College of Chemistry, Green Catalysis Center, Zhengzhou University, Zhengzhou, 450001, People's Republic of China.
Environ Sci Pollut Res Int. 2022 Sep;29(42):64177-64191. doi: 10.1007/s11356-022-20257-3. Epub 2022 Apr 26.
We engineered a tiger nut residue (TNR, a low-cost agricultural waste material) through a facile and simple process to take advantage of the introduced functional groups (cetylpyridinium chloride, CPC) in the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in batch mode and further investigated its impingement on bacterial growth in a yeast-dextrose broth. The surface characterizations of the adsorbent were achieved through Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller method (BET), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The batch adsorption studies revealed that solution pH, adsorbent dose, temperature, and salt affected the adsorptive capacity of TNR-CPC. The equilibrium data were best fitted by Langmuir isotherm model with a maximum monolayer adsorption capacity of 90.2 mg g at 318 K and pH 3. Pseudo-second-order model best fitted the kinetics data for the adsorption process. Physisorption largely mediated the adsorption system with spontaneity and a shift in entropy of the aqueous solid-solute interface reflecting decreased randomness with an exothermic character. TNR-CPC demonstrated a good reusability potential making it highly economical and compares well with other adsorbents for decontamination of 2,4-D. The adsorption of 2,4-D proceeded through a probable trio-mechanism; electrostatic attraction between the carboxylate anion of 2,4-D and the pyridinium cation of TNR-CPC, hydrogen bonding between the hydroxyl (-OH) group inherent in the TNR and the carboxyl groups in 2,4-D and a triggered π-π stacking between the benzene structures in the adsorbate and the adsorbent. TNR-CPC reported about 99% inhibition rate against both gram-positive S. aureus and gram-negative E. coli. It would be appropriate to investigate the potential of TNR-CPC as a potential replacement to the metal oxides used in wastewater treatment for antibacterial capabilities, and its effects against airborne bacteria could also be of interest.
我们通过一种简单易行的方法对巴旦木坚果渣（TNR，一种低成本的农业废料）进行了改性，利用引入的功能基团（氯化十六烷基吡啶，CPC）来去除 2,4-二氯苯氧乙酸（2,4-D），并进一步研究了其在酵母-葡萄糖肉汤中的对细菌生长的影响。通过傅里叶变换红外光谱（FTIR）、BET 法、X 射线衍射分析（XRD）和 X 射线光电子能谱（XPS）对吸附剂的表面特性进行了研究。批处理吸附研究表明，溶液 pH、吸附剂剂量、温度和盐度会影响 TNR-CPC 的吸附能力。吸附等温线数据最好用 Langmuir 等温模型拟合，在 318 K 和 pH 3 时最大单层吸附容量为 90.2 mg g。准二级动力学模型最适合吸附过程的动力学数据。物理吸附在很大程度上介导了吸附体系，具有自发性和水溶液固-液界面熵的变化，反映了界面无序性的降低和放热特征。TNR-CPC 表现出良好的可重复使用潜力，使其具有很高的经济性，并且在 2,4-D 的去除方面与其他吸附剂相比具有很好的效果。2,4-D 的吸附可能通过三种机制进行：2,4-D 的羧酸根阴离子与 TNR-CPC 的吡啶阳离子之间的静电引力、TNR 中固有的羟基（-OH）基团与 2,4-D 的羧基之间的氢键，以及吸附质和吸附剂中的苯环结构之间的引发π-π堆积。TNR-CPC 对革兰氏阳性菌金黄色葡萄球菌和革兰氏阴性菌大肠杆菌的抑制率均达到 99%。研究 TNR-CPC 作为金属氧化物在废水处理中抗菌能力的替代品的潜力，以及其对空气中细菌的影响可能也是合适的。
