CAJ | 학술논문

以甲基丙烯酸为单体、高锰酸钾/浓硫酸为引发体系对玉米芯进行接枝改性，成功引入羧基官能团，结合扫描电镜、红外光谱和zeta电位等分析手段研究了吸附条件对玉米芯吸附Cd2+过程的影响及其吸附机理。结果表明，吸附过程符合 Langmuir 模型和准二级动力学方程，改性玉米芯对 Cd2+的吸附主要是化学吸附过程，吸附速率是颗粒内扩散速率和膜扩散速率共同影响的结果；在pH=7、投加量为5 g·L?1、温度为30℃、吸附时间为6 h的条件下，接枝改性玉米芯和原玉米芯对Cd2+的最大吸附容量分别为28.00 mg·g?1和5.96 mg·g?1，提高了近4倍；玉米芯对Cd2+的吸附是一个自发的吸热反应，温度越高，自发程度越大；接枝改性玉米芯对Cd2+的吸附过程中，参与反应的主要官能团有羧基、羟基、酰胺基和甲基等，吸附Cd2+后的接枝改性玉米芯表面出现褶皱和白色小颗粒，孔隙消失，电负性增大。
이갑기병희산위단체、고맹산갑/농류산위인발체계대옥미심진행접지개성，성공인입최기관능단，결합소묘전경、홍외광보화zeta전위등분석수단연구료흡부조건대옥미심흡부Cd2+과정적영향급기흡부궤리。결과표명，흡부과정부합 Langmuir 모형화준이급동역학방정，개성옥미심대 Cd2+적흡부주요시화학흡부과정，흡부속솔시과립내확산속솔화막확산속솔공동영향적결과；재pH=7、투가량위5 g·L?1、온도위30℃、흡부시간위6 h적조건하，접지개성옥미심화원옥미심대Cd2+적최대흡부용량분별위28.00 mg·g?1화5.96 mg·g?1，제고료근4배；옥미심대Cd2+적흡부시일개자발적흡열반응，온도월고，자발정도월대；접지개성옥미심대Cd2+적흡부과정중，삼여반응적주요관능단유최기、간기、선알기화갑기등，흡부Cd2+후적접지개성옥미심표면출현습추화백색소과립，공극소실，전부성증대。
To modify corncob by graft copolymerization, the methacrylic acid and a potassium permanganate- sulfuric acid redox system were used as monomer and initiator, carboxyl groups was introduced successfully. Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR) and zeta potential analysis were used to characterize corncob and the effects of adsorption conditions on the adsorption of Cd2+ in aqueous solutions and its mechanism analyzed. The results showed that the experimental data obtained could be represented with a Langmuir isotherm, the adsorption rate followed pseudo-second-order kinetics and the rate-controlling step was the chemical sorption. Under certain conditions the adsorption rate was affected by both intra-particle and film diffusion rates. The maximal adsorption capacities of Cd2+ for methacrylic acid grafted and crude corncobs were 28.00 mg·g?1 and 5.96 mg·g?1, respectively, indicating improvement of nearly 4 times (adsorption conditions: pH 7, the dosage 5 g·L?1, temperature 30℃, adsorption time 6 h). The adsorption was a spontaneous endothermic process, the higher the temperature was, the greater the degree of spontaneous. During the process of adsorbing Cd2+, the groups on the surface of grafted corncob, including carboxyl, hydroxyl, amide and methyl groups could play important roles. It was found that there existed some wrinkles and white particles on the surface of grafted corncob after adsorbing Cd2+, and its porosity disappeared and electronegativity increased.