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Stainless steel dust (SSD) contains a high content of Cr and is listed as hazardous solid waste. However, SSD is mainly stockpiled in legacy waste sites due to its complexity and lack of investigation. Herein we comprehensively investigates the microscopic interaction between heavy metals and coexisting phases of SSD from the electric arc furnace (EAF). Furthermore, a new approach for extracting Cr from SSD was developed for the first time. It was found that SSD is enriched with Cr, Ni, Mn, and Zn. Most of these heavy metals are bound to stable spinel (e.g., FeCr 2 O 4 ) and encapsulated by silicate. Using Na 2 S 2 O 8 as the flux (1-24 mmol), under roasting at 350-750 °C in the air for 0.25-6 h, efficient heavy metal extraction can be achieved (Cr-80 %, Ni-86 %, Mn-93 %, Zn-94 %) at 650 °C for 1h. During the roasting processes, the silicate shell was broken, which facilitated the mass transfer of the oxidant. Fe(II) was oxidized to Fe(III) and collapsed the spinel structure, releasing the heavy metals during the following acid leaching. The total mass of SSD is reduced by 90-95 %, and detoxification of SSD is achieved after processing. In conclusion, efficient extraction refractory metals in SSD by Na 2 S 2 O 8 roasting and the mechanism was elucidated for the first time. This method might also be applied for the treatment of other slags/ash waste that have a stable spinel structure and are encapsulated by silicate., 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 Elsevier Ltd. All rights reserved.)

The thermal washing of oily sludge using sodium persulfate (SD) assisted by sodium lignosulfonate surfactant has been demonstrated to be an effective method for oily sludge remediation. To further explore the underlying mechanisms of this process, a systematic study was conducted by simulating oily sludge systems consisting of saturated hydrocarbons (SaH), aromatics hydrocarbons (ArH), resins (Res), and asphaltenes (Asp). The effects of reaction conditions, such as pH, sodium lignosulfonate alkyl (LSA) concentration, SD concentration, and washing temperature, were analyzed. Furthermore, the oxidative kinetic mechanism during the reaction process was investigated. The results demonstrated that neither petroleum hydrocarbons nor SD underwent significant chemical transformations when exposed to LSA, while SD exhibited a marked oxidative degradation effect on all four types of hydrocarbons. Oxidation kinetics indicated that sodium hydroxide played a catalytic role, with SD being the main oxidant and particularly efficient in degrading Asp and Res. Meanwhile, LSA contributed to the removal of hydrocarbons by reducing the surface tension of the solution, enhancing solubilization. This study not only elucidates the central role of SD in the thermal washing process but also provides a solid theoretical foundation for the practical application of this technology in oily sludge treatment.

Glasses from the system Na 2 O-Al 2 O 3 -SiO 2 -B 2 O 3 -Dy 2 O 3 are prepared with three different concentrations of the Dy 3+ ion-0.5, 1, and 2 at%. Glass-ceramics are obtained after thermal treatment of the parent glass at 580°С and 630°С during 2, 5, and 24 h. The crystallizing phases, the crystallinity degree, and the nano crystalline size are determined. The crystallizing phases after thermal treatment are NaAlSiO 4 in two different modifications and Na 3 B 3 O 6 . XRD analyses show the presence of third unknown phase in some samples. Emission and excitation spectra of the glass-ceramics show the characteristic peaks of Dy 3+ ( 4 F 9/2  →  6 H 15/2 , 4 F 9/2  →  6 H 13/2 and 4 F 9/2  →  6 H 11/2 at 483, 575, and 668 nm, respectively). The yellow peak is dominating in all samples. The spectra show different intensity depending on the Dy 3+ concentration, temperature, and time of the thermal treatment. This result suggests that the emission color can be controlled by these three factors., (© 2024 John Wiley & Sons Ltd.)

Although the xylose mutarotation and transformation have been investigated largely separately, their relationship has been rarely systematically elaborated. The effect of several factors such as xylose concentration, temperature, and salt concentration, affecting the mutarotation of xylose are discussed. Nine alkali halides (LiCl, NaCl, KCl, LiBr, NaBr, KBr, LiI, NaI, and KI) are used to test salt effects. The relationship between xylose rotation rate constant (k M ), specific optical rotation at equilibrium ([α] eqm ), α/β ratio, H chemical shift difference (ΔΔδ), Gibbs free energy difference (ΔG), hydrogen ion or hydroxide ion concentration ([H + ] or [OH - ]), and xylose conversion is discussed. Different salts dissolved in water result in different pH of the solutions, which affect the mutarotation of xylose, with the nature of both cation and anion. Shortly, the smaller the cation radius is and the larger the anion radius is, the greater the mutarotation rate is. In the dehydration of xylose to furfural in salty solutions, xylose conversion is positively correlated to mutarotation rate, H + or OH - concentration, and the energy difference between α-xylopyranose and β-xylopyranose. Although the [α] eqm of xylose is positively correlated with α/β configuration ratio, there is no obvious correlation with xylose dehydration. The conversion to furfural in chlorides is superior to that in bromines and iodides, which is due to the fact that the pH of chloride salts is smaller than that of the corresponding bromide and iodized salts. Higher H + concentration prefers to accelerate the formation of furfural. In basic salt solutions, the xylulose selectivity is higher than that of furfural at the initial stage of reaction. The furfural selectivity and carbon balance are better in acidic condition rather than in basic condition. In H 2 O-MTHF (2-Methyltetrahydrofuran) biphasic system, the optimal furfural selectivity of 81.0 % is achieved at 190 °C in 1 h with the assistance of LiI and a little HCl (0.2 mmol, 8 mmol/L in aqueous phase). A high mutarotation rate represents rapid xylose conversion, but a high furfural selectivity prefers in acidic solutions, which would be perfect if organic solvents were available to form biphasic systems., 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 Elsevier Ltd. All rights reserved.)

Efficient dewatering of sewage sludge is an energy- and carbon-saving procedure for sludge treatment in wastewater treatment facilities. The ultrasound-coupled divalent iron ion activated persulfate process can effectively promote sludge dewatering and improve organic substance content. Under the action of ultrasound (US 50 w/L), divalent iron ions (Fe 2+ ) 200 mg/g (TS), and persulfate (PDS) 200 mg/g (TS) for 60 min, the capillary suction time (CST) was reduced by 79.74%, and the moisture content of the dewatered sludge cake reached 56.51 wt%. The organic carbon content of treated sludge was also four times higher than the original sludge and types were richer in short-chain volatile species in US/Fe 2+ /PDS. Moreover, the correlation analysis found that the relationship of between CST and SV 30 , Zeta and lactate dehydrogenase (LDH) were positive correlation, and the relationship of SCOD and TC were positively correlated with the PN (SB-EPS). Mechanistic studies showed that the US/Fe 2+ /PDS system could produce oxygen activators by US coupling Fe 2+ to strengthen the effect of activated PDS strongly, while the sulfate radicals (SO 4 · - ) radical was a dominant role. The cracking mechanism is divided into two pathways effectively degraded the macromolecule EPS into a small-molecule acid and further reduced the water-holding interfacial affinity as follow: (1) the radical path dominated by hydroxyl radicals (·OH), SO 4 · - , and superoxide radical (O 2 · - ); (2) the non-radicals dominated by monoclinic oxygen ( 1 O 2 ). Afterwards, the electrostatic force and interfacial free energy were reduced, resulting in enhanced self-flocculation and mobility to enhanced dewaterability. These findings demonstrated the US/Fe 2+ /PDS system had significant advantages in sludge cracking and provided theoretical support for its practical application., 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 Elsevier Ltd. All rights reserved.)

