Organic pollutants like per- and polyfluoroalkyl substances (PFASs) exhibit persistence, bioaccumulation, resistance to degradation, and high toxicity, garnering significant attention from scholars worldwide. To better address and mitigate the environmental risks posed by PFASs, this paper employs bibliometric analysis to examine the literature on PFASs’ concentrations collected in the Web of Science (WoS) database between 2019 and 2024. The results show that the overall trend of PFASs’ pollution research is relatively stable and increasing. In addition, this study also summarizes the pollution status of traditional PFASs across different environmental media in typical freshwater basins. It analyzes PFASs’ concentrations in surface water, sediment, and aquatic organisms, elucidating their distribution characteristics and potential sources. While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) levels in water environments are declining annually, short-chain PFASs and their substitutes are emerging as primary pollutants. Short-chain PFASs are frequently detected in surface water, whereas long-chain PFASs tend to accumulate in sediments. In aquatic organisms, PFASs are more likely to concentrate in protein-rich organs and tissues. The environmental presence of PFASs is largely influenced by human activities, such as metal plating, fluoride industry development, and industrial wastewater discharge. Currently, the development of PFASs in China faces a complex dilemma, entangled by policy and legal constraints, industrial production demands, the production and use of new alternatives, and their regulation and restriction, creating a vicious cycle. Breaking this deadlock necessitates continuous and active scientific research on PFASs, particularly PFOS, with an emphasis on detailed investigations of environmental sources and sinks. Furthermore, ecological and health risk assessments were conducted using Risk Quotient (RQ) and Hazard Quotient (HQ) methods. Comprehensive comparison indicates that PFASs (such as PFOA) in the majority of freshwater basins are at a low-risk level (RQ < 0.1 or HQ < 0.2), PFOS in some freshwater basins is at a medium-risk level (0.1 < RQ < 1), and no freshwater basin is at a high-risk level. The adsorption and removal approaches of PFASs were also analyzed, revealing that the combination of multiple treatment technologies as a novel integrated treatment technology holds excellent prospects for the removal of PFASs.

In agricultural production, pesticides play an important role in increasing crop yields. However, pesticide residues are caused by improper handling by users during the production process. Chlorine dioxide and ozone, as strong oxidants with similarity in spatial structure, effectively degrade pesticide residues and are widely used in water treatment and the food industry. In order to better understand the mechanism of chlorine dioxide and ozone on pesticides, the properties of chlorine dioxide and ozone are introduced in this review. Herbicides, insecticides, and fungicides were selected for this study, and the influencing factors, kinetics, and degradation pathways of degraded pesticides are presented. The degradation of pesticides by chlorine dioxide follows the second-order kinetic model, reacting with functional groups with high electron density in pesticides by electron transfer. Ozone selectively undergoes electrophilic reactions with pesticides in solution. In addition, when the reaction system is alkaline, ozone accelerates the decomposition to form hydroxyl radicals ($·\mathrm{O}\mathrm{H}$), which react with pesticides. Ozone degradation of pesticides satisfies the pseudo-first-order kinetic model. By comparing the mechanism of pesticide degradation by chlorine dioxide and ozone, this paper provides a theoretical basis for solving the problem of pesticide residues in the food industry and water treatment in the future.

With the development of the chemical industry, benzene, toluene, ethylbenzene, and xylene (BTEX) have gradually become the major indoor air pollutants. Various gas treatment techniques are widely used to prevent the physical and mental health hazards of BTEX in semi-enclosed spaces. Chlorine dioxide (ClO₂) is an alternative to chlorine as a secondary disinfectant with a strong oxidation ability, a wide range of action, and no carcinogenic effects. In addition, ClO₂ has a unique permeability which allows it to eliminate volatile contaminants from the source. However, little attention has been paid to the removal of BTEX by ClO₂, due to the difficulty of removing BTEX in semi-enclosed areas and the lack of testing methods for the reaction intermediates. Therefore, this study explored the performance of ClO₂ advanced oxidation technology on both liquid and gaseous benzene, toluene, o-xylene, and m-xylene. The results showed that ClO₂ was efficient in the removal of BTEX. The byproducts were detected by gas chromatography-mass spectrometry (GC-MS) and the reaction mechanism was speculated using the ab initio molecular orbital calculations method. The results demonstrated that ClO₂ could remove the BTEX from the water and the air without causing secondary pollution.

2,2′,4,4′,6,6′-hexanitrostilbene (HNS) is a heat-resistant, low-sensitivity energetic material with widespread applications in pliable linear-shaped charges, high-temperature-resistant oil well perforating charges, and rocket propellants. However, the presence of highly toxic and mutagenic nitroaromatic compounds in HNS wastewater necessitates efficient and accurate detection methods. Unfortunately, the existing analytical methods for HNS detection are outdated and incompatible with modern equipment. This limits their application due to issues with detection range, accuracy, and cost. To address this gap, an improved method was developed using an Ultimate 3000 UHPLC system with methanol and water as the mobile phase and UV-Vis detection at 271 and 226 nm wavelengths. The results indicate that the optimal detection conditions are achieved with a methanol-to-water ratio of 70:30 and a flow rate of 0.5 mL/min, providing high accuracy and efficiency. Compared to traditional methods, this approach reduced the detection time by nearly 70%, with the shortest analysis time ranging from 6 to 6.5 min, significantly lowering the cost of HNS detection. The method demonstrated excellent linearity (R² > 0.9999) and high sensitivity within the concentration range of 0.50–150.00 mg/L, with precise and reliable results. This work provides both theoretical insights and experimental validation for the detection and analysis of HNS in wastewater.