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As an emerging advanced oxidation technology, ultraviolet/peracetic acid (UV/PAA) shows great potential in removing pharmaceuticals and personal care products (PPCPs) in the field of wastewater treatment. In this work, ibuprofen (IBP) was chosen as the contaminant to study the degradation effects and PAA activation mechanisms by UV irradiation. The experimental results showed that UV/PAA had an excellent degradation efficiency (99.22 %) of IBP after 15 min reaction, and the synergistic effect between UV and PAA was also observed. Increasing the dosage of PAA caused the increase in IBP degradation reaction rate. Under acidic conditions, the increase in pH values increased the degradation reaction rate, whereas the opposite was true in alkaline conditions. In addition, the coexisting substrates (e.g., NO 3 -, CO 3 2-, Ca2+, and HA) could exert inhibition on the degradation. Quenching experiments were carried out using various quenchers to identify reactive oxygen species (ROSs) in the system. The results demonstrated that ·OH and carbon centered radicals (R-C·) played a dominant part in the degradation, and the contribution of CH 3 C(O)OO·,·O 2 -, CH 3 C(O)O·, ·OH, and direct photolysis were estimated to be 29.9 %, 26.9 %, 21.5 %, 14.5 %, and 7.2 %, respectively. The results of IBP intermediates identification indicated that the degradation process was mainly related to its side chain decarboxylation, oxidative dehydrogenation, demethylation, and the oxidation of the aromatic ring. Furthermore, Toxicity Estimation Software Tool (T.E.S.T.) and ECOSAR were applied to evaluate the toxicity of the intermediate products was further evaluated. This study enriched the understanding of the PAA activation mechanism by UV involved, and improved the theory and technology of removing PPCPs by UV/PAA process. [Display omitted] [ABSTRACT FROM AUTHOR]

• The UV/SPC process presented better degradation performance of ODVEN. • ·OH and CO 3 ·− were involved in the degradation of ODVEN in the both processes. • The reactive sites and possible degradation pathways of ODVEN were proposed. • The UV-LED/PS process was more economical for the elimination of ODVEN. As an active metabolite of venlafaxine and emerging antidepressant, O-desmethylvenlafaxine (ODVEN) was widely detected in different water bodies, which caused potential harm to human health and environmental safety. In this study, the comparative work on the ODVEN degradation by UV (254 nm) and UV-LED (275 nm) activated sodium percarbonate (SPC) systems was systematically performed. The higher removal rate of ODVEN can be achieved under UV-LED direct photolysis (14.99%) than UV direct photolysis (4.57%) due to the higher values of photolysis coefficient at the wavelength 275 nm. Significant synergistic effects were observed in the UV/SPC (80.38%) and UV-LED/SPC (53.57%) systems and the former exhibited better performance for the elimination of ODVEN. The degradation of ODVEN all followed the pseudo-first-order kinetics well in these processes, and the pseudo-first-order rate constant (k obs) increased with increasing SPC concentration. Radicals quenching experiments demonstrated that both ·OH and CO 3 ·− were involved in the degradation of ODVEN and the second-order rate constant of ODVEN with CO 3 ·− (1.58 × 108 (mol/L)−1 sec−1) was reported for the first time based on competitive kinetic method. The introduction of HA, Cl−, NO 3 − and HCO 3 − inhibited the ODVEN degradation to varying degrees in the both processes. According to quantum chemical calculation, radical addition at the ortho-position of the phenolic hydroxyl group was confirmed to be the main reaction pathways for the oxidation of ODVEN by ·OH. In addition, the oxidation of ODVEN may involve the demethylation, H-abstraction, OH-addition and C-N bond cleavage. Eventually, the UV-LED/SPC process was considered to be more cost-effective compared to the UV/SPC process, although the UV/SPC process possessed a higher removal rate of ODVEN. [Display omitted]. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co 3 O 4 @β-CD composites were synthesized utilizing a hydrothermal method and employed as PMS activators. • The Co 3 O 4 @β-CD catalyst has shown excellent catalytic efficacy, leading to 99.13 % degradation of CIP. • The activation of PMS in the Co 3 O 4 @β-CD system proceeded through both radical and non-radical routes. • The conversion of Co2+/Co3+ couples in the Co 3 O 4 @β-CD/PMS system produced reactive species responsible for CIP degradation. • Co 3 O 4 @β-CD demonstrated excellent durability, recycling, and minimal metal leaching after performing five cycles. In this study, β-cyclodextrin-modified cobalt oxide (Co 3 O 4 @β-CD) composites were developed through hydrothermal processes and employed for heterogeneous activation of peroxymonosulfate (PMS) for the removal of ciprofloxacin (CIP) antibiotics. The results revealed that the degradation of CIP by Co 3 O 4 @β-CD/PMS was 99.13 %, which was significantly higher than the degradation of CIP by Co 3 O 4 /PMS (79.06 %) in a 25-minute period under optimal conditions ([Co 3 O 4 @β-CD] = 0.25 g/L, [PMS] = 0.25 mM, pH=7.0). The enhanced degradation of CIP contributed to the greater surface area (162.84 m2/g) of the Co 3 O 4 @β-CD to the Co 3 O 4 (121.47 m2/g). Besides, the study assessed the impact of several reaction variables and interrupting anions on the abatement of CIP. A possible degradation procedure for CIP has been established by identifying reaction intermediates. The activation of PMS was achieved by both radical and non-radical routes. Further, Co 3 O 4 @β-CD exhibited remarkable stability and maintained its degrading efficiency after five consecutive cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Photocatalytic breakdown of tetracycline (TC-HCl) under visible light stimulated via ZnFe 2 O 4 /Cr 2 O 3 /MXene NC. • Z-scheme mechanism of ZnFe 2 O 4 /Cr 2 O 3 /MXene NC was proposed. • Hazardous intermediates were addressed using the Toxicity Estimation Software Tool (TEST) for in-silico toxicity prediction. • Photocatalytic reduction of tetracycline and intermediate toxicity was achieved with excellent efficacy. Antibiotics containing tetracycline (TC-HCl) pose a risk to both human and natural ecosystems. MXene-based nanostructures achieve rapid photodegradation of antibiotics due to their distinctive structural and physicochemical properties. This study used hydrothermal method to synthesize the ZnFe 2 O 4 /Cr 2 O 3 /MXene nanocomposite (NC). MXene (Ti 3 C 2) was employed as a co-catalyst with a distinct layered structure. After 60 min of exposure to visible light, the TC-HCl photodegradation efficiency reached 94.2 %. In addition, the recyclability test confirmed that the ZnFe 2 O 4 /Cr 2 O 3 /MXene NC remains stable during the photodegradation of tetracycline. Following four cycles, a degradation efficiency of up to 86 % is maintained. The antibiotic was found to degrade by the action of free radicals · O 2 - and •OH, which prompted the proposal of plausible degradation mechanisms. The ESR analysis verifies the presence of DMPO- · O 2 - and DMPO-•OH, and it also shows that the signals were stronger as the visible irradiation period stretched to 15 min. In addition, the breakdown routes of TC photodegradation were identified using LC-MS spectrometry. The kinetics of photodegradation were studied, and the findings showed that the reaction was rapid, with a K value of 0.0983 min−1. Thus, the ZnFe 2 O 4 /Cr 2 O 3 /MXene nanocomposite is a promising candidate for toxicity testing and the treatment of wastewater owing to its high degrading efficiency and durability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pa WYT demonstrated the biodegradation capacity on refractory anthraquinone dyes. • Piperazine between the 9,10-anthraquinone chromophores were cleaved. • DNA damage possibly was mediated by the redox cycle of VB4 dye intermediates. • Total genotoxicity decreases correlated with the quantity of unsubstituted dyes. Dye biodegradation products may cause genotoxicity, raising concerns about the safety of bioremediated water. The underlying biotransformation mechanism and related genotoxicity during anthraquinone degradation remain unclear. In this study, we employed Pseudomonas aeruginosa WYT (Pa WYT) to investigate the biotransformation of Vat Blue 4 (VB4), a dye with a typical anthraquinone structure and low bioavailability. The genotoxicity of the resulting degradation products was also assessed. Novel mechanisms for VB4 biotransformation were identified, including piperazine cleavage, chromophore loss, and the formation of smaller molecular products. A real-time genotoxicity assay showed that VB4 induced oxidative and general stresses to microorganisms, while the total genotoxicity across five stress categories (oxidative, protein, membrane, DNA, and general stresses) gradually decreased as the dye degradation progressed. Overall, capturing and understanding the toxicity dynamics during VB4 bioremediation supports the reliability of this biodegradation method and its potential for treating VB4-contaminated wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • g-C 3 N 4 /NH 2 -MIL-125 showed enhanced separation efficiency of photogenerated carriers. • g-C 3 N 4 /NH 2 -MIL-125 has a broader photoresponse range and higher adsorption capacity. • g-C 3 N 4 /NH 2 -MIL-125 has great potential in eliminating antibiotics from water. Photocatalysis is an advanced oxidation process that shows excellent promise in degrading organic pollutants present in water. However, electrons and holes tend to combine easily during the transfer process, and the adsorption capacity of single-phase photocatalytic materials is weak, resulting in a low degradation rate. Therefore, a new composite semiconductor photocatalyst g-C 3 N 4 /NH 2 -MIL-125 was constructed using a two-step solvothermal method. The morphology, elemental composition, structure, photoelectric properties, and photocatalytic activity of g-C 3 N 4 /NH 2 -MIL-125 were characterized. The photocatalytic degradation of Sulfamethoxazole (SMX) in water was also carried out. Results indicated that g-C 3 N 4 /NH 2 -MIL-125 had been synthesized successfully, and g-C 3 N 4 /NH 2 -MIL-125 had a broader photoresponse range, higher adsorption capacity, and higher separation efficiency of photogenerated carriers. When pH was 4.0 and catalyst dosage was 0.15 g/L, g-C 3 N 4 /NH 2 -MIL-125 showed the highest degradation rate for SMX. It was confirmed that the main active groups in SMX degradation were OH, h+, and O 2 −. 15 kinds of intermediates of SMX and the possible degradation pathways were identified by high-performance liquid chromatography-mass spectrometry and DFT calculation. Toxicity analysis revealed that the intermediate products have a lower developmental toxicity than SMX. This work demonstrated that g-C 3 N 4 /NH 2 -MIL-125 has great potential in eliminating antibiotics from water. [ABSTRACT FROM AUTHOR]

