Li Shiyue, Zhao Zhen, Liu Jing, Zhang Boxuan, Han Baocang, Ma Yuntao, Jin Limin, Zhu Ningzheng, Gao Guoping, Lin Tian
College of Oceanography and Ecological Science, Shanghai Ocean University, Shanghai, 201306, China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Heliyon. 2024 Sep 6;10(18):e37551. doi: 10.1016/j.heliyon.2024.e37551. eCollection 2024 Sep 30.
Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a large class of toxic contaminants. Nutrients are closely related to the ecological health of aquatic systems. Both have received widespread global attention. This study investigated the concentrations, compositions, and spatial distributions of PFAS and nutrients in surface water from two constructed wetlands and the nearby drinking water treatment plants (DWTPs). We explored the natural environmental factors and human activities that affect the composition and distribution of pollutants in wetlands and assessed the ability of the DWTPs to remove contaminants. Concentrations of ∑PFAS varied from 153 to 405 ng/L. Hexafluoropropylene oxide trimer acid (HFPO-TA) was the predominant substance accounting for 45 % of ∑PFAS concentrations. It might originate from the emissions of indirect sources of PFAS related manufacturers. The detection rate of 6:2 fluorotelomer carboxylic acid (6:2 FTCA) was 100 % with concentrations ranging from 0.915 to 19.7 ng/L 6:2 FTCA might come from the biotransformation of indirect sources in the air. Concentrations of total nitrogen (TN) and total phosphorus (TP) were from 1.47 to 3.54 mg/L, and non-detect (ND) to 0.323 mg/L, respectively. Constructed wetlands could effectively remove PFAS under nutrient stress, however, the removal of PFAS depends on the characteristics of specific compounds and their sources. The removal rates for PFAS and nutrients could be promoted through artificial dredging. But wetland bioremediation could have two opposing effects. On the one hand, plants can take up pollutants from water via roots, leading to pollutant removal and purification. On the other hand, plants may also absorb precursor intermediates from the air through leaves and release them into the water, leading to increased pollutant concentrations. Thirty-two emerging PFAS were identified by high resolution mass spectrum. The drinking water treatment process removed PFAS and nutrients below the drinking water quality standards of China, however, 9 non-target PFAS compounds were still found in tap water. These results provide case support and a theoretical basis for the pollution control and sustainable development of typical ecological wetlands used as drinking water sources.
全氟烷基和多氟烷基物质（PFAS）是一大类有毒污染物。营养物质与水生系统的生态健康密切相关。两者都受到了全球广泛关注。本研究调查了两个人工湿地及附近饮用水处理厂（DWTPs）地表水中PFAS和营养物质的浓度、组成及空间分布。我们探究了影响湿地中污染物组成和分布的自然环境因素及人类活动，并评估了DWTPs去除污染物的能力。∑PFAS浓度在153至405纳克/升之间变化。六氟环氧丙烷三聚体酸（HFPO-TA）是主要物质，占∑PFAS浓度的45%。它可能源自PFAS相关制造商间接来源的排放。6:2氟调聚物羧酸（6:2 FTCA）的检出率为100%，浓度范围为0.915至19.7纳克/升，6:2 FTCA可能来自空气中间接来源的生物转化。总氮（TN）和总磷（TP）的浓度分别为1.47至3.54毫克/升和未检出（ND）至0.323毫克/升。人工湿地在营养胁迫下能有效去除PFAS，然而，PFAS的去除取决于特定化合物的特性及其来源。通过人工疏浚可提高PFAS和营养物质的去除率。但湿地生物修复可能有两种相反的效果。一方面，植物可通过根系从水中吸收污染物，从而实现污染物的去除和净化。另一方面，植物也可能通过叶片从空气中吸收前体中间体并将其释放到水中，导致污染物浓度增加。通过高分辨率质谱鉴定出32种新兴PFAS。饮用水处理过程将PFAS和营养物质去除至中国饮用水质量标准以下，然而，自来水中仍发现9种非目标PFAS化合物。这些结果为用作饮用水源的典型生态湿地的污染控制和可持续发展提供了案例支持和理论依据。
