The presence of emerging contaminants (ECs) in the environment poses a significant threat to water security and human welfare, which is an urgent problem to solve. Sulfur(IV) (S(IV)) combined with metal ions advanced oxidation technologies (AOTs) can generate diversified reactive oxygen species, showing great performance for ECs treatment. Importantly, the application of S(IV) can be considered a process of using waste to treat waste. This paper is aimed at reviewing the latest progress on ECs elimination by homogenous metal-catalyzed S(IV) oxidation. The in-depth mechanism analyses and enhancing strategies on S(IV) activation were summarized. Subsequently, the pivotal influence factors, such as pH, dissolved oxygen (DO), and S(IV) concentration for ECs removal performance were analyzed. And intermediate toxicity evaluation of ECs was conducted. This study also indicated that intermediate toxicity effectively decreased after application by such processes. Additionally, some helpful suggestions and prospects were proposed to guide the development direction for metal-catalyzed S(IV) processes. For instance, most current research is confined to the laboratory scale, necessitating the promotion of translating research outcomes into practical applications. Meanwhile, future studies should focus on improvement on paraments optimization via machine learning. A research gap has been identified for investigating the high-valent metal-oxo intermediates in such processes, especially for ECs degradation. This review is hopeful for promoting understanding and application of metal-catalyzed S(IV) processes for water purification.

Boric acid (BA) has been frequently utilized as a buffer in advanced oxidation processes (AOPs) under weakly alkaline conditions. This study unveiled a notable enhancement in the treatment of rhodamine B (RhB) achieved with the Cu(II)/PAA system operated in BA solution. Upon exploring the reaction mechanisms of the BA/Cu(II)/PAA system, it was intriguingly discovered that the formation of bidentate BA-Cu(II) complex (CuH2BO3+) could effectively boost the reactivity of Cu(II) with H2O2. This improvement promoted the generation of Cu(I) and subsequent PAA activation and RhB degradation. Conversely, the tridentate BA-Cu(II) complex (Cu(H2BO3)(2)(aq)) exhibited a diminishing effect. Furthermore, differential charge density calculations revealed distinct electron transfer dynamics between H2O2 and CH3C(O)OOH complexes with CuH2BO3+, highlighting H2O2 as the preferential electron-donating compound in BA/Cu(II)/PAA system. Results indicated that CH3C(O)O center dot was the major contributing radical, followed by O-1(2), to RhB degradation. Overall, this investigation provides valuable insights into the synergistic utilization of BA and copper as a novel strategy for enhancing the performance of copper-based AOPs on treating water contaminants. Additionally, it sheds light on the optimal dosage of BA when employing BA as the buffer.

Microplastic (MP) pollution poses an urgent environmental challenge. UV-based disinfection processes generate oxidative radicals (e.g., hydroxyl (HO•) and chloride radicals (Cl•, Cl2•¯)), which may alter MPs' polymer structures during water treatment. However, their impacts on MPs' characteristics and environmental behaviors remain insufficiently understood. This study evaluated UV/H2O2, UV/chlorine, and UV/peracetic acid treatments on polystyrene, polyethylene, and polyvinyl chloride MPs. Spectroscopic and microscopic analysis revealed significant morphological changes, including surface cracks and pits. Chemically, oxygen-containing functional groups (e.g., carboxyl, hydroxyl) formed, while water contact angle tests showed decreased hydrophobicity. LC-MS identified various low- and high-molecular-weight degradation products. Acute toxicity assessments (using ECOSAR software) indicated that small-molecule products from polystyrene and polyvinyl chloride MPs showed high toxicity, while medium-molecule products from polyethylene MPs also exhibited notable toxicity. These findings highlight the formation of potentially hazardous byproducts during UV-based disinfection. We further assessed the natural decomposition of aged MPs across different water matrices and their sorption behavior toward hydrophobic and hydrophilic micropollutants in mixed wastewater. This research aims to provide critical insights into MPs' transformations during UV-based treatments, informing strategies for mitigating MP pollution while minimizing associated environmental risks.

