Absorption of heavy metals using resorcinol formaldehyde aerogel modified with amine groups

摘要

Resorcinol-formaldehyde (RF) aerogels modified with amine groups were used to remove heavy metal ions from aqueous solutions. RF aerogel was synthetized under subcritical conditions and then was modified by 3-aminopropyl trimethoxysilane. The ability of modified RF aerogels to remove Pb(II), Hg(II), and Cd(II) ions from aqueous solution was investigated using batch-adsorption technique with respect to the changes in pH, contact time, sorbent concentration, initial metal concentration, and temperature. The maximum adsorption capacity of metal ions Pb(II), Hg(II), and Cd(II), was found to happen at pH 6, 6, and 5, respectively, after about one hour. The experimental findings showed that the ions' adsorption on the surface of the aerogel was endothermic. Adsorption isotherms indicated that the adsorption behavior of modified aerogel could fit in both Langmuir and Freundlich models. The outcomes of this study also showed that amine-modified RF aerogels can be used as an effective sorbent for the removal of heavy metal ions Pb(II), Hg(II), and Cd(II) from aqueous solutions.