Formation of the nanostructure on a silica surface as mercury(II) ions adsorption sites

The present work investigates the adsorptive interactions of Hg(II) ions with hydroxylated silica, aminopropylsilica and silica chemically modified by β-cyclodextrin in aqueous medium. Batch adsorption studies were carried out with various agitation time and mercury(II) concentration. The maximum adsorption was observed within 15–30 min of agitation. The kinetics of the interactions, tested with model of Lagergren for pseudo-first and pseudo-second order equations, showed better agreement with first order kinetics (k 1 = 3.4 ± 0.2 to 5.9 ± 0.3 min−1). The adsorption data gave good fits with Langmuir isotherms. The results have shown that β-cyclodextrin-containing adsorbent has the largest adsorption specificity to Hg(II) : KL = 14 400 ± 700 L/mg. “β-Cyclodextrin–View the MathML sourceNO3-” inclusion complexes with ratio 1:1 and super molecules with composition С42H70O35 · 3Hg(NO3)2 are formed on the surface of β-cyclodextrin-containing silica.