Andriamalala Aurore, Vieublé-Gonod Laure, Dumeny Valérie, Cambier Philippe
UMR ECOSYS, INRA, AgroParisTech, Université Paris-Saclay, 78850, Thiverval-Grignon, France.
UMR ECOSYS, AgroParisTech, INRA, Université Paris-Saclay, 78850, Thiverval-Grignon, France.
Chemosphere. 2018 Jan;191:607-615. doi: 10.1016/j.chemosphere.2017.10.093. Epub 2017 Oct 16.
Spreading organic waste products (OWP) issued from sewage sludge or manures into soil may disseminate antibiotics with unknown risks for human health and environment. Our objectives were to compare the fate of two sulfonamides, sulfamethoxazole (SMX) and its metabolite N-acetyl-sulfamethoxazole (N-ac-SMX), and one fluoroquinolone, ciprofloxacin (CIP), in an unamended soil, and two soils regularly amended since 1998 with a sewage sludge and green waste compost and with farmyard manure respectively. Incubations of soil spiked with C labelled SMX or N-ac-SMX (0.02 mg kg) or CIP (0.15 mg kg) allowed a quantification of radiolabeled molecules in the mineralized, easily, hardly and non-extractable fractions after 3 and 156 days. Nature of C molecules was also analyzed by HPLC in extractable fractions after 3 and 156 days. SMX and N-ac-SMX dissipation was fast and due to i) mineralization (∼10% of recovered C after 156 days) or incomplete degradation (production of metabolites), ii) adsorption, even if both sulfonamides present low Kd (<3 L kg) and iii) formation of non-extractable residues (NER), representing more than 50% of recovered radioactivity. N-ac-SMX was more mineralized than SMX, and formed more progressively NER, after a step of deacetylation. Adsorption of CIP was fast and formed mainly NER (>72%) whereas its mineralization was negligible. Repeated applications of OWP tend to enhance adsorption of antibiotics and lower their degradation, through the quantity and quality of the built up soil organic matter. If applications of sewage sludge compost favor adsorption and inhibit mineralization, applications of manure boost the formation of non-extractable residues.
将污水污泥或粪便产生的有机废弃物（OWP）施用于土壤中可能会传播抗生素，对人类健康和环境造成未知风险。我们的目标是比较两种磺胺类药物，即磺胺甲恶唑（SMX）及其代谢产物N-乙酰磺胺甲恶唑（N-ac-SMX），以及一种氟喹诺酮类药物环丙沙星（CIP），在未改良土壤、自1998年以来分别定期用污水污泥和绿色垃圾堆肥以及农家肥改良的两种土壤中的归宿。用碳标记的SMX或N-ac-SMX（0.02 mg/kg）或CIP（0.15 mg/kg）对土壤进行加标培养，在3天和156天后对矿化、易提取、难提取和不可提取部分中的放射性标记分子进行定量。在3天和156天后，还通过高效液相色谱法分析了可提取部分中碳分子的性质。SMX和N-ac-SMX的消散很快，原因如下：i）矿化作用（156天后回收碳的约10%）或不完全降解（代谢产物的产生）；ii）吸附作用，即使两种磺胺类药物的分配系数（Kd）都很低（<3 L/kg）；iii）不可提取残留物（NER）的形成，其占回收放射性的50%以上。N-ac-SMX比SMX矿化程度更高，在脱乙酰化步骤后，NER的形成更为渐进。CIP的吸附很快，主要形成NER（>72%），而其矿化作用可忽略不计。通过积累的土壤有机质的数量和质量，OWP的重复施用往往会增强抗生素的吸附并降低其降解。如果施用污水污泥堆肥有利于吸附并抑制矿化作用，那么施用粪肥则会促进不可提取残留物的形成。