Phthalate esters (PAEs) have become one of the most concerned emerging organic pollutants in the world, due to the toxicity to human health, and hard to remove it efficiently. In this study, the degradation performance of DBP and DEHP in the soil by water bath heating activated sodium persulfate (PS) method under different factors were studied, in which the degradation rate of DBP and DEHP were improved with the increasing of temperature, PS concentration and water/soil ratio, and higher diffusion efficiency treatments methods, due to the improved mass transfer from organic phase to aqueous media. However, the degradation rate of DEHP was much lower than that of DBP, because DEHP in the soil was more difficult to contact with SO 4 •- for reaction on soil surface, and the degradation rate of PAEs in soil was significantly lower than that in water. Redundancy analysis of degradation rate of DBP and DEHP in water demonstrated that the key factors that determine the degradation rate is time for DBP, and cosolvent dosage for DEHP, indicating that the solubility and diffusion rate of PAEs from soil to aqueous are predominance function. This study provides comprehensive scenes in PAEs degradation with persulfate oxidation activated by thermal in soil, reveal the difference of degradation between DBP and DEHP is structure-dependent. So that we provide fundamental understanding and theoretical operation for subsequent filed treatment of various structural emerging pollutants PAEs contaminated soil with thermal activated persulfate., 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 Elsevier Inc. All rights reserved.)

The study proposed improving the arsenic encapsulation efficiency (EE) in liposomes and make it pH responsive. Liposomes were prepared using the ethanol injection method (EIM), thin film dispersion method (TFM) and CAGM with sodium arsenite (NaAsO 2 ). The orthogonal experimental was used to optimize the preparation conditions of the CAGM. The arsenic-carrying liposomes were characterized by polydispersity index (PDI), transmission electron microscopy (TEM), in vitro release experiments and inductively coupled plasma emission spectrum (ICP). The toxicity was investigated by rat glioma cells (C6) and human brain micro vascular endothelial cells (HBMEC). The results indicated that the CAGM can effectively improve the EE of NaAsO2 and has a pH response compared with EIM and TFM. The size of nanoparticles prepared by CAGM was 118.8 ±56.67 nm, the arsenic EE was 54.3 ±9.82%, the drug loading rate was 7.13 ±0.72% (P <0.01), pH sensitivity was shown at pH 5.5. The optimal parameters of the CAGM were 3 mg NaAsO2, 5:1 egg phosphatidylcholine (EPC) to cholesterol (CHOL) and 240 mmol/L calcium acetate (CaAC2). The results showed that the CAGM has good biocompatibility and is one of the effective ways to improve the NaAsO2 encapsulation rate and pH response in liposome nanoparticles.

P-arsanilic acid (AA) has received widespread attention because of its conversion to more toxic inorganic arsenic compounds (arsenate and arsenite) in the natural ecosystems. Its removal process and mechanisms with co-existence of microplastics remain unkown. In this study, biochar loaded with nano zero-valent iron (nZVI) particles (ISBC) was prepared by using iron scrap obtained from a steel works and wood chips collected from a wood processing plant. The advanced oxidation system of sodium persulfate (PDS) activated by ISBC was applied for AA degradation and inorganic arsenic control in aqueous media. More than 99% of the AA was completely degraded by the ISBC/PDS system, and the As(III) on AA was almost completely oxidized to As(V) and finally removed by ISBC. HCO 3 - inhibited the removal of AA by the ISBC/PDS system, while Cl - had a dual effect that showing inhibition at low concentrations yet promotion at high concentrations. The effect of microplastics on the degradation of AA by the ISBC/PDS system was further investigated due to the potential for combined microplastic and organic arsenic contamination in rural/remote areas. Microplastics were found to have little effect on AA degradation in the ISBC/PDS system, while affect the transport of inorganic arsenic generated from AA degradation. Overall, this study provides new insights and methods for efficient removal of p-arsanilic acid from water with coexisting microplastics., 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. Published by Elsevier B.V.)

This work is devoted to the study of the features of isomorphism in compounds of a Ca-Na-Bi-P-O-F system with a crystalline structure of the mineral apatite, as well as its effect on the biocompatibility of substances in relation to human cells in an in vitro model. A Ca 10-2 x Bi x Na x (PO 4 ) 6 F 2 system ( x = 0, 1, 2, 3, 4, and 5) is characterized by continuous isomorphism, which follows from the minimum deviations of the unit cell parameters from the Vegard and Rötgers rules. The refinement of the crystal structure showed that the cations are unevenly distributed between the 4 f and 6 h positions of the crystal structure of apatite: the bismuth ions are predominantly localized in the 6 h position, while the sodium ions are concentrated in the 4 f position. A standard MTT test of the biocompatibility of compounds with x = 1, 2, 3, and 4, and at x = 1 showed an anomaly in the form of an increased relative cell growth rate. This paper discusses the possible crystal-chemical and morphological reasons for this phenomenon.

The removal of mixture of two azo dyes, Acid blue 29 and Ponceau xylidine, was studied by heterogeneous Fenton and Fenton-type processes using hydrogen peroxide and sodium persulphate as oxidants in the presence of and nano and micro- particles as catalysts. The synthesised nano- particles were characterised using analytical techniques viz. FT-IR, TEM, EDX, powder XRD and VSM. We have examined the effects of particle size on the COD removal efficiency and the reusability of the catalyst after optimising pH, and concentrations of catalyst and oxidant. Combination of nano-  and hydrogen peroxide possessed higher COD removal efficiency, which was accelerated in acidic pH and inhibited at pH > 6. Total consumption of hydrogen peroxide confirmed the efficiency of the optimised parameters. The mechanism of the formation of intermediate ions and products are proposed. COD removal and consumption of hydrogen peroxide follow pseudo-first-order kinetics. The toxicity of the solutions was assessed using Aliivibrio fischeri light loss and Escherichia coli growth inhibition assays. Both the assays showed different toxicity levels for the same solution.

The hydrogen bond structure of water was examined by comparing the temperature dependent OH-stretching bands of water and aqueous NaClO 4 , KClO 4 , Na 2 SO 4 , and K 2 SO 4 solutions. Results called attention to the role of cations on top of the importance of anions determining the emerging structure of a multi-layered system consisting single water rings or multi-ring water-clusters.

In this study, a novel pH-sensitive hydrogel beads that is based on gelatin/sodium alginate/chitosan (GEL/SA/CS) loaded with propolis ethanolic extracts (PE) were synthesized. The swelling behavior of GEL/SA/CS hydrogel beads was studied in different pH solutions and compared with unloaded CS (GEL/SA) hydrogel beads. The in vitro release studies have been revealed using four different pH (1.3, 5.0, 6.0, and 6.8), a saliva environment (pH 6.8), a simulated gastric fluid (SGF) (pH 1.3), and a simulated intestinal fluid (SIF) (pH 6.8) to simulate the physiological conditions in gastrointestinal (GI) tract. Propolis-loaded hydrogel beads were found to be stable at pH 1.3, 5.0, 6.0, simulated saliva, SGF, and SIF mediums, whereas the beads lose their stability at pH 6.8 buffer solution. Tested microorganisms displayed greater sensitivity to PE-loaded hydrogel beads compared with pure propolis. Contrary to antimicrobial activity results, antibiofilm activity results of PE-loaded GEL/SA and GEL/SA/CS hydrogel beads were found at low levels. According to the obtained results, the propolis-loaded GEL/SA/CS hydrogel beads synthesized within this study can be used in the treatment of GI tract diseases such as oral mucositis, gastric ulcer, ulcerative colitis, and GI cancer, as controlled releasing carriers of propolis., (© 2020 International Union of Biochemistry and Molecular Biology, Inc.)

