摘要

生物固体在农业土壤中的应用是抗生素进入农业生态系统的途径之一。通过盆栽试验，用生物固体重复进行土壤修正，研究了4种抗生素(四环素类、磺胺类、氟喹诺酮类和大环内酯类)在小麦-水稻轮作中的浓度及其在3种不同土壤类型中的消解动态。重复施用生物固体后，抗生素在土壤中积累。氟喹诺酮类药物在供试土壤中的积累和持久性强于其他三类抗生素。在典型的单孢-滞育型人为土(水稻土)中，诺氟沙星的最大残留抗生素浓度为155±16 μg kg-1。预计半衰期可达3.69年，比生物固体应用(平均每年两次)半衰期长得多。抗生素的积累顺序为氟喹诺酮类>四环素类>大环内酯类>磺胺类，很少见到磺胺类药物。当暂停施用生物固体时，耗散速率加快。施用高浓度重金属的生物固体时，抗生素的耗散稍慢，微生物降解可能是其耗散的主要机制。诺氟沙星的持效性与土壤吸附量呈正相关。阳离子交换容量和土壤有机质含量对氟喹诺酮类药物在土壤中的吸附有重要影响。由于氟喹诺酮类药物的持久性，在农业生产中的生物固体应用规划中必须考虑氟喹诺酮类药物。

Application of biosolids to agricultural soils is one of the pathways by which antibiotics can be introduced into agricultural ecosystems. A pot experiment was conducted with repeated soil amendment with biosolids to examine the concentrations of four classes of antibiotics (tetracyclines, sulfonamides, fluoroquinolones, and macrolides) and their dissipation in three different soil types in wheat-rice rotations. Antibiotics accumulate in the soils after repeated application of biosolids. Fluoroquinolones showed stronger accumulation and persistence in the test soils than the other three classes of antibiotics. The maximum residual antibiotic concentration was that of norfloxacin at 155 ± 16 μg kg−1 in the Typic Hapli-Stagnic Anthrosols (paddy soil). Predicted half-lives were up to 3.69 years, a much longer period than that between biosolid applications (twice each year on average). Antibiotic accumulation followed the rough order fluoroquinolones > tetracyclines > macrolides > sulfonamides, and the sulfonamides were seldom encountered. When biosolid application was suspended, the dissipation rate accelerated. Antibiotic dissipation was slightly slower when biosolids with high heavy metal concentrations were applied and microbial degradation may have been the main mechanism of dissipation. Norfloxacin persistence was positively correlated with its soil adsorption capacity. Cation exchange capacity and soil organic matter content may have vital roles in the soil adsorption of fluoroquinolones. Because of their persistence, the fluoroquinolones must be taken into account in the planning of biosolid applications in agricultural practice.

https://link.springer.com/article/10.1007/s11356-016-8062-6