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Light yellow, air‐sensitive single‐crystals of the rhodium(III) orthoperiodato K8[Rh(IO6)2]OH ⋅ 3H2O were synthesized starting from Rh2O3 and KIO4. The reaction was carried out in a potassium hydroxide hydroflux with a molar water‐base ratio of 1.8 at 200 °C. Single‐crystal X‐ray diffraction revealed a triclinic crystal structure (space group P1‾). The most striking feature of the structure is the [Rh(IO6)2]7− anion, a linear sequence of three face‐sharing octahedra. It can be interpreted as a rhodium(III) cation coordinated by two orthoperiodato groups. A water molecule and a hydroxide ion form an associate (H3O2)−. Together with other water molecules, they connect the [Rh(IO6)2]7− anions via hydrogen bridges to form layers. Upon heating, the compound first loses its crystal water, then the iodine is gradually reduced before evaporating during the final decomposition step, which results in K0.63RhO2. In K8[Rh(IO6)2]OH ⋅ 3H2O, the unusually short RhIII−IVII distance of only 276.38(1) pm should allow direct charge transfer in the [Rh(IO6)2]7− anion. An electron‐poor rhodium cation, accessible from the side, could be the active center in the rhodium‐catalyzed oxidation of unsaturated organic molecules by periodate. [ABSTRACT FROM AUTHOR]

Pollutant degradation via periodate ( IO 4 - ) and transitional metal oxides provides an economical, energy-efficient way for chemical oxidation process in environmental remediation. However, catalytic activation of periodate by manganese dioxide and the associated mechanism were barely investigated. In this study, four MnO2 polymorphs (α-, β-, γ- and δ-MnO2) were synthesized and tested to activate IO 4 - for the degradation of sulfamethoxazole (SMX). The reactivity of different MnO2 structures followed the order of α-MnO2 > β-MnO2 > γ-MnO2 > δ-MnO2, suggesting that the particular crystalline structure in α-MnO2 would exhibit higher activities via IO 4 - activation. Herein, in α-MnO2/ IO 4 - system, 91.1% of SMX was eliminated within 30 min with degradation rate constant of 0.0649 min−1, and the neutral pH exhibited higher efficiency in SMX degradation compared with acidic and alkaline conditions. Singlet oxygen (1O2) was unveiled to be the dominant ROS according to the results of electron paramagnetic resonance, chemical probes and radical quenching experiments, whereas O 2 ∙ - and •OH were mainly acted as a free-radical precursor. Six oxidation products were identified by LC–MS, and the elimination of sulfonamide bond, hydroxylation and direct oxidation were found to be the important oxidation pathways. The study dedicates to the mechanistic study into periodate activation over alpha-MnO2 and provides a novel catalytic activation for selective removal in aqueous contaminants. [ABSTRACT FROM AUTHOR]

[Display omitted] • There are four active species including OH, 1O 2 , O 2 − and IO 3 in GF-PI system. • H 2 O 2 was the source of 1O 2 and O 2 − in electro-activation PI system. • The pollutants removal did not depend on H 2 O 2 in GF-PI system. • GF-PI electro-activation system demonstrated excellent resistance performance in water treatment processes. The existence of hydrogen peroxide (H 2 O 2) within the electro-activation of periodate (PI) system is conventionally considered as conducive to the removal of pollutants. However, this study discovered an unusual phenomenon: the contaminants removal efficiency and the yield of strong oxidizing species such as hydroxyl radical (OH) and iodate radical (IO 3 ) were improved when H 2 O 2 in the solution was quenched. The study deeply explored the role of H 2 O 2 in graphite felt-based electro-activated PI system (GF-PI), particularly in the mechanism of active species generation and contaminants removal. Bisphenol A (BPA), as the model contaminant, achieves a degradation efficiency of 82.1% and 83.9% within 40 min in w/wo H 2 O 2 system, respectively. Meanwhile, multiple probing techniques clearly identify the variety of active species and generation pathway such as Electron paramagnetic resonance (EPR), LC-QTOF-MS, and quenching experiment. There exist two distinct pathways for PI activation, including direct cathodic electroreduction and indirect in-situ generated H 2 O 2 catalysis. The GF-PI system incorporated both of two pathways, while the GF-PI-catalase system only had the direct activation pathway. Electrogenerated H 2 O 2 serves as a precursor for the generation of superoxide radical anions (O 2 −) and singlet oxygen (1O 2), yet it diminishes the efficiency of direct cathode activation due to the consumption of PI. Furthermore, the system demonstrated excellent stability, applicability, and cleanliness, effectively removing contaminations without the accumulation of iodine byproducts. The degradation intermediates products of BPA are monitored and the toxicities are evaluated. The study provides novel insights into the regulation of active species for contaminant elimination, holding significant implications for specialized sewage treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • AO7 removal was markedly enhanced by Cl− in the FeBC/PI system. • •OH, 1O 2 , O 2 •−, HClO, and Fe(IV) species are responsible for AO7 degradation. • Cl− can promote electron transfer and the formation of reactive species. • Main pathways for the generation of reactive species are proposed. • AO7 removal pathways were proposed using DFT calculations and intermediate products. Ubiquitous in water environments, the chloride ion (Cl−) can impact the decontamination capacity of an oxidation system. However, minimal studies are available on its effects in periodate (PI)-based advanced oxidation processes. In this study, a novel biochar-based iron-carbon (FeBC) granule was synthesized to activate PI and remove organic pollutants from water containing Cl−. The FeBC/PI/Cl− system (FeBC: 0.5 g/L; PI: 0.5 mM; AO7: 20 mg/L; NaCl: 50 mM) exhibited excellent performance on various organic pollutants, with ＞ 85 % of Acid Orange (AO7) removal over a pH range of 3–10. Within 20 min after the tenth run, approximately 80 % of AO7 was removed. Inorganic ions and natural organic matter had a negligible effect on AO7 removal. Characterization results confirmed that the presence of Cl− enhanced Fe corrosion, thereby improving PI activation efficiency for removing AO7. Electron paramagnetic resonance spectroscopy and active species trapping experiments verified that radicals (•OH and O 2 •−) and nonradical (1O 2 , Fe(IV), and electron transfer) oxidation processes participated in the FeBC/PI system. Moreover, the presence of Cl− accelerated •OH, O 2 •−, 1O 2 , and Fe(IV) formation and generated active chlorine, such as HOCl. The main pathways involved in the generation of multiple reactive species were evaluated. AO7 degradation pathways were proposed, and numerous intermediates exhibited decreased toxicity. These findings provide new insights for the decontamination of organic contaminants in water containing Cl−. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mn(II) can activate PI to efficiently degrade sulfadiazine in water. • The Mn(II)/PI system is a non-radical process dominated by electron transfer. • The generated MnO 2 -PI complex plays an important role in SDZ degradation. • Stable iodates are the main iodine species in the Mn (II)/PI system. The present study investigated the mechanism of manganese ion (Mn(II))-activated periodate (PI) for rapid removal of sulfadiazine (SDZ). The Mn(II)/PI system showed excellent SDZ degradation results with 99.8 % degradation efficiency within 2 min at pH = 5.5. Mechanism study reveals that the degradation of SDZ in the Mn(II)/PI system takes place mainly through an electron transfer process. Mn(II) can be oxidized by PI to formed the in-situ MnO 2 , followed by the generation of MnO 2 -PI complex. Electrochemical methods have confirmed that the generated MnO 2 -PI complex significantly contributes to the degradation of pollutants. MnO 2 -PI mediates the transfer of electrons from SDZ to PI surface through surface vacancies, thereby achieving efficient degradation of pollutants. p -methoxyphenyl sulfone (PMSO) is used as a probe compound, and almost 90 % of PMSO is converted into PMSO 2 in the Mn(II)/PI/SDZ system, manifesting that excessive PI may oxidize active Mn(IV) to Mn(V). And the generated Mn(V) also contributes to the SDZ degradation. The SDZ degradation pathway is proposed and the transformation of iodine species is detected. The final iodine species in the system are iodate. The chloride culture experiment has confirmed that the production of organic iodine is very low, indicating no significant health risks. This study reveals mechanism of periodate-based process, providing theoretical and technical implementation guidelines of periodate in water treatment. [ABSTRACT FROM AUTHOR]

