Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, PR China; School of Earth Science and Engineering, Nanjing University, Nanjing 210093, PR China.
Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, School of Life Sciences, Taizhou University, Taizhou 318000, PR China.
Int J Biol Macromol. 2023 Jun 30;241:124511. doi: 10.1016/j.ijbiomac.2023.124511. Epub 2023 Apr 21.
Developing an eco-friendly, sustainable and antibacterial adsorbent is significant for actual water treatment. Herein, a bio-based antibacterial adsorbent based on titanium dioxide (TiO) nanoparticles functionalized chitosan (CS) was prepared through an in-situ hydrolysis strategy using titanium oxysulfate as the source of TiO. The as-obtained CS/TiO nanocomposite was characterized by a variety of analytical techniques. According to the Langmuir mode, the adsorption capacity of CS/TiO reached 23.64 mg P g, almost 8 times higher than that of CS. In addition, the normalized adsorption capacity (adsorption value per Ti) of CS/TiO was calculated to be 102.68 mg P g Ti, much higher than pure TiO (60.11 mg P g Ti). Moreover, CS/TiO exhibited a highly selective capacity for phosphate removal in the presence of competing anions, and showed high stability in a wide pH range of 3.0-8.0. When the phosphate concentration was 2.0 mg P L, the removal efficiency of phosphate reached 99.5 % and the residual concentration was only 10 μg P L, which meets the USEPA standards for eutrophication prevention and control. In addition, after treatment by CS/TiO, the phosphate concentration of two sewage water samples decreased from 1.50 and 1.0 mg P L to <0.10 mg P L, meeting the standard of level II water based on the Environmental Quality Standard of China (GB3838-2002). Ligand exchange and electrostatic interactions are mainly responsible for phosphate adsorption by CS/TiO. Furthermore, the CS/TiO nanocomposites exhibited excellent antibacterial activity, which could avoid biofouling contamination caused by microorganisms. Benefiting from the above advantages, the as-designed CS/TiO nanocomposite has great potential as a bio-based antibacterial adsorbent for phosphate capture or removal from wastewater.
开发环保、可持续和抗菌的吸附剂对于实际的水处理具有重要意义。本文通过钛氧硫酸为钛源的原位水解策略，制备了基于纳米二氧化钛（TiO）修饰壳聚糖（CS）的生物基抗菌吸附剂。采用多种分析技术对所制备的 CS/TiO 纳米复合材料进行了表征。根据朗缪尔模式，CS/TiO 的吸附容量达到 23.64mg P g，几乎是 CS 的 8 倍。此外，CS/TiO 的归一化吸附容量（每钛的吸附值）计算为 102.68mg P g Ti，远高于纯 TiO（60.11mg P g Ti）。此外，CS/TiO 在存在竞争阴离子的情况下对磷酸盐具有高度选择性的去除能力，并在 3.0-8.0 的宽 pH 范围内表现出高稳定性。当磷酸盐浓度为 2.0mg P L 时，磷酸盐的去除效率达到 99.5%，残留浓度仅为 10μg P L，符合美国环保署用于防止富营养化的标准。此外，经过 CS/TiO 处理后，两份污水水样中的磷酸盐浓度从 1.50 和 1.0mg P L 分别降低到 <0.10mg P L，符合中国（GB3838-2002）《地表水环境质量标准》中二级水的标准。配位交换和静电相互作用是 CS/TiO 吸附磷酸盐的主要机制。此外，CS/TiO 纳米复合材料表现出优异的抗菌活性，可避免微生物引起的生物污垢污染。得益于上述优点，所设计的 CS/TiO 纳米复合材料具有作为生物基抗菌吸附剂从废水中捕获或去除磷酸盐的巨大潜力。