Lithium recovery from shale gas wastewater (SGW) is essential for the growth of a sustainable economy. However, traditional powder adsorbents suffer significant loss and poor recyclability, limiting their practical utility. Here, we fabricate an HMO/MXene/PSF adsorptive membrane, in which 2D MXene serves as the hydrogen bond interacting agent between H1.33Mn1.67O4 (HMO) and polysulfone (PSF). Notably, MXene incorporation effectively mitigates Mn leaching due to the hydrogen bond interaction. Efficient lithium recovery from Sichuan Basin SGW is achieved, with a lithium adsorption capacity of 21.18 mg/g. After ten consecutive cycles of adsorption and desorption, the HMO/MXene/PSF membrane shows remarkable cyclic stability, with a negligible decrease in lithium adsorption capacity of merely 0.16 %. Filtration studies reveal that the membrane with a surface area of 12.56 cm2 can effectively filter 160 mL of SGW. The stability of the membrane due to hydrogen bond interactions and the selective adsorption mechanism are further confirmed through DFT calculations. This work presents a novel concept for constructing a mixed matrix membrane for lithium extraction from SGW and is expected to inspire further efforts in developing LIS-based adsorbents for lithium recovery.

The growing demand for electric vehicles and renewable energy has increased the need for efficient lithium extraction. Here, we introduce a novel Fe-doped H2TiO3/MXene/Polysulfone (Fe-HTO/MXene/PSF) lithium ion-sieve membrane (LISM) for lithium extraction from shale gas wastewater (SGW). The efficient and selective extraction of lithium from SGW was simultaneously accomplished during the low-pressure membrane filtration process. A self-assembly structure of Fe-HTO on the membrane surface was achieved by MXene nanosheet, which efficiently prevented the particle aggregation, and enhanced the adsorption capacity and structural stability. The Fe-HTO/MXene/PSF LISM achieved a lithium adsorption capacity of 28.50 mg/g within 8 h from SGW. The membrane retains 98.70 % of its initial performance after 10 adsorption/desorption cycles, demonstrating good cyclic stability. Furthermore, filtration experiments showed that a membrane with an area of 12.56 cm2 could process 120 mL of SGW, demonstrating its potential for low-pressure filtration applications. Density functional theory (DFT) calculations indicated that Fe doping reduced lithium migration barriers and accelerated lithium adsorption rates, while the interfacial engineering of Fe-HTO with MXene enhanced lithium adsorption. The findings highlight the promising scalability of the Fe-HTO/MXene/PSF LISM for practical lithium extraction from SGW, with significant implications for sustainable lithium recovery.

Pickering emulsions stabilized by functionalized natural macromolecules have emerged with promising responsiveness for pesticide encapsulation and release. This study developed Pickering emulsions using amine- modified cellulose nanocrystals (ACNCs) as stabilizers. The resultant O/W ACNCs-Pickering emulsions (ACNCs-Pickering) exhibited long-term storage stability and showed increasing emulsion stability depending on the concentration of ACNCs. Imidacloprid (IMI) was subsequently loaded onto the ACNCs-Pickering to form the IMI@ACNCs-Pickering via the in-situ loading route. The release rate of IMI demonstrated a notable pH responsiveness. Moreover, the IMI@ACNCs-Pickering prepared with an ACNCs concentration of 3 wt% showed optimal performances. Its foliar adhesion on Chinese cabbage ( Brassica rapa L.ssp.pekinensis) was significantly higher than that of the commercial IMI formulation (70 WS, Bayer (R), LS200032) (DG). In detail, the pesticide residue for the IMI@ACNCs-Pickering was 3.8 folds to that for DG after spraying and washing for 10 min. Also, the green peach aphid mortality rate was 98.33 %, which was 1.1 folds higher than that of the DG group. The present work developed a Pickering emulsion-based fat-soluble pesticide formulation with excellent foliar adhesion, resistance to rainfall washout, and insecticidal effect. It provided a new option to ensure the sustainable development of green agriculture.