Proposed sorption and degradation mechanisms of DMP and BPA by biochar. [Display omitted] • Higher sorption of aromatic organics is associated with an increased degradation by biochar. • Surface sorption is the predominant organic removal mechanism compared to pore filling. • More aromatic rings lead to higher sorption but lower degradation of organics by biochar. • Improving biochar's degradation ability can promote the mineralization of adsorbed organics. Sorption and degradation occur simultaneously during the removal of aromatic organics by biochar. However, the unclear association between sorption and degradation limited our understanding of the underlying mechanisms of organic removal by biochars. Herein, the removal of monocyclic 2,6-dimethylphenol (DMP) and bicyclic bisphenol A (BPA) by raw and potassium hydroxide modified biochars was comparatively investigated by batch removal experiments and theoretical calculations. Under identical initial concentrations, biochar displayed lower sorption but higher degradation for DMP compared to BPA, whilst higher sorption corresponded to greater degradation for the same chemical. Sorption mechanisms revealed by molecular dynamic simulations include π-π, hydrophobic, and hydrogen bonding interactions. Density functional theory calculations identified the preferred degradation sites on biochar for adsorbed organics are graphitic nitrogen, defects, carboxyl, and hydroxyl functional groups. Analysis of free radicals and degradation intermediates concluded that the degradation pathways involve both free radical pathways and electron transfer processes for DMP, while only free radicals for BPA. Experimental and computational results indicated an increase in ring quantity can lead to higher sorption affinity but lower degradability of aromatic organics by biochar. Findings of this research provide theoretical support for the advancement of biochar based aromatic contaminant mitigation strategies. [ABSTRACT FROM AUTHOR]

[Display omitted] • S-C 3 N 4 /Bi 2 O 3 -20 % removed 87 % of 10 mg/L SMZ under visible light in batch studies. • Treated SMZ solution showed an increase in CFU, indicating reduction in toxicity. • A/O MBBR and photocatalysis showed better TOC and SMZ removal from real wastewater. • Economic assessment was performed to evaluate the feasibility at field-scale level. The widespread occurrence of sulfamethoxazole (SMZ), one of the widely used antibiotics, in aqueous environments, poses a significant threat to ecosystem health. In this study, the combination of a biofilm-based treatment system and photocatalysis was explored for the effective removal of SMZ. Initially, sulfur-doped g-C 3 N 4 (S-C 3 N 4) was synthesized and then combined with Bi 2 O 3 to improve the overall photocatalytic performance. Characterization of as-prepared photocatalysts was performed to understand the chemical structures, morphologies, and optical properties. Batch studies have shown that, at neutral pH, using 1 g/L of S-C 3 N 4 /Bi 2 O 3 (CNBI) composite results in the removal of 87.2 % of SMZ with an initial concentration of 10 mg/L. In accordance with the scavenging study, O 2 –• was identified as the dominant reactive species for the degradation of SMZ. After that, the identification of SMZ degradation products was carried out, and possible degradation pathways were proposed. After obtaining the optimal dosage, continuous experimentation was conducted using a photocatalytic reactor coated with CNBI composite combined with anoxic/oxic moving bed biofilm reactor. The investigation of real municipal and hospital liquid wastes containing SMZ showed an overall total organic carbon removal of 87 % and 81 %, respectively. Economic assessment, including capital and operational expenditures and synthesis costs involved in photocatalyst material, was performed to check the feasibility of photocatalysis integrated with biological systems at large-scale treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Recent advances in coupling pollutants degradation with hydrogen production (CPDWHP) are reviewed. • Different pollutant types and degradation pathways with H 2 evaluation are comprehensive summarized. • The influencing factors and synergistic enhancement in the single and composited photocatalysts are uncovered. • Prospects and challenges of the efficient photocatalysis system in CPDWHP are outlooked. Coupling pollutants degradation with hydrogen production (CPDWHP) by semiconductor photocatalysis technique provides a significant approach to tackle with the environmental and energy challenges we are currently facing. This technology capitalizes on two crucial half-reactions of the photocatalytic oxidation–reduction process. It is of significance to design suitable semiconductor catalysts and composite materials according to different pollutant systems. This review introduces and categorizes recent breakthroughs and advancements in CPDWHP. Firstly, it outlines the fundamental principles of this technology. Subsequently, it categorizes and summarizes various pollutants, highlighting the progress of coupled photocatalysis and emphasizing different pollutant types, degradation pathways in photocatalysis, and the activity of simultaneous hydrogen production. Furthermore, it summarizes the effects of crystal facets, surface wettability, crystallinity, and co-catalytic effects in composite catalytic systems, as well as the enhancement of catalytic activity by single and multiple heterojunctions. Finally, the challenges and solutions facing CPDWHP are looked forward, including emerging pollutant types and corresponding photocatalyst design, charge separation regulation in CPDWHP system, precise control of photocatalytic pollutant degradation and the selection of reduction process corresponding to hydrogen production, and the influence of element content on the system. [ABSTRACT FROM AUTHOR]

This article presents, in detail, the paths and mechanisms, main by-products, and a kinetic study of the oxidation of profenofos (PFF) by HO• radicals. Photo-assisted peroxidation was the precursor reaction for generation of radicals; the effect of UV-C (245 nm) radiation was evaluated. The results of the kinetics study indicated that the best fit for the experimental data was the pseudo-first-order model; further, that oxidation occurs in a fast initial stage and a slow final stage. In an acidic environment, the fast oxidation stage was favored over the slow stage; while in the basic medium the opposite behavior was observed. Eight oxidation by-products and 29 reaction intermediates were identified. The main mechanisms involved in the mineralization of PFF were reactions of electron abstraction, HO• abstraction, H• abstraction, substitution, displacement, and addition of electrons. The rapid oxidation step was related to the mining of the O–C2 H5 and S–C3 H7 chains of the intermediate O-ethyl S-propyl phosphonothioate. The slow oxidation step included the mineralization of 4-bromo-2-chlorophenyl and derivatives. [ABSTRACT FROM AUTHOR]