Lipid membranes are a key component of contemporary living systems and are thought to have been essential to the origin of life. Most research on membranes has focused on situations restricted to ambient physiological or benchtop conditions. However, the influence of more extreme conditions, such as the deep subsurface on Earth or extraterrestrial environments are less well understood. The deep subsurface environments of Mars, for instance, may harbor high concentrations of chaotropic salts in brines, yet we know little about how these conditions would influence the habitability of such environments for cellular life. Here, we investigated the combined effects of high concentrations of salts, including sodium and magnesium perchlorate and sulfate, and high hydrostatic pressure on the stability and structure of model biomembranes of varying complexity. To this end, a variety of biophysical techniques have been applied, which include calorimetry, fluorescence spectroscopies, small-angle X-ray scattering, dynamic light scattering, and microscopy techniques. We show that the structure and phase behavior of lipid membranes is sensitively dictated by the nature of the salt, in particular its anion and its concentration. We demonstrate that, with the exception of magnesium perchlorate, which can also induce cubic lipid arrangements, long-chain saturated lipid bilayer structures can still persist at high salt concentrations across a range of pressures. The lateral organization of complex heterogeneous raft-like membranes is affected by all salts. For simple, in particular bacterial membrane-type bilayer systems with unsaturated chains, vesicular structures are still stable at Martian brine conditions, also up to the kbar pressure range, demonstrating the potential compatibility of environments containing such ionic and pressure extremes to lipid-encapsulated life.

Fast photochemical oxidation of proteins (FPOP) has demonstrated the ability to inform on the higher order structure of proteins. Recent technological advances have extended FPOP to live cells (IC-FPOP) using multiple cell lines and in vivo (IV-FPOP) using C. elegans . These innovations allow proteins to be studied in their native cellular environment. Hydroxyl radicals are generated via the photoloysis of hydrogen peroxide. Hydrogen peroxide is a signaling molecule that can induce changes to some proteins in the cell limiting the proteins that can be studied by IC-FPOP. Here, we evaluate the sulfate radical anion as a footprinting label in IC-FPOP with sodium persulfate as the precursor. Our findings show a 1.5-fold increase in the number of modified proteins compared to IC-FPOP using hydroxyl radicals at the same precursor concentration demonstrating the amenability of this radical with IC-FPOP.

Triple-helical aggregates (THAs) have been proven to affect the biological activities and functional properties of triple-helix polysaccharides. Thus, it's urgent to seek a method to reduce the size of THAs while preserving independent triple helices (ITHs). In this study, the effects of alkali-neutralization (AN) treatment on THAs and ITHs of curdlan were studied. The positive values of the Congo red test data (R 2 >0.99) fitted using a Logistic model indicated that AN treatment (C NaOH/HCl >0.28 mol/L) facilitated the disaggregation of THAs. Congo red test, sedimentation test, and turbidity test showed that AN treatment (C NaOH/HCl = 1.0 mol/L) significantly reduced the size of THAs to approximately 1 μm while effectively increasing the relative amount of ITHs to approximately 199 %. Fourier transform infrared spectroscopy and X-ray diffraction analysis showed that AN treatment basically unchanged the primary structure of curdlan chains, but affected the crystalline structure and the intermolecular and intramolecular hydrogen bonding of curdlan., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Sodium chloride (NaCl) is an indispensable ingredient in meat products, but the consumption of high doses of sodium contained in their formulations may bring about negative health implications. The replacement of NaCl by other salts in meat products has been a technological challenge. Accordingly, this review highlights the importance of NaCl over other sodium and non‑sodium salts in the saltiness perception and proposes the use of reduced-size and shapes of NaCl to maximize saltiness perception, while using less NaCl dosages in meat products. However, the effect of matrix components (water, proteins and fats) on the final salty taste is of special consideration. To counteract the effect of the matrix components, two main routes of incorporation of different NaCl types in meat products are discussed: encapsulation and protection of NaCl by the hydrophobic component of the meat product. Given the limited number of publications using this potential strategy, more studies on the application of these technological strategies are required., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This study concerns the performance evaluation of 6-carboxyl chitin for its wound healing application. 6-Carboxyl chitins were prepared by the oxidation of chitin at C-6 with NaClO/TEMPO/NaBr after α-chitin was pretreated in NaOH/urea solution. The products with different molecular weights were obtained by changing reaction conditions. They all were completely oxidized at C-6 and N-acetylated at C-2 according to FT-IR and NMR results. 6-Carboxyl chitins could stimulate significantly the proliferation of human skin fibroblasts (HSF) and human keratinocytes (HaCaT), and the bioactivities were concentration and Mws dependent. Within the scope of the study, 10-40 kDa of Mws and 10-100 μg/mL of concentrations were most suitable for the HSF proliferation, but the proliferation of HaCaT increased with decreasing the concentration and Mw. In addition, 6-carboxyl chitins could also induce macrophages and fibroblasts to secrete growth factors. Therefore, 6-carboxyl chitins could be expected to be an active ingredient for wound healing., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Waste lignin is a potential source of renewable fuels and other chemical precursors under catalytic pyrolysis. For this purpose, four mixed metal oxide catalytic mixtures (Cat) derived from Na 2 CO 3 , CeO 2 and ZrO 2 were synthesised in varying compositions and utilised in a fixed bed reactor for catalytic vapour upgrading of Etek lignin pyrolysis products at 600 °C. The catalytic mixtures were analysed and characterised using XRD analysis, whilst pyrolysis products were analysed for distribution of products using FTIR, GC-MS and EA. Substantial phenolic content (20 wt%) was obtained when using equimolar catalytic mixture A (Cat&#95;A), however the majority of these phenols were guaiacol derivatives, suggesting the catalytic mixture employed did not favour deep demethoxylation. Despite this, addition of 40-50% ceria to NaZrO 2 resulted in a remarkable reduction of coke to 4 wt%, compared to ~9 wt% of NaZrO 2 . CeO 2 content higher than 50% favoured the increase in conversion of the holo-cellulose fraction, enriching the bio-oil in aldehydes, ketones and cyclopentanones. Of the catalytic mixtures studied, equimolar metal oxides content (Cat&#95;A) appears to showcase the optimal characteristics for phenolics production and coking reduction.

Metal nanoclusters (NCs) have attracted extensive interest in electrochemiluminescence (ECL) field, but it is still a significant challenge to prepare high ECL efficiency NCs, which tremendously precludes their application in sensing and imaging. Herein, we report poly(3,4-ethylenedioxythiophene) (PEDOT) as a functional ligand for NCs with a "kill three birds with one stone" role, acting as a stabilizer like existing templates, excitingly, excellent electrical conductivity to accelerate the injection of interfacial electrons, and outstanding electrocatalytic activity toward coreactants (S 2 O 8 2- ), which breaks the convention that traditional ligands act as a double-edged sword in ECL field. As an illustration, PEDOT-hosted Ag NCs were prepared with an unprecedented ECL intensity with S 2 O 8 2- as a cathodic coreactant, which indicates that this novel ligand strategy will bring exciting opportunities, not only in opening up new horizons for rational development of high ECL efficiency metal NCs but also in advancing their potential applications in light-emitting devices and clinical biosensing. As a proof of concept, the PEDOT-hosted Ag NCs were applied as neoteric ECL emitters to achieve sensitive detection of dopamine (DA), which showcased a wide linear response from 1 nM to 10 mM and a low detection limit of 0.17 nM.

Although more attention has been attracted to the therapy based on reactive oxygen species (ROS) for tumor therapy in recent years, such as photodynamic therapy and chemodynamic therapy, the limited ROS production rate leads to their poor treatment effect owing to the relatively low content of O 2 and H 2 O 2 in tumor microenvironments, confined light penetration depth, strict Fenton reaction conditions (pH 3-4), and so on. Therefore, it is urgent to explore the new agents with highly efficient ROS generation capacity. Herein, we first prepared phospholipid coated Na 2 S 2 O 8 nanoparticles (PNSO NPs) as new ROS generation agents for in situ generating Na + and S 2 O 8 2- through gradual degradation, which can then be changed to toxic • SO 4 - (a novel reported ROS) and • OH regardless of the amount of H 2 O 2 and pH value in the tumor microenvironment (TME). As the generation of a large amount of Na + , PNSO NPs can bypass the ion transport rules of cells through endocytosis to deliver large amounts of Na + into the cells, resulting in a surge of osmolarity and rapid cell rupture and lysis. Osmotic pressure induced by PNSO NPs will further lead to an unusual manner of cell death: caspase-1-related pyroptosis. Moreover, all of above effects will cause high immunogenic cell death, regulate the immunosuppressed TME, and then activate systemic antitumor immune responses to combat tumor metastasis and recurrence. We believe PNSO NPs will be new and potential ROS generation agents, and this work will broaden the thinking of the exploring of new antitumor nanodrugs.

