Design spherical particles of potassium peroxymonosulfate compound salt with high stability and good powder properties via an agglomeration-dissolution mechanism

With the outbreak of COVID-19, disinfection protection has become a necessary measure to prevent infection. As a new type of disinfectant, potassium peroxymonosulfate compound salt (PMS) has the advantages of good bactericidal effect, non-toxicity, high safety and stability. However, the current PMS products with irregular particle shapes lead to poor flowability, high hygroscopicity, poor stability of reactive oxygen species (ROS) and serious caking problems. In this work, an agglomeration-dissolution mechanism was designed to prepare spherical PMS particles with large size (>300 mm) and high sphericity (up to 90%), effectively addressing the above problems. Shaping (dissolution and abrasion) is the key to improving sphericity, which is mainly controlled by the design of the heating mode, residence time and stirring rate. Compared with the irregular PMS particles, the large spherical particles present better flowability (angle of repose decreased by 35.80%, Carr's index decreased by 64.29%, Hausner's ratio decreased by 19.14%), lower hygroscopicity (decreased by 38.0%), lower caking ratio (decreased by 84.50%), and higher stability (the monthly loss of ROS was reduced by 61.68%). The agglomeration -dissolution mechanism demonstrates the crystallization, agglomeration, dissolution and abrasion pro-cess of inorganic salt crystals, providing an opportunity to prepare high-end inorganic crystal materials with high-quality morphologies.(c) 2022 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Enhanced activation of PMS by a novel Fenton-like composite Fe3O4/S-WO3 for rapid chloroxylenol degradation.

Chloroxylenol (PCMX) is widely used as disinfectant since the epidemic outbreak due to its effective killing of Covid-19 virus. Its stable chemical properties make it frequently detected in surface water. Herein, we successfully modified Fe3O4 nanoparticles with S-WO3 (X-Fe3O4/S-WO3) to accelerate the Fe2+/Fe3+ cycle. The composite has outstanding PCMX degradation and peroxymonosulfate (PMS) decomposition efficiency over a wide pH range (3.0 âˆ¼ 9.0). 80-Fe3O4/S-WO3/PMS system not only increased PMS decomposition efficiency from 27.7% to 100.0%, but also realized an enhancement of PCMX degradation efficiency by 16 times in comparison with that of Fe3O4 alone. The catalyst utilization efficiency reached 0.3506 mmol∙g-1∙min-1 which stands out among most Fenton-like catalysts. The composite has excellent degradation ability to a variety of emerging pollutants, such as antibiotics, drugs, phenols and endocrine disrupters, and at least a 90% removal efficiency reached in 10 min. The degradation of PCMX was dominated by HO•, SO4 •- and 1O2. The degradation pathways of PCMX were analyzed in detail. The component WS2 in S-WO3 plays a co-catalytic role instead of WO3. And the exposed active W4+ surf. efficiently enhanced the Fe3+/Fe2+ cycle, thereby complete PMS decomposition and high catalytic efficiency were achieved. Our findings clarify that applying two-dimensional transition metal sulfide WS2 to modify heterogeneous Fe3O4 is a feasible strategy to improve Fenton-like reaction and provide a promising catalyst for PCMX degradation.

Antiviral Activity of Interferon Alpha-2b and Taurine Combination Against SARS-CoV-2 in vitro.