• Microcystis aeruginosa could be inactivated by periodate activation with sunlight. • ·OH, IO 3 ·, and IO 4 · radicals contributed to algae inactivation in PI-SSL system. • The released microcystin-LR could be synchronously degraded in PI-SSL system. • PI-SSL system could inactivate algae in real waters and a continuous-flow reactor. • Natural sunlight could activate PI to achieve efficient algae inactivation. Harmful algal blooms pose tremendous threats to ecological safety and human health. In this study, simulated solar light (SSL) irradiation was used to activate periodate (PI) for the inactivation of Microcystis aeruginosa and degradation of microcystin-LR (MC-LR). We found that PI-SSL system could effectively inactivate 5 × 106 cells·mL−1 algal cells below the limit of detection within 180 min. ·OH and iodine (IO 3 · and IO 4 ·) radicals generated in PI-SSL system could rupture cell membranes, releasing intracellular substances including MC-LR into the reaction system. However, the released MC-LR could be degraded into non-toxic small molecules via hydroxylation and ring cleavage processes in PI-SSL system, reducing their environmental risks. High algae inactivation performance of PI-SSL system in solution with a wide pH range (3–9), with the coexisting anions (Cl−, NO 3 − and SO 4 2−) and the copresence of natural organic matters (humic acid and fulvic acid), real water (lake water and river water), as well as in continuous-flow reactor (14 h) were also achieved. In addition, under natural sunlight irradiation, effective algae inactivation could also be achieved in an enlarged reactor (1 L). Overall, our study showed that PI-SSL system could avoid the inference by the background substances and could be employed as a feasible technique to treat algal bloom water. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • 96% TC degradation was achieved within 16 min in the UCN/PI/Vis system. • The UCN/PI/Vis system could withstand a wide range of pH changes, and the impact of multiple co-existing substances and natural water bodies. • IO 3 • was the major pathway for TC degradation, followed by O 2 •−, h+, •OH, and 1O 2. • UCN/PI/Vis system exhibited a much higher degradation rate than PCN/PI/Vis system. • PI as an electron acceptor promoted efficient electron utilization in the UCN/PI/Vis system. This study developed a novel activated periodate (PI, IO 4 −) system mediated by ultra-thin carbon nitride (UCN) and visible light (Vis), and investigated its efficiency and kinetics of tetracycline hydrochloride (TC) degradation in water. UCN/PI/Vis system could remove 96% TC within 16 min through the mixed radical/non-radical pathway dominated by IO 3 •, 2.3 times higher than that of polymerized carbon nitride (PCN)/PI/Vis system. This gap was attributed to UCN having a greater specific surface area, more active sites, and a shorter charge transfer path. The UCN/PI/Vis system has outstanding recyclability, attractive pH adaptability, and remarkable tolerance to co-existing substances and natural water bodies. The fascinating degradation efficiency was ascribed to the synergistic effect among UCN that produced photoelectrons, TC as an electron donor, and PI as an electron acceptor. The quantum confinement effect of the ultra-thin structure improved the band gap and enhanced the redox capacity of photogenerated carriers, which greatly improved the photocatalytic activation of PI by UCN. [ABSTRACT FROM AUTHOR]

• Colloidal Mn(IV) coupled with periodate could induce the polymerization of phenolics in water. • The oxidative polymerization mechanism can be generalized to various substituted phenolics. • The catenulate oligomerized products could participate in the post-coagulation process. • The post-coagulation could efficiently remove the oligomerized products and residual oxidants. Natural manganese oxides could induce the intermolecular coupling reactions among small-molecule organics in aqueous environments, which is one of the fundamental processes contributing to natural humification. These processes could be simulated to design novel advanced oxidation technology for water purification. In this study, periodate (PI) was selected as the supplementary electron-acceptor for colloidal manganese oxides (Mn(IV) aq) to remove phenolic contaminants from water. By introducing polyferric sulfate (PFS) into the Mn(IV) aq /PI system and exploiting the flocculation potential of Mn(IV) aq , a post-coagulation process was triggered to eliminate soluble manganese after oxidation. Under acidic conditions, periodate exists in the H 4 IO 6 − form as an octahedral oxyacid capable of coordinating with Mn(IV) aq to form bidentate complexes or oligomers (Mn(IV)-PI*) as reactive oxidants. The Mn(IV)-PI* complex could induce cross-coupling process between phenolic contaminants, resulting in the formation of oligomerized products ranging from dimers to hexamers. These oligomerized products participate in the coagulation process and become stored within the nascent floc due to their catenulate nature and strong hydrophobicity. Through coordination between Mn(IV) aq and H 4 IO 6 −, residual periodate is firmly connected with manganese oxides in the floc after coagulation and could be simultaneously separated from the aqueous phase. This study achieves oxidizing oligomerization through a homogeneous process under mild conditions without additional energy input or heterogeneous catalyst preparation. Compared to traditional mineralization-driven oxidation techniques, the proposed novel cascade processes realize transformation, convergence, and separation of phenolic contaminants with high oxidant utilization efficiency for low-carbon purification. [Display omitted] [ABSTRACT FROM AUTHOR]

Currently, there are well-operated iron removal water plants in the northeast region of China. Among them, the backwash process produces a large amount of iron-containing sludge (IS) year by year, which can cause some harm to the environment if not treated. The main form of existence for IS is amorphous γ-FeOOH, and this work demonstrates that IS is a natural and highly active catalyst for periodate(PI). Moreover, IS showed strong stability in environmental factor effects and reproducibility experiments. EPR with quenching experiments proved that IS could activate PI to produce •OH, O 2 •−, 1O 2 , and IO 3 •. In the degradation experiments where methylene blue was chosen as the model pollutant, IO 3 •, and 1O 2 were the substances that served the prominent role in degradation. This work provides an inexpensive and feasible way to dispose of waste iron-containing sludge from water plants and provides fundamental insights into the degradation mechanism of organic pollutants through the activation of PI by IS. [Display omitted] • The IS from groundwater treatment plant is a natural, cheap, and accessible catalyst for PI activation. • IO 3 • and 1O 2 are found to play a vital role in IS/PI system. • IS is a promising catalyst with excellent catalytic performance, stability, and reusability. [ABSTRACT FROM AUTHOR]

This work represents a new method that uses electrochemically generated periodate to oxidize side‐stream lignins. Using periodate, a lignin‐derived product other than vanillin becomes accessible. The development of an eco‐friendly method for generating 5‐iodovanillin from lignin is reported and is of significant interest for the wood‐based industry. Wider utilization of lignin can substitute fossil‐based chemicals and fuels, reduce the emission of greenhouse gases, and facilitate the dependence on fossil energy. The reaction conditions are easy to conduct, the lignin is modified, and no specific setup is required. This one‐pot cost‐efficient method does not use toxic or harmful metals and yields more than 15 wt% 5‐iodovanillin. 5‐Iodovanillin represents an advanced building block for the synthesis of complex molecules, such as active pharmaceutical ingredients. [ABSTRACT FROM AUTHOR]

Incorporating catechols into polymers can provide strong adhesion even in moist environments, and these polymers show promise for use in several biomedical applications. Surgical adhesives must have strong bonds, be biocompatible, and function in a moist environment. Poly(lactic acid) (PLA) has a long history as a biocompatible material for hard tissue device fixation. By combining these concepts, catechol‐containing poly(lactic acid) (cPLA) polymers are created that are strongly adhesive and degrade in physiological environments. Here, we evaluated the cytocompatibility of cPLA with iron(III) or periodate (IO4−) cross‐linkers. Fibroblasts cultured in cPLA leachate or on cPLA films generally had slower growth and lower metabolism compared with PLA controls but no differences in viability. These results demonstrated that cPLA was not cytotoxic but that including catechols reduced cell health. When cPLA was cross‐linked with periodate, cells generally had reduced metabolism, slower cell growth, and poor actin fiber formation compared with PLA. These results are attributed to the cytotoxicity of periodate since cells cultured with periodate leachate had extremely low viability. Cells grown on the films of iron‐cross‐linked cPLA generally had high viability and metabolism but slower proliferation than PLA controls. These results indicate that the cPLA and iron‐cross‐linked cPLA systems are promising materials for biomedical adhesive applications. [ABSTRACT FROM AUTHOR]

The photoactivated periodate (UV/IO4−) process is used to investigate the degradation of acid orange 10 (AO10) dye. The photodecomposition of periodate ions produces highly reactive radicals (i.e., •OH, IO3•, and IO4•) that accelerate dye degradation. Increasing the initial concentration of periodate to 3 mM enhances the dye removal rate, but over 3 mM periodate, the degradation rate slows down. On the contrary, increasing initial dye concentrations reduces the degradation performance. pH is the most critical factor in AO10 breakdown. Salts slow down the degradation of the dye. However, UV/IO4− is more efficient in distilled water than natural water. Even at low concentrations, surfactants may affect the dye’s decomposition rate. The addition of sucrose reduced the breakdown of AO10. Although tertbutanol is a very effective •OH radical scavenger, it does not affect the dye breakdown even at the highest concentrations. Accordingly, the AO10 degradation is a non-•OH pathway route. According to retrieved data, the photoactivated periodate method eliminated 56.5 and 60.5% of the initial COD after 60 and 120 min of treatment time; therefore, it can be concluded that the UV/IO4− system may treat effluents, especially those containing textile dyes.

