温模型符合Langmuir等温式;吸附动力学以及脱附研究显示稻壳与脱硅稻壳活性炭对品红的吸附过程主要由化学吸附控制。

The activated carbons were prepared from rice husks and silicon-freed rice husks by composite activator. The difference between rice husk-based activated carbon（ RAC） and silicon-freed rice husk based activated carbon（ FAC） in pore structure and surface chemistry were analyzed. The synthesized activated carbon was used as adsorbents in water treatment. The adsorption properties,isotherms and kinetics of fuchsine on activated carbons were investigated. The results indicated that the BET surface area of RAC and FAC reached 1 924 and 2 433 m^2/g,respectively. There FAC has more functional groups compared with RAC.RAC and FAC could improve the removal efficiency of fuchsine at high pH value. The adsorbents could be used in high salt concentration conditions. When the initial pH 7,initial mass concentration 400 mg /L and the adsorbents dosages 0. 8 mg /g were used,the adsorption capacity of RAC and FAC was 439 and 483 mg /g,respectively. The Langmuir isotherm model was found to fit well with the adsorption process of RAC and FAC. Both the kinetics and desorption study indicated that the adsorption process was controlled by chemisorption.