Interferons (IFN) have antiviral activity against many viruses, including SARS-CoV-2. A combination of IFN-a2b and the antioxidant taurine is widely used in the Russian Federation, and its antiviral activity has not been studied before. The aim of this study was to determine the antiviral activity of interferon drugs, in combination with taurine and without it. The study included cytotoxicity and antiviral activity assays of IFN-a2b preparations, when stored according to the instructions at 2-8degreeC, and after 1 month storage at the temperature of 20-26degreeC in a pre-opened state. The combination of IFN alpha-2b with taurine has a higher antiviral activity compared to IFN alpha-2b mono-preparation by more than 25% at a <<low>> and 85% at a <<high>> multiplicity of infection. Selectivity index for combinations of IFN-a2b (50,000 IU/dose) + taurine (1 mg/ml) and IFN-a2b (10,000 IU/ml) + taurine (0.8 mg/ml) was more than 600 units, whereas for the IFN-a2b (10,000 IU/ml) it was 200 units. Antiviral activity does not change after one month at room temperature. The combination of interferon with taurine at high concentrations was less toxic than interferon. The results obtained demonstrate practicability of interferon alpha-2b and taurine combination use for treatment and prevention of COVID-19.Copyright © Team of Authors, 2022.

Fe-Fe Double-Atom Catalysts for Murine Coronavirus Disinfection: Nonradical Activation of Peroxides and Mechanisms of Virus Inactivation.

Peroxides find broad applications for disinfecting environmental pathogens particularly in the COVID-19 pandemic; however, the extensive use of chemical disinfectants can threaten human health and ecosystems. To achieve robust and sustainable disinfection with minimal adverse impacts, we developed Fe single-atom and Fe-Fe double-atom catalysts for activating peroxymonosulfate (PMS). The Fe-Fe double-atom catalyst supported on sulfur-doped graphitic carbon nitride outperformed other catalysts for oxidation, and it activated PMS likely through a nonradical route of catalyst-mediated electron transfer. This Fe-Fe double-atom catalyst enhanced PMS disinfection kinetics for inactivating murine coronaviruses (i.e., murine hepatitis virus strain A59 (MHV-A59)) by 2.17-4.60 times when compared to PMS treatment alone in diverse environmental media including simulated saliva and freshwater. The molecular-level mechanism of MHV-A59 inactivation was also elucidated. Fe-Fe double-atom catalysis promoted the damage of not only viral proteins and genomes but also internalization, a key step of virus lifecycle in host cells, for enhancing the potency of PMS disinfection. For the first time, our study advances double-atom catalysis for environmental pathogen control and provides fundamental insights of murine coronavirus disinfection. Our work paves a new avenue of leveraging advanced materials for improving disinfection, sanitation, and hygiene practices and protecting public health.

Insights into the performance and kinetics of face mask-derived nitrogen-doped porous carbon as peroxymonosulfate activator for gatifloxacin removal

The outbreak of COVID-19 has led to the increase in face mask waste globally. In this study, face mask-derived carbocatalysts doped with nitrogen (N-Mask) were fabricated through one-step pyrolysis of 1:5 w/w mixture of face mask and urea at different temperatures to activate peroxymonosulfate (PMS) for gatifloxacin (GAT) degradation. The N-Mask prepared at 800 degrees C (N-Mask800) exhibited the highest GAT degradation rate with k(app) = 0.093 min(-1) which could be attributed to its high N doping level (17.1 wt%) and highest specific surface area (237.13 m(2) g(-1)). The relationship between k(app), catalyst loading and PMS dosage at various pHs on GAT degradation were successfully established. It was also found that the GAT degradation rate was inhibited in the sequential operating mode compared to the simultaneous operating mode. It was construed that adsorption and catalysis share the same active sites. Deterioration in catalytic performance was observed over successive cycles due to the surface chemistry change during catalysis, and difficulty in catalyst recovery after treatment. Radical scavenger study revealed that both radical and nonradical pathways were involved during GAT degradation, with nonradical pathway playing a dominant role. XPS analysis revealed that pyrrolic N and graphitic N can facilitate PMS activation via radical and nonradical pathways. Based on the LC-MS/MS analysis, the GAT degradation intermediates were identified, and the possible degradation pathways were tentatively proposed. Overall, this study demonstrated that carbocatalyst derived from face mask could be transformed into costeffective and environmentally friendly PMS activator for environmental wastewater treatment applications.