Diclofenac (DCF), a widely used drug, is frequently found in natural waters, and its removal has caused extensive concern. Sulfate radical-based advanced oxidation processes are efficient for the degradation of organic pollutants, but the self-decomposition of persulfates is always sluggish and restricted. Herein, self-N doped biochar derived from food waste digestate (FWDB) was evaluated as the activator of peroxylmonosulfate (PMS) in terms of DCF degradation. The effects of several key operating variables were examined, and the results indicated that ∼93% of DCF with an initial concentration of 20 mg/L was removed at FWDB dosage of 0.3 g/L and PMS concentration of 1.0 mM. Thereafter, the machine learning method was explored to simulate and predict the DCF removal process. The reactive oxygen species participated in the reaction was identified as 1O 2 , and the reaction sites on FWDB were determined as graphitized carbon, C O structure, doped-N, and defective edges. Moreover, based on the identification of intermediates and products, the possible DCF destruction pathways were proposed as hydroxylation, cleavage of N−C bond, and decarboxylation. This study provided an economical and convenient heterogeneous PMS activator for remediation of organic wastewater and confirmed the feasibility of optimizing the contaminant degradation process via data mining. [Display omitted] [ABSTRACT FROM AUTHOR]

• Multi-element isotopic fractionation (ε) (2H, 13C, 15N, 37Cl) of 3-CA were assessed. • Fractionation factors (ε) of 3-chloroanilin has been employed to probe reactions. • Degradation pathways of 3-CA were characterized using fractionation pattern. • The ε of direct photolysis, hydrolysis and TiO 2 photocatalysis were compared. • ME-CSIA for identification of degradation pathways in aquatic environments. This study investigates carbon, hydrogen, nitrogen and chlorine isotope fractionation during the transformation of 3-chloroaniline (3-CA) via direct photolysis, TiO 2 photocatalytic degradation at neutral condition and hydrolysis at pH 3, pH 7 and pH 11. Direct photolysis and ∙OH reaction (UV/H 2 O 2) showed similar inverse isotope fractionation (ε) for carbon (1.9 ± 0.4 ‰ and 1.9 ± 0.6 ‰), for hydrogen (6.9 ± 1.6 ‰ and 5.0 ± 2.6 ‰), and inverse chlorine (13.9 ± 3.8 ‰ and 11.9 ± 2.9 ‰) and no nitrogen isotope fractionation, respectively. In contrast, significantly different normal carbon (-0.5 ± 0.1 ‰), inverse hydrogen (6.6 ± 1.5 ‰), and normal nitrogen (-0.8 ± 0.2 ‰) and inverse chlorine (5.2 ± 3.7 ‰) isotope fractionations were observed for the photocatalysis of 3-CA by TiO 2 indicating a different degradation pathway as expected from ∙OH. For hydrolysis, inverse carbon (0.7 ± 0.3 ‰) and hydrogen (12.5 ± 3.3 ‰) isotope fractionation have been found at pH 3 while a normal carbon isotope fractionation was observed at pH 7 (-0.9 ± 0.3 ‰) and pH 11 (-1.3 ± 0.4 ‰), respectively. The correlation of 2H and 13C, 15N and 13C, and 37Cl and 13C isotope fractionation (Λ) allowed to distinguish direct photodegradation (Λ H C = -4.6 ± 1.7 (Λ H C-YORK =-5.2 ± 1.0) and Λ Cl- C = 8.7 ± 0.9 (Λ Cl-C-YORK =8.0 ± 0.3)), UV/H 2 O 2 oxidation (Λ H C = -4.7 ± 1.0 (Λ H C-YORK =-4.5 ± 0.6) and Λ Cl- C = 6.7 ± 0.8 (Λ Cl-C-YORK =7.0 ± 1.0)), UV/TiO 2 photocatalysis (Λ H C = -9.2 ± 3.1 (Λ H C-YORK =-9.3 ± 1.4), Λ Cl-C = -10.2 ± 1.5 (Λ Cl-C-YORK =-12.4 ± 1.7) and Λ N C -2.2 ± 0.3 (Λ N C-YORK =-2.3 ± 0.4)) and the modes of hydrolysis (Λ H C = 15.2 ± 5.3 (Λ H C-YORK =17.9 ± 2.9) and Λ Cl- C = 0.9 ± 0.2 (Λ Cl-C-YORK =1.1 ± 0.1) at pH 3) of 3-CA. The results were mechanistically interpreted highlighting the potential of CSIA to elucidate chemical oxidation and hydrolysis mechanisms of 3-CA. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • PVDF-supported N, S-semicoke (SC) membrane was prepared for persulfate activation. • A binary NOR and CIP mixture was used for their simultaneous degradation. • Mechanisms of pH-dependent species mediating degradation pathways were revealed. • N, S-SC-PVDF/PS had degradation efficiencies of 97.4 % for NOR and 96.8 % for CIP. • N, S-SC-PVDF/PS showed high tolerance at pH 3.0–9.0 and common Cl−/HCO 3 − at 5–20 mM. In persulfate-based advanced oxidation processes (PS-AOPs), pH is the most important factor affecting the degradation efficiency. However, the mechanism of pH-dependent generation of active species to mediate degradation pathways in PS-AOPs is currently unclear. In this study, N, S-modified semi-coke (N, S-SC) was first prepared by pyrolysis, and then poly (vinylidene fluoride) (PVDF) was used as support to obtain N, S-SC-PVDF membrane. Subsequently, N, S-SC-PVDF was used to activate peroxomonosulfate for the construction of N, S-SC-PVDF/PS system to promote the co-degradation of a binary mixture of norfloxacin (NOR) and ciprofloxacin (CIP) in water. Under optimized conditions of 0.4 g/L PS, pH = 7.0 and T = 30 °C, N, S-SC-PVDF/PS showed the degradation efficiencies of 97.4 % for NOR and 96.8 % for CIP within 240 min. Also, this system exhibited high resistance to Cl−/HCO 3 − at 5–20 mM and humic acid at 10–40 mg/L, with a wide pH tolerance of 3.0–9.0 and excellent cycle stability. Combining electron spin resonance and fluorescence quantification analysis, hydroxyl radicals (·OH) were the dominant species with a small amount of singlet oxygen (1O 2) at pH = 3.0, whereas radicals (·OH, SO 4 ·−) and non-radicals (1O 2) co-dominated at pH = 7.0. LC-MS analysis was used to identify the degradation products under different pH conditions, and different reactive oxygen species selected different sites to attack, resulting in different degradation pathways for the target binary pollutants. This study combines carbon-based catalyst and membrane separation process to construct an N, S-SC-PVDF/PS system for simultaneous degradation of binary NOR and CIP, and the relevant findings can not only provide a theoretical basis towards high-efficiency degradation of multi-component mixed antibiotics, but also new insights into pH-dependent degradation mechanism for the development of carbon-based PS-AOPs system in practical wastewater treatment. [ABSTRACT FROM AUTHOR]

This study investigated the degradation of aflatoxin B 1 (AFB 1) in food by using dual-frequency ultrasound (DFUS) and the effects of sonochemical oxidation on the efficacy. It was found that the degradation of AFB 1 by bath ultrasound (BU), probe ultrasound (PU), and DFUS were all consistent with first-order kinetics. The use of DFUS significantly increased the AFB 1 degradation to 91.3%, and compared with BU and PU, it increased by about 177.0% and 61.5% after 30 min treatment. DFUS could generate a synergistic effect to accelerate the generation of free radicals, which promoted sonochemical oxidation to degrade AFB 1. It could be speculated that hydroxyl radical (·OH) probably acted a dominant part in the AFB 1 degradation by DFUS, and the hydrogen atoms (·H) might also are contributed. These results indicated that DFUS was an effective method of AFB 1 degradation. [Display omitted] • DFUS carried out by combining bath and probe ultrasound can degrade AFB 1 • DFUS can increase AFB 1 degradation compared with bath and probe ultrasound • DFUS can enhance the AFB 1 degradation by promoting the ·OH • Degradation pathways and mechanisms of AFB 1 are proposed [ABSTRACT FROM AUTHOR]