Biochar supported nanosized iron (nFe(0)/BC) was synthesized and used as a persulfate (PS) activator to degradation tetracycline (TC). The influence of the initial pH values, PS and nFe(0)/BC dosage, initial TC concentration, and coexist anions were investigated. In the nFe(0)/BC-PS system, TC could be effectively removed at various pH values (3.0-9.0). The degradation efficiency of TC (100 mg/L) was 97.68% using nFe(0)/BC (0.4 g/L) and persulfate (1 mM) at pH 5.0. Coexisting ions (HCO 3 - and NO 3 - ) had an inhibitory effect on TC degradation. The removal of TC could be fitted by a pseudo-second-order model. Electron-Spin Resonance (ESR) analysis and scavenging tests suggested that sulfate radicals (SO 4 · - ) and hydroxyl radicals (HO·) were responsible for TC degradation. Details of the advanced oxidation process (AOP)-induced degradation pathways of TC were determined based on liquid chromatography mass-spectrometry (LC-MS) analysis. The nFe(0)/BC could still maintain 86.38% of its original removal capacity after five cycles. The findings of this study proved that nFe(0)/BC can be applied to activate PS for the treatment of pollution caused by TC., 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 © 2020 Elsevier Ltd. All rights reserved.)

In this work, UVA radiation that is part of solar light is taken as the irradiation source and radicals (HO, SO 4 - and HO 2 /O 2 - ) are generated through activation of hydrogen peroxide (H 2 O 2 ), sodium persulfate (Na 2 S 2 O 8 ) and Bismuth catalyst (BiOCl), respectively. The distinguished performance in removing acetaminophen (ACTP), a model pharmaceutical pollutant, by these three radicals was compared for the first time. Effect of pH, halide ions concentration and interfacial mechanism have been investigated in detail. Interestingly, results show that heterogeneous UVA/BiOCl process has higher degradation efficiency than homogeneous UVA/H 2 O 2 and UVA/Na 2 S 2 O 8 systems whatever the solution's pH. To explain these results, second order reaction rate constant (k radical, ACTP ) have been determined with laser flash photolysis (LFP) or radical scavenging experiments. The strongly interfacial-depended HO 2 /O 2 - radicals have the lowest second order rate constant with ACTP but highest steady state concentration. BiOCl is much easier activated by UVA, and outstanding ACTP mineralization can be achieved. Combination of BiOCl and Na 2 S 2 O 8 exhibits synergistic effects rather than antagonism effects with H 2 O 2 . This study highlights the relative effective utilization of solar light through interfacial directed BiOCl photocatalysis and its synergistic effects with traditional oxidants., 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 © 2020 Elsevier Ltd. All rights reserved.)

C-6 oxidized chitosan is of great interest in obtaining a new moisture retention polymer like hyaluronic acid. The direct C-6 specific oxidation of chitosan mediated by the TEMPO/NaClO/NaBr system has proven to be difficult because of the high crystalline and high C-2 amino group content. In this work, the pre-modification of chitosan by N -succinylation was investigated and followed by the TEMPO-mediated C-6 specific oxidation under homogeneous conditions. The desired 6-oxidized N -succinyl chitosan product was obtained within 15 min with a yield of about 92%. The structure of these chitosan derivatives was confirmed by FTIR and NMR spectroscopy. Moreover, it was observed that the selective oxidation led to a great improvement in water solubility and moisture retention ability. These results present a wide range of possibilities for expanding the utilization of chitosan resources.

Commercially available drug-eluting embolization beads (100-500 μm) reduced the occurrence of adverse events related to an anticancer drug, but were unascertained to remarkably benefit the transcatheter arterial chemoembolization (TACE) treatment of intermediate-stage liver cancer. Dextran-coated arsenite nanoparticles with the size ranging from 400 to 600 nm were developed as a nanosized drug-eluting bead (NDEB) for chemoembolization therapy of the rabbit VX2 liver tumor. We fully characterized their relevant physicochemistry and drug release properties. Their hemolysis was investigated before vessel embolization. The introduction of the NDEB allowed continuous embolization of tumor feeding vessels and sustained release of arsenic trioxide, thereby causing severe tumor necrosis and reduced vascularity. Sonography including B mode ultrasound, color Doppler flow imaging (CDFI) and dynamic contrast-enhanced ultrasound (CEUS) were performed to evaluate the tumor vascularity and viability. Additionally, its hepatotoxicity was tolerable at a medium dose. NDEB-TACE might be an effective therapeutic strategy for interventional therapy.

Turning biomass into biochar as a multifunctional carbon-based material for water remediation has attracted much research attention. Sawdust and rice husk were selected as feedstock for biochar (BC) production, aiming to explore their performance as a catalyst to activate persulfate (PS) for degrading acid orange 7 (AO7). There was an excellent synergistic effect in the combined BC/PS system. Sawdust biochar (MX) showed a faster and more efficient performance for the AO7 degradation due to its abundant oxygen functional groups, compared to rice husk biochar (DK). In the BC/PS system, AO7 was well decolorized and mineralized. Based on the two-dimensional correlation analysis method, the azo conjugation structure and naphthalene ring of AO7 molecule changed first then benzene ring changed during the reaction. Moreover, AO7 decolorization efficiency increased with the increase of PS concentration and biochar dosage, and the deacrease of pH. Biochar deactivated after used twice. When the biochar reached its adsorption equilibrium of AO7, the AO7 could not be degraded in the BC/PS system. SO 4 - and OH participated in the reaction together and OH played the main role in activating PS to AO7 decolorization based on the radical scavengers experiment. All of results indicate using biochar to activate PS for degradation of AO7 contaminated water is a promising method., 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 © 2020 Elsevier Inc. All rights reserved.)

The performance of trichloroethene (TCE) removal was initially investigated in sodium persulfate (SPS) or potassium monopersulfate triple salt (PMS) oxidative environment by reduced graphene oxide (rGO) supported nZVI (nZVI-rGO) catalyst and further the role of sulphur by anchoring nano FeS on nZVI-rGO (FeS@nZVI-rGO) was evaluated. The high usage of oxidants and stability of FeS@nZVI-rGO catalyst were significantly improved due to the insoluble nature of this innovative catalyst by involvement of nano FeS which limited the rapid iron loss caused by the corrosion of active sites and mitigated rapid oxidants decomposition in FeS@nZVI-rGO/SPS and FeS@nZVI-rGO/PMS systems. The tests for target contaminant removal showed that over 95 % TCE could be removed at 100 mg L -1 FeS@nZVI-rGO and 1.2 mM SPS or 0.3 mM PMS dosages, in which over 85 % TCE could be dechlorinated. The reactive oxygen radicals (ROSs) generation mechanisms and their contribution to TCE removal were investigated through radical scavenge tests in both systems, indicating that both HO and SO 4 - were the major ROSs rather than O 2 - . In conclusion, this study revealed the well function and fundamental mechanism of this innovative catalyst by anchoring nano FeS and worth of further demonstration of this technique in TCE contaminated groundwater remediation application., 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 © 2020 Elsevier B.V. All rights reserved.)