Dissolved copper and iron ions are regarded as friendly and economic catalysts for peroxymonosulfate (PMS) activation, however, neither Cu(II) nor Fe(III) shows efficient catalytic performance because of the slow rates of Cu(II)/Cu(I) and Fe(III)/Fe(II) cycles. Innovatively, we observed a significant enhancement on the degradation of organic contaminants when Cu(II) and Fe(III) were coupled to activate PMS in borate (BA) buffer. The degradation efficiency of Rhodamine B (RhB, 20 mu mol/L) reached up to 96.3% within 10 min, which was higher than the sum of individual Cu(II)- and Fe(III)- activated PMS process. Sulfate radical, hydroxyl radical and high-valent metal ions (i.e., Cu(III) and Fe(IV)) were identified as the working reactive species for RhB removal in Cu(II)/Fe(III)/PMS/BA system, while the last played a predominated role. The presence of BA dramatically facilitated the reduction of Cu(II) to Cu(I) via chelating with Cu(II) followed by Fe(III) reduction by Cu(I), resulting in enhanced PMS activation by Cu(I) and Fe(II) as well as accelerated generation of reactive species. Additionally, the strong buffering capacity of BA to stabilize the solution pH was satisfying for the pollutants degradation since a slightly alkaline environment favored the PMS activation by coupling Cu(II) and Fe(III). In a word, this work provides a brand-new insight into the outstanding PMS activation by homogeneous bimetals and an expanded application of iron-based advanced oxidation processes in alkaline conditions. (c) 2024 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Lithium is a critical strategic resource in the transition to clean energy, and developing efficient, sustainable recycling technologies is essential to achieving carbon neutrality goals. The study addresses challenges such as low lithium-ion concentrations and the presence of competing cations in shale gas produced water (SGPW). An innovative composite adsorbent enhanced by a hydrogen bond network, consisting of H1.33Mn1.67O4 (HMO), MXene, and chitosan (CTS), is introduced. Directional bonding among MXene, CTS, and HMO forms an interpenetrating structure that stabilizes the HMO lattice, with only 0.005 % Mn loss after ten cycles. Adsorption tests with actual SGPW demonstrated that the material adsorbs lithium-ion capacity at 11.80 mg/g, exhibiting higher lithium selectivity compared to other cations. A laboratory-scale experiment was conducted using a fixed-bed filtration system, the most effective adsorbent reached saturation close to 52 h under a near approach velocity of 0.13 cm/min (hydraulic loading) with a full bed volume of 7.7 cm3, containing around 4.92 g of adsorbent. A novel material design paradigm for lithium extraction from neutral to alkaline wastewater is presented, combining high selectivity with long cycle life.

Sustainable lithium-based energy storage and conversion systems, such as lithium-ion batteries, rely on efficient lithium extraction methods from brine sources. Traditional H2TiO3 (HTO) lithium-ion sieves (LIS), though effective, face challenges in optimizing lithium adsorption efficiency and stability. Herein, we introduce a Fe- doping strategy in HTO (Fe-HTO) that artificially substitutes Ti sites, generating lattice defects and oxygen vacancies (OVs). This modification enhances lithium-ion diffusion kinetics and increases active adsorption sites, significantly improving selective lithium extraction efficiency. With Fe-HTO, the equilibrium adsorption time for lithium-ion in shale gas wastewater (SGW), with pH adjustment to 12, is reduced by 20 h compared to undoped HTO. Fe-HTO reaches an adsorption capacity of 37.20 mg/g within 4 h and retains 99.2 % of this capacity after 10 adsorption/desorption cycles at room temperature, demonstrating high structural stability. Density functional theory (DFT) calculations clarify that Fe doping lowers the diffusion energy barrier for lithium-ion, accelerating both lithium-ion diffusion and adsorption. Given this, the work illustrates the potential of heteroatom doping to boost adsorption kinetics, offering promising applications for rapid lithium extraction and similar resource recovery challenges.

H2TiO3 (HTO) emerges as a highly promising lithium-ion sieve (LIS) material for selectively and efficiently extracting lithium from liquid-phase systems. However, the practical use of conventional powdered HTO adsorbents is hindered by difficulties in recovery and titanium leaching, which limits their reusability. Herein, we design a novel HTO/MXene/polysulfone (HTO/MXene/PSF) hybrid membrane, where two-dimensional (2D) MXene nanosheets bridge PSF and HTO via enhanced hydrogen bonding and enable the in-situ self-assembly of HTO into spindle-like nanostructures. As anticipated, the hybrid membrane exhibits selective lithium adsorption, achieving a capacity of 25.80 mg·g−1 from shale gas wastewater (SGW). Moreover, it maintains remarkable cyclic stability with a negligible decrease in adsorption capacity of merely 0.25% after ten consecutive adsorption–desorption cycles. Besides, filtration studies demonstrate that a membrane with a surface area of 12.56 cm² can effectively process 230 mL of SGW. Theoretical calculations reveal that hydrogen bonding and electronic interactions drive the self-assembly of HTO on MXene and further elucidate the adsorption strength and spatial hindrance mechanisms for selective lithium ion adsorption. This study introduces an innovative concept of in-situ self-assembled LIS in a hybrid membrane for lithium recovery from SGW, which is expected to inspire further research on self-assembled sieve-based adsorbents.