The ecological impact of emerging contaminants (ECs) in aquatic environments has raised concerns, particularly with regards to urine as a significant source of such contaminants in wastewater. The current investigation used the UV/Peracetic Acid (UV/PAA) processes, an innovative advanced oxidation technology, to effectively separate two emerging pollutants from urine at its source, namely, ciprofloxacin (CIP) and bisphenol A(BPA). The research findings demonstrate that the presence of the majority of characteristic ions has minimal impact on the degradation of ECs. However, in synthetic hydrolyzed urine, only NH 4 + inhibits the degradation of two types of ECs, with a more pronounced effect observed on CIP degradation compared to BPA.The impact of halogen ions, specifically Cl− and I−, on the degradation of CIP in synthetic hydrolyzed urine was a complex phenomenon. When these two halogen ions are present individually, the generation of reactive halogen species (RHS) within the system enhances the degradation of CIP. However, when both types of ions coexist, the formation of diatomic radical species partially inhibits degradation. In terms of BPA degradation, while the production of reactive chlorine species (RCS) to some extent hinders the reaction rate, the generation of reactive iodine species (RIS) promotes the overall process. CIP undergoes fragmentation of the piperazine and quinoline rings, decarboxylation, defluorination reactions, as well as substitution reactions, leading to the formation of products with simplified structures. The degradation of BPA occurs gradually through hydroxyl and halogen substitution as well as isopropyl cleavage. The preliminary toxicity analysis confirmed that the presence of halogen ions in urine resulted in the formation of halogenated products in two types of ECs, albeit with an overall reduction in toxicity. The UV/PAA processes was considered to be an effective and relatively safe approach for the separation of ECs in urine. [Display omitted] • The effectiveness of UV/PAA was minimally impacted by the composition of urine. • The generation of halogen diatomic free radicals inhibits the degradation of CIP. • The characteristic anion reduced the contribution of.•OH • The majority of ECs products have lower toxicity compared to the parent material. [ABSTRACT FROM AUTHOR]

• First quantitative evaluation of cVOC remediation in a contaminated site treated with S-nZVI. • Resolve degradation signature from observed δ13C influenced by multiple processes. • Derive degradation rate/extent/pathway insights for evaluating remediation efficiency. • Degradation continues remediating various cVOC a year after S-nZVI field application. • Dichloroelimination dominance suggests S-nZVI sustains long-term abiotic PCE/TCE degradation. Sulfidated nanoscale zerovalent iron (S-nZVI) has demonstrated promising reactivity and longevity for remediating chlorinated volatile compounds (cVOC) contaminants in laboratory tests. However, its effectiveness in field applications remains inadequately evaluated. This study provides the first quantitative evaluation of the long-term effectiveness of carboxymethyl cellulose-stabilized S-nZVI (CMC-S-nZVI) at a cVOC-contaminated field site. A reactive transport model-based numerical approach delineates the change in cVOC concentrations and carbon isotope values (i.e., δ13C from compound-specific stable isotope analysis (CSIA)) caused by dissolution of dense non-aqueous phase liquid, sorption, and pathway-specific degradation and production, respectively. This delineation reveals quantitative insights into remediation effectiveness typically difficult to obtain, including extent of degradation, contributions of different degradation pathways, and degradation rate coefficients. Significantly, even a year after CMC-S-nZVI application, degradation remains an important process effectively removing various cVOC contaminants (i.e., chlorinated ethenes, 1,2-dichloroethanes, and chlorinated methanes) at an extent varying from 5 %-62 %. Although the impacts of CMC-S-nZVI abundance on degradation vary for different cVOC and for different sampling locations at the site, for the primary site contaminants of tetrachloroethene and trichloroethene, their predominance of dichloroelimination pathway (≥ 88 %), high degradation rate coefficient (0.4–1.7 d-1), and occurrence at locations with relatively high CMC-S-nZVI abundance strongly indicate the effectiveness of abiotic remediation. These quantitative assessments support that CMC-S-nZVI supports sustainable ZVI-based remediation. Further, the novel numerical approach presented in this study provides a powerful tool for quantitative cVOC remediation assessments at complex field sites where multiple processes co-occur to control both concentration and CSIA data. [Display omitted] [ABSTRACT FROM AUTHOR]

Antiretroviral drugs (ARVDs), used in the treatment of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) have been recognised as emerging contaminants (ECs). Various ARVDs have been identified and quantified in surface waters worldwide. This research presents the first degradation of efavirenz using dielectric barrier discharge (DBD) plasma. Efavirenz was successfully degraded with 93 % removal efficiency at discharge power of 59.3 W and pH 9. Incorporating free radical promoters (Fe2+/H 2 O 2) significantly improved the rate constants from 0.134 min−1 to 0.269 min−1 resulting in a 40 % increment in energy yield, from 235 mg/kWh to 330.5 mg/kWh. The presence of free radical promoters also eliminated the need for upward pH adjustments. The optimal gas flow rate of 0.6 L/min enabled maximized production of reactive species that resulted to highest efavirenz removal efficiency (93 %). Electron paramagnetic resonance (EPR) confirmed the presence of •OH and ONOO- radical species during plasma discharge. Subsequent chemical probes confirmed the dominance of e- aq and •OH in efavirenz degradation. Coexisting inorganic ions largely retarded efavirenz degradation. Six degradation by-products were identified, and possible degradation pathway was proposed. Electron transfer and hydrogen abstraction were the primary mechanisms through which the radicals attacked the efavirenz contaminant. DBD demonstrated adaptability to actual water matrices contaminated with efavirenz, signifying its practical feasibility as a treatment option for ARVD-contaminated waters in the environment. This study provides an invaluable reference for understanding the degradation of ARVDs in the environment using DBD plasma, contributing to the collective endeavours aimed at preserving the integrity of terrestrial and aquatic ecosystems. [Display omitted] • DBD plasma effectively degraded efavirenz in water. • •OH radicals and e aq − were the dominant functional reactive species. • Alkaline pH favored efavirenz degradation. • Gas flow rate influenced gas availability in the reaction system hence efavirenz degradation rate. • Radical promoters improved the reaction rates and the energy yield. [ABSTRACT FROM AUTHOR]

• The UV/chlorine/Fe(III) process performed best in PNP degradation. • OH and RCSs were the dominant reactive species for PNP degradation. • Fe(III)/Fe(II) cycle worked efficiently to enhance OH and RCSs production. • Reaction mechanisms of PNP degradation were elucidated based on DFT calculation. • The UV/chlorine/Fe(III) process might decrease the yields and toxicity of DBPs. Para-nitrophenol (PNP) enters aquatic environments through wastewater discharge, potentially threatening ecological security and public health. This work investigated the enhanced degradation of PNP in wastewater during the UV/chlorine process with the addition of Fe(III) (UV/chlorine/Fe(III)). The UV/chlorine/Fe(III) process (61.85 %) exhibited higher performance in PNP degradation in 10 min compared to the UV/chlorine process (40.00 %) because the synergistic effect of Fe(III) and free chlorine enhanced hydroxyl radicals (OH) and reactive chlorine species (RCSs) production. Furthermore, OH and RCSs were identified as the primary contributors to degrade PNP during the UV/chlorine/Fe(III) process, and their corresponding contributions accounted for 40.09 % and 37.10 %, respectively. Besides, the degradation efficiencies of PNP were promoted by increasing the dosages of Fe(III) and free chlorine and declined by increasing pH and PNP concentration. Also, Cl− could promote PNP degradation, while SO 4 2− and HCO 3 − inhibited it. Then, the reaction mechanisms of PNP degradation during the UV/chlorine/Fe(III) process were proposed based on the identified transformation products (TPs) and the density functional theory (DFT) calculation. Meanwhile, PNP, TPs, and other possible intermediate products presented different ecotoxicity. Finally, the formation and toxicity of disinfection by-products (DBPs) with different Fe(III) concentrations, chlorine dosages, initial pHs, and PNP concentrations were explored. Overall, the obtained findings can provide deep insights into the mechanisms of PNP degradation and a new approach to enhancing PNP degradation in wastewater. [ABSTRACT FROM AUTHOR]

