沉积物和腐殖质对诺氟沙星的吸附

通过化学方法,对中国不同区域4种沉积物中的胡敏酸和胡敏素进行了分离定量,并研究了沉积物、胡敏酸和胡敏素对诺氟沙星的吸附行为.结果表明,沉积物中胡敏素在有机碳中的质量分数为0.419 ～0.746,远高于胡敏酸在有机碳中的质量分数（0.074 5 ～0.287）.胡敏酸的H/C和O/C原子比分别为1.18～ 1.38和0.47～0.58.胡敏酸的（N＋O）/C原子比为0.579 ～0.671,最高的是太湖沉积物,说明太湖沉积物中胡敏酸样品的极性最强.与原始沉积物相比,胡敏素对诺氟沙星的吸附非线性更强,吸附参数n值为0.498 ～0.563,说明胡敏素比沉积物具有更多的非均质性的吸附位.在给定液相平衡浓度Ce下,胡敏酸的吸附能力参数koc值较沉积物样品低,而胡敏素的Koc值高于沉积物样品,说明沉积物腐殖质对诺氟沙星吸附能力由大到小顺序为：胡敏素,原始沉积物,胡敏酸.其中,太湖沉积物对诺氟沙星的吸附能力最强,而长江沉积物对诺氟沙星的吸附能力最弱.

Norfloxacin Sorption to Different Sediment Humus

Humic acids and humins in four sediments from different areas in China were isolated upon chemical treatments and their sorption isotherms for norfloxacin （NOF） were determined. The mass fraction of humin in total organic carbon （TOC） in sediments was of 0. 419 - 0. 746, higher than that of humic acid in TOC （0. 074 5 -0.287）. The H/C and O/C atomic ratios of humic acids were of 1.18 -1.38 and 0.47 -0.58, respectively. The （N ＋ O）/C atomic ratios of humie acids were of 0. 579 - 0. 671, with the highest of Tai lake, indicating the highest polarity for humic acid sample from Tai lake. Compared to original sediments, hu- mins exhibited more nonlinear sorption with n values of 0.498 - 0.563, indicating that humin possessed more heterogeneous sorption sites for NOF. At a given Ce, humic acids had lower Koc values than the original sedi- ments, but humins had higher Koo values than the original sediments. This revealed a following trend of NOF sorption on sediment humus： humin,original sediment,humic acid, with the highest sorption capacity for Tai lake, and the lowest sorption capacity for Yangtze River.