A massive amount of coal gangue(an accompanying solid waste)is produced during coal mining and washing processes,leading not only to the wastage of land resources but also to environmental impacts.Due to the abundant presence of metal oxides such as Fe2O3 and Al2O3 in coal gangue,the extraction of iron and aluminum from it serves as a crucial pathway for the resource utilization of coal gangue.In this study,a thermal activation-acid leaching method was used to extract Fe3+and Al3+from coal gangue.Through single-factor experiments,with variables including liquid-to-solid ratio,acid concentration,acid leaching time,and acid leaching temperature,the influence of these factors on the leaching rates of Fe and Al was investigated.Subsequently,response surface optimization experiments were conducted using Design-Expert 13 and Box-Behnken methods,and a regression model with a high fitting degree was established.The results of the regression model indicated that the optimal conditions for leaching Fe and Al were as follows:Acid leaching temperature of 91.71 ℃,acid concentration of 2.84 mol·L-1,liquid-to-solid ratio of 5.90∶1 mL g-1,and acid leaching time of 3.04 h.Under these conditions,the leaching rates of Fe and Al were 66.039％and 35.844％,respectively.These findings provide a valuable reference for the resource utilization of coal gangue.

In this work, it was found that the presence of nitrilotriacetic acid (NTA) could enhance the elimination of sulfamethoxazole (SMX) significantly in Mn(II)/peracetic acid (PAA) process. NTA firstly complexed with Mn(II) to produce Mn(II)-NTA complex, which could activate PAA producing CH3C(O)O and Mn(III)-NTA complex. Subsequently, Mn(V) was generated via two-electron transfer between Mn(III)-NTA complex and PAA. According to the results of UV-vis spectrum analysis, scavenging experiments and chemical probe method, organic radicals and Mn(V) were proved to participate in SMX abatement and Mn(V) was the predominant reactive oxidant. Four possible degradation pathways of SMX in Mn(II)/PAA/NTA process including hydroxylation, amino oxidation, bond cleavage and coupling reaction were proposed based on six identified degradation products. Mn(II)/PAA/NTA process worked only in acidic and neutral conditions and the increase in PAA, Mn(II) or NTA concentration could accelerate SMX removal. This study provides a strategy for improving PAA activation by Mn(II) and an insight into SMX degradation mechanism by Mn(II)/PAA/NTA process.

To overcome the shortcomings of Fe(Ⅱ)/peroxydisulfate (PDS) system including the limited working pH range and large iron sludge production, a Fe-doped alginate (Fe-Alg) catalyst was prepared and combined with hydroxylamine (HA) to continuously activate PDS for the removal of organic pollutants in neutral condition. Due to the strong reductive capability of HA, it could significantly enhance the catalytic capability of Fe-Alg for PDS. The results of characterization suggested that Fe(Ⅲ)/Fe(Ⅱ) was evenly distributed in Alg through its complexation with carboxyl groups, and the reduction of Fe(Ⅲ) to Fe(Ⅱ) initiated by HA enabled Orange G (OG) to be continuously degraded in the Fe-Alg/HA/PDS system. The results of quenching experiments suggested that SO4∙- and HO• played a dominant role for OG removal in the Fe-Alg/HA/PDS process. The effect of influence factors (e.g. initial pH, HA concentration, Fe-Alg dose and PDS concentration) and water matrix components (i.e. SO42-, NO3-, Cl-, HCO3- and dissolved organic matters (DOM)) on the performance of Fe-Alg/HA/PDS system was systematically investigated. Other refractory organic contaminants, including diclofenac (DCF), sulfamethoxazole (SMX), oxytetracycline (OTC) and bisphenol AF (BPAF) were also efficiently eliminated in Fe-Alg/HA/PDS system, suggesting the feasibility of this system for the treatment of organic pollutants. This work provides a method to optimize Fe(Ⅱ)/PDS system and a novel process applied to degrade refractory pollutants.

