STOTEN | 华南师范大学应光国：纺织废水和受纳河流中全氟烷基和多氟烷基物质（PFAS）的非靶向和靶向筛查及风险评估

PFAS在纺织污水处理厂（WWTPs）中持久存在，并且无法完全去除。我们利用靶向和非靶向分析方法，为期两年调查了广西一个纺织工业园区的两个WWTPs和一条受纳河流中的PFAS，定量到11种PFAS，筛查到648种PFAS。全氟辛酸（PFOA）是主要物质，WWTP对PFAS的除效率较低，平均去除率为22.0%，这意味着现有的处理方法不能有效降低PFAS浓度。在受纳河流中，全氟辛烷磺酸（PFOS）和两种PFAS同系物具有较高的生态风险，它们在污水处理厂中的赋存情况尚未报道。这些发现强调了当前纺织WWTPs中PFAS的广泛使用和持久性，表明可能对受纳环境造成长期风险。

PFAS are known to be persistent and incompletely removed in textile wastewater treatment plants (WWTPs). Here we investigated PFAS in two WWTPs and a receiving river of a textile industrial park in Guangxi, China, by using both target and non-target analyses over a two-year period. The target analysis identified 11 specific PFAS, while the non-target analysis revealed a list of 648 different PFAS. Notably, perfluorooctanoic acid (PFOA) was the most prevalent compound. The investigated WWTPs exhibited a poor removal efficiency for PFAS and the average removal rate was only 22.0%, indicating that the current treatment processes are inadequate in effectively mitigating PFAS contamination. Perfluorooctane sulfonate (PFOS) and two homologue PFAS were identified to have high ecological risks in the receiving river, and their presence in WWTPs has been poorly reported. The findings highlight the wide use and persistence of PFAS in current textile WWTPs, indicating potential long term risks to the receiving environment.

WWTPs共检测到11种PFAS，受纳河流中共检测到7种PFAS，均以短链PFAS为主(C≤8)。全氟辛酸（PFOA）在WWTPs和受纳河流中均为主要PFAS。在污水处理过程中存在PFOA和其他PFAS的浓度升高的现象，这可能由于未知前体和中间体的转化。

WWTPs的平均PFAS去除率分别为40.1%、36.0%和-32.0%，表明传统的A/O工艺对PFAS的去除效率相对较低。

11 PFAS were detected in WWTPs and 7 in receiving river, of which mainly consisted of short-chain PFAS (C≤8). PFOA was predominant in both WWTPs and receiving river. Furthermore, the significantly higher concentrations of PFOA and other PFAS in the wastewater treatment process could possibly be due to the transformation of some unknown precursors and intermediates. 

The average PFAS removal rates for the WWTPs were 40.1%, 36.0%, and -32.0%, respectively, indicating that traditional A/O processes exhibit relatively low removal efficiency for PFAS.

图1 靶向分析PFAS的浓度及分布规律。(A): PFAS浓度。(B、C、D): PFAS在处理过程中的浓度变化。(仅显示浓度相对较高且变化显著的PFAS) (E): PFAS的相对贡献。

Fig.1 Concentrations and distribution patterns of PFAS by target analysis. (A): Concentrations of 11 quantified PFAS. (B, C and D): The concentration changes of PFAS in the treatment process. (Only displayed PFAS with relatively high concentrations and significant changes.) (E): Patterns of the relative contribution of target PFAS.

共鉴定出648个PFAS，置信水平为L1 - L5，其中有40种PFAS被鉴定为置信水平为L1 - L3。一些PFAS的响应在芬顿处理后不降反升，这表明芬顿法对于PFAS去除有限。在受纳河流中，河流下游的响应略高于河流上游。

A total of 648 PFAS were identified at confidence levels L1 - L5. Among these chemicals, 40 PFAS were identified at confidence levels L1 - L3. The standardized intensity levels of some PFAS did not decrease but rather increased to varying degrees after the Fenton process, this suggests that the Fenton process may not be very effective in treating these specific PFAS identified through non-target screening. In the receiving river, the standardized intensity levels in downstream water were slightly higher than in upstream water.

图2 通过非靶向筛查鉴定出的PFAS (PFAS无缩写的用DSSTox物质识别号表示)。

Fig.2 Occurrence and relative intensities of identified PFAS (PFAS without abbreviation were expressed as DSSTox Substance ID) through non-target screening.

