This work explores silica (SiO₂) extraction from sugarcane bagasse ash using NaOH solution. The obtained SiO₂ with 98 wt% purity is further used to synthesize zeolite NaA for CO₂ adsorption, showing comparable capacity to commercial NaA.

Zeolites in powder form have the potential to agglomerate, lowering access to active sites. Furthermore, a suspension of fine zeolite powder in liquid media is difficult to separate. Such drawbacks could be improved by dispersing zeolite crystals on support materials. This work demonstrates the dispersion of zeolite NaY crystals on bamboo wood by mixing the wood with zeolite gel before hydrothermal treatment. The syntheses were performed with acid-refluxed and non–refluxed wood. The phase of zeolites, particle distribution and morphology, zeolite content in the wood, and zeolite–wood interaction were investigated using X-ray diffraction, X-ray tomography, scanning electron microscopy, thermogravimetric analysis, nitrogen sorption analysis, and X-ray photoelectron spectroscopy. Higher zeolite content and better particle dispersion were obtained in the synthesis with the acid–refluxed wood. The composite of NaY on the acid-refluxed wood was demonstrated to be an effective adsorbent for Ni(II) ions in aqueous solutions, providing a higher adsorbed amount of Ni(II) per weight of NaY.

Adsorption of paraquat and pirimiphos-methyl in water was performed on four adsorbents including montmorillonite (Mt), organoclay (TDA-Mt) from intercalation of Mt with tetradecylammonium chloride, and mesoporous Mt from intragallery templating method (with and without Ti addition). The adsorbents were characterized by X-ray diffraction, N₂ adsorption–desorption, and transmission electron microscopy. Paraquat adsorption isotherms followed Langmuir model and the adsorption capacity was as follows: TDA-Mt > Mt > mesoporous Ti-Mt > mesoporous Mt. The adsorption mechanism on TDA-Mt and Mt might be via ion exchange. The adsorption on mesoporous samples was on the external surface with negative charge. The presence of Ti enhanced the adsorption capacity. Pirimiphos-methyl adsorbed on negative charge of the external surface of Mt samples. The adsorbed amount increased with the initial concentration due to a strong intermolecular interaction.

The goal of this work is to synthesize zeolite NaY inside Lead tree wood. The wood is mixed with zeolite seed gel before mixing with feed gel and subsequent hydrothermal treatment. In the first trial, the dried and untreated Lead tree wood is mixed with the gel of zeolite NaY before the hydrothermal process. Only zeolite NaP is produced. Then, sonication is applied to the wood and zeolite gel mixture before the hydrothermal process. The product is mixed with the phase of NaP and NaY. In the next attempt, the wood is treated with acid reflux before mixing with the zeolite seed gel. NaY is successfully produced inside the wood. When sonication is also applied, the amount of NaY is increased. The presence of zeolites in the wood are confirmed by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, and thermogravimetric analysis. Moreover, the composites are tested for the adsorption of nickel (II) ions from aqueous solutions. The novel Lead tree wood-zeolite NaY composite has the potential as an adsorbent which could be separated easily from the liquid media.