(583ar) Adsorption Performance of Basic Gas Over Pellet-Type Adsorbents Prepared From Water Treatment Sludge

The major components of water treatment sludge are Al₂O₃ and SiO₂, and it also contains a variety of clay minerals. The heat treatment method turns it into a new crystalline form through decomposition, recombination, and fusion. This approach has attracted the attention of scientists and engineers because the adsorption capacities of sludge derived materials are comparable to those of classic adsorbents such as activated carbons. Considering that water treatment sludge also contains 30% Al₂O₃, an inorganic matter, it can also be turned into zeolite to be used in absorbents, catalysts, and ion exchangers. In this study, the pellet-type adsorbents were prepared by extrusion using water treatment sludge. Effects of binder and calcination on physical and chemical properties of pellet-type adsorbents were investigated. The porous structure and surface characteristics of the adsorbents were studied using nitrogen adsorption, compression strength, scanning electron microscope, X-ray diffraction, and infrared spectroscopy of adsorbed pyridine. With increasing of binder content to 5 wt%, the compressive strength of pellet-type adsorbent could be improved more than three times, but the surface area reduced , and thus the breakthrough time of trimethylamine was shortened. The breakthrough time of the trimethylamine, a basic gas, could be increased more than three times through calcination, which seems to be due to generation of acid sites composed of Lewis acid and Brönsted acid sites on the adsorbent surface.