2021年纺织厂A厂对应纺织厂相较于2020年订单增多后，在进水、出水和下游检测到21种PFAS，远大于2020年，说明污水排放引入了许多不存在于河流中的化合物，表明对PFAS处理效率较差。

污水处理厂出水与下游存在强正相关性，推测污水排放对受纳河流有影响。同时，河流上下游之间不相关，表明河流的污染主要来源于污水排放。

In 2021, after the corresponding textile factory of Plant A received more orders than in 2020, 21 PFAS were detected in influent, effluent and downstream, suggesting the discharge of WWTP introduces many compounds not naturally present in the river, shows a poor efficiency of PFAS treatment.

There was a strong positive correlation between effluent and downstream, speculated that wastewater discharge affect the receiving rivers. At the same time, there is no correlation between upstream and downstream rivers, indicating that the pollution of rivers mainly comes from wastewater discharges.

图3 两年内不同污水处理厂与受纳河流的维恩图(A、B、C)和相关网络图(D、E、F)。

Fig.3 Venn Diagrams (A, B, and C) and correlation network (D, E, and F) of different WWTPs to receiving river in two years.

通过靶向分析和半定量分析的15种PFAS中，PFOA和PFOS为高、中等生态风险。在基于非靶向筛查结果的ToxPi评估中，一对PFAS同系物 (DTXSID30240816和DTXSID90240817) 的得分高于PFOS。表明这些化合物可能至少构成中等风险，甚至可能构成高风险。

Among the 15 PFAS assessed through target and semi-quantified analyses, PFOA and PFOS exhibited high and medium ecological risk levels. For ToxPi analysis based on the non-target results, a pair of homologues (DTXSID30240816 and DTXSID90240817) exhibited scores higher than PFOS. Scores higher than PFOS indicate that these compounds may pose at least a medium risk, potentially even a high risk.

图4(A和C)两年下游水体中确定的PFAS(1- 3级)的优先级。(B、D)下游水体中鉴定出的PFAS (Level 1-Level 3) 前12 ToxPi评分及其得分比例。

Fig. 4 (A and C) The prioritization of identified PFAS (Level 1-Level 3) in downstream water of two years. (B and D) Top 12 ToxPi Scores of identified PFAS (Level 1-Level 3) and their score proportion in downstream water.

结果表明，PFAS广泛存在于纺织废水和受纳河流中。污水处理厂采用的A/O废水处理工艺对纺织废水中PFAS的平均去除率较低(22%)。研究证明了下游水与污水处理厂排放之间的密切联系，表明纺织污水处理厂是受纳河流中PFAS污染的主要来源。风险评估表明，PFOA和PFOS在受纳河流中可构成高、中风险。此外，一对同系物显示出比PFOS更高的风险水平。本研究丰富了我们对A/O和芬顿处理工艺的处理效率的理解，并为纺织废水中不同PFAS的存在、去除以及环境风险提供了有价值的见解。

The results from this study showed wide presence of PFAS in the textile wastewater and receiving river. The A/O wastewater treatment process applied in the industrial park had a relatively low average removal rate for PFAS in textile wastewater (22%). This study demonstrated a strong linkage between downstream water and WWTP effluent, suggesting that textile WWTPs are the primary source of PFAS pollution for the receiving river. Preliminary risk assessment showed that PFOS and PFOA could pose high and medium risks in the receiving river. Additionally, a pair of homologues exhibited even higher risk levels than PFOS. This research enriches our understanding of the effectiveness of A/O and Fenton treatment processes and provides valuable insights into the presence, removal and risk of different PFAS in textile wastewater.

本文内容来自ELSEVIER旗舰期刊Sci Total Environ第927卷发表的论文：

Xiao, S., Liu, T., Hu, L.-X., Yang, B. and Ying, G.-G. (2024) Non-target and target screening and risk assessment of per- and polyfluoroalkyl substances in textile wastewater and receiving river. Science of The Total Environment 927, 171876.

DOI: https://doi.org/10.1016/j.scitotenv.2024.171876.

近年在 Sci Total Environ 发表的其他论文：

Liu et al., 2022. Non-target and target screening of per- and polyfluoroalkyl substances in landfill leachate and impact on groundwater in Guangzhou, China. Sci Total Environ 844, 157021.

Han et al., 2022. Non-target, suspect and target screening of chemicals of emerging concern in landfill leachates and groundwater in Guangzhou, South China. Sci Total Environ 837, 155705.

Han et al., 2024. Discovering transformation products of pharmaceuticals in domestic wastewaters and receiving rivers by using non-target screening and machine learning approaches. Sci Total Environ 948, 174715.

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