College of Natural Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
J Environ Sci (China). 2009;21(5):632-40. doi: 10.1016/s1001-0742(08)62318-9.
Norfloxacin sorption and the factors (soil organic matter (SOM), pH, and exogenous copper (Cu) influencing the sorption were investigated in a black soil (soil B), a fluvo-aquic soil (soil F), and a red soil (soil R). With increasing norfloxacin concentrations, sorption amount of norfloxacin increased in both the bulk soils and their SOM-removed soils, but the sorption capacity of SOM-removed soils was higher than that of their corresponding bulk soils, indicating that the process of norfloxacin sorption in soil was influenced by the soil properties including SOM. The sorption data in all bulk soils and SOM-removed soils were fitted to Freundlich and Langmuir models. The correlation coefficients suggested that the experimental data fitted better to Freundlich equation than to Langmuir equation. Furthermore, the data from soil F and SOM-removed F could not be described by Langmuir equation. The norfloxacin sorption amount decreased in soil B and soil F, whereas it increased in soil R as solution pH increased. The maximum K(D) and K(OC) were achieved in soil R when the equilibrium solution pH was 6. The norfloxacin sorption was also influenced by the exogenous Cu2+, which depended on the soil types and Cu2+ concentrations. With increasing Cu2+ concentrations in solution, generally, sorption amount, K(D) and K(OC) for norfloxacin in soils increased and were up to a peak at 100 mg/L Cu2+, and then the sorption amount decreased regardless of norfloxacin levels.
诺氟沙星在黑土（土壤 B）、潮土（土壤 F）和红壤（土壤 R）中的吸附及其受土壤有机质（SOM）、pH 值和外源铜（Cu）的影响因素。随着诺氟沙星浓度的增加，在原状土及其去除 SOM 的土壤中，诺氟沙星的吸附量均增加，但去除 SOM 的土壤的吸附容量高于相应的原状土，表明诺氟沙星在土壤中的吸附过程受到包括 SOM 在内的土壤性质的影响。所有原状土和去除 SOM 的土壤的吸附数据均拟合为 Freundlich 和 Langmuir 模型。相关系数表明，实验数据更符合 Freundlich 方程而不是 Langmuir 方程。此外，土壤 F 和去除 SOM 的土壤 F 的数据不能用 Langmuir 方程描述。随着溶液 pH 值的升高，土壤 B 和土壤 F 中的诺氟沙星吸附量减少，而土壤 R 中的吸附量增加。当平衡溶液 pH 值为 6 时，土壤 R 中的最大 K(D)和 K(OC)达到。外源 Cu2+也影响诺氟沙星的吸附，这取决于土壤类型和 Cu2+浓度。随着溶液中 Cu2+浓度的增加，通常情况下，土壤中诺氟沙星的吸附量、K(D)和 K(OC)均增加，并在 100mg/L Cu2+时达到峰值，然后无论诺氟沙星水平如何，吸附量均下降。
