Physical Chemistry Department, Faculty of Marine and Environmental Sciences, University of Cadiz, Campus de Excelencia Internacional del Mar (CEI·MAR), Cádiz 11510, Spain.
Physical Chemistry Department, Faculty of Marine and Environmental Sciences, University of Cadiz, Campus de Excelencia Internacional del Mar (CEI·MAR), Cádiz 11510, Spain.
Environ Pollut. 2018 Apr;235:312-321. doi: 10.1016/j.envpol.2017.12.085. Epub 2018 Jan 4.
The use of reclaimed wastewater for irrigation is foreseen as a possible strategy to mitigate the pressure on water resources in dry regions. However, there is the risk of potential accumulation of contaminants of emerging concern (CECs) in the edaphic environment, their percolation and consequently contamination of aquifers. In the present study, we measured the levels of a wide range of commonly used pharmaceutically active compounds (PhACs) in sewage from a local wastewater treatment plant (WWTP) and in soils irrigated with treated wastewater. Analysis of target compounds showed total concentrations between 73 and 372 μg L in WWTP influents, and from 3 to 41 μg L in effluents. The total concentrations of PhACs detected in surface soil samples were in the range of 2 and 15 ng g, with predominance of analgesics and anti-inflammatories (maximum concentration = 10.05 ng g), followed by antibiotics and psychiatric drugs (maximum concentration = 5.45 ng g and 3.78 ng g, respectively). Both effluent samples and irrigated soils shared similar compositional patterns, with compounds such as hydrochlorothiazide and diclofenac being predominant. Additionally, PhACs were also detected in soil samples at a depth of 150 cm, indicating that these chemical undergo leaching associated with heavy-rain episodes. Their occurrence in soils was affected by temperature too, as maximum concentrations were measured in colder months (up to 14 ng g), indicating higher persistence at lower temperatures. Finally, the ecotoxicological risk of PhACs in soil was evaluated by calculating their risk quotients (RQs). The risk was very low as RQ values ranged between <0.01 and 0.07. However, this initial assessment could be improved by future works on toxicity using specific terrestrial organisms.
将再生废水用于灌溉被预见为缓解干旱地区水资源压力的一种可能策略。然而，在土壤环境中，新兴关注污染物（CECs）有可能会积累，从而发生渗滤并污染含水层。在本研究中，我们测量了当地污水处理厂（WWTP）污水和用处理后的废水灌溉的土壤中广泛使用的药用活性化合物（PhACs）的水平。对目标化合物的分析表明，WWTP 进水总浓度为 73-372μg/L，出水总浓度为 3-41μg/L。地表土壤样本中检测到的 PhACs 总浓度范围为 2-15ng/g，以镇痛药和消炎药为主（最高浓度为 10.05ng/g），其次是抗生素和精神类药物（最高浓度分别为 5.45ng/g 和 3.78ng/g）。污水和灌溉土壤样本具有相似的组成模式，其中氢氯噻嗪和双氯芬酸等化合物占主导地位。此外，在 150cm 深的土壤样本中也检测到 PhACs，表明这些化学物质会随着大雨事件发生淋滤。土壤中 PhACs 的存在也受温度的影响，因为在较冷的月份（高达 14ng/g）检测到最高浓度，表明在较低温度下它们的持久性更高。最后，通过计算其风险商数（RQ）评估了土壤中 PhACs 的生态毒理学风险。由于 RQ 值在 0.01-0.07 之间，风险非常低。然而，通过使用特定的陆地生物进行未来的毒性评估，这种初步评估可以得到改善。