Sensitive biomaterials subjected to surface modification require delicate methods to preserve their structures and key properties. These include collagen-sealed polyester vascular prostheses. For their functionalization, coating with polycatecholamines (PCAs) can be used. PCAs change some important biological properties of biomaterials, e.g., hydrophilicity, bioactivity, antibacterial activity, and drug binding. The coating process can be stimulated by oxidants, organic solvents, or process conditions. However, these factors may change the properties of the PCA layer and the matrix itself. In this work, collagen-sealed vascular grafts were functionalized with a poly(l-DOPA) (PLD) layer using novel seawater-inspired ion combination as an accelerator, compared to the sodium periodate, Cu 2+ /H 2 O 2 mixture, and accelerator-free reference methods. Then, poly(l-DOPA) was used as the interface for antibiotic binding. The coated prostheses were characterized (SEM, FIB-SEM, FTIR, UV/vis), and their important functional parameters (mechanical, antioxidant, hemolytic, and prothrombotic properties, bioactivity, stability in human blood and simulated body fluid (SBF), antibiotic binding, release, and antibacterial activity) were compared. It was found that although sodium periodate increased the strength and drug-binding capacity of the prosthesis, it also increased the blood hemolysis risk. Cu 2+ /H 2 O 2 destabilized the mechanical properties of the coating and the graft. The seawater-inspired ion-accelerated method was efficient, stable, and matrix- and human blood-friendly, and it stimulated hydroxyapatite formation on the prosthesis surface. The results lead to the conclusion that selection of the PCA formation accelerator should be based on a careful analysis of the biological properties of medical devices. They also suggest that the ion-accelerated method of PLD coating on medical devices may be highly effective and safer than the oxidant-accelerated coating method.

In this study, a potassium ferrate (K 2 FeO 4 )-modified biochar (Fe-BC) was prepared and characterized. Afterwards, Fe-BC was applied to activated periodate (PI) to degrade tetracycline (TC), an antibiotic widely used in animal farming. The degradation effects of different systems on TC were compared and the influencing factors were investigated. In addition, several reactive oxygen species (ROS) generated by the Fe-BC/PI system were identified, and TC degradation pathways were analyzed. Moreover, the reuse performance of Fe-BC was evaluated. The results exhibited that the Fe-BC/PI system could remove almost 100% of TC under optimal conditions of [BC] = 1.09 g/L, initial [PI] = 3.29 g/L, and initial [TC] = 20.3 mg/L. Cl - , HCO 3 - , NO 3 - , and humic acid inhibited TC degradation to varying degrees in the Fe-BC/PI system due to their quenching effects on ROS. TC was degraded into intermediates and even water and carbon dioxide by the synergistic effect of ROS generated and Fe on the BC surface. Fe-BC was reused four times, and the removal rate of TC was still maintained above 80%, indicating the stable nature of Fe-BC., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY-NC-ND 4.0), which permits copying and redistribution for non-commercial purposes with no derivatives, provided the original work is properly cited (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

In this study, sludge biochar was prepared under four pyrolysis temperatures (SBC300, SBC500, SBC700, and SBC900) and then was employed to activate periodate (PI) for the degradation of sulfamethoxazole (SMX). Various characterization methods were employed to investigate the effect of pyrolysis temperature on the physicochemical properties of sludge biochar and the activation capacity of periodate. The SMX adsorption capacity of SBCs and the ability of activating PI to degrade SMX increased with the increasing pyrolysis temperature. The degradation of SMX by the SBCs/PI systems was highly dependent on the initial pH of the solution and the dosage of SBCs. Mechanistic studies indicated that the degradation of SMX by the SBCs/PI system was mainly based on an electron-mediated transfer mechanism. Additionally, the electron transfer capacity of the SBCs affected the defects and the degree of graphitization. The contribution of free radicals to SMX degradation decreases with increasing pyrolysis temperature. Toxicity experiments demonstrated that the toxic elimination of SMX by the SBCs/PI system was enhanced with increasing pyrolysis temperature.

Successful conversion of cellulose hydroxyl (OH) to carboxyl (COOH) groups is the goal of many modification procedures since COOH groups enhance the polarity of the fibers' surface and can be used for further fibers' functionalization. In this work, in order to obtain 2,3-dicarboxycellulose, the regenerated cellulose fibers (viscose) in the form of fabric were functionalized through two-step oxidation: with NaIO4 to introduce CHO groups followed by NaClO2 for CHO conversion to COOH groups. After oxidations, the fibers' morphology, surface chemistry, crystallinity, and surface charge were investigated using scanning electron microscopy (SEM), Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction analysis (XRD), and zeta potential measurements, respectively, as well as content of COOH groups determined by volumetric titrations. Sorption properties, i.e. moisture sorption, water retention power, and sorption of silver ions (Ag+) were evaluated and correlated with oxidation parameters. The interaction with model ion — Ag+ revealed that COOH groups, when maximum content obtained in oxidized fibers was 0.27 mmol·g−1, were available for binding Ag+ in nearly 1:1 ratio. The proposed oxidative protocol represents an effective method for COOH groups' introduction into regenerated cellulose fibers, improvement of fibers' sorption properties without deterioration of their crystallinity, and opens up a possibility for further functionalization of 2,3-dicarboxycellulose. [ABSTRACT FROM AUTHOR]

The proliferation of antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) caused by antibiotic abuse has raised concerns about the global infectious-disease crisis. This study employed periodate (PI)/ferrate (VI) (Fe (VI)) system to disinfect Gram-negative ARB (Escherichia coli DH5α) and Gram-positive bacteria (Bacillus subtilis ATCC6633). The PI/Fe (VI) system could inactivate 1 × 108 CFU/mL of Gram-negative ARB and Gram-positive bacteria by 4.0 and 2.8 log in 30 min. Neutral and acidic pH, increase of PI dosage and Fe (VI) dosage had positive impacts on the inactivation efficiency of ARB, while alkaline solution and the coexistence of 10 mM Cl-, NO 3 -, SO 4 2- and 20 mg/L humic acid had slightly negative impacts. The reactive species generated by PI/Fe (VI) system could disrupt the integrity of cell membrane and wall, leading to oxidative stress and lipid peroxidation. Intracellular hereditary substance, including DNA and ARGs (tetA), would leak into the external environment through damaged cells and be degraded. The electron spin resonance analysis and quenching experiments indicated that Fe (IV)/Fe (V) played a leading role in disinfection. Meanwhile, PI/Fe (VI) system also had an efficient removal effect on sulfadiazine, which was expected to inhibit the ARGs transmission from the source. [Display omitted] • PI/Fe (VI) system could efficiently remove antibiotic resistant bacteria and genes. • PI/Fe (VI) system inactivated ARB by destroying cell structure and DNA. • PI/Fe (VI) system induced oxidative stress and lipid peroxidation in ARB cells. • Fe (IV)/Fe (V) played a dominant role in disinfection of PI/Fe (VI) system. • PI/Fe (VI) system achieved efficient sulfadiazine degradation in 2 min. [ABSTRACT FROM AUTHOR]

• 89.5% TC removal were obtained in CuFeS 2 /PI system under weak alkaline conditions. • TC removal performance in CuFeS 2 /PI was superior to that in CuFeS 2 /SPC and CuFeS 2 /CaO 2. • 1O 2 , ·OH, and ·O 2 – were involved in TC decomposition, wherein 1O 2 were predominant species. • TC decontamination was promoted by the Fe(III)/Cu(II) and Fe(II)/Cu(I) cycle. • DFT calculations indicated the FeFeCu site as the primary active site. Activation of periodate (PI) has been widely recognized as an efficient and economical technique for the elimination of contaminants. In this study, a novel system with PI triggered by chalcopyrite (CuFeS 2) was applied in the decomposition of tetracycline hydrochloride (TC). Effects of CuFeS 2 dosage, PI concentration, pH value, inorganic anions, valence state change of Iodine ions (I-) were tested. The experimental findings demonstrated that the CuFeS 2 /PI system could successfully decompose TC in water under mild alkaline conditions (89.5 %, pH = 8). Compared with the other catalysts and the other CuFeS 2 /peroxide systems, CuFeS 2 /PI system exhibited more superior decontamination performance. Involvement of multiple reactive oxygen species such as superoxide radical (·O 2 –), hydroxyl radical (*OH) and singlet oxygen (1O 2) in TC decomposition was confirmed by Electron spin resonance (ESR) tests and quenching experiment, and the interactions between Cu(Ⅱ)/Fe(III) and Cu(I)/Fe(Ⅱ) was confirmed. Based on a calculation using the density functional theory (DFT), the active sites of CuFeS 2 for PI activation were revealed. Additionally, the analysis of degradation intermediates was conducted, with the toxicity of the intermediates analyzed. The CuFeS 2 /PI system was then applied in the treatment of real water samples, and the reusability of CuFeS 2 was also investigated. This research presents a novel strategy as well as a theoretical foundation for CuFeS 2 triggered PI to remove antibiotic contaminants. [ABSTRACT FROM AUTHOR]