Currently, the research on bisulfite (BS) activation by Mn(II) is very limited probably because of the low catalytic efficiency of Mn(II). Adding ligands to Mn(II)/BS system is likely to improve the BS activation, but the relative information is very rare. Therefore, the effect of nitrilotriacetic acid (NTA) on Mn(II)/BS system was investigated in this work using sulfamethoxazole (SMX) as the target contaminant. The results showed that the addition of NTA enhanced SMX removal in Mn(Ⅱ)/BS system through forming Mn(Ⅱ/III)-NTA complexes driving Mn(III)/Mn(II) cycle and stabilizing Mn(III). Alcohol scavenging experiments and competitive kinetic experiments indicated that sulfate radical (SO4•−) and hydroxyl radical (HO•) were not the main reactive species in Mn(II)/NTA/BS system. Mn(Ⅲ) was the primary oxidant for SMX elimination in this system and its existence was proved by UV-Vis absorption spectrum of reaction solution. Mn(Ⅱ)/NTA/BS system could greatly degrade SMX in near-neutral conditions, while nearly no SMX removal was observed at pH 3.0. The decrease of dissolved oxygen concentration significantly inhibited BS autocatalytic stage, thus suppressing the removal of SMX. Due to the competitive complexation of HCO3− and FA with NTA for Mn(II), their addition in Mn(Ⅱ)/NTA/BS system obviously inhibited SMX degradation. Four intermediates were detected during SMX degradation in Mn(Ⅱ)/NTA/BS system, and the possible SMX transformation pathways were speculated as N-S bond breaking, hydroxylation, amino oxidation and coupling reaction.

Although Cu(II)/peroxymonosulfate (PMS) process has been successfully applied to degrade varied organic contaminants in water, the slow transformation of Cu(II) to Cu(I) that works only in alkaline conditions retards the treatment efficiency of this process. In this study, a new finding was observed, that is, oxytetraczdycline (OTC) could effectively enhance the degradation of organic pollutants in Cu(II)/PMS process where it was also removed in acidic conditions. With the addition of OTC in Cu(II)/PMS system, 85.5% of rhodamine B (RhB) was degraded in 90 min at pH 4.0, which was far more than that without OTC (36.1%), and simultaneously 98.1% of OTC was eliminated. The added OTC could form OTC-Cu(II) complexes which might powerfully improve the reduction of Cu(II) to Cu(I), exerting a positive effect on the PMS activation and subsequent degradation of RhB. Electron paramagnetic resonance (EPR) experiments assisted with radical scavenging experiments and Raman spectrum detection results suggested that Cu(III) and hydroxyl radical (HO center dot) were the predominant reactive species for RhB degradation, while OTC removal in this system was mainly ascribed to direct PMS oxidation. The Cu(II)/PMS process also showed a promising success on the synergistic degradation of OTC with the other four refractory organic pollutants, indicating the potential application of PMS oxidation in water treatment.

This study proposed and established a comprehensive evaluation system for the pollution degree of the waterbody by taking overlying water and sediment as a whole. By dividing different sampling points into three gradients according to the pollution degree, the changes in sedimentary microbes under various pollution gradients were compared. The results showed that microbial diversity, abundance and specific OTUs decreased significantly with the increase in pollution degree. Meanwhile, Firmicutes, Bacteroidota and Caldiseriota increased in the severely polluted group, while Chloroflexi and Acidobacteriota decreased. Spearman correlation analysis and co-occurrence network revealed that COD, pH in overlying water, and Mn, Fe in sediments were the most significant pollution degree evaluation indicators affecting sedimentary microorganisms, which drove the sedimentary microbial communities dominated by Proteobacteria and Firmicutes. FAPROTAX functional prediction indicated that increased pollution levels led to the weakening of functional genes related to nitrogen metabolism and sulfur metabolism and the increase of functional genes related to carbon metabolism in sediment microorganisms. This study not only provided new insights into waterbody pollution evaluation but also verified the feasibility of this evaluation method by the response of sedimentary microbial communities to different pollution degrees.