Preparation of Ag 2 O/CaMoO 4 S-type heterojunction and its sonocatalytic degradation of crystal violet (CV). [Display omitted] • S-type of Ag 2 O/CaMoO 4 heterojunction had excellent sonocatalytic activity. • Degradation rate of CV reached 97.36 ± 1.46(%) using Ag 2 O/CaMoO 4 as sonocatalyst. • O 2 –, OH and h + generated during sonocatalysis played major roles for CV degradation. • Ag 2 O/CaMoO 4 was an appropriate sonocatalyst for degradation of organic pollutants. Herein, an S-type of Ag 2 O/CaMoO 4 heterojunction was prepared by combining CaMoO 4 with Ag 2 O and characterized. The sonocatalytic performance of the Ag 2 O/CaMoO 4 composite was evaluated by analyzing the degradation of basic dye crystal violet (CV). The results showed that the Ag 2 O/CaMoO 4 composite had the best sonocatalytic performance when the molar ratio of Ag 2 O to CaMoO 4 in the Ag 2 O/CaMoO 4 composite was 10 %. When the ultrasonic time was 120 min, the ultrasonic power was 200 W, the addition amount of 10 % Ag 2 O/CaMoO 4 composite was 1.00 g/L and the initial concentration of CV solution was 5 mg/L, the removal rate of CV could reach 97.36 ± 1.46(%). In addition, 10 % Ag 2 O/CaMoO 4 composite showed excellent sonocatalytic degradation performance to cationic dyes Rhodamine B (RhB) and methylene blue (MB), anionic dye Orange II (AO II) and azo dye Congo red (CR), indicating that the catalyst had a wide range of application. The study on the mechanism of sonocatalysis showed that the construction of S-type Ag 2 O/CaMoO 4 heterojunction effectively separated the electron-hole (e −- h +) pairs in the sonocatalysis process, significantly improved the sonocatalytic performance of CaMoO 4 , and effectively degraded CV, and the degradation of CV was caused by the active components such as h +, superoxide anion radical (O 2 –) and hydroxyl radical (OH). Furthermore, the 10% Ag 2 O/CaMoO 4 composite showed excellent repeatability and stability. In addition, the sonocatalytic degradation products of CV were detected and the possible degradation pathways of CV were summarized. These results suggested that the Ag 2 O/CaMoO 4 composite was an extremely appropriate sonocatalyst for sonocatalytic degradation of organic pollutants and would provide a valuable research basis for the development of efficient sonocatalysts. [ABSTRACT FROM AUTHOR]

• UV synergized with OCBC was the first time used to activate PAA to degrade SDZ. • 1O 2 , R-O• and •OH were the main contributors to SDZ degradation in UV/OCBC/PAA. • Degradation by-products and pathways of SDZ in UV/OCBC/PAA system was detected. • UV/OCBC/PAA performed an environmental safety and reusability in recycles. A novel UV/oxalic acid functionalized corn straw biochar (OCBC)/peroxyacetic acid (PAA) system was built to degrade sulfadiazine from waters. 94.7 % of SDZ was removed within 30 min by UV/OCBC/PAA. The abundant surface functional groups and persistent free radicals (PFRs) on OCBC were responsible for these performances. Cyclic voltammetry (CV) and other characterization analysis revealed, under UV irradiation, the addition of OCBC served as electron donor, which might promote the reaction of electrons with PAA. The quenching and electron paramagnetic resonance (EPR) tests indicated that R-O•, 1O 2 and •OH were generated. Theoretical calculations indicated sulfonamide bridge was vulnerable under the attacks of reactive species. In addition, high removal effect achieved by 5 reuse cycles and different real waters also suggested the sustainability of UV/OCBC/PAA. Overall, this study provided a feasible approach to remove SDZ with high mineralization efficiency, in addition to a potential strategy for resource utilization of corn straw. [ABSTRACT FROM AUTHOR]

In this study, complete tetracycline (TTC) and above 50% of total organic carbon (TOC) were removed by FeS/PS after 30 min under optimized conditions. Although free radicals and high-valent iron ions were identified to generate in the process, the apparent similarity between intermediate products of FeS/PS, Fe/PS, and UV/PS systems demonstrated that the degradation of TTC was due to sulfate radicals (SO 4 ⋅−) and hydroxyl radicals (⋅OH). Based on the reaction between free radicals and organic matter, we speculated that TTC in the FeS/PS system was decomposed and mineralized by dehydration, dehydrogenation, hydroxyl addition, demethylation, substitution, E-transfer, and ring-opening. Furthermore, a new understanding of FeS-mediated PS activation based on stoichiometry and kinetic analysis showed that there were both homogeneous and heterogeneous reactions that occurred in the entire progress. However, due to the effect of pH on the dissolution of iron ions, the homogeneous reaction became the principal process with iron ions concentration exceeding 1.35 mg/L. This work provides a theoretical basis for the study of the degradation of TTC-containing wastewater by the iron-based advanced oxidation process. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • BPAF was efficiently degraded in the heat-enhanced CoFe 2 O 4 @BC activated PMS system. • HCO 3 − and HPO 4 2− were the activators for PMS decomposition in the process. • SO 4 •− was the main reactive oxidation species in the degradation process. • Hydroxylation and β-scission mainly contributed to BPAF degradation. Carbon-based materials and heat activated peroxymonosulfate (PMS) have emerged as promising technologies for the remediation of contaminated water. This study investigated the feasibility of Bisphenol AF (BPAF) degradation by coupling CoFe 2 O 4 @BC catalyst with heat activated PMS technology. Heat significantly enhanced the catalytic performance of CoFe 2 O 4 @BC for PMS activation, resulting in 87.0 % removal of BPAF. Meanwhile, the effects of PMS concentration, CoFe 2 O 4 @BC catalyst dosage, initial pH, and the inorganic anions on BPAF degradation were investigated. The presence of HCO 3 − and HPO 4 2− were found to enhance BPAF degradation by promoting PMS decomposition, while humic acid (HA) significantly inhibited BPAF removal. Electron paramagnetic resonance (EPR) and quenching experiments suggested that sulfate radicals (SO 4 •−) were the dominant reactive oxygen species (ROS) in the system, with hydroxyl radicals (•OH) and singlet oxygen (1O 2) also contributing to BPAF degradation. Based on the Density Functional Theory (DFT) and intermediates analysis, two degradation pathways of BPAF were proposed, including hydroxylation and β-scission reactions. This work reveals the underlying mechanism of PMS activation under the coupling of heat with the CoFe 2 O 4 @BC system and presents a potential method for contaminants decomposition. [ABSTRACT FROM AUTHOR]

Designing efficient catalyst for peroxymonosulfate (PMS) activation is beneficial for eliminating the adverse effects of sulfamethoxazole (SMX) on human health. A novel boron (B) and nitrogen (N) co-doped sludge biochar (BNSBC) was synthesized by one-pot hydrothermal activation, and its remarkable PMS activation performance facilitated the rapid elimination of SMX from water. The degradation rate of SMX by BNSBC/PMS system could reach 92.1% within 60 min ([SMX] 0 = 10 mg/L, [BNSBC] 0 = 0.4 g/L, [PMS] 0 = 1 mM). B and N exhibited the synergistic enhancement effects on the physico-chemical characteristics of SBC, and abundant pores, defects, C O, -O-B-O-, graphitic-N and pyridinic N were confirmed as the main active sites of BNSBC for PMS activation. Characterization, quenching, electron paramagnetic resonance (EPR) and electrochemical tests proved that non-radicals of surface-bound, 1O 2 and electron transfer were the main contributors to SMX degradation. The high anti-interference of BNSBC/PMS system to pH range, co-existing inorganic anions and organic matter guaranteed its outstanding purification performance for SMX in diverse environmental waters. Four potential degradation pathways of SMX in BNSBC/PMS system were proposed by its intermediates identification and density functional theory (DFT) calculation, and pathway Ⅳ was the main one. The toxicity levels of its intermediates were lower than that of SMX regardless of chronic and acute toxicity. Also, BNSBC/PMS system exhibited the board-spectrum removal performance for other typical antibiotics (e.g., sulfadiazine (SDZ), sulfamethoxypyridazine (SMP), ciprofloxacin (CIP), tetracycline (TC)). BNSBC/PMS has great application potential for eliminating diverse antibiotics in actual wastewater due to its high tolerance to complex environmental conditions and outstanding detoxification ability, also it offers a harmless disposal approach for sludge. [Display omitted] [ABSTRACT FROM AUTHOR]

• The degradation efficiencies of TCH by NZVI@MOF-545/PDS is 94.1% in 15 min. • The TCH degradation conditions are optimized by the RSM model. • The dominant reactive species toward TCH degradation is 1O 2 , SO 4 -•, HO•, and O 2 -•. • The TCH degradation mechanisms can be identified as three pathways. • The NZVI@MOF-545/PDS system can significantly reduce the toxicity of TCH. Four different porphyrinic zirconium-based metal–organic frameworks (Zr-MOFs) were comparatively studied to activate peroxydisulfate (PDS) for tetracycline hydrochloride (TCH) degradation. Results indicated NZVI@MOF-545 was the optimal catalyst and the NZVI@MOF-545/PDS system exhibited a high TCH (initial concentration of 100 mg L-1) removal efficiency of 95.9 %. The catalytic reaction conditions of NZVI@MOF-545/PDS were optimized using response surface methodology (RSM) and results showed that the TCH (initial concentration of 800 mg L-1) degradation rate of 90.34 ± 0.66 % was obtained under optimal conditions of 1.03 g L-1 PDS, 0.84 g L-1 NZVI@MOF-545 with the initial pH of 9.80, temperature of 45 °C, and rotation speed of 265 rpm. The high degradation rate was attributed to the reactive species generated by the carbon-containing functional groups and metal sites of NZVI@MOF-545, and the relative contribution was 1O 2 > SO 4 -•>HO•>O 2 –•. Moreover, the LC-MS results suggested that TCH could be degraded into 15 intermediates through three potential degradation pathways. Toxicity evaluation demonstrated an alleviation in median lethal concentration at 96 h (LC 50 -96 h), low bioaccumulation, significant reductions in developmental toxicity and mutagenicity for most intermediates. In brief, NZVI@MOF-545 possessed remarkable catalytic ability and acceptable reusability to active PDS for TCH degradation, and the toxicity of TCH could be significantly reduced after the degradation. [ABSTRACT FROM AUTHOR]