Strategic modulation of the advanced oxidation processes for the selective oxidation of micropollutants has attracted accumulating attention in water decontamination. This study first reported the combination of the coagulant polyferric sulfate (PFS) and oxidant periodate (PI) to accomplish synergistic abatement of the antibiotic sulfamethoxazole (SMX). The oxidizing performance of SMX by this system was almost unaffected by coexisting water constituents, indicating the great promise of selective oxidation. Different from the current hydroxyl radicals (•OH)-mediated coagulant/oxidant systems (e.g., PFS/H 2 O 2 and PFS/ozone), the dominance of high-valent Fe(IV)/Fe(V) intermediates was unambiguously verified in the PFS/PI treatment. The PFS colloids before and after the oxidation were characterized and the iron speciation was analyzed. The transformation of monomeric iron configurations (Fe(a)) to oligomeric iron configurations (Fe(b)) could maintain the homeostasis of surface-bound Fe(III) and Fe(II). The interaction mechanisms included the production of reactive species and dynamic reaction equilibrium for micropollutant degradation. Finally, the transformation pathways of SMX and carbamazepine (CMZ) in the PFS/PI system were postulated. Overall, this study provided a novel coagulant/oxidant strategy to achieve selective and sustainable water purification. [Display omitted] • A novel coagulant/oxidant strategy was found for micropollutant abatement. • PFS is desirable to be an in-situ PI activator for sustainable water treatment. • Highly reactive Fe(IV)/Fe(V) mediate the selective oxidation of micropollutants. • Reactive species production and dynamic equilibrium are the main mechanisms. • PFS/PI system does not produce any toxic iodine end product. [ABSTRACT FROM AUTHOR]

[Display omitted] • An advanced oxidation system with nZVI-BC/PI at low temperature has been constructed. • ACT degradation (5℃) reached 100 % within 1 min under the optimal condition. • ·OH cooperate with 1O 2 , Fe (IV), ·O 2 – and electron transfer for ACT degradation. • nZVI-BC/PI system has durability, reusability and practicality. The development of more efficient advanced oxidation systems for serving various advanced treatment of wastewater is quite necessary and urgent. In this study, a nano-zero valent iron/periodate (nZVI−BC/PI) advanced oxidation system has been constructed, achieving a rapid degradation of acetaminophen (ACT, 1 mg/L) within 1 min (100 % at pH = 11) at low temperature (5℃). This system shows a great degradation in a wide range of pH (1 ∼ 11), improving the pH limitation of PI oxidation system. During the reaction process, ·OH as the main active species collaborate with 1O 2 , Fe (IV), ·O 2 – and electron transfer to degrade ACT. In this system, iron ion leaching is low (0.019 mg/L), ACT was effectively degraded (74.36 %∼97.32 %) under different water, moreover, the material has an expected recyclability. The research provides a significant guidance for the advanced treatment of wastewater especially in cold regions. [ABSTRACT FROM AUTHOR]

The periodate (PI)-based advanced oxidation process is valued for environmental remediation, but current activation methods involve high costs, secondary contamination risks, and limited applicability due to external energy inputs (e.g., UV), catalyst incorporation (e.g., Fe 2+ ), or environmental modifications (e.g., freezing). In this work, novel bioelectric activation of PI using the electrons generated by electroactive bacteria was developed and investigated for rapid removal of carbamazepine (CBZ), achieving 100 %, 100 %, and 76 % removal efficiency for 4.22 µM of CBZ in 20 min at pH 2, 120 min at pH 6.4, and HRT of 30 min at pH 8.5, respectively, with a 1 mM PI dose and without an input voltage. It was deduced that electrons derived from bacteria could directly activate PI using Ti mesh electrodes and generate •IO 3 via single electron transfer under strongly acidic conditions (e.g., pH 2). Nevertheless, under weak alkaline conditions (e.g., pH 8.5), biogenic electrons indirectly activated PI by generating OH - via 4e - reduction at the Ti mesh cathode, resulting in the formation of •O 2 - and 1 O 2 . In addition to the metal cathode, a carbon-based cathode finely modulates the 2e - reduction, yielding H 2 O 2 and activating PI to mainly form •OH. Moreover, primarily non-toxic IO 3 - was produced during treatment, while no detectable reactive iodine species (HOI, I 2 , and I 3 - ) were observed. Furthermore, the bioelectric activation of PI demonstrated its capability to remove various micropollutants present in secondary-treated municipal wastewater, showcasing its broad-spectrum degradation ability. This study introduces a novel, cost-effective, and environmentally friendly PI activation technique with promising applicability for micropollutant elimination in water treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Kinetic study of oxidation of toluidine blue (TB+) by periodate was carried out in aqueous medium and also in the cetyl trimethyl ammonium bromide (CTAB) reverse micellar medium. In both the media reaction obeys first order kinetics with respect to each of the reactants. In the reverse micellar medium, the reaction is forty times faster compared to aqueous medium under identical experimental conditions. The pronounced acceleration is accounted for by the lower micro polarity and the concentration effect present in the bound water of reverse micelles. In CTAB reverse micellar medium, the pseudo first order rate constant (k’) of the reaction is almost constant at all values of W, {W=[H2O]/[CTAB]} indicating that the reaction takes place on the micellar surface and results were explained by modified Berezin pseudo phase model..

The limited access to fast and facile general analytical methods for cellulosic and/or biocomposite materials currently stands as one of the main barriers for the progress of these disciplines. To that end, a diverse set of narrow analytical techniques are typically employed that often are time-consuming, costly, and/or not necessarily available on a daily basis for practitioners. Herein, we rigorously demonstrate a general quantitative NMR spectroscopic method for structural determination of crystalline cellulose samples. Our method relies on the use of a readily accessible ionic liquid electrolyte, tetrabutylphosphonium acetate ([P4444][OAc]):DMSO-d6, for the direct dissolution of biopolymeric samples. We utilize a series of model compounds and apply now classical (nitroxyl-radical and periodate) oxidation reactions to cellulose samples, to allow for accurate resonance assignment, using 2D NMR. Quantitative heteronuclear single quantum correlation (HSQC) was applied in the analysis of key samples to assess its applicability as a high-resolution technique for following cellulose surface modification. Quantitation using HSQC was possible, but only after applying T2 correction to integral values. The comprehensive signal assignment of the diverse set of cellulosic species in this study constitutes a blueprint for the direct quantitative structural elucidation of crystalline lignocellulosic, in general, readily available solution-state NMR spectroscopy. [ABSTRACT FROM AUTHOR]

A convenient oxidative cyclodesulfurization method toward the synthesis of benzofused nitrogen heterocycles using inexpensive and readily available potassium periodate as an oxidant was developed. Upon treating isothiocyanates with ortho -substituted anilines bearing N , N -, N , O -, and N , S -bis-nucleophiles, followed by an intramolecular cyclization of the in situ generated monothioureas, substituted 2-aminobenzazole series were rapidly accessible in good to excellent yields. The protocol can accommodate various substituents on both substrates while allowing more efficient, greener, and operational simpler process relative to other oxidative coupling reactions. Tetracyclic quinazolinone derivatives were also afforded in high yields in a single preparative step and chromatography-free. [ABSTRACT FROM AUTHOR]

High‐grade periodate is relatively expensive, but is required for many sensitive applications such as the synthesis of active pharmaceutical ingredients. These high costs originate from using lead dioxide anodes in contemporary electrochemical methods and from expensive starting materials. A direct and cost‐efficient electrochemical synthesis of periodate from iodide, which is less costly and relies on a readily available starting material, is reported. The oxidation is conducted at boron‐doped diamond anodes, which are durable, metal‐free, and nontoxic. The avoidance of lead dioxide ultimately lowers the cost of purification and quality assurance. The electrolytic process was optimized by statistical methods and was scaled up in an electrolysis flow cell that enhanced the space–time yields by a cyclization protocol. An LC‐PDA analytical protocol was established enabling simple quantification of iodide, iodate, and periodate simultaneously with remarkable precision. [ABSTRACT FROM AUTHOR]

