Newly developed Zn-Mn-Mg alloys can be invoked as biomedical materials because of their excellent mechanical properties. However, the corrosion behavior of Zn-Mn-Mg alloys was still lacking in research. It had grown to be a hot research topic to improve the corrosion behavior of Zn alloys by surface treatment to meet the application of degradable Zn alloys in biomedical applications. Micro arc oxidation (MAO) is a simple and effective method to improve the corrosion behavior of the alloy. MAO coatings were successfully prepared on the surface of Zn-Mn-Mg alloys by MAO in silicate-based solutions with different NaF concentrations. The microstructure and phase composition of MAO coatings prepared on Zn-Mn-Mg alloys with different NaF concentrations in the electrolyte was examined by a scanning electron microscope and X-ray diffraction. The results showed that the MAO coatings are porous and mainly composed of ZnO. With the increasing NaF concentration in the electrolyte, the average thickness increases. The distribution of the micro/nanopores was uniform, and the pore size ranged from the submicron scale to several micrometers after MAO treatment in the electrolyte containing different concentrations of NaF. Potential dynamic polarization curves and electrochemical impedance spectroscopy were employed to assess the corrosion behavior of MAO coatings in Hank’s solution. The highest corrosion rate can be achieved after MAO treatment, with an electrolyte concentration of 1.5 g/L NaF in Hank’s solution. These results indicated that MAO coating can accelerate the corrosion resistance of a Zn-Mn-Mg alloy.

The availability and phytotoxicity of heavy metals in sewage sludge is the key restrictive factor that limits sludge application. In this study, municipal sewage sludge was stabilized by alkaline slag or coal fly ash, then the leaching characteristic and fraction distributions of Cu, Cd, Pb and Zn were studied, and their effects on seed germination, root length, and plant accumulating were compared. The results showed that mixed sewage sludge with alkaline slag and coal fly ash decreased the percentage of available heavy metals in sewage sludge. The percentage of exchangeable Cu, Pb, Zn and Cd in stabilized sewage sludge (S1–S4) was 1.50–8.67 times lower than that in SS-only treatment. Leachate Cd, Cu, Pb and Zn from stabilized SS was much lower than the limit threshold. The addition of alkaline materials to SS reduced the inhibitory effect on seed germination and root growth. Pearson’s correlation analysis indicated that there was a significant negative correlation between pH and available heavy metals, while a significant positive correlation between the percentage of exchangeable fraction of heavy metals, the leaching potential, tissue concentration and accumulation of heavy metal and toxicity for seed germination was observed.

Peroxynitrite-based advanced oxidation technology has gradually become a research hotspot for degrading dye wastewater due to its high efficiency and environmentally friendly features. Transition metal elements, which are commonly used as catalysts for the activation of persulfates, suffer from problems such as easy deactivation and leaching of metal ions, which limit their practical application. In this study, Co₇₈Si₈B₁₄/g-C₃N₄ composite catalysts were prepared by wet milling and ball milling methods to investigate their degradation of Orange II dyes by assisting the activation of peroxynitrite under visible light, and the effects of the catalyst ratio, light intensity, and the dosage of catalysts on the degradation performance were investigated. It was shown that the optimum ratio of Co₇₈Si₈B₁₄ to g-C₃N₄ was 1:3, and the reaction rate constants for the degradation of orange dye by Co₇₈Si₈B₁₄/g-C₃N₄ + PMS + VIS were 4.3 and 5.37 times higher than those of single g-C₃N₄ + PMS and Co₇₈Si₈B₁₄ + PMS, respectively. Meanwhile, the composite catalyst also showed good degradation performance for rhodamine B, methyl orange, and methylene blue dyes, and the degradation effect could reach more than 75%. Cyclic stability tests showed that the catalyst maintained a high degradation efficiency of more than 94% over multiple cycles with low ion dissolution concentration. Its high catalytic activity is attributed to the lowest adsorption energy of the composite catalyst to PMS (E_ads = −1.97 eV), which facilitates the degradation reaction, while the synergistic effect of g-C₃N₄ and Co₇₈Si₈B₁₄ promotes the production of ·SO₄, ·OH, and ·O²⁻. This study provides new ideas for the development of stable and efficient catalysts to expand the synergy between PMS-based and other advanced oxidation technologies.

Metallic glasses (MGs) with a unique atomic structure have been widely used in the catalytic degradation of organic pollutants in the recent years. Fe₇₈Si₉B₁₃ MGs exhibited excellent catalytic performance for the degradation of oily wastewater in a Fenton-like system for the first time. The oil removal and chemical oxygen demand (COD) removal from the oily wastewater were 72.67% and 70.18% within 60 min, respectively. Quenching experiments were performed to verify the production of active hydroxyl radicals (·OH) by activating hydrogen peroxide (H₂O₂). The formation of ·OH species can significantly contribute to the degradation reaction of oily wastewater. Fe₇₈Si₉B₁₃ MG ribbons were highly efficient materials that exhibited superior reactivity towards H₂O₂ activation in oily wastewater treatment. The study revealed the catalytic capability of metallic glasses, presenting extensive prospects of their applications in oily wastewater treatment.