• Oxygen vacancy tailored N@TiO 2-x nanoassembly is prepared from 1D-2D protonated titanate. • N@TiO 2-x with porous structure increases the adsorption and activation sites of CIP molecules. • N@TiO 2-x enhances the light absorption and facilitates photogenerated electrons-holes separation. • N@TiO 2-x -350 ℃ showing the highest CIP photodegradation is unveiled. Oxygen vacancy (Vo) enriched 1D-2D N@TiO 2-x nanoassembly is fabricated from amine-modified protonated titanate template, and the calcination temperature tailoring assists the oxygen vacancy regulation. In particular, the band gap (E g) in N@TiO 2-x gradually increase while both of the N-dopant and V O concentration reduce with increasing of calcination temperature. The as-prepared three N-TiO 2-x samples have porous structures, comparable surface wettability, and interface charge transfer capability, affecting photocatalytic degradation of ciprofloxacin (CIP) antibiotic. Among them, the N@TiO 2-x -350 ℃ displays the highest efficiency for photocatalytic ciprofloxacin (CIP) antibiotic remediation. This is due to the formation of a large number of oxygen vacancy, which facilitates the adsorption of CIP as well as the separation and migration of photoinduced electron-hole pairs. In this regard, the predominant ·O 2 − active specie is produced more and used effectively, allowing a synergistic interaction in CIP photodegradation. The possible degradation path of CIP is also studied and the acute toxicity changes in the degradation process are predicted, which confirms pollution-free degradation of CIP molecules upon the N@TiO 2-x nanoassembly. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, two metal compounds were combined and successfully prepared a Z-type BiOCl/NiAl-LDH(B/NL) heterojunction for the degradation of various antibiotics in industrial wastewater under visible light. The optical properties and photocatalytic activity of B/NL can be adjusted by varying the amount of NiAl-LDH. In the simulated degradation of tetracycline (TC) under visible light, B/NL-11 showed the best photodegradation efficiency, with a degradation rate of 92.57 % within 100 min. By using catalytic materials to degrade industrial wastewater, the degradation rate of tetracycline antibiotics (tetracycline, oxytetracycline) is more than 70 %, and the degradation rate of quinolone antibiotics (ciprofloxacin, norfloxacin) is more than 50 %. Mineralization process of the B/NL-11 system to degrade antibiotics in industrial wastewater was evaluated by 3D EMMS technology, and the degradation pathways were analyzed by LC-MS. The toxicity of the intermediate products produced is much lower than that of the pollutants themselves, and there is no secondary pollution. The degradation activity of BiOCl/NiAl-LDH is due to the construction of heterojunction adds many active sites, and the formed band structure promotes the efficient separation and transfer of photogenerated electron-holes. The free radical trapping experiment proved that h+, ∙O 2 −, ∙OH was the main active substance in the degradation process, and finally proposed the Z-type heterojunction mechanism. [Display omitted] • First synthesis of Z-type heterojunction BiOCl/NiAl-LDH. • BiOCl/NiAl-LDH can efficiently degrade various antibiotics in industrial wastewater. • The photocatalytic mechanism has been demonstrated through free radical capture experiment and ESR. • The degradation pathway of antibiotic has been analysed. • The toxicity of intermediate products during the degradation process is relatively weak. [ABSTRACT FROM AUTHOR]

[Display omitted] • The defect level of graphite felt was improved by CeO 2. • Cu 2 PO 4 exhibited better catalytic performance than Cu x O. • P-doped Cu 2 PO 4 /EGF electrodes efficiently removed SMX over a pH range of 5.6–11. • Phosphorus doping promoted the production of O 2 –. Non-metallic atom doping is a good strategy to promote the cathode performance in the electro-Fenton process. Therefore, a mixed-valence copper (I and II) phosphate (Cu 2 PO 4) catalyst on P-doped etched graphite felt (EGF), with a strip-groove rough surface, was prepared in this study. The P-doped Cu 2 PO 4 /EGF electrode completely removed sulfamethoxazole (SMX) from contaminated water within 90 min over a wide pH range of 5.6–9 and removed 99.6% of SMX at pH 11. Quenching experiments showed that the main reactive oxygen species (ROS) was O 2 –. According to density functional theory calculations, the adsorption reaction energy (E P = −2.149) of P atoms doped on the EGF surface was lower than that of pyrrolic nitrogen atoms (E N = −0.434), indicating that they were more conducive to oxygen adsorption. Finally, we investigated the mechanism of P-doped Cu 2 PO 4 /EGF adsorption and the catalytic production of O 2 – from O 2. Four main degradation pathways were identified based on the intermediates identified during degradation. Toxicity analysis of the intermediates showed that electro-Fenton degradation reduced the ecotoxicity of SMX. The enhanced electrocatalytic activity obtained by P doping of heterogeneous catalysts provides a new method for preparing efficient and stable composite electrodes for pollutant degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • CuFe 2 O 4 @β-CD composites were fabricated through the hydrothermal method and employed as a PMS activator. • Levofloxacin (LEV) degradation using CuFe 2 O 4 @β-CD/PMS reached 98.87 % in 24 min. • LEV abatement in the CuFe 2 O 4 @β-CD/PMS system was accomplished via radical and non-radical pathways. • The conversion of Fe3+/Fe2+ and Cu+/Cu2+ pairs produced the SO 4 •−, •OH, and 1O 2 liable for LEV degradation. • CuFe 2 O 4 @β-CD exhibited high stability, reusability, and low metal leaching after five consecutive cycles. In this study, a highly magnetic β-cyclodextrin-modified copper ferrite (CuFe 2 O 4 @β-CD) catalyst was developed utilizing a hydrothermal method, which was subsequently utilized to degrade Levofloxacin (LEV) antibiotic in aqueous solution via heterogeneous activation of peroxymonosulfate (PMS). The findings demonstrated that the 98.87 % degradation of LEV was achieved with CuFe 2 O 4 @β-CD/PMS, much higher than that of pure CuFe 2 O 4 /PMS (87.78 %) within a 24-minute time frame under optimal parameters ([CuFe 2 O 4 @β-CD] = 0.4 g/L, [PMS] = 0.4 mM, [LEV] = 25 mg/L, pH = 6), and CuFe 2 O 4 @β-CD/PMS was present. The rate constant of CuFe 2 O 4 @β-CD/PMS (0.1608 min−1) was much greater than that of the CuFe 2 O 4 /PMS system (0.0822 min−1). The increased availability of active sites for PMS activation may be credited to the larger surface area (189.42 m2/g) of the CuFe 2 O 4 @β-CD catalyst in comparison to the pristine CuFe 2 O 4 (87.76 m2/g), which facilitated the improved degradation of LEV. Additionally, the impact of various reaction parameters and intervening anions on the degradation of LEV was investigated. The emergence of free radicals (SO 4 •−, •OH, and 1O 2) was corroborated via electron paramagnetic resonance and scavenging experiments. On the basis of recognizing reaction intermediates, a hypothetical degradation mechanism for LEV was developed. PMS activation was caused by the transformation of Cu+/Cu2+ and Fe3+/Fe2+ pairs, which was accomplished via radical and non-radical pathways. Also, CuFe 2 O 4 @β-CD demonstrated exceptional stability and retained its catalytic activity after five concurrent cycles. In conclusion, the CuFe 2 O 4 @β-CD catalyst demonstrated encouraging potential in the context of purifying LEV-contaminated water. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is a typical endocrine disruptor, which can be used as an industrial raw material for the synthesis of polycarbonate and epoxy resins, etc. Recently, BPA has appeared on the list of priority new pollutants for control in various countries and regions. In this study, phenolic resin waste was utilized as a multi-carbon precursor for the electrocatalytic cathode and loaded with cobalt/nitrogen (Co/N) on its surface to form qualitative two-dimensional carbon nano-flakes (Co/NC). The onset potentials, half-wave potentials, and limiting current densities of the nitrogen-doped composite carbon material Co/NC in oxygen saturated 0.5 mol H 2 SO 4 were −0.08 V, −0.61 V, and −0.41 mA cm−2; and those of alkaline conditions were −0.65 V, −2.51 V, and −0.38 mA cm−2, and the corresponding indexes were improved compared with those of blank titanium electrodes, which indicated that the constructed nitrogen-doped composite carbon material Co/NC was superior in oxygen reduction ability. The catalysis by metallic cobalt as well as the N-hybridized active sites significantly improved the efficiency of electrocatalytic degradation of BPA. In the electro-Fenton system, the yield of hydrogen peroxide generated by cathodic reduction of oxygen was 4.012 mg L−1, which effectively promoted the activation of hydroxyl radicals. The removal rate of BPA was above 95% within 180 min. This work provides a new insight for the design and development of novel catalyst to degrade organic pollutants. [Display omitted] • Carbon materials prepared from phenolic resin waste as electrocatalytic cathodes. • Removal rate of BPA was above 95% within 180 min. • In situ activation of H 2 O 2 generated by cathodic reduction using Co. • Graphite-type nitrogen and pyridine-type nitrogen form catalytic sites. [ABSTRACT FROM AUTHOR]