The oxidation of paper by periodate was investigated and systematically characterized by Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy, X-ray diffraction, goniometry, and dynamic mechanical analysis. For the first time, in situ FTIR microscopy analysis was performed, yielding chemical images of carbonyl groups on the cellulose fibers. The enhancement of protein immobilization on oxidized paper was quantified by a colorimetric assay with Ponceau dye, demonstrating that 0.5-h oxidation suffices to functionalize the paper-based devices. The oxidized paper was applied as a sensor for protein quantification in urine, a test able to detect levels of proteinuria and even microalbuminuria. The quantification was based on the capture of proteins through covalent bonds formed with the carbonyl groups on the oxidized paper followed by the staining of the region with Ponceau dye. There is a linear dependency between human serum albumin (HSA) concentration and the length of the stained blot from 0.1 to 3 mg mL−1. This method correlated linearly with a reference method showing a higher sensitivity (0.866 cm mL mg−1) than the latter. The limit of quantification was 0.1 mg mL−1, three times lower than that of the commercial strip. [ABSTRACT FROM AUTHOR]

• The IBMs was systematically summarized and classified. • The valence transformation of Fe and the formation route of radicals/non-radicals were sorted out. • Fe (II) plays the most critical role in IBMs/PI. • The mechanism of IBMs/PI was comprehensive discussed, emphasizing the essential of electron transfer pathway. • The future opportunities and challenges of IBMs/PI have been described. In recent years, Iron-based materials(IBMs)/Periodate(PI) systems have gained attention in the treatment of water environments due to their excellent high oxidizing capacity, high stability, and strong resistance to environmental impacts. This work provides a synthetical overview of the current research status and progress of IBM/PI systems, and the vital role of Fe species is emphasized. The IBMs were categorized into three main groups by the different substances complexed with Fe: iron-carbon composites, iron-metal/nonmetallic composites, and iron with iron oxides. The possible catalytic influences of the aqueous species were explored. The mechanistic discussion was categorized into four groups, Fe0, Fe(II), Fe(IV), and Electron transfer pathway(ETP), depending on the valence of Fe at the beginning. Among them, Fe (II) is the most important valence state because it is an indispensable valence state before the formation of Fe(IV), and Fe(II) is also the valence state that can activate most kinds of active substances in PI. Interestingly, ETP-dominated PI activation systems tend to occur in iron-carbon complexes, and carbon materials may be necessary for triggering the ETP. In addition, the applicable state of IBMs/PI systems in water environments was explored from both the radical and non-radical perspectives. In the end, the deficiencies and improvements of the current IBMs/PI systems were summarized. Hoping that new inspirations can be provided for the subsequent IBMs/PI systems development. [ABSTRACT FROM AUTHOR]

Periodate (PI) based advanced oxidation processes (AOPs) have recently attracted much attention due to their high application potential in water purification through production of reactive species. In the study, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) was used as a representative electron shuttle, and its reaction with PI was investigated in detail. It was found that PI can be activated by ABTS via one-electron transfer to produce ABTS•+ and IO 3 •, cooperatively promoting oxidation of organic contaminants such as bisphenol A (BPA). Their contribution in BPA oxidation at pH 7 was estimated as 81.9% and 18.1%, respectively. With phosphate, BPA oxidation rate in the PI/ABTS process increased linearly with raised phosphate concentrations from 0 to 10 mM. The enhancement effect of phosphate is attributed to formation of PI-phosphate complexes, which facilitate PI activation by ABTS, and production of more ABTS•+ and IO 3 •, and additional phosphate radicals. Accordingly, the contribution of IO 3 • and phosphate radicals in BPA oxidation raised to 57.7% in the process with 4 mM phosphate, while that of ABTS•+ decreased to 42.3%. The reaction stoichiometry ratio of ABTS to PI was measured as 1.1 at pH 7, suggesting the little involvement of IO 3 • and phosphate radicals in production of ABTS•+ due to their high self-quenching. The PI/ABTS process exhibited excellent anti-interference capacity towards water matrix components (e.g. Cl−, HCO 3 − and natural organic matters). Moreover, an immobilized ABTS (ABTS/ZnAl-LDH) was successfully developed as a heterogeneous electron shuttle for PI oxidation, which resultantly exhibited the good catalytic activity and stability in degradation of BPA, further improving feasibility of the process in treatment of actual water. This work advances understanding on reaction of PI with ABTS from stoichiometric and kinetic aspects, and provides a high performance AOP for selective oxidation of trace organic contaminants. [Display omitted] • PI can be activated by ABTS via one-electron transfer. • ABTS•+ was the main reactive specie in the PI/ABTS process. • Phosphate boosted oxidation performance of the PI/ABTS process. • Phosphate facilitated generation of more ABTS•+, IO 3 • and phosphate radicals. [ABSTRACT FROM AUTHOR]

Exploring efficient catalyst and unveiling relevant intrinsic mechanism for pollutants control based on periodate (PI) activation is urgently required. Herein, an effective catalyst Cu 2 O with peculiar exposed facets and crystal edges was firstly developed to activate PI towards antibiotic wastewater degradation. Intriguingly, Cu 2 O nanocrystals with {100}+ {111} co-exposed facets together with their shared crystal edges exhibited the intrinsic high catalytic activity, and 88.90% of tetracycline (20 mg L−1) could be rapidly degraded within 5 min with k obs = 0.378 min−1, which outperformed the {100}, {110}, {111} solely exposed ones or {100}+ {110}, {100}+ {110}+ {111} co-exposed ones. A comprehensive mechanism study revealed that the crystal edges of {100}/{111} in Cu 2 O nanocrystals are conducive to better electron transfer, charge separation, and PI adsorption properties, thus triggering highly efficient PI activation over other crystal edges exposed nanocrystals. Besides, {100}/{111} crystal edges in Cu 2 O crystal made the PI activation-induced antibiotic degradation change from the non-radical/radical mixed reaction to 1O 2 (75.71%) dominated nonradical reaction. This work provides systematical insights into constructing effective catalysts for wastewater treatment via structure engineering. [Display omitted] ● A series of Cu 2 O with different facets and crystal edges is synthesized. ● Cu 2 O with {100}+ {111} co-exposed facets exhibits the prominent PI activation. ● {100}/{111} edges makes for electron transfer, charge separation, and PI adsorption. ● {100}/{111} edges switch the active species from mixed radical/non-radical to 1O 2. [ABSTRACT FROM AUTHOR]

In this study, the manganese oxide/biochar composites (Mn@BC) were synthesized from Phytolacca acinosa Roxb. The Mn@BC was analyzed via techniques of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction analysis (XRD). The results show that MnO x is successfully loaded on the surface of BC, and the load of MnO x can increase the number of surface functional groups of BC. X-ray photoelectron spectroscopy (XPS) shows that MnO x loaded on BC mainly exists in three valence forms: Mn(Ⅱ), Mn(Ⅲ), and Mn(Ⅳ). The ability of Mn@BC to activate periodate (PI) was studied by simulating the degradation of methylene blue (MB) dye. The degradation experiment results showed that the MB removal rate by the Mn@BC/PI system reached 97.4% within 30 min. The quenching experiment and electron paramagnetic resonance (EPR) analysis confirmed that Mn@BC can activate PI to produce iodate (IO 3 •), singlet oxygen (1O 2), and hydroxyl radical (•OH), which can degrade MB during the reaction. Response surface methodology (RSM) based on Box-Behnken Design (BBD) was used to determine the interaction between pH, Mn@BC and PI concentration in the Mn@BC/PI system, and the optimum technological parameters were determined. When pH = 5.4, Mn@BC concentration 0.56 mg/L, PI concentration 1.1 mmol/L, MB removal rate can reach 98.05%. The cyclic experiments show that Mn@BC can be reused. After four consecutive runs, the removal rate of MB by the Mn@BC/PI system is still 82%, and the Mn@BC/PI system also shows high performance in treating MB in actual water bodies and degrading other pollutants. This study provides a practical method for degrading dyes in natural sewage. • MnOx was loaded in the surface of biochar to efficiently activate periodate. • The Mn@BC/PI system could work in a wide pH range (3.0–9.0). • The functional groups of BC and three valence of Mn played a role in degradation process. • The low ion leaching concentration and excellent recyclability of Mn@BC were found. • Mn@BC/PI system perform strong anti-interference ability and actual application potential. [ABSTRACT FROM AUTHOR]

