Development of surface-activated granular media for effective adsorption and filtration

Abstract

The conventional granular media applied in adsorption and filtration processes are not particularly effective in removing many pollutants or impurities in water and wastewater because of the unfavorable surface interactions between the media grains and the matters to be removed. The aim of this study was to develop surface-activated granular media for effective adsorption and filtration in water and wastewater treatment. Surface-activated granular media were prepared by coating the surfaces of inorganic (glass beads) and organic (nylon 6,6 granules) materials with polypyrrole (PPy), and immobilizing chitosan on the surfaces of poly(ethylene terephthalate) (PET) and nylon 6,6 granules through hydrolysis pretreatment. Adsorption and filtration experiments were carried out with humic acid and kaolin particles to evaluate the efficiency of the surface-modified granules. The surface interactions between humic acid or kaolin particles and the granular media were studied using SEM, AFM, and XPS techniques, as well as zeta-potential analysis.