A Thai-Taiwanese team coated polyurethane foam with milled activated carbon and a zirconium metal-organic framework to co-adsorb hexavalent chromium and Congo red. Under optimized conditions in a synthetic binary solution containing 50 mg/L of each pollutant, removal approached 100%.
Key findings
- The reported optimum was 25 degrees Celsius, pH 9, 150 rpm, and 24 hours. The hydrophilic composite had a 2.64 g/g swelling ratio. Modeling was consistent with endothermic physicochemical adsorption, pseudo-second-order kinetics, and contributions from electrostatic attraction and diffusion.
Why this matters globally
Simultaneous removal of metals and dyes is relevant to industrial wastewater. Immobilizing powdered adsorbents on foam could simplify material recovery and reuse. If validated in real effluent, the approach may consolidate treatment steps and reduce secondary waste.
Thai researcher contribution
Kasetsart University's chemical-engineering team led major materials and process work in collaboration with National Chung Hsing University, demonstrating Thai capability in circular materials and environmental engineering.
Limitations to consider
Testing used a two-solute synthetic solution at fixed concentrations, without competing ions, organic matter, solids, or variable pH typical of real effluent. A 24-hour contact time is operationally long. MOF leaching, cost, spent-sorbent disposal, and continuous-flow performance remain unresolved.