Dept. of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Spain.
Dept. of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Spain.
Sci Total Environ. 2021 May 20;770:145490. doi: 10.1016/j.scitotenv.2021.145490. Epub 2021 Jan 30.
Managed Aquifer Recharge (MAR) is a key strategy to increase freshwater resources in many regions facing water scarcity. MAR issues are related to both quantity and quality of the infiltrating water. In most countries, very high quality of the infiltrating water is required, to limit the impact on the aquifer geochemistry. In this paper, the possibility of injecting water of lower quality in the aquifer and letting the biogeochemical reactions take place in order to enhance its quality is explored. Here, we present the fate of nutrients (C, N) in the biogeochemical system of a reactive barrier formed by mixture of different proportions of sand and compost, supplied with treated wastewater to mimic MAR. An integrated conceptual model involving the nutrient cycles and biomass dynamics (auto- and heterotrophic) was developed, and then tested with a number of solute transport experiments in columns with different compost fraction in the column filling. The model incorporated both saturation and inhibition processes (regarding the nutrients and their byproducts) to provide a comprehensive picture of the nutrient dynamics within the column. The model developed (three if considering the 3 column setups) allowed to discriminate the processes that govern the fate of nutrients in relation with the compost enhancing long-term nutrient degradation, yet hindering hydraulic parameters that affect infiltration rates.
含水层人工补给（MAR）是许多面临水资源短缺的地区增加淡水资源的关键策略。MAR 问题与渗入水的数量和质量都有关。在大多数国家，都要求渗入水具有非常高的质量，以限制其对含水层地球化学的影响。本文探讨了在含水层中注入低质量水并让生物地球化学反应发生以提高其质量的可能性。在这里，我们展示了在由不同比例的沙子和堆肥混合物形成的反应性屏障的生物地球化学系统中，养分（C、N）的归宿，该系统用处理后的废水进行供应以模拟 MAR。开发了一个涉及养分循环和生物量动态（自养和异养）的综合概念模型，然后通过在填充柱中具有不同堆肥部分的一系列柱溶质传输实验进行了测试。该模型结合了饱和度和抑制过程（关于养分及其副产物），以提供柱内养分动态的全面描述。所开发的模型（如果考虑三个柱设置，则为三个）能够区分控制与堆肥相关的养分归宿的过程，堆肥可增强长期养分降解，但会阻碍影响渗透速率的水力参数。
