Redox sensitivity and long-term persistence of organic trace pollutants in groundwater - wastewater-bound compounds

药物残留等大量有机微污染物对水生环境的污染日益严重，这是一个令人震惊的全球性问题。初步研究表明，有必要将地下水中有机微污染物的行为和降解（以及同样的持久性）与现场普遍存在的瞬态水力和水化学（特别是氧化还原）条件联系起来，以便确定控制其消除的关键参数。拟议的研究将调查地下水中废水结合有机微污染物的行为，特别关注其氧化还原依赖的生物降解和长期持久性。首先进行“氧化还原筛选”，将被废水残渣污染的缺氧地下水在缺氧或缺氧条件下孵育，以确定氧化还原敏感化合物。同时还将对以前的污水灌溉区下游受污染的地下水进行实地调查，对其进行有机微污染物分析，并用氚/氦法测定年代。这些结果将提供在给定的水化学条件下微污染物长期持久性的信息。在可变氧化还原条件下进行更详细的柱研究将模拟现场条件。最后，将进行反应输运建模，以确认开发的概念模型，并得出与氧化还原制度有关的降解速率常数。

The increasing pollution of the aquatic environment with numerous organic micropollutants such as pharmaceutical residues is a problem of alarming global dimensions. Preliminary studies have shown that it is necessary to correlate the behaviour and degradation (and likewise persistence) of organic micropollutants in groundwater with the prevailing transient hydraulic and hydrochemical (in particular redox) conditions in the field in order to identify the key parameters controlling their elimination. The proposed research will investigate the behaviour of wastewater- bound organic micropollutants in groundwater with a particular focus on their redoxdependent biodegradation and long-term persistence. A “redox screening”, where anoxic groundwater contaminated with wastewater residues will be incubated under anoxic or oxic conditions, will first be done to identify redox-sensitive compounds. It will be accompanied by field investigations on contaminated groundwater downstream of former sewage irrigation fields, which will be analysed for organic micropollutants and dated with the tritium/helium method. The results will deliver information on the long-term persistence of the micropollutants under the given hydrochemical conditions. More detailed column studies under variable redox conditions will be conducted mimicking field conditions. Finally, reactive transport modelling will be carried out to confirm developed conceptual models and to derive degradation rate constants in relation to the redox regime.