Solution pH is one of the primary factors affecting the efficiency of water decontamination. Although the influence of pH on oxidants activation, catalyst activity, and reactive oxygen species have been widely explored, there is still a scarcity of systemic studies on the changes in the oxidation behavior of organic pollutants at different pH levels. Herein, we report the influence laws of pH on the forms, reactivities, active sites, degradation pathways, and products toxicities of organic pollutants. Changes in pH cause the protonation or deprotonation of organic pollutants and further affect their forms and chemistry (e.g., electrostatic force, hydrophobicity, and oxidation potential). The oxidation potential of organic pollutants follows the order: protonated form > pristine form > deprotonated form. Moreover, protonation or deprotonation can modify the active sites and degradation pathways of organic pollutants, wherein deprotonation renders them more susceptible to electrophilic attack, while protonation reduces their activity against electrophilic and nucleophilic attacks. Additionally, pH adjustments can modify the degradation pathway and the toxicity of transformation products. Overall, pH changes can affect the oxidation fate of organic pollutants by altering their structure, which distinguishes it from the effect of pH on oxidants or oxidant activation processes. [Display omitted] • Solution pH alters the oxidation behavior of organic pollutants. • Deprotonation augments the reactivity of organic pollutants while protonation diminishes it. • Protonation and deprotonation modify the active sites and degradation pathways. • The toxicity of the transformation products can be controlled by adjusting the solution pH [ABSTRACT FROM AUTHOR]

• rGO-supported bimetallic Pd/nZVI composites (Pd/nZVI/rGO) were prepared by liquid-phase reduction • Hybrid of rGO avoided aggregation of Pd/nZVI particles and retarded transformation of iron corrosion products • Pd/nZVI/rGO composites enhanced OTC removal contributed by adsorption, Fenton reactions, and reduction • pH notably affected the contribution of adsorption, Fenton-like reactions, and reduction to OTC removal In this study, the reduced graphene oxide-supported bimetallic palladium-zero-valent-iron (Pd/nZVI/rGO) composites were synthesized using a facile one-step liquid-phase reduction method. Physicochemical and textural properties as well as chemical composition of the as-prepared composites were firstly characterized. Transmission electron microscopy (TEM) and X-ray diffractometry (XRD) analysis revealed that the presence of rGO sheets prevented the aggregation of Pd/nZVI nanoparticles and retarded the transformation of iron corrosion products from magnetite/maghemite to lepidocrocite, inducing such nanoparticles to be dispersed more homogeneously. In addition, the loading of Pd/nZVI nanoparticles could avoid the stacking of rGO sheets effectively. The synthesized Pd/nZVI/rGO composites were then used to remove antibiotic oxytetracycline (OTC) from aqueous solutions. It was found that the introduction of an optimal amount of rGO into Pd/nZVI nanoparticles enhanced significantly OTC removal. In particular, the presence of 5 wt.% of rGO in Pd/nZVI/rGO composite (dose, 0.1 g/L) exhibited the highest OTC removal of 96.5% (initially, 100 mg/L) after 60-min reaction at pH 5.0 and 25°C. The removal of OTC by Pd/nZVI/rGO composite was contributed by adsorption process, Fenton-like reactions, and reduction reactions. The Pd/nZVI/rGO composites exhibited better reusability than pristine nZVI particles. The pathways of OTC degradation over Pd/nZVI/rGO nanocomposite were also proposed. The reduced graphene oxide-supported bimetallic palladium-zero-valent-iron nanocomposites (Pd/nZVI/rGO) were synthesized using a facile one-step liquid-phase reduction method. The presence of rGO sheets with a large surface area prevented the aggregation of Pd/nZVI nanoparticles and retarded the transformation of iron corrosion products, inducing such nanoparticles to be dispersed more homogeneously. In addition, the loading of Pd/nZVI nanoparticles can avoid the stacking of rGO sheets effectively. The removal of OTC by Pd/nZVI/rGO composite was contributed by adsorption process, Fenton-like reactions, and reduction reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

In this research, Ni/Co/Fe 2D nanosheets-crosslinked frameworks (Ni-Co LDHs, Ni-Fe LDHs, Co-Fe LDHs) were synthetized to achieve a better performance on phenacetin (PNT) degradation in catalytic ozonation. The mechanism of enhanced degradation efficiency and mineralization in catalytic ozonation system were explored with the help of different kinds of catalysts characterization, including X-ray diffraction, Fourier transform infrared, Brunauer-Emmett-Teller, scanning electron microscopy, and energy-dispersive X-ray. The results showed that Ni-Co LDHs@ Al2O3 catalyst could not only greatly enhance the degradation of PNT, but also have better stability and reusability by ozonation. The COD removal with Ni-Co LDHs@Al2O3 catalyst could reach 65.3%, while 63.8% with Ni-Co layered double hydroxides (LDHs) catalyst, 61.8% with Fe-Co LDHs catalyst, 55.5% with Ni-Fe LDHs catalyst and only 48% with ozonation alone after 120 min. In addition, based on the intermediates detected by gas chromatography-mass spectrometry, a possible degradation pathway of PNT was proposed. [ABSTRACT FROM AUTHOR]

• Bimetallic Pt/nZVI nanocomposite was synthesized by a one-pot liquid-phase reduction method. • The formation of flake-like iron shells in the nanocomposites enhanced the adsorption for OTC. • Adsorption (major), Fenton oxidation, and reduction contributed the OTC removal by Pt/nZVI. • Intermediates showed that Pt metal created H atoms for enhanced OTC degradation by Pt/nZVI. The bimetallic platinum-nanoscale zero-valent iron (Pt/nZVI) composites were synthesized by a liquid-phase reduction method. The as-prepared nanomaterials were first characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area analysis, and zeta potential measurements. Results revealed that the introduction of Pt into bimetallic particles strongly affected their morphologies, which caused the improvement in the adsorption ability for organics. With 0.5 wt.% of Pt in Pt/nZVI composite (denoted as Pt0.5/nZVI), it exhibited the highest removal of antibiotic oxytetracycline (OTC). Nearly 100% of OTC (initially, 100 mg/L) was removed only after 20-min treatment under an optimal pH of 5.0 and a dose of 0.5 g/L. This study also confirmed that the removal of OTC by Pt/nZVI composite was contributed by adsorption (major), Fenton reactions, and reduction, although the fractional contribution changed during the reaction process. The intermediates formed during OTC degradation by nZVI and Pt/nZVI composite were finally detected and compared by UPLC®-QTof/MS analysis, which confirmed that the presence of Pt metal in bimetallic Pt/nZVI composites generated extra reactive hydrogen atoms for enhanced degradation of OTC. [ABSTRACT FROM AUTHOR]

