The application of bioflocculants has become an alternative to that of chemical flocculants in wastewater treatment due to their environmental friendliness and non-toxic effects. This study aimed at isolating a bioflocculant-producing bacterium from marine water, optimisation of its culture conditions, and investigation of the removal efficiency of its bioflocculant on pollutants in wastewater. The bacterium was identified by 16S rRNA gene analysis. Optimal carbon and nitrogen sources, inoculum size, temperature, pH, and time were determined by the one-factor-at-a-time assay. The cytotoxicity of the bioflocculant was assessed on African green monkey kidney and bovine dermis cells using a tetrazolium-based columetric (MTT) method. Its removal efficiencies on chemical oxygen demand (COD), biological oxygen demand (BOD) and sulphur were determined using the Jar test method. The bacterial isolate was identified as Ochrobactrum oryzae AB84113. A maximum flocculating activity of 92% and a yield of 3.768 g/L were obtained when a 1% (v/v) inoculum size was used in the presence of starch and yeast extract at pH 7, 30 °C, and after 72 h of cultivation. The bioflocculant demonstrated non-cytotoxic effects on bovine dermis and African green monkey kidney cells. The bioflocculant removed 98% COD, 91% BOD and 86% of Sulphur. The bioflocculant has potential for pollutant removal from industrial wastewater.

This study investigates the high-temperature corrosion behaviour of directed energy deposited (DED) Ti6Al4V (Ti64) and its in-situ composites (TiC/Ti64 and TiBw/Ti64) in oxygen-rich NaCl- Na ₂ SO ₄ environments at 300 °C, 600 °C, and 900 °C. DED produces refined microstructures with reinforcement phases distributed along grain boundaries, fundamentally altering corrosion mechanisms. Thermogravimetric analysis revealed that TiBw/Ti64 exhibited superior resistance (activation energy: 282 kJ/mol) due to the formation of stable boron oxides (B2O3) that maintained protective layer integrity through self-healing mechanisms. TiC/Ti64 showed intermediate performance (276 kJ/mol), with TiC particles acting as oxygen diffusion barriers but undergoing oxidation at > 800 °C to form TiO2 and carbon residues. Unreinforced Ti64 suffered severe material loss (198 kJ/mol) via volatile TiCl4 formation that disrupted the oxide scale. Microstructural analysis demonstrated that AM-induced grain refinement enhanced oxide nucleation site density, while reinforcement distribution influenced galvanic interactions. These findings establish that in- situ TiBw/Ti64 fabricated by DED offers optimal performance for aerospace and marine. applications below 600 °C, with degradation mechanisms transitioning from surface oxidation to bulk volatilization above this threshold.