Harbin Institute of Technology

This study aims to develop an enhanced method that eliminates the dependence of calculated flow number on the termination strain to allow for better anal. of flow number test data.The two-step secant method, the Francken model, and the double-tangent method are firstly evaluated.It is found that the flow number determined by the Francken model or the two-step secant method depends on the termination strain, as do the transition points identified by the double-tangent method.To address this issue, an enhanced two-step secant method is proposed based on the combined use of the secant method and the translation method.The idea behind the translation method is to specify a standardised criterion for flow number tests with different termination conditions, thereby avoiding the effect of the termination strain on the calculated flow numberThe results show that the flow number obtained by the enhanced two-step secant method is no less than that obtained by the two-step secant method.It is also found that there is a unique relationship between flow number and strain rate during the secondary stage, which is independent of asphalt mixture type, stress level, and test temperature

Developing resilient and stable carbon-based metal catalysts for activating peroxymonosulfate (PMS) has attracted great attention in the advanced oxidation processes (AOP) area for removing organic pollutants in wastewater.This study synthesized CoFe₂S₄/CNTs (CFS-CNTs) nanocomposites using hydrothermal technique, which can activate PMS for efficient degradation of tetracycline (TC).A detailed characterization of the synthesized catalysts was conducted, and their catalytic performance was assessed by varying parameters such as catalyst dosage, PMS concentration, pH, and the presence of co-existing substances.The results demonstrated that CFS-CNTs showed excellent TC removal efficiency and reusability, even showing satisfactory degrading performance for various surface water matrixes.The superior activities of the prepared catalysts are attributed mainly to the synergistic interaction of the bimetallic sulfides and CNTs.This synergy aids in the uniform dispersion of the catalysts and increases the availability of catalytic sites, which are essential in producing more active species.Free radical quenching experiments, chem. probe analyses, and ESR (EPR) demonstrated that SO₄·^- and ¹O₂ were the primary reactive oxygen species generated during the reaction environment.XPS and electrochem. assessments also indicate that carbon nanotubes also functioned as high-speed charges, facilitating channels to achieve rapid electron transfer and accelerating the cycling of metal valence states.The TC degradation pathways, intermediate toxicity assessment, and CFS-CNTs/PMS system response mechanisms were also proposed.These findings provide new insights into the application of metal sulfides in PMS systems for the treatment of wastewater containing refractory organic pollutants.

Herein, we demonstrate how the magnetic modulation of the e_g-orbital occupancy of Co ions can become a novel approach to enhance the two-electron oxygen reduction reaction (2e^- ORR) for advanced wastewater treatment by electro-Fenton (EF) process.Nickel foam (NF) substrate coated with ZIF67 was prepared and thermally treated to obtain ferromagnetic NF-supported Co/Co₃O₄ cathodes, whose response to a small magnetic field was further evaluated in EF.The results show an increase of 62.3 % increase in H₂O₂ yield and 46.5 % in faradaic efficiency, improving the degradation rate of the antibiotic sulfamerazine from 77.2 % to 92.4 % in 120 min.This enhancement is attributed to improved electron transfer facilitated by the alteration of e_g-orbital occupancy of Co ions caused by spin regulation under the magnetic field, rather than to mass transport effects.Therefore, magnetic modulation of the e_g-orbital occupancy emerges as a promising strategy to boost EF process for more efficient water decontamination.