Photocatalytic technology having the advantages of low-cost, environmental friendliness, is important in removing organic pollutants. To enhance the catalytic efficacy of well-established TiO 2 photocatalyst, TiO 2 -conjugated/coordination polymer heterojunction photocatalysts have been rapidly developed in the area of environmental remediation. However, a comprehensive summary and description of these advancements are lacking. To fill this gap, the research progress of TiO 2 -conjugated/coordination polymer heterojunction photocatalysts for organic pollutants degradation is reviewed. Firstly, classifications, working principles, and photodegradation pathways of TiO 2 -based heterostructures are introduced. Subsequently, the synthesis strategies, photocatalytic performance, and mechanisms of TiO 2 -conjugated/coordination polymer photocatalysts are comprehensively summarized. The effects of operational parameters on photodegradation are discussed. Lastly, promising prospects of TiO 2 -based heterojunction photocatalysts systems and urgent issues to be solved are foreseen. It is hoped that this review sets the trajectory for providing references in preparation and catalytic capacities of TiO 2 -based heterojunction photocatalysts, providing new ideas for resourceful wastewater remediation. [Display omitted] • First review of photodegradation pollutants by TiO 2 -conjugated/coordination polymer. • The detailed degradation pathways of common organic pollutants are discussed. • Properties and mechanisms of TiO 2 -conjugated/coordination polymer are elaborated. • The influence of operating parameters on photodegradation efficiency is recalled. • Challenges and prospects of TiO 2 -conjugated/coordination polymer are presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 3 S 4 was synthesized and used for the enhancement of advanced oxidation systems. • The enhanced mechanisms on the surface of Fe 3 S 4 were elucidated. • The existing reactive species and their contributions were evaluated. • The degradation pathways and the toxicities of intermediates were investigated. In this research, greigite (Fe 3 S 4) was innovatively applied for the enhancement of PDS/Fe(II) system. From XRD and SEM analyses, Fe 3 S 4 was successfully synthesized and appeared uniform sphere-like particles with a petal-like structure. Trichloroethylene (TCE), as the target, was significantly degraded from 28.5 % to 92.8 % in PDS/Fe(II)/Fe 3 S 4 system. The enhanced mechanisms, differences, and superiority of Fe 3 S 4 against the other three iron sulfides were elucidated as follows: (1) on account of the abundant reduction sites on its surface, Fe 3 S 4 could not only directly release Fe(II) and accelerate Fe(II) regeneration by sulfur substances, but also participate in the process of O 2 −• generation, and (2) the reaction mainly took place on Fe 3 S 4 surface, in which the surface-bound reactive species (RSs) were of great importance for TCE degradation. Through EPR, quantification, and scavenging tests of RSs, HO•, SO 4 −•, and O 2 −• were all the dominant RSs responsible for TCE removal. Besides, these enhanced systems had high tolerance on complex water conditions and could remediate various contaminants in actual groundwater. Three TCE degradation pathways were deduced in four iron sulfide-enhanced systems and the toxicities of intermediates were evaluated, recommending that Fe 3 S 4 -enhanced system was of the least toxicity and most favorable for application in practice. [ABSTRACT FROM AUTHOR]

[Display omitted] • A C 3 N 4 modified Ti3+ self-doping TiO 2 -NTAs material was innovatively fabricated. • PAO process demonstrated high removal efficiency of SDZ using C 3 N 4 -Ti3+/TiO 2 -NTA. • Hydroxyl radical and superoxide radical are predominant reactive species. • The possible degradation pathways and biosafety of SDZ were explored. In this study, a C 3 N 4 modified Ti3+ self-doping TiO 2 nanotube arrays (C 3 N 4 -Ti3+/TiO 2 -NTA) material was innovatively fabricated using a three-step procedure consisting of anodization, chemical vapor deposition, and in-situ cathodic polarization. Simultaneously introducing C 3 N 4 and Ti3+ significantly enhanced the light absorption property and charge separation efficiency of TiO 2 -NTA, while also increasing the oxygen evolution overpotential to 2.61 V vs the silver/silver chloride electrode. C 3 N 4 -Ti3+/TiO 2 -NTA with excellent optoelectronic properties was first applied as an anode in the simulated solar-driven photo-assisted anodic oxidation (PAO) system. It was found that the PAO system for the degradation of sulfadiazine (SDZ) exhibited 12.1-fold and 1.9-fold higher activity compared to the photocatalytic system and the anodic oxidation system alone, respectively, indicating the optoelectronic synergistic interactions over C 3 N 4 -Ti3+/TiO 2 -NTA. Quenching experiments and electron spin resonance results suggested that main reactive species during the degradation of SDZ by the PAO system were hydroxyl radical and superoxide radical. Additionally, three possible degradation pathways of SDZ by the PAO were proposed based on the identification of intermediate byproducts and theoretical calculation. Furthermore, the biosafety evaluation revealed a significant reduction in the biological toxicity of intermediate byproducts of SDZ. These findings provide new insights into the design and manufacturing of novel anode material for efficient degradation of recalcitrant pollutants in practical applications under solar irradiation. [ABSTRACT FROM AUTHOR]

Furosemide (FRSM) is a cardiovascular drug with high concentration (up to μg L−1) in the surface water environment, which are not properly removed by traditional wastewater treatment plants, resulting in negative impact on organisms. In this study, the use of characteristic electron beam (EB) irradiation degraded FRSM with high efficiency. The degradation process precisely conformed to the pseudo first-order kinetic model (R2 > 0.99). The radical scavenger experiments indicated that •OH was the main free radical for the degradation of FRSM. Adding oxidants such as H 2 O 2 (1 mM) had a positive effect on the degradation of 150 mg L−1 FRSM, while adding more than 10 mM H 2 O 2 resulted in the negative effect. The addition of K 2 S 2 O 8 enhanced the degradation and mineralization of FRSM, with a mineralization rate of 57.1% under 1.5 kGy, which was 2.14 times that of the control group. The degradation of FRSM by EB irradiation in actual water was studied, and the results showed that the presence of N O 3 − and C O 3 2 − (10 mM) inhibited the degradation of FRSM, while the presence of S O 3 2 − , S O 4 2 − and Cl − slightly accelerated the degradation. The degradation effect of adding tap water and river water was similar to that of the control group. Moreover, transformation products (TPs) were identified (11 types) and FRSM was mainly oxidized and ultimately converted into small molecule acids, inorganic ions and CO 2. Based on toxicity assessment, most TPs have much lower acute and chronic toxicity than maternal FRSM, suggesting EB irradiation is an alternative advanced treatment process to degrade FRSM in wastewater. • Electron beam irradiation was efficient to degrade furosemide. • •OH played a major role during the degradation. • Four possible degradation pathways by electron beam were proposed. • The acute and chronic toxicity of furosemide and transformation products were evaluated. [ABSTRACT FROM AUTHOR]

CuO is currently used as an effective activator for peroxymonosulfate (PMS), which exhibits complex radical, nonradical, or both activation pathways. However, there exists a knowledge gap concerning the relationship between CuO exposed facets and the PMS activation pathway, which should require further investigation. This study employed a simple and facile hydrothermal method to controllably prepare CuO samples with exposed {010} and {001} facets (referred to as CuO-010 and CuO-001, respectively). The main aim was to further study the facet-dependent PMS activation mechanism. The experimental results showed that the CuO-001 exhibited significantly higher activation efficiency than the CuO-010 due to the different surface atomic arrangement. Furthermore, scavenging experiments and EPR analyses revealed that CuO-010 exhibited both radical (SO 4 • − and •OH) and non-radical (1O 2) pathways, synergistically degraded tetracycline (TC) and 4-nitrophenol (4-NP). Conversely, the CuO-001 displayed non-radical (1O 2) and Cu(Ⅲ) intermediates, collaborating to oxidize the degradation of TC and 4-NP. More importantly, the generated 1O 2 species and Cu(Ⅲ) intermediates exhibited a preference for reacting with amino or phenolic compounds containing electron-rich functional groups. Moreover, the CuO-001 also showed excellent resistance to anion interference, stability, and compatibility of a wide pH range. The outcomes of this study provide new insights into the comprehensiveness facet-dependent activation of PMS and the design of efficient metal oxide catalysts using the facet strategy for effective degradation of amino/phenolic pollutants in wastewater. [Display omitted] • CuO with controllably exposed facets was successfully prepared. • CuO with {001} and {010} facets exhibit different activity PMS pathways. • CuO with {001} facets exhibited better catalytic activity than that of {010} facets. • Cu(Ⅲ) intermediates and 1O 2 generated by CuO-001 preferentially degrade electron-rich compounds. [ABSTRACT FROM AUTHOR]