Unlocking the potential of Tunisian dam sediment: optimizing zeolite X synthesis via Taguchi and Box-Behnken methods for sustainable resource recovery and versatile applications.

The Tunisian Lebna dam sediment was utilized to create the zeolite faujasite type Na-X. The aim of this investigation is to optimize the yield of Na-X zeolite using alkaline fusion hydrothermal treatment. Taguchi orthogonal array design was employed with nine trials to explore operating parameters including fusion temperature and time, activator type, and sediment type. The efficiency of alkaline fusion was evaluated using acid solubility. After dissolving the optimal alkali-fused sample in water, the Box-Behnken plan was used to identify the influence of L/S ratio, crystallization temperature, and time on zeolite Na-X yield. Rietveld analysis identified the mineral phases in the sediment as quartz (82.0%), calcite (8.8%), kaolinite (6.0), and illite (1.2%). With a NaOH activator, 850 °C fusion temperature for 30 min, 15 L/S ratio, and 75 °C crystallization temperature for 4 days, highly crystalline zeolite Na-X was created. FTIR, TGA, N2 adsorption-desorption isotherm, and X-ray diffraction were used to thoroughly describe this sample. The findings reveal the substantial zeolitization potential of the raw Lebna dam sediment, resulting in a high yield of zeolite Na-X.

Synthesis and Characterization of Wood Rigid Polyurethane Composites.

Incorporating biodegradable reinforcement, such as wood particles, into rigid polyurethane foams (RPUFs) is among the alternatives to reduce their environmental impact. This study aims to assess the effect of different wood particles as reinforcement in RPUFs. Reinforced rigid polyurethane foams are synthesized with milled wood particles of various forms and sizes and commercial polyol and isocyanate. The effect of fiber treatments and mechanical stirring on foams' properties is also studied. Additional tests on polyisocyanurate foams (PIR) were undertaken to assess the effect of reinforcement on their properties. Mechanical properties are measured to investigate the impact of wood particle reinforcement on the foam. Confocal microscopy and Fourier-transform infrared spectroscopy (FTIR) showed the interaction between the wood fibers and the matrix. Despite the adhesion observed for some fibers, most of the cell walls of RPUFs were punctured by the rigid wood fibers, which explained the decrease in the compressive strength of the composites for manually mixed foams. Mechanical stirring proved to be an efficient method to enhance the reinforcement power of untreated fibers. RPUF foams' properties showed similar changes when untreated wood flour was introduced to the formula, increasing compressive strength significantly.