DST-CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001, South Africa.
DST-CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001, South Africa; Department of Applied Chemistry, University of Johannesburg, Doornfontein, 2028, Johannesburg, South Africa.
Water Res. 2017 Mar 15;111:213-223. doi: 10.1016/j.watres.2017.01.003. Epub 2017 Jan 3.
Disinfection of bacterially-contaminated drinking water requires a robust and effective technique and can be achieved by using an appropriate disinfectant material. The advanced use of nanomaterials is observed as an alternative and effective way for the disinfection process and water treatment as a whole. Hence, the inactivation of Escherichia coli (E. coli) using chitosan-Bentonite (Cts-Bent) composites was studied in a fixed bed column. Cts-Bent composites were synthesized using in situ cross-linking method using Bent-supported silver and zinc oxide nanoparticles. These composites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. The effect of the composite bed mass, initial concentration of bacteria, and flow rate on the bacterial inactivation was investigated. The characterization results revealed that the composites were successfully prepared and confirmed the presence of both silver and zinc oxide nanoparticles in the chitosan matrix. The growth curves of E. coli were expressed as breakthrough curves, based on the logistic, Gompertz, and Boltzmann models. The breakthrough time and processed volume of treated water at breakthrough were used as performance indicators, which revealed that the composites performed best at low bacterial concentration and flow rate and with substantial bed mass. The chitosan composites were found to be highly effective, which was demonstrated when no bacteria were observed in the effluent sample within the first 27 h of analysing river water. All the models were suitable for adequately describing and reproducing the experimental data with a sigmoidal pattern. Therefore, the prepared composite is showing potential to work as a disinfectant and provide an alternative solution for water disinfection; hence this study should propel further research of the same or similar materials.
对受细菌污染的饮用水进行消毒需要一种强大且有效的技术，可通过使用适当的消毒剂来实现。纳米材料的先进应用被视为消毒过程和整体水处理的替代和有效方法。因此，使用壳聚糖-膨润土（Cts-Bent）复合材料在固定床柱中研究了对大肠杆菌（E. coli）的灭活作用。Cts-Bent 复合材料是使用原位交联法，使用 Bent 支撑的银和氧化锌纳米粒子合成的。通过傅里叶变换红外光谱、X 射线衍射、扫描电子显微镜和能量色散光谱对复合材料进行了表征。研究了复合床质量、细菌初始浓度和流速对细菌灭活的影响。表征结果表明，成功制备了复合材料，并证实了壳聚糖基质中存在银和氧化锌纳米粒子。大肠杆菌的生长曲线表示为突破曲线，基于逻辑斯蒂、戈珀兹和玻尔兹曼模型。突破时间和处理水的处理体积在突破时用作性能指标，结果表明，当以低细菌浓度和流速以及大量床质量运行时，复合材料的性能最佳。壳聚糖复合材料被证明是非常有效的，当在分析河水的最初 27 小时内，在流出物样品中未观察到细菌时，就证明了这一点。所有模型都适合充分描述和再现具有类正态模式的实验数据。因此，所制备的复合材料显示出作为消毒剂的潜力，并为水消毒提供了替代解决方案；因此，这项研究应该推动对相同或类似材料的进一步研究。