This work demonstrates a facile route to assemble MIL-53(Fe) by solvothermal method. Sulfate radical-based advanced oxidation processes (SR-AOPs) coupling with photocatalysis based on MIL-53(Fe) were investigated under visible light. The catalytic effect of MIL-53(Fe) for the degradation of tetracycline hydrochloride (TC-HCl) was systematically studied, as well as the reusability of the catalyst and the effect of operating parameters. The results indicated that 99.7 % of TC (300 mg/L) could be degraded within 80 min in the SR-AOPs coupling with photocatalysis processes, as compared to 71.4 % for the SR-AOPs and only 17.1 % for the photocatalysis. The trapping experiments and electron spin-resonance spectroscopy (ESR) showed the photogenerated electrons of MIL-53(Fe) under visible light irritation were trapped by persulfate to generated sulfate radicals which effectively suppressed the recombination of photogenerated carriers. And also, the SO 4 - could be formed by the conversion between Fe (Ⅲ) and Fe (Ⅱ) in MIL-53(Fe). Moreover, OH and O 2 - generated by the reaction increased significantly due to the increase of SO 4 - which generated more OH and reduced photogenerated carrier recombination respectively. Thus, the degradation efficiency of TC-HCl was improved. Furthermore, the degradation pathway for TC-HCl was proposed using the theoretical calculations and liquid chromatography coupled with mass spectrometry., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The effects of salts on protein systems are not yet fully understood. We investigated the ionic dynamics of three halide salts (NaI, NaBr, and NaCl) with two protein models, namely poly(N-isopropylacrylamide) (PNIPAM) and poly(N,N-diethylacrylamide) (PDEA), using multinuclear NMR, dispersion corrected density functional theory (DFT-D) calculations and dynamic light scattering (DLS) methods. The variation in ionic line-widths and chemical shifts induced by the polymers clearly illustrates that anions rather than cations interact directly with the polymers. From the variable temperature measurements of the NMR transverse relaxation rates of anions, which characterize the polymer-anion interaction intensities, the evolution behaviors of Cl - /Br - /I - during phase transitions are similar in each polymer system but differ between the two polymer systems. The NMR transverse relaxation rates of anions change synchronously with the phase transition of PNIPAM upon heating, but they drop rapidly and vanish about 3-4.5 °C before the phase transition of PDEA. By combining the DFT-D and DLS data, the relaxation results imply that anions escape from the interacting sites with PDEA prior to full polymer dehydration or collapse, which can be attributed to the lack of anion-NH interactions. The different dynamic evolutions of the anions in the PNIPAM and PDEA systems give us an important clue for understanding the micro-mechanism of protein folding in a complex salt aqueous solvent.

Peripheral nerve injuries often cause different degrees of sensory and motor function loss. Currently, the repair effect of the "gold standard", autologous nerve transplantation, is unsatisfactory. Tissue engineering has the potential to tissue manipulation, regeneration, and growth, but achieving personalization and precision remains a challenge. In this study, we used 3D bioprinting to construct a nerve scaffold composed of gelatin/alginate hydrogel containing rat Schwann cells. On day 1 after printing, the Schwann cell survival rate was 91.87 ± 0.55%. Cells could be cultured in the hydrogel for 7 days, and were well attached to the surface of the scaffold. On days 4 and 7, the 3D bioprinted scaffold released higher levels of nerve growth factor (NGF) than 2D culture group. Further, the mRNA levels of NGF, brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and platelet-derived growth factor (PDGF) expressed on day 4 by Schwann cells were higher in the 3D bioprinted scaffold culture than in 2D culture. After 4 weeks of implantation, the cell-containing scaffold still showed partial lattice structure and positive S-100β immunofluorescence. These results indicated that the 3D bioprinted gelatin-sodium alginate/Schwann-cell composite scaffold improved cell adhesion and related factor expression. This 3D bioprinted composite scaffold showed good biocompatibility and could be a promising candidate in neural tissue engineering in the future., 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 © 2019 Elsevier B.V. All rights reserved.)

Varying formulations in the glass system of 40P 2 O 5 ─(24 - x)MgO─(16 + x)CaO─(20 - y)Na 2 O─yTiO 2 (where 0 ≤ x ≤ 22 and y = 0 or 1) were prepared via melt-quenching. The structure of the glasses was confirmed by X-ray diffraction (XRD), Fourier transform infrared (FTIR), micro Raman and solid-state nuclear magnetic resonance (NMR) spectroscopies. The thermal properties and the activation energy of crystallization (E c ) were measured using thermal analysis and the Kissinger equation, respectively. The glass forming ability of the formulations investigated was seen to decrease with reducing MgO content down to 8 mol% and the glass stability region also decreased from 106 to 90°C with decreasing MgO content. The activation energy of crystallization (E c ) values also decreased from 248 (for 24 mol% MgO glass) to 229 kJ/mol (for the 8 mol% MgO content) with the replacement of MgO by CaO for glasses with no TiO 2 . The formulations containing less than 8 mol% MgO without TiO 2 showed a strong tendency toward crystallization. However, the addition of 1 mol% TiO 2 in place of Na 2 O for these glasses with less than 8 mol% MgO content, inhibited their crystallization tendency. Glasses containing 8 mol% MgO with 1 mol% TiO 2 revealed a 12°C higher glass transition temperature, a 14°C increase in glass stability against crystallization and a 38 kJ/mol increase in E c in comparison to their non TiO 2 containing counterpart. NMR spectroscopy revealed that all of the formulations contained almost equal percentages of Q 1 and Q 2 species. However, FTIR and Raman spectroscopies showed that the local structure of the glasses had been altered with addition of 1 mol% TiO 2 , which acted as a network modifier, impeding crystallization by increasing the cross-linking between phosphate chains and consequently leading to increased E c as well as their glass forming ability., (© 2019 Wiley Periodicals, Inc.)

The cell envelope of Gram-positive bacteria generally comprises two types of polyanionic polymers linked to either peptidoglycan (wall teichoic acids; WTA) or to membrane glycolipids (lipoteichoic acids; LTA). In some bacteria, including Bacillus subtilis strain 168, both WTA and LTA are glycerolphosphate polymers yet are synthesized through different pathways and have distinct but incompletely understood morphogenetic functions during cell elongation and division. We show here that the exolytic sn -glycerol-3-phosphodiesterase GlpQ can discriminate between B. subtilis WTA and LTA. GlpQ completely degraded unsubstituted WTA, which lacks substituents at the glycerol residues, by sequentially removing glycerolphosphates from the free end of the polymer up to the peptidoglycan linker. In contrast, GlpQ could not degrade unsubstituted LTA unless it was partially precleaved, allowing access of GlpQ to the other end of the polymer, which, in the intact molecule, is protected by a connection to the lipid anchor. Differences in stereochemistry between WTA and LTA have been suggested previously on the basis of differences in their biosynthetic precursors and chemical degradation products. The differential cleavage of WTA and LTA by GlpQ reported here represents the first direct evidence that they are enantiomeric polymers: WTA is made of sn -glycerol-3-phosphate, and LTA is made of sn -glycerol-1-phosphate. Their distinct stereochemistries reflect the dissimilar physiological and immunogenic properties of WTA and LTA. It also enables differential degradation of the two polymers within the same envelope compartment in vivo , particularly under phosphate-limiting conditions, when B. subtilis specifically degrades WTA and replaces it with phosphate-free teichuronic acids., (© 2020 Walter et al.)

Sulfate radical (SO 4 - )-based conditioning methods, such as zero-valent iron (ZVI, i.e., Fe 0 ) or ferrous iron (Fe 2+ ) activated peroxydisulfate (S 2 O 8 2- ), have recently developed to improve sludge dewaterability, but it remains unclear how they impact the intracellular and extracellular antibiotic resistance genes (ARGs) in sewage sludge. In this study, it was found that conditioning treatments that used ZVI/S 2 O 8 2- or Fe 2+ /S 2 O 8 2- system, at an acidic initial sludge pH, removed the intracellular ARGs and intI1 and the extracellular intI1 from sewage sludge, but led to the accumulation of extracellular ARGs of aadA-01, aadA-02, aadA1, aadA2-03, and strB in conditioned sludge. During sludge conditioning with ZVI/S 2 O 8 2- or Fe 2+ /S 2 O 8 2- , bacterial hosts of ARGs and intI1 were seriously lysed to release the intracellular ARGs and intI1 to the extracellular environment, thus removing intracellular ARGs and intI1 in sludge, while the released ARGs and intI1 were primarily degraded by the produced SO 4 - to attenuate most extracellular ARGs and intI1. However, the relatively lower degradation ability of SO 4 - for extracellular ARGs of aadA-01, aadA-02, aadA1, aadA2-03, and strB led to their accumulation in conditioned sludge. Therefore, SO 4 - -based conditioning methods can be employed to reduce ARGs in sludge, but the subsequent treatment of sludge dewatering filtrate requires more attention., 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 © 2019 Elsevier B.V. All rights reserved.)

