Bayberry tannin-functionalized melamine foam: A recyclable scaffold for nZVI-catalyzed metronidazole reductive degradation.

The presence of metronidazole (MNZ) in medical wastewater poses a potential threat to environmental safety and people's health. Herein, we report an innovative strategy to fabricate a recyclable bayberry tannin (BT)-functionalized melamine foam (MF)-supported nanoscale zero-valent iron (MFBT-Fe) catalyst for efficient MNZ degradation in medical wastewater. The through-pore structure of MF reduced mass transfer resistance in heterogeneous systems, while the amphiphilic BT stabilized nZVI via steric hindrance and chelating interactions and created a high-concentration MNZ microenvironment through hydrophobic combined with hydrogen bonding.

Calculation of Volume Fractions of In Situ TiB and Residual Stress Distributions in Functionally Graded Composite of Ti-TiB-TiB.

Ti matrix composite with a polylaminate structure was successfully fabricated via spark plasma sintering (SPS) process. A temperature gradient field (TGF) was obtained during the sintering to form functionally graded material (FGM) in a vacuum under 40 MPa for 5 min. The actual volume fractions of TiB in the matrix were calculated based on the X-ray diffraction pattern.