Design spherical particles of potassium peroxymonosulfate compound salt with high stability and good powder properties via an agglomeration-dissolution mechanism

With the outbreak of COVID-19, disinfection protection has become a necessary measure to prevent infection. As a new type of disinfectant, potassium peroxymonosulfate compound salt (PMS) has the advantages of good bactericidal effect, non-toxicity, high safety and stability. However, the current PMS products with irregular particle shapes lead to poor flowability, high hygroscopicity, poor stability of reactive oxygen species (ROS) and serious caking problems. In this work, an agglomeration-dissolution mechanism was designed to prepare spherical PMS particles with large size (>300 μm) and high sphericity (up to 90%), effectively addressing the above problems. Shaping (dissolution and abrasion) is the key to improving sphericity, which is mainly controlled by the design of the heating mode, residence time and stirring rate. Compared with the irregular PMS particles, the large spherical particles present better flowability (angle of repose decreased by 35.80%, Carr's index decreased by 64.29%, Hausner's ratio decreased by 19.14%), lower hygroscopicity (decreased by 38.0%), lower caking ratio (decreased by 84.50%), and higher stability (the monthly loss of ROS was reduced by 61.68%). The agglomeration-dissolution mechanism demonstrates the crystallization, agglomeration, dissolution and abrasion process of inorganic salt crystals, providing an opportunity to prepare high-end inorganic crystal materials with high-quality morphologies. © 2022 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences

Plasma boosted the conversion of waste plastics into liquid fuel by a peroxymonosulfate-hydrothermal process

Plastic wastes are growing fast over the world and impose great burden to eco-system. However, the plastics nurture abundant carbon resource and can be used as ideal raw materials to produce fuels. Hydrothermal process is considered as a promising strategy to convert plastics into fuel under a mild condition, but the conversion efficiency is often limited by the chemical inertness of plastics. Here, we propose a facile plasma treatment method to modify the plastic surface, aimed to boost the conversion of waste plastics into liquid fuel through a peroxymonosulfate (PMS) coupled hydrothermal process. We find that the sample after plasma treatment for 40 s displays 9.2 wt% weight loss with 8 h, which is 6 times that of the pristine sample. The plasma treatment can not only activate the inert surface but also enhanced the PMS activation process by establishing a balance between the radical effect and etching effect.

Transformation of antiviral ribavirin during ozone/PMS intensified disinfection amid COVID-19 pandemic.

Due to the spread of coronavirus disease 2019 (COVID-19), large amounts of antivirals were consumed and released into wastewater, posing risks to the ecosystem and human health. Ozonation is commonly utilized as pre-oxidation process to enhance the disinfection of hospital wastewater during COVID-19 spread. In this study, the transformation of ribavirin, antiviral for COVID-19, during ozone/PMS­chlorine intensified disinfection process was investigated. •OH followed by O3 accounted for the dominant ribavirin degradation in most conditions due to higher reaction rate constant between ribavirin and •OH vs. SO4•- (1.9 × 109 vs. 7.9 × 107 M-1 s-1, respectively). During the O3/PMS process, ribavirin was dehydrogenated at the hydroxyl groups first, then lost the amide or the methanol group. Chloride at low concentrations (e.g., 0.5- 2 mg/L) slightly accelerated ribavirin degradation, while bromide, iodide, bicarbonate, and dissolved organic matter all reduced the degradation efficiency. In the presence of bromide, O3/PMS process resulted in the formation of organic brominated oxidation by-products (OBPs), the concentration of which increased with increasing bromide dosage. However, the formation of halogenated OBPs was negligible when chloride or iodide existed. Compared to the O3/H2O2 process, the concentration of brominated OBPs was significantly higher after ozonation or the O3/PMS process. This study suggests that the potential risks of the organic brominated OBPs should be taken into consideration when ozonation and ozone-based processes are used to enhance disinfection in the presence of bromide amid COVID-19 pandemic.