The use of three-dimensional electrode is a new electrochemical oxidation technology for landfill leachate treatment. In this study, a particle electrode was developed using Fe/C granules, which were suspended between the cathode and the anode to create a three-dimensional electrode. The three-dimensional electrode activated sodium persulfate to treat landfill leachate. Fe/C granules were prepared by incorporating iron filings and hydrothermally carbonized biochar into alginate beads. The optimal parameters of the three-dimensional electrode for chemical oxygen demand (COD) removal from landfill leachate were determined based on a series of single factor experiments as an operating voltage of 5 V, a sodium persulfate concentration of 28 mM, and 1 g of Fe/C granules. Treatment with the three-dimensional electrode at optimized conditions achieved 72.9% removal of COD and 99.9% removal of ammonia nitrogen, resulting in landfill leachate being clear and transparent. The changes in total organic carbon, nitrite, and nitrate concentrations indicated that most organic pollution and ammonia nitrogen were converted into CO 2 and N 2 . This study provides an alternative technology for the treatment of refractory organic pollutants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Recently, clean-up of resistant organic compounds has attracted growing attention. In this study, a novel heterogeneous ultrasound-enhanced sludge biochar catalyst/persulfate (BC/PS/US) process was firstly developed for the degradation of bisphenol A (BPA) in water. The results revealed that BC/PS/US process could successfully achieve a positively synergistic effect between sonochemistry and catalytic chemistry on the degradation of BPA compared to its corresponding comparative process. Nearly 98% of BPA could be degraded within 80 min at optimum reaction conditions. The coexisting substances including Cl - , SO 4 2- and NO 3 - had no obvious inhibition on the BPA degradation, whereas HCO 3 - and humic acid (HA) had significant inhibition effects on that. PS decomposition of BC/PS/US process was superior to that of BC/PS or US/PS process. Both SO 4 - and HO participated in the degradation of BPA, but SO 4 - was predominant radical in the BC/PS/US process. A possible pathway of BPA degradation was proposed, and the BPA molecule was attacked by SO 4 - and degraded into five kinds of intermediate products through hydroxylation and demethylation processes. This study helps to comprehend the application of sludge biochar catalyst as a persulfate activator for the degradation of organic compounds under ultrasound irradiation, and provides a new strategy in wastewater treatment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The structural modification of polysaccharides directly affects their physicochemical properties and applications. Dextran, a chained polysaccharide, consists of multiple d-glucose molecules with repetitive structures. In this study, the physicochemical properties of oxidized dextran (DO) at different concentrations of NaClO/NaBr and H 2 O 2 were compared. The results showed that NaClO/NaBr oxidation is more conducive to the formation of carboxyl groups. Oxidized dextran with NaClO/NaBr (DOB) showed good iron (III) chelating ability, and the DOB‑iron (III) complex (DOBIC) had an iron content of 28.31%. According to structural analysis, NaClO/NaBr (2 g/100 g of active chlorine) and H 2 O 2 (4 g/100 g), respectively, oxidize the C1 and C2 hydroxyl groups of dextran to carboxyl groups and open the ring when DO and iron have the strongest chelation ability. The complex is indeed a chelate iron complex, and iron core is composed of iron oxyhydroxide or the β-FeOOH mineral polymorph. These results indicate that DOBIC is expected to be a good iron supplement or food additive to strengthen iron., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The study focuses on degradation efficiency of non-radical activation and radical activation systems of persulfate (PS) to degrade imidacloprid (IMI) by using sodium persulfate (SPS) as PS source. Copper oxide (CuO)-SPS and CuO/biochar (BC)-SPS were selected as PS non-radical activation systems, and pyrite (PyR)-SPS was selected as PS radical activation system. The degradation by CuO-SPS, CuO/BC-SPS and PyR-SPS systems was investigated from acidic to basic conditions (pH 3.0-11.0). Highest degradation by CuO-SPS and CuO/BC-SPS systems was achieved over pH 11.0. In contrast, highest degradation by PyR-SPS system was achieved over pH 3.0, however, PyR-SPS system was also found effective up to pH 9.0. It was found that degradation was more efficient in PS radical activation system, indicating that IMI could be oxidized by radicals rather than by activated PS. Electron paramagnetic resonance (EPR) analysis was carried out to investigate the generation of sulfate (SO 4 - ) and hydroxyl (OH) radicals, which indicated the presence of SO 4 - and OH in CuO-SPS, CuO/BC and PyR-SPS systems. However, free radical quenching analysis indicated that radicals were main reactive oxygen species for degradation. The lower degradation in PS non-radical activation systems was probably resulted from radicals existed as minor reactive oxygen species. The findings indicated that non-radical oxidation systems showed low reality for degradation and good degradation could be achieved by radical oxidation system. The degradation was also carried out in real waters to investigate the potential applicability of applied systems, which supported PyR-SPS system for effective degradation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

