The Preparation of Na-A Zeolite Using Sludge Gasification Ash and Its Application in Cu2+ Removal from Wastewater

As the generation of sewage sludge increases, the gasification thermochemical treatment of sewage sludge has been regarded as an important alternative. So, this study Na-A zeolite was synthesized from the gasification solid residue (ash) of sewage sludge to evaluate its recycling potential. The crystallinity of synthesized Na-A zeolite could be enhanced up to 84.8% optimizing by the Si/Al ratio to 0.8, the reaction temperature to 100 degrees C, and reaction time to 8 h. The Na-A zeolite, synthesized under these optimal conditions, was employed as an adsorbent for Cu2+ removal in wastewater. The adsorption interaction between Cu2+ and Na-A zeolite was well-described by the pseudo-second-order model, indicating an ion exchange mechanism with electron transfer between the contaminant ion and the adsorbent. The theoretical equilibrium adsorption capacity for Na-A, derived from the pseudo-second-order model, was found to be 80.99 mg/g. Adsorption isotherm analysis revealed that the Langmuir model, which posits monolayer adsorption, was more appropriate than other models. These findings indicate that gasification sewage sludge residues can serve as an economical alternative and have potential as an adsorbent material.