Salvi-Taga Raisa Gabriela, Meffe Raffaella, Martínez-Hernández Virtudes, De Miguel Garcia Angel, De Bustamante Irene
Department of Geology, Geography and Environment, University of Alcala, 28802 Alcalá de Henares, Madrid, Spain.
IMDEA Water Institute, 28805 Alcalá de Henares, Madrid, Spain.
Toxics. 2024 May 4;12(5):334. doi: 10.3390/toxics12050334.
In small populations and scattered communities, wastewater treatment through vegetation filters (VFs), a nature-based solution, has proved to be feasible, especially for nutrient and organic matter removal. However, the presence of pharmaceuticals in wastewater and their potential to infiltrate through the vadose zone and reach groundwater is a drawback in the evaluation of VF performances. Soil amended with readily labile carbon sources, such as woodchips, enhances microbial activity and sorption processes, which could improve pharmaceutical attenuation in VFs. The present study aims to assess if woodchip amendments to a VF's soil are able to abate concentrations of selected pharmaceuticals in the infiltrating water by quantitatively describing the occurring processes through reactive transport modelling. Thus, a column experiment using soil collected from an operating VF and poplar woodchips was conducted, alongside a column containing only soil used as reference. The pharmaceuticals acetaminophen, naproxen, atenolol, caffeine, carbamazepine, ketoprofen and sulfamethoxazole were applied daily to the column inlet, mimicking a real irrigation pattern and periodically measured in the effluent. Ketoprofen was the only injected pharmaceutical that reached the column outlet of both systems within the experimental timeframe. The absence of acetaminophen, atenolol, caffeine, carbamazepine, naproxen and sulfamethoxazole in both column outlets indicates that they were attenuated even without woodchips. However, the presence of 10,11-epoxy carbamazepine and atenolol acid as transformation products (TPs) suggests that incomplete degradation also occurs and that the effect of the amendment on the infiltration of TPs is compound-specific. Modelling allowed us to generate breakthrough curves of ketoprofen in both columns and to obtain transport parameters during infiltration. Woodchip-amended columns exhibited K and μ values from one to two orders of magnitude higher compared to soil column. This augmentation of sorption and biodegradation processes significantly enhanced the removal of ketoprofen to over 96%.
在小规模人口和分散社区中，通过植被过滤（VF）进行废水处理作为一种基于自然的解决方案已被证明是可行的，特别是在去除营养物质和有机物方面。然而，废水中存在药物以及它们通过渗流区渗入并到达地下水的可能性，是评估VF性能时的一个缺点。用易分解的碳源（如木屑）改良土壤，可增强微生物活性和吸附过程，这可能会改善VF中药物的衰减。本研究旨在通过反应性传输模型定量描述所发生的过程，评估向VF土壤中添加木屑是否能够降低渗透水中选定药物的浓度。因此，进行了一项柱实验，使用从运行中的VF收集的土壤和杨木木屑，同时设置一个仅含土壤的柱作为参考。每天将对乙酰氨基酚、萘普生、阿替洛尔、咖啡因、卡马西平、酮洛芬和磺胺甲恶唑等药物施加到柱入口，模拟实际灌溉模式，并定期在流出物中进行测量。酮洛芬是在实验时间范围内唯一到达两个系统柱出口的注入药物。两个柱出口均未检测到对乙酰氨基酚、阿替洛尔、咖啡因、卡马西平、萘普生和磺胺甲恶唑，这表明即使没有木屑它们也会衰减。然而，作为转化产物（TPs）的10,11-环氧卡马西平和阿替洛尔酸的存在表明也会发生不完全降解，并且该改良对TPs渗透的影响具有化合物特异性。建模使我们能够生成两个柱中酮洛芬的穿透曲线，并获得渗透过程中的传输参数。与土壤柱相比，添加木屑的柱的K和μ值高出一到两个数量级。这种吸附和生物降解过程的增强显著提高了酮洛芬的去除率，超过96%。