Periodate-based advanced oxidation processes have been diffusely practiced for pollutant decontamination. However, the thermo-activation of periodate process (heat/PI), an effective water pollution removal process, has been rarely discussed, and the degradation pathway of this heat/PI system requires investigation. In this work, tetracycline antibiotics were selected as the model micropollutant for the comprehensive evaluation of the heat/PI system. The heat/PI system exhibited good performance for tetracycline (TC) remediation with temperature increases. The principal reactive oxidative species in the heat/PI system was confirmed using quenching experiments and electron paramagnetic resonance experiments. Further, the potential reactive sites in the TC were identified based on the density functional theory calculation. Based on the detection results of intermediates, there was no significant difference in byproducts generated during TC degradation under various temperatures in the heat/PI system. The Toxicity Estimation Software Tool (T.E.S.T.) method was applied to calculate the individual toxicity of the byproducts. This study contributes to a comprehensive explanation of the process of the thermal activation of periodate, and in particular, it explains the source of oxidation power, the transformation of byproducts, and the toxicity of reaction systems. [Display omitted] • The decontamination of tetracycline in the heat/periodate system was firstly investigated. • Quenching experiments and EPR experiments unveiled that 1O 2 and HO• are the principal ROS in the heat/PI system. • Potential reactive sites in tetracycline were identified based on the DFT calculation. • Toxicity of generated byproducts was evaluated according to the QSAR model and TEST. [ABSTRACT FROM AUTHOR]

[Display omitted] • Visible light enhanced the system efficiency by promoting Fe3+/Fe2+ cycling. • The system had a wide pH tolerance for BPA elimination. • 1O 2 , HO•, O 2 •−, •IO 3 and •IO 4 dominated BPA degradation. • Humic acid significantly accelerated the degradation of BPA. • The system could remove multiple organic pollutants simultaneously. The current study demonstrates, for the first time, the effectiveness of an innovative visible light (VL) photo-Fenton like system using periodate (PI) mediated by Fe3+ and gallic acid (GA) for bisphenol A (BPA) elimination at neutral pH. The promotion of VL irradiation and GA on the Fe2+/Fe3+ cycle in the system allowed the VL/GA/Fe3+/PI system to exhibit excellent performance for BPA removal. Complete degradation of BPA was carried out in the VL/GA/Fe3+/PI process after 30 min reaction under the optimum conditions (0.10 mM Fe3+, 0.10 mM GA, 1 mM PI, and initial pH 7.0). Electron paramagnetic resonance analysis and quenching tests confirmed that the singlet oxygen, iodate radical, and hydroxyl radical were primarily involved in the elimination of BPA with minor contribution from superoxide anion radical and high-valent iron species (Fe4+ and Fe5+). BPA abatement was slightly inhibited by the addition of Cl−, NO 3 −, and SO 4 2−, whereas the addition of HCO 3 − obviously hindered this process. Notably, Huimic acid dramatically expedited BPA decomposition. Besides, the VL/GA/Fe3+/PI process demonstrated remarkable removal efficiency over a broad range of initial pH values (3.01–8.97). Meanwhile, based on the eight identified intermediates, the possible degradation pathways of BPA were predicted. The phytotoxicity test concluded that a decrease in toxicity of the degraded intermediates to the growth of radish seed compared to BPA. In addition, the VL/GA/Fe3+/PI system demonstrated favorable potential for application in different actual water matrices. Moreover, efficient and simultaneous abatement of various organic contaminants by the GA/Fe3+/PI process was success accomplished under natural solar light or VL. Consequently, all results implied that the VL/GA/Fe3+/PI process might be a perspective technique for the treatment of organic contaminants. [ABSTRACT FROM AUTHOR]

A new method for the quantification of trace periodate (PI) concentration was developed. The Br--ABTS method was based on the oxidation coloration reaction. Under Br- catalysis, the PI rapidly oxidized ABTS to the green ABTS•+, which could be accurately determined by UV-Vis spectrophotometer. The absorbance of ABTS•+ was remarkably correlated linearly with the concentration of PI at 415 nm, and the slope of standard curve was (3.77 ± 0.01)× 104 M−1·cm−1. The proposed method had high sensitivity and the slope at different optical paths showed a good multiplicative relationship for concentration values as low as 0.02 μM to be measured. The existence of different solutes in river and lake water did not affect the accuracy of Br--ABTS method, the generated ABTS•+ could maintain good stability within 30 min, and the recovery of PI was between 95%− 105%. The stoichiometric coefficient between PI and ABTS•+ was 1.12 at pH 3.0. In addition, a common reductant (hydroxylamine), transition metal ions and inorganic anions (Cl-, SO 4 2- and HCO 3 -) did not affect the Br--catalyzed oxidation of ABTS for the measurement of PI concentration. Consequently, Br--ABTS is a feasible method to determine the concentration of PI. • The Br−-ABTS method was based on the oxidative coloration of ABTS by Br−-induced PI. • The Br−-ABTS method was convenient, rapid, accurate, and sensitive. • The Br−-ABTS method could measure as low as 0.03 μM PI in water. • The Br−-ABTS method tolerated the interference of water matrix, hydroxylamine and metal ions. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes (AOPs) often employ strong oxidizing inorganic radicals (e.g., hydroxyl and sulfate radicals) to oxidize contaminants in water treatment. However, the water matrix could scavenge the strong oxidizing radicals, significantly deteriorating the treatment efficiency. Here, we report a periodate/catechol process in which reactive quinone species (RQS) including the o -semiquinone radical ( o -SQ •- ) and o -benzoquinone ( o -Q) were dominant to effectively degrade anilines within 60 s. The second-order reaction rate constants of o -SQ •- and o -Q with aniline were determined to be 1.0 × 10 8 and 4.0 × 10 3 M -1 s -1 , respectively, at pH 7.0, which accounted for 21% and 79% of the degradation of aniline with a periodate-to-catechol molar ratio of 1:1. The major byproducts were generated via addition or polymerization. The RQS-based process exhibited excellent anti-interference performance in the degradation of aniline-containing contaminants in real water samples in the presence of diverse inorganic ions and organics. Subsequently, we extended the RQS-based process by employing tea extract and dissolved organic matter as catechol replacements as well as metal ions [e.g., Fe(III) or Cu(II)] as periodate replacements, which also exhibited good performance in aniline degradation. This study provides a novel strategy to develop RQS-based AOPs for the highly selective degradation of aniline-containing emerging contaminants.

Modification of Hyaluronic acid (HA) with Sodium metaperiodate (NaIO 4) results in the formation of oxidized HA (OHA). OHA containing multiple aldehyde groups can easily react with the materials having amino functionality via formation of Schiff base linkage, resulting in the formation of OHA based hydrogel scaffolds. These hydrogels have recently attracted considerable attention as scaffolds for tissue engineering (TE) applications. Thus, the aim of the present review is to give an overview on OHA based hydrogels as scaffolds and their potential application in the field of TE along with the method of synthesis and important properties of OHA. Unlabelled Image [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Different transition metal ions were investigated for periodate activation. • Periodate was activated for BPA degradation with low amount of Mn2+. • Humic acid and aeration improved the BPA degradation efficiency. • Superoxide radical and singlet oxygen were main reactive species for BPA degradation. Abstract A highly efficient destruction of bisphenol A (BPA) was explored through Mn2+-mediated activation of periodate under ambient conditions. The conjunction of periodate with different transition metals was investigated, and Mn exhibited the best catalytic performance. The periodate oxidation of BPA could be rapidly proceeded loading with low amount of Mn2+ and in a wide pH range. The presence of humic acid significantly enhance the degradation efficiency due to its electron transfer characteristic. Besides, molecular oxygen played an indispensable role during the reaction, and superoxide radicals was discriminated as the leading reactive species for BPA degradation. The homogeneous periodate activation initiated by Mn2+ provides a feasible approach for the degradation of organic contaminants without external energy. [ABSTRACT FROM AUTHOR]

The reaction kinetics of oxidation of m-toluidine by periodate in the acetone-water medium in the presence of MnII as catalyst was investigated systematically by detecting the change in absorbance of the intermediate of reaction. Results manifest that the reaction was first order with respect to both reactant and catalyst. It has been found that the reaction rate is not affected by free radical scavengers. However, the dielectric constant decreases in the medium decrease the reaction rate. Consequently, 1/kcat versus [H+] plot was found to be in accordance with the rate law. The thermodynamic parameters were evaluated and the mechanism of the reaction has been proposed. [ABSTRACT FROM AUTHOR]

