GHS, Dept. of Geosciences, Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
Sci Total Environ. 2012 Jun 1;426:256-63. doi: 10.1016/j.scitotenv.2012.02.058. Epub 2012 Apr 23.
Soil-aquifer processes have proven to work as a natural treatment for the attenuation of numerous contaminants during artificial recharge of groundwater. Nowadays, significant scientific effort is being devoted to understanding the fate of pharmaceuticals in subsurface environments, and to verify if such semipersistent organic micropollutants could also be efficiently removed from water. In this context we carried out a series of batch experiments involving aquifer material, selected drugs (initial concentration of 1 μg/L and 1 mg/L), and denitrifying conditions. Diclofenac and sulfamethoxazole exhibited an unreported and peculiar behavior. Their concentrations consistently dropped in the middle of the tests but recovered toward the end, which suggest a complex effect of denitrifying conditions on aromatic amines. The transformation products Nitro-Diclofenac and 4-Nitro-Sulfamethoxazole were detected in the biotic experiments, while nitrite was present in the water. Their concentrations developed almost opposite to those of their respective parent compounds. We conjecture that this temporal and reversible effect of denitrifying conditions on the studied aromatic amines could have significant environmental implications, and could explain at least partially the wide range of removals in subsurface environments reported in literature for DCF and SMX, as well as some apparent discrepancies on SMX behavior.
土壤-含水层过程已被证明是人工补给地下水时衰减许多污染物的一种自然处理方法。如今，人们正在投入大量的科学努力来了解药物在地下环境中的归宿，并验证这些半持久性有机微污染物是否也可以有效地从水中去除。在此背景下，我们进行了一系列涉及含水层物质、选定药物（初始浓度为 1μg/L 和 1mg/L）和反硝化条件的批量实验。双氯芬酸和磺胺甲恶唑表现出一种未被报道的特殊行为。它们的浓度在实验中期持续下降，但在实验后期又恢复，这表明反硝化条件对芳香胺有复杂的影响。在生物实验中检测到转化产物硝基双氯芬酸和 4-硝基磺胺甲恶唑，而水中存在亚硝酸盐。它们的浓度发展与各自的母体化合物几乎相反。我们推测，反硝化条件对研究中芳香胺的这种暂时和可逆的影响可能具有重要的环境意义，至少可以部分解释文献中报道的 DCF 和 SMX 在地下环境中的广泛去除率，以及 SMX 行为的一些明显差异。
