Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
J Hazard Mater. 2018 Jan 5;341:187-197. doi: 10.1016/j.jhazmat.2017.07.046. Epub 2017 Jul 21.
The effect of tetracycline (TC) on the behavior of TiO nanoparticles (NPs) in solution is investigated. The results illustrate that TC molecules do not exhibit an obvious effect on the aggregation of TiO NPs under circumneutral conditions (pH of approximately 5.5). However, the TC molecules exhibit a remarkable effect on the behavior of TiO NPs when the environmental factors (such as pH, ionic strength, and humic acid; HA) are adjusted. In the pH range from 3.0 to 10.0, the zeta potentials of NPs become more positively charged after TC adsorption. The point of zero charge of the TiO NPs increases from 6.5 to 7.5. The stability of the TiO NPs is improved after TC adsorption in different salt solutions. The critical coagulation concentration (CCC) increases from 10.57mmol/L to 17.21mmol/L, 4.95mmol/L to 9.73mmol/L, and 0.23-1.67mmol/L in the presence of NaCl, CaCl, and NaSO (where Cl and SO are the counter-ions), respectively. Under different HA concentrations, the C (the HA concentration that causes the zeta potential of NPs to be zero) increases from 0.5mg/L to 1.3mg/L after TC adsorption. The sizes of the TiO NP aggregates are larger than those without TC adsorption. All of these results are due to an increase in the surface charge of the TiO NPs after TC adsorption. The adsorption of H during TC adsorption causes protonation of the dimethylamine group on the TC molecules.
研究了四环素（TC）对溶液中 TiO 纳米粒子（NPs）行为的影响。结果表明，TC 分子在近中性条件（约 pH5.5）下对 TiO NPs 的聚集没有明显影响。然而，当环境因素（如 pH、离子强度和腐殖酸；HA）得到调整时，TC 分子对 TiO NPs 的行为有显著影响。在 pH 3.0 至 10.0 范围内，TC 吸附后 NPs 的动电电位变得更带正电。TiO NPs 的零电荷点从 6.5 增加到 7.5。在不同盐溶液中 TC 吸附后，TiO NPs 的稳定性得到提高。在 NaCl、CaCl 和 NaSO（其中 Cl 和 SO 是抗衡离子）存在的情况下，临界聚沉浓度（CCC）分别从 10.57mmol/L 增加到 17.21mmol/L、4.95mmol/L 增加到 9.73mmol/L 和 0.23-1.67mmol/L。在不同 HA 浓度下，TC 吸附后，导致 NPs 动电电位为零的 HA 浓度从 0.5mg/L 增加到 1.3mg/L。TiO NP 聚集体的尺寸大于没有 TC 吸附的聚集体。所有这些结果都是由于 TC 吸附后 TiO NPs 表面电荷增加所致。TC 吸附过程中 H 的吸附导致 TC 分子上二甲胺基团的质子化。
