Plasma alloying technique capable of producing metallic coatings with metallurgical bonding has attracted much attention in dental and orthopedic fields. In this study, the effects of temperature and time of plasma tantalum (Ta) alloying technique on the mechanical, electrochemical, and osteoblastic properties of Ta coatings were systematically investigated. Ta coatings prepared at 800 °C possess better interfacial strengths than those prepared at 750 and 850 °C, and the interfacial strength increases with prolonged alloying time (30–120 min). At 800 °C, however, the increased proportion of the soft Ta deposition layer with alloying time in the whole coating impairs the surface mechanical properties of the entire coating, as convinced by decreased microhardness and wear resistance. Moreover, Ta coatings exhibit better corrosion resistance than the Ti6Al4V substrate in Dulbecco’s modified Eagle medium. The enhanced adhesion and extracellular matrix mineralization level of osteoblasts demonstrate the better cytocompatibility and osteogenic activity of the Ta coating. Ta30 (Ta coating prepared at 800 °C for 30 min) exhibits excellent mechanical, electrochemical, and osteoblastic behaviors and is promising in biomedical applications.

Soil microplastic pollution poses a significant threat to the integrity of terrestrial ecosystems and agricultural sustainability. This review provides a comprehensive synthesis of recent progress on soil microplastic (MP) sources, ecological impacts, and separation technologies. Agricultural practices (e.g., residual plastic mulch and wastewater irrigation) and atmospheric deposition serve as primary drivers of contamination accumulation, with pronounced spatial heterogeneity observed across regions. Predominant MP types such as polyethylene, polystyrene, and polypropylene disrupt soil structure and biogeochemical processes through three core mechanisms: physical interference, chemical toxicity, and biological accumulation. These particles further form carrier–pollutant complexes, exacerbating ecotoxicological impacts across trophic levels. While emerging separation techniques like magnetic separation and solvent extraction demonstrate enhanced efficiency, their implementation faces challenges stemming from soil matrix complexity and high operational costs. This article underscores the need for global collaborative efforts to accelerate innovation in biodegradable polymers, offering practical pathways for sustainable soil management.