UV-activated persulfate (UV/PS) and peroxymonosulfate (UV/PMS) processes as alternative methods for removal of imidacloprid (IMP) were conducted for the first time. The reaction rate constants between IMP and the sulfate or hydroxyl radical were calculated as 2.33×10 9   or 2.42×10 10  M -1  s -1 , respectively. The degradation of IMP was greatly improved by UV/PS and UV/PMS compared with only UV or oxidant. At any given dosage, UV/PS achieved higher IMP removal rate than UV/PMS. The pH range affecting the degradation in the UV/PS and UV/PMS systems were different in the ranges of 6-8 and 9 to 10. SO 4 2- , F - and NO 3 - had no obvious effect on the degradation in the UV/PS and UV/PMS systems. CO 3 2- and PO 4 3- inhibited the degradation of IMP in the UV/PS system, while they enhanced the degradation in the UV/PMS system. Algae organic matters (AOM) were used to consider the impact of the degradation of IMP for the first time. The removal of IMP were restrained by both AOM and natural organic matters. The higher removal rate of IMP demonstrated that both UV/PS and UV/PMS were suitable for treating the water containing IMP, while UV/PS was cost-effective than UV/PMS based on the total cost calculation. Finally, the degradation pathways of IMP were proposed., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Bioactive ceramics, glasses and glass ceramics have the ability to enhance the bone formation and bond to surrounding tissue. In this study, we report on the synthesis of mesoporous nanobioactive glass ceramic with the modified composition of quaternary system 50% SiO 2 - 26% Na 2 O - 20% CaO- 4% P 2 O 5 (Ca/P: 5) [i.e.50S20C] by sol-gel method and succeeded by heat treatment. The as-dried sample was calcined at various temperatures such as 100 °C, 300 °C, 500 °C, 700 °C and 900 °C for 24 h.The weight loss measurement was carried out using Thermogravimetric (TG) analysis. The structural features were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM) & Energy Dispersive Spectroscopy (EDS) analysis. The results revealed that the synthesized glass ceramic stabilized at higher temperature (700 °C and 900 °C)making more formation of the crystalline phase of sodium calcium silicate. The density and porosity measurements were carried out by using the Archimedes immersion method. The mechanical properties of the glass ceramic exhibit the compressive strength as69 MPa and 72 MPa for 700 °C and 900 °C, respectively. From the obtained results, we confirmed the calcined bioactive glass ceramic nanoparticles at 700 °C and 900 °C having a better crystallization, crystallite size with high surface area, high density, suitable porosity of mesoporous with dense microstructure and adequate mechanical properties. Furthermore, in vitro bioactivity character of calcined nanobioactive glass ceramics were studied by using an immersion of nanopowders into Stimulated Body Fluid (SBF) solution for two different time periods such as 7 and 14 days. After soaking the glass ceramic nanopowders in SBF, the structural and morphological changes were determined by using XRD, FTIR and FESEM & EDS analysis, respectively. The in vitro results exhibited that crystallization did not retard the samples bioactivity which indicates the increase of material bioactivity while calcining temperature was increased and it is used to fabricate tissue engineering scaffolds with sustained mechanical properties. Moreover, the enhanced bactericidal behavior of glass ceramic has also been studied. An antibacterial study revealed that the prepared bioactive glass ceramic show a significant effect on two bacteria E. coli and S. aureus., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Chemical oxidation has been applied to remove soil contaminants and thereby reduce human and ecological risks from contaminated sites. However, few studies have been conducted on the natural infiltration of oxidant solutions into unsaturated soil. Moreover, the infiltration capacity of oxidant solutions at various concentrations in unsaturated soil has not yet been studied. This study investigated the natural infiltration tendency of oxidant solutions like hydrogen peroxide (H 2 O 2 ), potassium permanganate (KMnO 4 ), and sodium persulfate (Na 2 S 2 O 8 ), in sand and sandy loam. Cumulative infiltration was recorded from a soil column equipped with a Mariotte reservoir. The infiltration rate, sorptivity, and unsaturated hydraulic conductivity were obtained from the cumulative infiltration results. Na 2 S 2 O 8 showed the highest infiltration rate in both sand and sandy loam, and the infiltration of Na 2 S 2 O 8 increased as the concentration was increased from 0.05 to 1%. However, the infiltration of KMnO 4 and H 2 O 2 solutions was governed more by chemical reaction behavior than by liquid physical properties or soil hydraulic properties. The production of oxides and gas due to reaction induced clogging in flow paths, resulting in less infiltration. Infiltration of H 2 O 2 at concentrations greater than 0.5% was not observed in sand or sandy loam due to gas formation and swelling., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The activation of peroxydisulfate (PDS) by gas/liquid dielectric barrier discharge (DBD) plasma in a flat plate configuration was assessed through phenol removal. The results indicated that PDS addition exhibited a significantly promoting effect on phenol removal and mineralization. In the reaction lacking PDS, phenol in aqueous solution was removed from the initial 10 mg L -1 to 4.75 mg L -1 (by 52.5%), whereas the addition of 1770 mg L -1 PDS increased the overall removal to 78.7%, as indicated by a one-fold increase in the pseudo-first-order kinetic constant. In addition, the corresponding total organic carbon (TOC) removal was increased from 27.5% to 48.4%. Furthermore, an increased input voltage was favourable for increases in phenol removal, the kinetic constant and PDS utilization, which were also influenced by the PDS dose, initial solution pH and water matrix. In addition, through the analysis of radical quenching experiments, the enhancement could be mainly attributed to the production of SO 4 •- and •OH by PDS activation by discharge plasma. The DBD system coupled with PDS exhibited a high removal efficiency for phenol, and thus, the overall findings could provide new insight into wastewater treatment., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this study, the effects of key parameters on the degradation kinetics of sulfamethoxazole (SMX) in an Fe(ii)-activated persulfate (PS) process were elucidated. SMX could be completely degraded within 240 min at an initial pH of 3.3. It was found that 1 : 10 is the optimum molar ratio of Fe(ii) : PS. Typical water quality parameters, including solution pH, SMX concentration, inorganic ions and humic acid, are discussed for the degradation process. Although the SMX degradation kinetics varied for different water quality parameters, relatively high SMX removal could always be achieved. The Fe(ii)-activated persulfate process could maintain excellent SMX degradation under optimum reaction conditions. In addition, the reaction sites and intermediates of SMX were predicted by density functional theory (DFT) calculations and wave function analysis. The results of different calculations consistently indicate that N7 is the site with the highest electrophilic reactivity of SMX. The main intermediates formed were characterized through accurate mass measurement using UHPLC-HRMS/MS. Combined with the theoretical computations, the SMX degradation pathways in the Fe(ii)-activated persulfate process are proposed. This research could provide theoretical guidance for the degradation mechanism of sulfonamides and provide technical support for the design of efficient degradation reactions in the future.

Nucleic acid aptamers have been widely used as synthetic probes for bioanalytical applications. Herein, we carried out a detailed study on the immobilization of a series of aptamers ranging from 37 to 88 bases, which are specific to either Escherichia coli (E. coli) or Staphylococcus aureus (S. aureus), on a planar gold substrate via a polyadenine-mediated immobilization method. The resultant surfaces were characterized by both surface plasmon resonance spectroscopy (SPR) and X-ray photoelectron spectroscopy. The results clearly show that the aptamer solution at a lower ionic strength gives rise to a higher lateral density of the aptamer when compared to that at a higher ionic strength. The SPR aptasensors are then employed for detecting their corresponding bacteria (i.e., E. coli and S. aureus, respectively). The data indicate that the SPR aptasensor with a higher density of aptamer exhibits a better capture of target bacteria.

Excess sulfonamides are discharged into the environmental system due to the abuse of antibiotics, which threatens the ecological environment and human health. In this study, the ferric and ferrous as well as calcium peroxide (CP), sodium percarbonate (SPC) and sodium persulfate (SPS) have been used to build Fenton-like system for the sulfanilamide (SA) removal. Compared with other Fenton-like system, the Fe 3+ /CP system exhibited better degradation capacity and 94.65% SA was removed with 3.0 mM CP and 3.0 mM Fe 3+ . A response surface and corresponding quadratic regression equation were obtained by using a three-level Box-Behnken factorial design with the initial pH value and the dosage of Fe 3+ and CP as the model parameters. Depended on the result of the response surface, the optimum conditions of the removal of SA in Fe 3+ /CP system could be obtained: [Fe 3+ ] = 2.96 mM, [CaO 2 ] = 2.33 mM and [pH] = 6.45. Besides that, the influences of Na + , Mg 2+ , Cl - , HCO 3 - , NO 3 - and HA on SA removal were also investigated under the optimum condition. The results revealed that the high concentration of HCO 3 - was able to inhibit degradation of SA while other ions and HA have little effect on SA degradation. These results provided a novel strategy to evaluate the catalyst/oxidant system by combining experiment and computer simulation in wastewater treatment., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The removal of 17 pesticides (pymetrozine, flonicamid, imidacloprid, acetamiprid, cymoxanil, thiachloprid, spinosad, chlorantraniliprole, triadimenol, tebuconazole, fluopyram, difenoconazole, cyflufenamid, hexythiazox, spiromesifen, folpet and acrinathrin) found in agro-wastewater from washing of containers and phytosanitary treatments equipment, has been carried out using sodium persulfate (Na 2 S 2 O 8 ) at pilot plant scale under natural sunlight. Persulfate is a strong oxidant, inexpensive and environmentally appropriate. However, this oxidant is slow in kinetics under ordinary conditions. Na 2 S 2 O 8 can be activated by ultraviolet light, generating SO 4 - radicals, which are also a very strong oxidizing species (E 0  = 2.6 V). Previously, preliminary experiments were carried out at laboratory scale using a photoreactor to optimize the Na 2 S 2 O 8 (300 mg L -1 ) concentration on the rate constants of the found pesticides. The residual levels of the studied pesticides in agro-wastewater (900 L) were in the range 0.02-1.17 mg L -1 for acrinathrin and fluopyram, respectively. After treatment, nearly complete degradation (>97%) of the parent molecules was achieved although 13% of initial DOC was measured. No significant differences (p < 0.05) were found when comparing grown broccoli using reclaimed and unreclaimed water., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, a multielement compound fertilizer (MCF) was fabricated using ammonium zinc phosphate (AZP) as kernel nutrient element, and polydopamine (Pdop) film as inner coating. Besides, sodium carboxymethyl starch (SCS) was proposed as a constituent in AZP@Pdop mixture due to its adhesion, gelling and swelling abilities, to prepare well dispersed suspensions and consolidate the single-coated fertilizer. What's more, iron (Fe), the vital microelement for the growth of crops and alleviating the leaf chlorosis, was chelated by the carboxylate groups of SCS, contributing to make the outer coating compact. The release behavior showed that zinc (Zn), phosphorus (P) and Fe reached 60% cumulative release in 30 days, and the use efficiency of nutrients for corn was about 60%. In summary, this work provides a novel approach to improve the utilization efficiency and prolong duration of the MCF, which might have a potential application in agronomics., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study investigates a novel approach to controlling biofilms of the most frequent pathogens implicated in the etiology of biomaterials-associated infections. New bactericidal filler based on a non-toxic glass, belonging to B 2 O 3 -SiO 2 -Al 2 O 3 -Na 2 O-ZnO system, was used to formulate composites of the most widely used polymers in biomedical applications [i.e. thermoplastic polyurethane (TPU) and polydimethyl siloxane (PDMS)], with varying percentage by weight of the bactericidal glass (5, 15, 25, 35, 50%). Glass-filled polymer composites show dramatically restricted bacterial colonisation and biofilm formation. They exhibit time- and dose-dependent killing, with maximal action at 5 days. The highest activity was found against S.epidermidis biofilm (99% of reduction), one of the most common cause of nosocomial infections. The tensile properties of the obtained glass-filled composites are comparable with the literature data concerning polymeric biomaterials for medical implants and devices. In addition, all the materials presented in this research, revealed an excellent biocompatibility. This was disclosed by cell viability values above 70%, none alteration on erythrocyte membrane or cell functionality in contact with materials (haemolytic index 0-2%), and absence of interferences in blood coagulation (intrinsic, extrinsic and final pathways).

