活性炭纤维电吸附重金属及磺胺甲恶唑性能研究

使用盐酸对吸附剂活性炭纤维（activated carbon fiber，ACF）进行改性，通过SEM、BET和FTIR对改性前后的ACF形貌及结构进行系统表征发现，改性后ACF较改性前表面杂质减少且沟壑更加明显，比表面积提高22%，微孔体积增加5%，含氧官能团（C-O和C=O）明显增多. 以水中重金属离子（Zn(II)及Cr(VI)）和抗生素磺胺甲恶唑（Sulfamethoxazole，SMX）为目标污染物，研究改性后ACF对目标污染物的吸附（静吸附和电吸附）性能，考察了浓度、pH、外加电压对吸附的影响. 结果表明，ACF用量为5 g，电压为1.2 V，Zn(II)、Cr(VI)及SMX浓度均为10 mg·L^-1，Zn(II)溶液pH为5时，ACF吸附水中Zn(II)的最大吸附量为9.25 mg·g^-1，是静吸附条件的2.15倍；Cr(VI)溶液pH为4时，ACF吸附Cr(VI)的最大吸附量为8.86 mg·g^-1，是静吸附条件的1.96倍；SMX溶液pH为6时，ACF吸附SMX的最大吸附量为8.32 mg·g^-1，是静吸附条件的1.84倍. ACF吸附Zn(II)、Cr(VI)及SMX的动力学曲线均符合准二级动力学模型，吸附过程为化学吸附. Freundlich等温模型能更好地描述ACF对Zn(II)、Cr(VI)及SMX的吸附特性，其吸附形式为多分子层吸附. ACF通过电极反接方式进行循环再生，脱附速率快且脱附效果明显，经4次循环再生后，ACF对Zn(II)、Cr(VI)及SMX的去除率均在90%以上.

Study on Electro-Sorption of Heavy Metals and Sulfamethoxazole on Activated Carbon Fibers

To study the optimal removal condition, adsorption mechanism and comparative analysis of the three typical cationic pollutants, i.e., Zn(II), anionic pollutant Cr(VI) and molecular pollutant sulfamethoxazole (SMX), using self-made upflowed electro-sorption device for adsorptions of above three pollutants by modified activated carbon fiber were researched. The activated carbon fiber (ACF) was modified by hydrochloric acid. The ACF morphology and structure before and after modification were characterized by SEM, BET and FTIR. The characterization results show that the modified ACF had fewer surface impurities than the modified surface and the gully is more obvious, the specific surface area was increased by 22%, while the micropore volume was increased by 5%, and the oxygen-containing functional groups (C-O, C=O) are significantly increased. Using the heavy metal ions (Zn(II), Cr(VI)) and the antibiotic Sulfamethoxazole (SMX) in water as the target pollutants, the adsorptions of ACF after hydrochloric acid modification on the target pollutants (static adsorption and electro-sorption) were studied. The effects of concentration, pH and applied voltage on adsorptions were investigated. The results showed that when the ACF dosage was 5 g, voltage was 1.2 V, Zn(II), Cr(VI) and SMX concentrations were 10 mg·L^-1, Zn(II) solution pH was 5, the maximum adsorption capacity of Zn(II) adsorbed by ACF was 9.25 mg·g^-1, which is 2.15 times of the static adsorption condition; when the pH of Cr(VI) solution was 4, the maximum adsorption amount of Cr(VI) adsorbed by ACF was 8.86 mg·g^-1, which is 1.96 times of static adsorption condition; when the pH of SMX solution was 6, the maximum adsorption capacity of ACF to adsorb SMX was 8.32 mg·g^-1, which is 1.84 times of static adsorption condition. The kinetic curves for the adsorptions of Zn(II), Cr(VI) and SMX by ACF were consistent with the pseudo-second-order kinetic model, and the adsorption process was chemical adsorption. The Freundlich isotherm model can better describe the adsorption characteristics of ACF on Zn(II), Cr(VI) and SMX, whose adsorption is multi-molecular layer adsorption. ACF was recycled by electrode reverse connection, whose desorption rate was fast and the desorption effect was obvious. After 4 cycles of regeneration, the removal rates of Zn(II), Cr(VI) and SMX by ACF were above 90%, and great regeneration efficiency, which can be reused in practical applications, saving resources.