Highlights • Complex 1 is the first long-lived probe to detect IO 4 − in living cells. • Complex 1 has a detection limit of 0.077 μM for IO4− in aqueous buffer, more sensitive than reported fluorescence probes. • The long lifetime of Complex 1 enables its luminescence response to IO4− to be detected in the presence of organic dyes. Abstract Periodate (IO 4 −) is a widely used reagent in organic synthesis and for biomolecular modification. However, highly sensitive fluorescence detection methods for IO 4 − are lacking. In this work, we designed and synthesized iridium(III) complexes for the detection of IO 4 − by the incorporation of a methylthio group to serve as a luminescence trigger. The results showed that complex 1 could detect IO 4 − in a sensitive and selective manner with a detection limit of 0.077 μM, rendering it more sensitive than reported fluorescence methods. Meanwhile, its inherently long emission lifetime enables its luminescence response to IO 4 − to be detected even in the presence of organic dyes by the use of time-resolved emission spectroscopy (TRES). This probe was further demonstrated to detect IO 4 − in living cells. To our knowledge, complex 1 is first long-lived iridium(III)-based probe for the sensitive detection of IO 4 −, and is also one of few existing imaging probes for IO 4 −. [ABSTRACT FROM AUTHOR]

The surface of a glassy carbon electrode modified with multi-walled carbon nanotubes (GCE/MWCNTs) was coated with a layer of phosphomolybdic acid (PMo12) and ionic liquid (n-dodecyl pyridinium hexafluorophosphate, [C12Py][PF6]). Cyclic voltammetry was performed to investigate the effect of [C12Py][PF6] on the electrochemical behavior of the prepared modified electrode, GCE/MWCNTs/[C12Py][PF6]-PMo12. The surface coverage and the rate constant of electron transfer for three redox pairs of the immobilized PMo12 were evaluated and compared with those obtained for GCE/MWCNTs/n-octyl pyridinium hexafluorophosphate ([C8Py][PF6])-PMo12 fabricated using [C8Py][PF6] in our previous study to find a correlation between the structure of ionic liquid and its effect. Thereafter, the electrocatalytic activity of GCE/MWCNTs/[C12Py][PF6]-PMo12 towards the reduction of nitrite, H2O2, iodate, bromate, chlorate, and periodate was investigated and the rate constant for the chemical reaction of each analyte with PMo12 at the electrode surface was calculated. The prepared electrode was then applied for the amperometric measurements of the mentioned analytes with the satisfactory electroanalytical characteristics. [ABSTRACT FROM AUTHOR]

Abstract A hydroxythiophene-bearing benzothiazole (HB) in phosphate buffer solution showed strong yellow fluorescence emission, which selectively and sensitively decreased by addition of IO 4 −. The reaction between HB and IO 4 − dramatically accelerated by UV irradiation. The fluorescence emission of HB was gradually recovered upon thermal heating of the IO 4 −-adducted product, indicating IO 4 − release. Using these properties, the solution containing HB and IO 4 − has been used as a fluorescence-based security ink. Graphical abstract Image 1 Highlights • The probe, HB , has successfully recognized IO 4 − in various anions, which is accelerated by UV irradiation. • The fluorescence emission of HB was recovered upon thermal heating of the IO 4 − adducted product. • Using the reversible properties, the solution containing HB and IO 4 − could be used as a fluorescence-based security ink. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar/periodate showed specific selectivity towards organic pollutants. • Sulfadiazine was oxidized by singlet oxygen and superoxide radicals. • Electron-transfer mechanism was responsible for the degradation of bisphenol A. • The selectivity was closely related to the redox potentials of the organics. Selecting appropriate biochar catalyzed advanced oxidation processes (BC-AOPs) for the abatement of emerging organic contaminants remained challenging. In this study, five BC-AOPs with different chemical oxidants were established and employed to degrade organic contaminants. Among others, BC activated periodate (PI) process showed advantages in oxidation rate and selectivity. Specifically, both BC 350 /PI and BC 800 /PI showed extremely rapid degradation kinetics towards sulfadiazine (SDZ, k app = 0.1503 min−1 and 0.0905 min−1) while bisphenol A (BPA) was relatively recalcitrant (k app = 0.0170 min−1 and 0.0475 min−1). Intriguingly, SDZ was primarily eliminated by singlet oxygen (1O 2)/superoxide radicals (O 2 –) (accounted for 78.4% in BC 350 /PI/SDZ system), while BPA was mainly oxidized through the electron-transfer mechanism (accounted for 96.8% in BC 800 /PI/BPA system). Density functional theory (DFT) calculations revealed that BPA was more inclined to provide electrons to metastable complexes compared with SDZ due to the more positive highest occupied molecular orbital. Therefore, the selectivity behavior was further expanded from the perspective of the electron-donating capabilities (i.e., half-wave potential φ 1/2) of 8 organic pollutants and a threshold of 0.9 V was clearly identified. This study revealed the difference in oxidation rate towards emerging contaminants of multiple BC-AOPs and uncovered the mysterious selective oxidation behaviors of the BC activated PI process for the first time. In summary, the outcomes of this work provided guidelines for the application of BC-AOPs in treating wastewater containing different organic pollutants. [ABSTRACT FROM AUTHOR]

Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have drawn much more attention due to their high risk on human health and ecosystem. In this study, the performance of sulfidated nanoscale zero-valent iron (S-nZVI)/periodate (PI) system toward ARB inactivation and ARGs removal was systematically investigated. The S-nZVI/PI system could realize the complete inactivation of 1 × 108 CFU/mL kanamycin, ampicillin, and tetracycline-resistant E. coli HB101 within 40 min, meanwhile, possessed the ability to remove the intracellular ARGs (iARGs) (including aphA , tetA , and tnp A) carried by E. coli HB101. Specifically, the removal of aphA , tetA , and tnp A by S-nZVI/PI system after 40 min reaction was 0.31, 0.47, and 0.39 log 10 copies/mL, respectively. The reactive species attributed to the E. coli HB101 inactivation were HO• and O 2 •−, which could cause the destruction of E. coli HB101 morphology and enzyme system (such as superoxide dismutase and catalase), the loss of intracellular substances, and the damage of iARGs. Moreover, the influence of the dosage of PI and S-nZVI, the initial concentration of E. coli HB101, as well as the co-existing substance (such as HCO 3 −, NO 3 −, and humic acid (HA)) on the inactivation of E. coli HB101 and its corresponding iARGs removal was also conducted. It was found that the high dosage of PI and S-nZVI and the low concentration of E. coli HB101 could enhance the disinfection performance of S-nZVI/PI system. The presence of HCO 3 −, NO 3 −, and HA in S-nZVI/PI system showed inhibiting role on the inactivation of E. coli HB101 and its corresponding iARGs removal. Overall, this study demonstrates the superiority of S-nZVI/PI system toward ARB inactivation and ARGs removal. The inactivation of E. coli HB101 by sulfidated nanoscale zero-valent iron (S-nZVI) activating periodate (PI). [Display omitted] • S-nZVI/PI system realized the removal of E. coli HB101 and its iARGs. • HO• and O 2 •− were available reactive species for E. coli HB101 inactivation. • The inactivation mechanism of E. coli HB101 by S-nZVI/PI was revealed. • Co-existing substance could inhibit the sterilization efficacy of S-nZVI/PI. [ABSTRACT FROM AUTHOR]

Mn(II) is among the most efficient catalysts for the periodate (PI)-based oxidation process. In-situ formed colloidal MnO 2 simultaneously serves as the catalyst and oxidant during the degradation of organic contaminants by PI. Here, it is revealed that the complexation of Mn(II) by ethylene diamine tetraacetic acid (EDTA) further enhances the performance of PI-based oxidation in the selective degradation of organic contaminants. As evidenced by methyl phenyl sulfoxide probing, 18O-isotope labeling, and mass spectroscopy, EDTA complexation modulates the reaction pathway between Mn(II) and PI, triggering the generation of high-valent manganese–oxo (MnV–oxo) as the dominant reactive species. PI mediates the single-electron oxidation of Mn(II) to Mn(III), which is stabilized by EDTA complexation and then further oxidized by PI via the oxygen-atom transfer step, ultimately producing the MnV–oxo species. Ligands analogous to EDTA, namely, [S,S]-ethylenediaminedisuccinic acid and L -glutamic acid N , N -diacetic acid, also enhances the Mn(II)/PI process and favors MnV–oxo as the dominant species. This study demonstrates that functional ligands can tune the efficiency and reaction pathways of Mn(II)-catalyzed peroxide and peroxyacid-based oxidation processes. [Display omitted] • Trace Mn(II)-EDTA efficiently catalyzes micropollutant oxidation by periodate. • High-valency Mn dominantly contributes to the degradation of contaminant. • Complexed Mn(III) serves as the intermediate for high-valency Mn formation. • Analogs of EDTA could also enhance the performance of the Mn(II)/PI process. [ABSTRACT FROM AUTHOR]

