State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
Sci Total Environ. 2021 May 10;768:144450. doi: 10.1016/j.scitotenv.2020.144450. Epub 2021 Jan 6.
The demand for powerful and multifunctional water-treatment materials and reagents is increasing, because we are facing worse raw water quality, various tolerant bacteria, and risky disinfection by-products (DBPs) in drinking water. Quaternary ammonium resins (QARs) are promising candidates for water disinfection and purification, but their limited bactericidal capacities are difficult to improve because of the lack of guidelines for enhancing antibacterial efficiency. Therefore, we first systematically studied the structure-dependent antimicrobial mechanism of QARs and found that the best resin skeleton is acrylic-type, the optimal bactericidal alkyl is hexyl or octyl, the most applicable sizes are 80-100 meshes, the best counter anion is iodide ion, and the optimum quaternization reagent is iodoalkane. Moreover, the antibacterial capacity was demonstrated to depend on surficial N groups, correlating with surficial N charge density (R of 0.98) but not with exchange capacity (R of 0.26), physical adsorption of resin skeleton, or electrostatic adsorption of N groups. Based on these principles, we synthesized a new resin, Ac-81, with a surficial antibacterial design, which simultaneously exhibited better antimicrobial efficiency (two orders of magnitude) as well as higher contaminant removal potential (61.92%) compared to the traditional Ac-8C antibacterial resin. Furthermore, the new resin showed remarkable broad-spectrum antibacterial effects against Gram-negative E. coli and P. aeruginosa and Gram-positive B. subtilis and S. aureus in simulated water and actual water. Simultaneously, water quality was significantly improved, with HCO, SO, TN, TP, and TOC reduced by 79-90%, >99%, 66-85%, >99%, and 22-26%, respectively. Ac-81 is characterized by facile reusability, high treatment capacity of 1500 bed volume, and good adaptability for treating actual water, providing a promising alternative for drinking-water disinfection and purification.
对功能强大且多功能的水处理材料和试剂的需求正在增加，因为我们面临着更差的原水水质、各种耐受细菌以及饮用水中存在的风险消毒副产物 (DBP)。季铵树脂 (QAR) 是水消毒和净化的有前途的候选物，但由于缺乏提高抗菌效率的指导方针，其有限的杀菌能力难以提高。因此，我们首先系统地研究了 QAR 的结构依赖性抗菌机制，发现最佳树脂骨架为丙烯型，最佳杀菌烷基为己基或辛基，最适用粒径为 80-100 目，最佳抗衡阴离子为碘离子，最佳季铵化试剂为碘代烷烃。此外，抗菌能力被证明取决于表面 N 基团，与表面 N 电荷密度（R 为 0.98）相关，而与交换容量（R 为 0.26）、树脂骨架的物理吸附或 N 基团的静电吸附无关。基于这些原则，我们合成了一种新的树脂 Ac-81，其表面具有抗菌设计，与传统的 Ac-8C 抗菌树脂相比，它同时表现出更好的抗菌效率（两个数量级）和更高的污染物去除潜力（61.92%）。此外，新树脂对模拟水中和实际水中的革兰氏阴性大肠杆菌和铜绿假单胞菌以及革兰氏阳性枯草芽孢杆菌和金黄色葡萄球菌表现出显著的广谱抗菌作用。同时，水质得到了显著改善，HCO3-、SO42-、TN、TP 和 TOC 分别降低了 79-90%、>99%、66-85%、>99%和 22-26%。Ac-81 的特点是易于重复使用、处理能力高达 1500 床体积和对实际水的良好适应性，为饮用水消毒和净化提供了一种有前途的替代方法。
