Suárez-Avendaño D, Martínez-Correa E, Cañas-Gutierrez A, Castro-Riascos M, Zuluaga-Gallego R, Gañán-Rojo P, Peresin M, Pereira M, Castro-Herazo C
School of Engineering, Universidad Pontificia Bolivariana (Pontificia Bolivariana University), Medellín, Antioquia.
Tourist and Agroindustrial Technological Complex of the West Antioquia, Servicio Nacional de Aprendizaje (National Training Service), Santafé de Antioquia, Antioquia.
Front Bioeng Biotechnol. 2022 Mar 14;10:815892. doi: 10.3389/fbioe.2022.815892. eCollection 2022.
A comparative study was conducted on the efficiency of mercury removal using bacterial nanocellulose (BNC) membranes obtained from the fermentation of the microorganism , in contrast with its oxidized analog obtained by modifying the bacterial nanocellulose membranes oxidation with 2,2,6,6-Tetramethylpiperidine-1-oxyl. Both types of membranes (modified and unmodified) were characterized to identify variations in the Physico-chemical parameters after modification. FTIR spectra confirmed the chemical modification of cellulose in all reaction conditions by the presence of a new characteristic band at ∼1730 cm, corresponding to the new carboxylic groups produced by the oxidative process, and the decline of the band at ∼1,650 cm, corresponding to the hydroxyl groups of the C6 carbon. While the XRD profiles indicated that the percentage of BNC crystallinity decreased and the SEM images showed that the nanoribbon network was interrupted as the amount of oxidizing agent increased. The kinetics of mercury removal from both types of membrane was evaluated by calculating the concentration of mercury at different times and establishing a mathematical model to describe the kinetics of this process. The modified membranes improved significantly the adsorption process of the metal ion and it was found that the modification that results in the greatest adsorption efficiency was BNC-m 7.5 with a value of 92.97%. The results obtained suggest that the modification of the bacterial nanocellulose membranes by oxidation transcendentally improves the mercury removal capacity, outlining the modified membranes as an excellent material for mercury removal in wastewater.
对通过微生物发酵获得的细菌纳米纤维素（BNC）膜与通过用2,2,6,6-四甲基哌啶-1-氧基对细菌纳米纤维素膜进行氧化改性而获得的氧化类似物的汞去除效率进行了比较研究。对两种类型的膜（改性和未改性）进行了表征，以确定改性后物理化学参数的变化。傅里叶变换红外光谱（FTIR）证实，在所有反应条件下，纤维素都发生了化学改性，在约1730 cm处出现了一个新的特征峰，对应于氧化过程产生的新羧基，而在约1650 cm处对应于C6碳羟基的峰下降。X射线衍射（XRD）图谱表明，随着氧化剂用量的增加，BNC的结晶度百分比降低，扫描电子显微镜（SEM）图像显示纳米带网络被打断。通过计算不同时间的汞浓度并建立数学模型来描述该过程的动力学，评估了两种类型膜的汞去除动力学。改性膜显著改善了金属离子的吸附过程，发现吸附效率最高的改性是BNC-m 7.5，其值为92.97%。所得结果表明，通过氧化对细菌纳米纤维素膜进行改性极大地提高了汞去除能力，表明改性膜是废水中汞去除的优良材料。