Converting waste activated sludge into catalysts for the removal of antibiotics in water fulfils the dual purpose of waste-to-resource and hazardous pollution elimination. In this study, sludge-derived biochar (SDB) for efficient periodate (PI) activation was first prepared via one-step pyrolysis of potassium permanganate-polyhexamethylenebiguanide conditioned sludge without additional modification. The SDB (750 °C)-PI system degraded 100% ofloxacin (OFL, 41.5 μM) within 6 min and was almost undisturbed by inorganic ions or humic acids. The experimental results confirmed that the predominant role of reactive iodine species (RIS) and the auxiliary involvement of singlet oxygen (1O 2) jointly contributed to the OFL degradation. Theoretical calculations further indicated that the synergy between Mn and N/O induced local charge redistribution and improved electron transfer capability of SDB, leading to the formation of electron-rich Mn sites and enhanced Mn(II)↔Mn(III)↔Mn(IV) redox to promote PI activation. More importantly, the enhanced adsorption and charge transfer of PI on the Mn site of the Mn-N/O-C structures induced the I-O bond stretching and the rapid generation of RIS. This study offered a cost-effective strategy for developing SDB-based catalysts, further advancing the comprehension of sludge management and the intricate mechanisms underlying RIS formation in PI-advanced oxidation processes. [Display omitted] • Mn-N/O sites sludge biochar (SDB) for periodate (PI) activation was target-prepared. • The SDB (750 °C)-PI system degraded 100% ofloxacin (OFL, 41.5 μM) within 6 min. • Reactive iodine species were mainly responsible for OFL degradation followed by 1O2. • Mn and N/O synergy induces enhanced charge transfer from the Mn sites to the PI. [ABSTRACT FROM AUTHOR]

Herein, we presented an ingenious method for the detection of trace ascorbic acid (AA) using fluorescent sensing system, which was composed of periodate (IO 4 −) and nitrogen-boron co-doped carbon dots (N, B-CDs). Highly photoluminescent carbon dots with a quantum yield of 84.5% were synthesized by a one-step hydrothermal method using citric acid, ethylenediamine and boric acid as raw materials. The fluorescence of N, B-CDs could be statically quenched by IO 4 −, and non-fluorescent complexes were formed on the surface of carbon dots at the same time. With the pre-addition of ascorbic acid, the process of fluorescence quenching by IO 4 − was inhibited due to the preferential redox reaction between AA and IO 4 −. Based on the principle mentioned above, we designed the "inhibition" fluorescent sensor that can easily realize the detection of AA, and an extremely low limit of detection of 0.035 nM with a linear interval of 0–1600 pM was obtained. In addition, the sensing system has been applied to the detection of AA in human urine and obtained satisfactory results. The developed "inhibition" fluorescent sensor with high sensitivity and selectivity, has shown great potential and application prospects in the field of biosensing. [Display omitted] • The carbon dots (N, B-CDs) were synthesized by citric acid, ethylenediamine and boric acid. • The N, B-CDs showed a high quantum yield of 84.5% with an intense blue fluorescence. • The "inhibition" fluorescent sensor was constructed of periodate (IO 4 −) and N, B-CDs. • The sensing platform was highly sensitive with a very low detection limit of 0.035 nM. [ABSTRACT FROM AUTHOR]

Periodate-based advanced oxidation processes (AOPs) have received mounting attention in scientific research in the past two decades due to their fair oxidizing capability for satisfactory decontamination performance. Unlike iodyl (IO 3 •) and hydroxyl (•OH) radicals are widely recognized as the predominant species generated from periodate activation, the role of high-valent metal as a dominant reactive oxidant has been proposed recently. Although several excellent reviews concerning periodate-based AOPs have been reported, there are still prevalent knowledge roadblocks to high-valent metals' formation and reaction mechanisms. Therefore, this work aims to provide a comprehensive overview of high-valent metals, especially concerning the identification methods (e.g., direct and indirect strategies), formation mechanisms (e.g., formation pathways and interpretation based on density functional theory calculation), reaction mechanisms (e.g., nucleophilic attack, electron transfer, oxygen-atom transfer, electrophilic addition, and hydride and hydrogen-atom transfer), and reactivity performance (e.g., chemical properties, influencing factors, and practical applications). Furthermore, points for critical thinking and further prospects for high-valent metal-mediated oxidation processes are suggested, emphasizing the need for parallel efforts to enhance the stability and reproducibility of high-valent metal-mediated oxidation processes in real world applications. [Display omitted] • High-valent iron and manganese species generated during PI activation are reviewed. • Fe(IV) was more thermodynamically favorable to be formed in Fe(II)/PI system. • PI could be almost completely converted to IO 3 − in Fe(IV)-mediated PI activation. • High-valent metal owns moderate E0, long lifetime, and substrate-specific reactivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar activated periodate effectively removed sulfadiazine antibiotic from urine. • HCO 3 − and NH 4 + in urine matrix effectively inhibited the elimination of sulfadiazine. • Electron-transfer mechanism was revealed to lead to the removal of sulfadiazine. • Biochar/periodate process showed relatively low environmental risk in urine matrix. Source-separation and treatment of urine are recognized as promising strategies to recover nutrients, as well as reduce the stress of terminal wastewater treatment plants. As a ubiquitous constituent of urine, NH 4 + has been demonstrated to induce the generation of nitro-byproducts in sulfate radical (SO 4 •−) dominated oxidation processes. In this work, wheat straw derived biochar (BC X , X represents the pyrolysis temperature) was prepared and adopted to eliminate sulfadiazine (SDZ) and its main human metabolite N4 -acetyl-sulfadiazine (NSDZ) from hydrolyzed urine by coupling with periodate (PI). Specifically, BC 800 /PI process achieved excellent SDZ (0.190 h−1) abatement, which was more efficient than NSDZ. HCO 3 − and NH 4 + significantly inhibited the removal processes whilst Cl− showed neglected effect. Both in situ and ex situ analysis excluded the dominant role of •OH, 1O 2 , O 2 •– and/or •IO 3. Instead, electron-transfer regime driven by the high potential BC 800 -PI* complexes played a significant role. Interestingly, BC 800 /PI and CoFe 2 O 4 /peroxymonosulfate (PMS) (a typical SO 4 •−-dominated oxidation process) exhibited comparable removal efficiencies towards SDZ. Four nitro-byproducts were identified in CoFe 2 O 4 /PMS process but negligible in BC 800 /PI process during SDZ treatment, revealing the merit of BC 800 /PI process. Eventually, the toxicity prediction and bactericidal experiments further implied that BC 800 /PI process was eco-friendly. This study proposed a heterogeneous BC 800 /PI process for the treatment of source-separated urine and comprehensively demonstrated the advantages of its low costs and environmental risk. [ABSTRACT FROM AUTHOR]

[Display omitted] • Single-atom Mn catalyst is synthesized for highly effective activation of periodate. • IO 3 • is identified as the dominant ROS for the degradation of sulfonamide antibiotics. • Mn facilitates electron transfer from carbon support to IO 4 - to generate IO 3 • and MnIV/V = O. • SO 2 extrusion is the main degradation step, with products of lower antibacterial activity. • MnN@CNT/PI is a powerful AOP for removing sulfonamides from complex water matrix. Sulfonamides, such as sulfadiazine (SDZ), are widely used antibiotics that pose a significant threat to the environment due to their poor biodegradability and potential to induce antibiotic resistance. In this study, a new catalyst with atomically dispersed Mn on carbon nanotubes (MnN@CNT) was applied for the first time to activate periodate (PI) for rapid degradation of SDZ. MnN@CNT/PI system achieved 100% SDZ removal in 15 min, and the kinetic rate constant (k nor) reaches 406.1 min−1·g−2·L2, higher than those of the reported catalytic PI systems. Multiple reactive oxygen species (ROS), including IO 3 •, O 2 –•, 1O 2 , high-valent Mn-oxo complexes, and •OH, were detected, with IO 3 • being the most predominant. The Mn atom bridged the electron from the carbon support to IO 4 - via the Mn-O bond, which induced the prolonged I-O bond and thus the generation of IO 3 •. SDZ was degraded through S-N bond cleavage, pyrimidine destruction, SO 2 extrusion, and N-N coupling. The intermediate products of the SDZ degradation process showed little antibacterial activity, indicating the greatly reduced risk of the treated water to induce antibiotic resistance in the environment. The superior performance of MnN@CNT/PI in the environmental water samples suggests its high application potential for selective degradation of SDZ in complex waters. The research presents a novel advanced catalytic oxidation technology for efficiently removing sulfonamides and similar antibiotics from water for adequate environmental and ecological protection. [ABSTRACT FROM AUTHOR]