Chemical oxidation and microbial degradation are promising treatments to remediate soils contaminated with persistent organic pollutants. Moderate pre-oxidation is able to enhance the subsequent bioremediation of organic pollutants in soil. In this study, the effects of pre-oxidation on the subsequent biodegradation of benzo[a]pyrene (BaP) were evaluated. The tested oxidants included potassium permanganate (PP) and iron-activated sodium persulfate (PS) at the concentration of 1-40 mmol L -1 . The results showed that 20 mmol L -1 PS and 10 mmol L -1 PP treatments had the highest degradation efficiency of BaP in soil, up to 98.7% and 84.2%, without inhibiting subsequent microbial degradation. 10-20 mmol L -1 of the two oxidants significantly promoted viability of microbial community. Especially, PS facilitated the occurrence of more PAHs-degrading microorganisms. The expression of PAH-degradation gene in PS treatment was significantly higher than that in PP treatment (P < 0.05), leading to 12.0-18.4% higher degradation efficiencies of BaP. In general, proper oxidants of moderate dosages were able to promote microbial bioremediation of persistent organic pollutants in soil., (Copyright © 2018. Published by Elsevier B.V.)

This study evaluates the technical, economical, and environmental impact of sodium persulfate (Na 2 S 2 O 8 ) as an enhancing agent in a photo-Fenton process within a solar-pond type reactor (SPR). Photo-Fenton (PF) and photo-Fenton intensified with the addition of persulfate (PFPS) processes decolorize 97% the azo dye direct blue 71 (DB71) and allow producing a highly biodegradable effluent. Intensification with persulfate allowed reducing treatment time in 33% (from 120 to 80 min) and the consumption of chemical auxiliaries needed for pH adjustment. Energy, reagents, and chemical auxiliaries are still and environmental hotspot for PF and PFPS; however, it is worth mentioning that their environmental footprint is lower than that observed for compound parabolic concentrator (CPC)-type reactors. A life-cycle assessment (LCA) confirms that H 2 O 2 , NaOH, and energy consumption are the variables with the highest impact from an environmental standpoint. The use of persulfate reduced the relative impact in 1.2 to 12% in 12 of the 18 environmental categories studied using the ReCiPe method. The PFPS process emits 1.23 kg CO 2 (CO 2 -Eqv/m 3 treated water). On the other hand, the PF process emits 1.28 kg CO 2 (CO 2 -Eqv/m 3 treated water). Process intensification, chemometric techniques, and the use of SPRs minimize the impact of some barriers (reagent and energy consumption, technical complexity of reactors, pressure drops, dirt on the reflecting surfaces, fragility of reactor materials), limiting the application of advanced oxidation systems at an industrial level, and decrease treatment cost as well as potential environmental impacts associated with energy and reagents consumption. Treatment costs for PF processes (US$0.78/m 3 ) and PFPS processes (US$0.63/m 3 ) were 20 times lower than those reported for photo-Fenton processes in CPC-type reactors.

The reaction of ozone with bromide is an initiation process in bromine activation resulting in the formation of reactive bromine species with impacts on the fate of compounds in the lower atmosphere. Environmental halide sources often contain organics, which are known to influence aqueous bulk reactivity. Here, we present a study investigating the temperature dependence of bromide oxidation by ozone using a coated wall flow tube reactor coated with an aqueous mixture of citric acid, as a proxy for oxidized secondary organic matter, and sodium bromide. Using the resistor model formulation, we quantify changes in the properties of the aqueous bulk relevant for the observed reactivity. The reactive uptake coefficient decreased from 2 × 10-6 at 289 K to 0.5 × 10-6 at 245 K. Our analysis indicates that the humidity-driven increase in concentration with a corresponding increase in the pseudo-first order reaction rate was countered by the colligative change in ozone solubility and the effect of the organic fraction via increased viscosity and decreased diffusivity of ozone as the temperature decreased. From our parameterization, we provide an extension of the temperature dependence of the reaction rate coefficients driving the oxidation of bromide, and assess the temperature-dependent salting effects of citric acid on ozone solubility. This study shows the effects of the organic species at relatively mild temperatures, between the freezing point and eutectic temperature of sea as is typical for the Earth's cryosphere. Thus, this study may be relevant for atmospheric models at different scales describing halogen activation in the marine boundary layer or free troposphere including matrices such as sea-spray aerosol and brine in sea ice, snow, and around mid-latitude salt lakes.

Effects of two salt additives, NaCl and NaClO 4 , at the fixed concentrations of 0.215 M on the properties of aqueous two-phase systems (ATPSs) formed by dextran (Dex) and polyethylene glycol (PEG), and the effects of NaClO 4 at the same concentration on the properties of ATPS formed by PEG and Na 2 SO 4 were examined. The effects of these salt additives on partitioning of 12 small organic compounds and five proteins in the above ATPSs were studied. In each system with a given salt additive, 0.5 M sorbitol, 0.5 M sucrose, and 0.5 M and 1.5 M trimethylamine N-oxide (TMAO) were also used as additives. The results obtained were compared with those reported previously for the Dex-PEG ATPS without salt additives and PEG-Na 2 SO 4 ATPS without salt additives and in the presence of 0.215 M NaCl. It is shown that the differences between the solvent properties of the phases in the systems formed by polymer and salt exceed those observed in the systems formed by two polymers. The three most significant solvent features of the systems are hydrophobic and electrostatic properties and hydrogen bonding donor acidity of the solvent media. Osmolyte additives were found to have a significant effect on the differences between the electrostatic properties of the phases. Analysis of the partition coefficients of 12 organic compounds and five proteins showed that the osmolyte additives may affect the partition behavior of compounds in a compound-specific manner. The relative contributions of different types of interactions of a given compound with aqueous media change in the presence of salt and osmolyte additives. Analysis of the variability ranges of partition coefficient, K, in the systems studied showed that for small organic compounds, the ranges of K-values observed in the PEG-Na 2 SO 4 ATPSs exceed those determined in the Dex-PEG ATPSs quite significantly, whereas for proteins, the range of K-values in Dex-PEG ATPSs exceeded those in PEG-Na 2 SO 4 ATPSs for three proteins, and were very similar for two proteins. This observation supported the notion that the ATPSs formed by two polymers are more suitable for protein analysis than those formed by a single polymer and a salt. The single polymer-salt ATPSs have an advantage for protein isolation/separation., (Copyright © 2018 Elsevier B.V. All rights reserved.)