摘要
抗生素是目前使用较为广泛的药物之一,全球抗生素年均使用总量为10×104～20×104t。而大部分抗生素不能被机体完全吸收,约占用药量40%～90%的抗生素以母体或代谢物形式经由病人和畜禽粪尿排入环境,并经由施肥等途径对土壤和水体环境造成污染。近年来,对于抗生素在土壤中的环境行为已成为国内外研究的热点。而对于抗生素在热带土壤中的残留和环境行为研究较少。文章选取典型氟喹诺酮类抗生素-诺氟沙星,研究其在热带土壤中的吸附解吸特征,揭示其在不同土壤中的吸附机理,以期为氟喹诺酮类抗生素在热带土壤中的环境风险评价提供理论依据。以OECD Guideline 106为基础,采用批量平衡方法研究诺氟沙星在3种热带土壤上的吸附解吸特征。结果表明,诺氟沙星在3种热带土壤上的吸附和解吸数据均能用Freundlich方程和Langmuir方程进行较好的拟合,在3种土壤上的吸附等温线呈"L型"。其Kf值变化较大,分别为燥红土322.4L.kg-1,砖红壤967.2L.kg-1,水稻土1370.9L.kg-1,最大吸附量分别为燥红土198.9mg.kg-1、砖红壤355.3mg.kg-1和水稻土371.9 mg.kg-1。显示诺氟沙星在3种热带土壤中的吸附行为存在较大的差异。此外,诺氟沙星在3种热带土壤上的解吸常数均明显高于吸附常数,解吸过程存在明显的滞后现象,在同一土壤中随着平衡溶液中诺氟沙星质量浓度的增加,滞后系数逐渐增大,水稻土的解吸滞后现象明显高于其他2种土壤(p<0.05)。
Antibiotics are widely used drugs in the world. Quantity of global antibiotics consumption has reached 10,000 to 200,000 tons per year. A high percentage, up to 40%-90%, of administered antibiotics, unchanged or changed, is ultimately excreted via urine and feces into soil and surface water. Recently, Environmental behavior of antibiotics in soil becomes a research hotspot. While few studies have focused either on antibiotic residues or environmental behavior in tropical soils. This paper focused on adsorption and desorption of fluoroquinolones antibiotics （ Norfloxacin ） on tropical soil, in order to reveal the dominant mechanism of norfloxacin antibiotics adsorption, and provide basis and reference for environmental risk assessment of fluoroquinolones antibiotics in tropical soil. On the basis of the OECD Guideline 106, Batch equilibrium experiments were used to reveal norfloxacin adsorption/desorption on three kinds of soil. Results show that the experimental data are best described by the Freundlich and Langrnuir model. Adsorption isotherms resembled the L-type curves. Different sorption behaviors of norfloxacin are observed in three kinds of tropical soil, with the Kf values varying greatly from 322.4 L·kg-1 （torrid red soils） and 967.2 L·kg-1 （latosols） to 1370.9 L·kg-1 （paddy soils）, and the maximum adsorption from 198.9 mg·kg-1 （torrid red soils） and 355.3 mg·kg-1 （latosols） to 371.9 mg·kg-1 （Paddy soils） respectively. In addition, desorption rate of norfloxacin was higher than adsorption rate on three kinds tropical soil, and the apparent sorption-desorption hysteresis is observed. With increase of norfloxacin concentration, hysteresis index increases gradually. And the hysteresis index of antibiotic in paddy soils was higher than that in torrid red soils and latosols （p〈0.05）
出处
《生态环境学报》
CSCD
北大核心
2012年第11期1891-1896,共6页
Ecology and Environmental Sciences
基金
海南省自然科学基金项目(项目编号:809003)
海南大学科研启动基金资助项目(项目编号:kyqd1068)
海南大学青年基金项目(项目编号:qnjj1013)
海口市重点科技项目(项目编号:NO.2009-47)
海南大学211工程建设项目
关键词
诺氟沙星
热带土壤
吸附
解吸
抗生素
norfloxacin
tropical soils
adsorption and desorption
antibiotics
