Release and dissipation of antibiotics and disinfectants in different soil types as influenced by irrigation water quality

废水回用灌溉农田是解决水资源短缺和增加粮食生产的一种有效和广泛的做法，在世界许多地区有着悠久的传统。过去用未经处理的废水灌溉导致化学污染物的积累，如土壤中的药物残留物和消毒剂。为实现可持续发展目标6“清洁水和环境卫生”而进行的基础设施投资导致从使用未经处理的废水灌溉转向使用经处理的废水灌溉。我们假设，这种转变将暂时i）触发遗留污染物从土壤释放回土壤水，ii）导致抗生素和消毒剂的环境浓度足够大，以促进抗生素耐药性的选择，iii）抗生素的释放和浓度取决于土壤类型。SP 2将在研究单位的三个联合实验和两个卫星实验中，利用三种土壤类型（轻壤、黑土和变性土），针对不同结构和作用模式的常用抗生素（磺胺甲恶唑、甲氧苄啶、环丙沙星、克林霉素、红霉素、阿奇霉素）和季烷基铵化合物消毒剂（烷基三甲基铵、二烷基二甲基铵和苄基烷基铵化合物），检验这些假设。土壤水浸提液浓度的时间序列分析（所有目标化合物），加压液体萃取（抗生素）和超声波提取（季铵化合物）的吸附-解吸动力学研究，将为研究目标污染物在土壤固定固相-溶液相-悬浮胶体三元体系中的吸附-解吸动力学和分布提供信息（与SP 1和SP 7协作）。污染物吸附（去）动力学和可解吸目标污染物的数量将通过人工汇（薄膜中的扩散梯度）和同位素交换实验进行额外评估。将SP 2的结果整合到研究单位的命运和影响模型（SP 7）中，并将其与SP 3-6的结果相关联，将显示与废水一起引入并从土壤中释放的抗生素和季铵化合物与抗生素耐药性的选择和传播的相关性。通过这种方式，SP 2有助于从机理上理解不断变化的废水灌溉系统中污染物、抗生素耐药性和病原体之间的相互作用。

The reuse of wastewater for irrigation of agricultural land is an efficient and widespread practice for dealing with water shortages and for increasing food production with a long tradition in many areas of the world. Irrigation with untreated wastewater in the past resulted in an accumulation of chemical pollutants like pharmaceutical residues and disinfectants in soils. Investments in infrastructure for reaching the Sustainable Development Goal 6 “Clean Water and Sanitation” cause a shift from irrigation with untreated wastewater to irrigation with treated wastewater. We hypothesize that this shift will transiently i) trigger the release of legacy pollutants from soil back into soil water, ii) lead to environmental concentrations of antibiotics and disinfectants that are large enough to promote the selection of antibiotic resistance, with iii) release and concentrations of antibiotics depending on soil type. SP 2 will test these hypotheses with the three soil types Leptosol, Phaeozem and Vertisol for highly used antibiotic agents of different structure and mode of action (sulfamethoxazole, trimethoprim, ciprofloxacin, clindamycin, erythromycin, azithromycin) and quaternary alkylammonium compound disinfectants (alkyltrimtethylammonium, dialkyldimethylammonium and benzylalkylammonium compound) in the Research Units three joint experiments and 2 satellite experiments. The analysis of time series of concentrations in soil extracts with water (all target compounds), pressurized liquid extraction (antibiotics) and ultrasonic extraction (quaternary ammonium compounds) by means of mathematical models will deliver information on the sorption/desorption kinetics and distribution of the target pollutants in the ternary system stationary soil solid phase – solution phase – suspended colloids (in collaboration with SP 1 and SP 7). The kinetics of pollutant (de)sorption and the amounts of desorbable target pollutants will be assessed additionally by means of artificial sinks (diffusive gradients in thin films) and isotope exchange experiments. Integration of the results of SP 2 into the Research Units fate and effects model (SP 7) and relating them to the results of SPs 3-6 will show the relevance of antibiotics and quaternary ammonium compounds introduced with wastewater and released from soil for the selection and spread of antibiotic resistance. In this way, SP 2 contributes to a mechanistic understanding of interactions between pollutants, antibiotic resistance and pathogens in changing wastewater irrigation systems.