饮用水源中不同粒径颗粒物吸附抗生素特征研究

Characteristics of antibiotics adsorption on particles with different diameters in natural waters

天然水体中存在大量的细小颗粒,它们往往与污染物相互作用并成为其载体,在饮用水传统处理工艺中亦不能被很好去除,进而随水厂出水进入人体,对人体健康造成潜在威胁.抗生素在饮用水源中的固、液相分配规律以及不同粒径颗粒对抗生素的吸附能力及影响因素亟待研究.实验利用微波萃取（MAE）和高效液相色谱与质谱联用（HPLC-MS/MS）的方法分别对颗粒物上吸附的抗生素进行了前处理和测定,进而分析了饮用水源颗粒物对4种典型抗生素的吸附特征.连续吸附平衡实验在360 min达到平衡,平衡时抗生素有32%~44%分布在颗粒上;除青霉素外,粒径0.05~1μm小颗粒的吸附量又占颗粒总吸附量的56%~70%.同时p H是影响饮用水源中颗粒吸附抗生素的重要因素,无论对于所有颗粒还是0.05~1μm的小颗粒,其吸附能力的最大值均出现在中性条件（p H=7）下.

A large number of small particles exist in natural water. They often interact with contaminants as their carrier, which are usually entering to the human body through drinking water and become a serious threat to human health. This study is conducted to investigate partitioning of antibiotics in nature water between liquid and soild phases, and the performance of antibiotics adsorption on particles with different physical-chemical properties. The adsorption of 4 kinds of typical antibiotics on the surface of the particles was analyzed. Element composition of the particles were concentrated with microwave extraction method and were analyzed by using environmental scanning electron microscopy and energy dispersive spectroscopy. HPLC-MS/MS （high performance liquid chromatography tandem mass spectrometry） was developed for simultaneous determination of 4 antibiotics. When the continuous adsorption experiments reached equilibrium in 360 min, 32%-44% of the antibiotic was distributed in solid phase. In addition to penicillin G, the adsorption of antibiotics on 0.05 - 1 ~xm particles accounted for 56% ~ 70% of the total adsorption amount. However, pH value has significant influence on particle adsorption capacity to antibiotics. All the particles reached the maximum adsorption under neutral pH. The experimental results have important implications for water quality improvement and increasing drinking water treatment processes.