ADSORPTION OF Mg(II) AND Ca(II) ON DISULFONATO-SILICA HYBRID

Abstract

Adsorption of Mg(II) and Ca(II) on disulfonato-silica hybrid (DSSH) in the aqueous solution has been studied. The hybrid was synthesized by sol-gel process with sodium silicate solution from rice hull ash, chloroprophyltrimethoxysilane (CTS) and 4-amino-5-hydroxy-naphtalene-2,7-disulfonic acid monosodium salt (ANSNa) as silica source, cross linker and active group, respectively. Sodium silicate solution was reacted with CTS and ANSNa that were added dropwise. Adsorption of magnesium and calcium ions on DSSH was carried out in a batch system. Solution pH significantly affected magnesium and calcium adsorption and the optimum condition was obtained at pH = 6. The synthesized DSSH showed a high adsorption capacity of 0.0844 mmol/g and 0.1442 mmol/g for Mg(II) and Ca(II), respectively. The adsorption isotherm obtained with Langmuir isotherm model gives the negative values of ΔG°, i.e. -23.334 kJ/mol and -22.757 kJ/mol for Mg(II) and Ca(II), respectively, indicating the spontaneous process of adsorption. Kinetic studies showed that the adsorption of Mg(II) and Ca(II) ions onto HDSS follows the pseudo-second-order kinetics.

Synthesis of Disulfonato-Silica Hybrid from Rice Husk Ash

“…The above structure eludation supports the reaction model proposed by Azmiyawati et al [11] that the attachment of AHNSNa onto silica gel occurs in a sequence of two distinct steps. The first step is consisted of binding CTS onto AHNSNa to form disulfonatoaminopropyltrimethoxysilane (PTMDS), Eq.…”

“…If the material contains sulfur, can be expected to emerge successful synthesis. Based on the data obtained by destruction, the sulfur content in DSSH 2825.05 ppm with existing sulfur percent is 2.8733% c/c [11]. The binding sulfur atom is supported by the emergence of other atoms as a supplement, such as the addition of an oxygen atom and a chlorine atom rest of CPTS.…”

“…3, No. 4, December 2014 The synthesis refered to the procedure reported by Azmiyawati et al [11] with litle modification (without reflux process). The first step of synthesis was attachment of sulfonato groups on the CPTS by mixing 50 mL solution of AHNSNa (4.08 %, w/v) in sodium carbonate solution 0.05 M, 4.85 mL triethylamine and 6 mL CPTS added dropwise and constantly stirring for 5 hours.…”

Preparation of Water Repellent Layer on Glass Using Hydrophobic Compound Modified Rice Hull Ash Silica

“…The preparation procedure of sodium silicate was adopted from previously reported work [13]. Rice husk was heated at 700 °C for 4 h and the rice husk ash obtained was washed with 4 M HCl solution.…”

“…Beside commercial precursors, silica may be extracted from rice husk ash, fly and bottom ash, bagasse ash, among others. Rice husk ash contains silica for about 87-97%, and can be used as a precursor to produce silica gel, sodium silicate, and amorphous silica [13]. Many authors have reported the use of rice husk ash in many applications [14][15][16].…”