In recent years, the extensive utilization of ofloxacin (OFX) has led to elevated concentration of OFX compound in the aquatic environment. At the same time, the inherent recalcitrance of OFX has presented a formidable challenge for OFX degradation. In this study, lanthanum cerium perovskite (LaCeO3) was prepared by citric acid sol–gel method to activate bisulfite (BS) for the effective degradation of OFX. The results revealed that the LaCeO3/BS system removed 87.5% of OFX within 180 min with a pseudo-first-order kinetic constant of 3 × 10−3 min−1. Radical quenching experiments and electron paramagnetic resonance (EPR) spectroscopy confirmed that sulfate radicals (SO4•_) and hydroxyl radicals (HO•) were the primary reactive species responsible for OFX removal in LaCeO3/BS system. The reaction mechanism indicated that Ce in LaCeO3/BS system served as the primary active site for BS activation, and a regenerating cycle involving ≡Ce(III)/≡Ce(IV) was present. Additionally, possible intermediate products were identified by a liquid chromatograph-mass spectrometer (LC-MS), revealing potential degradation pathways of OFX. Cycle tests and energy dispersive spectrometer (EDS) data demonstrated the favorable reusability and stability of LaCeO3.

Activating peroxides to produce active substances is the key to advanced oxidation processes (AOPs), but this usually requires energy or is accompanied by additional contaminants. In this study, diclofenac (DCF) was effectively removed by peracetic acid (PAA) in phosphate buffer (PBS). According to the results of radical scavenging experiments and electron paramagnetic resonance (EPR), hydroxyl radical (•OH) and organic radicals (i.e., CH3C(=O)OO• and CH3C(=O)O•) generated from PBS-activated PAA might be the dominant reactive species responsible for DCF degradation. At neutral pH, PBS/PAA system exhibited the best degradation efficiency on DCF. Presence of NO3-, SO42- and Cl- had little effect on the removal of DCF, while HCO3- and natural organic matter (NOM) significantly inhibited DCF degradation in PBS/PAA system, resulting in the lower degradation efficiency of DCF in natural waters than that in ultrapure water. Finally, four possible degradation pathways, including hydroxylation, formylation, dehydrogenation and dechlorination, were proposed based on the detected reaction products. This study suggests that PBS used to control solution pH should be applied cautiously in PAA-based AOPs.

Citric acid (CA) can effectively complex with Fe(III) to improve the solubility of Fe(III) and accelerate the reduction of Fe(III) to Fe(II), while its use in Fe(III)-activated peracetic acid (PAA) system has not been reported so far. Therefore, CA was introduced into Fe(III)/PAA system in this study to degrade oxytetracycline (OTC), and the degradation efficiency and mechanism of OTC in this system were systematically investigated. The results showed that the removal efficiency of OTC in Fe(III)-CA/PAA system at pH 7.0 could reach 81.5% after 20 min, and the degradation of OTC followed pseudo-first-order kinetic. The addition of CA into Fe(III)/PAA system could effectively reduce Fe(III) to Fe(II) driving the cycle of Fe(III)/Fe(II) and accordingly enhance the OTC removal in this system. According to the results of electron paramagnetic resonance (EPR) and scavenging experiments, hydroxyl radical (HO center dot) and organic radicals (CH3C(O)O center dot and CH3C(O)OO center dot) played major roles for the degradation of OTC in Fe(III)-CA/PAA system. Four possible transformation paths of OTC in this system were proposed, including demethylation, hydroxylation, dehydrogenation and dehydration, based on five detected degradation products. This study provides an idea to improve PAA activation by Fe(III) and broadens the practical application of Fe(III) in advanced oxidation processes.

A Cu(II)/heat coactivated peracetic acid (PAA) system for enhancing diclofenac (DCF) degradation was proposed in this work. The superiority of this synergetic activation strategy for PAA, working reactive species, catalytic mechanism and effects of reaction parameters on DCF elimination in this system were simultaneously investigated. Based on our results, the DCF loss rate in Cu(II)-heat/PAA process at pH 8.0 was about 49.3 and 4.2 times of that in Cu(II)/PAA and heat/PAA processes, respectively. Increasing the reaction temperature to 60 оC not only motivated the conversion of Cu(II) to Cu(I) but also facilitated the one-electron transfer between Cu(I) and PAA, boosting the generation of radicals. Organic radicals (mainly CH3C(O)O• and CH3C(O)OO•) were evidenced to be the core oxidizing substances dominating in the destruction of DCF while hydroxyl radical (•OH) made a minor contribution in this system by electron paramagnetic resonance (EPR) method together with scavenging experiments. This study broads the eyes into enhanced PAA activation initiated by homogenous Cu(II), providing a simple but efficient tool to degrade micropollutants.