Effects of natural organic matter with different properties on levofloxacin adsorption to goethite: Experiments and modeling
Effects of natural organic matter with different properties on levofloxacin adsorption to goethite: Experiments and modeling
复制标题
不同性质的天然有机物对针铁矿吸附左氧氟沙星的影响：实验和建模
DOI：
10.1016/j.cej.2018.03.125
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发表时间：
2018-08-01
影响因子：
15.1
通讯作者：
Weng, Liping
中科院分区：
文献类型：
--
作者：
Qin, Xiaopeng;Du, Ping;Weng, Liping
通过批量实验研究了在 pH 范围 3-10 以及不存在或存在以九种腐殖酸 (HA) 和黄腐酸 (FA) 为代表的天然有机物 (NOM) 的情况下，左氧氟沙星 (LEV) 对针铁矿的吸附。 LEV 对针铁矿的吸附很弱，在 pH 5.8 左右出现最大值。在针铁矿中添加 NOM 会大大增加针铁矿对 LEV 的吸附，但几乎不影响其 pH 依赖性。吸附包络线很好地拟合了线性加性模型，其中LEV对针铁矿的吸附采用电荷分布多位点络合(CD-MUSIC)模型进行模拟，LEV对NOM的吸附采用Langmuir模型进行模拟。 LEV对NOM吸附的拟合亲和力常数（log K）与NOM的SUVA（280 nm处的特定紫外吸光度）值呈显着正相关，与E-2/E-3（250 nm和365 nm处的吸光度比）值、羧基含量和NOM的极性呈负相关。结果表明，NOM的芳香族部分在LEV与NOM之间的相互作用中起关键作用，疏水相互作用和p-p相互作用是LEV吸附NOM的主要机制，而氢键或表面络合可能不起重要作用。结果表明，NOM的浓度和性质对抗生素在土壤和水体中的分布或处理有显着影响，最终将影响抗生素对环境系统中微生物的影响。
Adsorption of levofloxacin (LEV) to goethite in the pH range of 3-10, and in the absence or presence of natural organic matter (NOM) represented by nine types of humic acid (HA) and fulvic acid (FA), was studied using batch experiments. The adsorption of LEV to goethite was weak and showed a maximum around pH 5.8. Adding NOM to goethite strongly increased LEV adsorption to goethite, but hardly affected its pH dependency. The adsorption envelopes were well fitted to a linear additive model, in which LEV adsorption to goethite was simulated with the Charge Distribution Multi-Site Complexation (CD-MUSIC) model, and LEV adsorption to NOM was simulated with the Langmuir model. The fitted affinity constants (log K) for LEV adsorption to NOM were significantly and positively correlated with the SUVA (specific ultraviolet absorbance at 280 nm) values of NOM, and negatively correlated with E-2/E-3 (absorbance ratio at 250 nm and 365 nm) values, carboxyl contents, and the polarity of NOM. The results indicated that aromatic moieties of NOM play a key role in the interactions between LEV and NOM, and hydrophobic interactions and p-p interactions were the major mechanisms for LEV adsorption to NOM, whereas H-bond or surface complexation might not play an important role. Results show that both the concentrations and properties of NOM have a significant effect on the distribution or treatment of antibiotics in soils and waters, which will eventually affect the influence of antibiotics on microorganisms in the environmental systems.