• Rancic, Milica
• Vuksanovic, Marija
• Savic, Andrija
• Kokunesoski, Maja
• Pantic, Krstimir
• Egelja, Adela
• Savic, Marjetka

Abstract

<jats:p>In present study FeAl-LDH@SiO2 adsorbent was used for phosphate and arsenateremoval from aqueous solutions. Silica, obtained from rice husks, was usedas a substrate for the deposition of FeAl based layered double hydroxides(FeAl-LDH) particles. Synthesis of FeAl-LDH, obtained at Fe/Al molar ratioof 3:1, was performed via co-precipitation and concomitant deposition onSiO2 carrier at 1:1, 2:1, and 3:1 LDH/silica mass ratios. The preparedmaterials were characterized by scanning electron microscopy (FE-SEM), X-raydiffraction (XRD), N2 adsorption/desorption isotherms (BET method) andFourier transform infrared spectroscopy (FTIR). SEM analysis revealeduniform precipitate of LDH on SiO2 substrate, while XRD analysis confirmedcrystallographic structure of LDH deposit. Optimization of adsorptionproperties of synthesized adsorbents confirmed best performances ofFeAl-LDH@SiO2, obtained at 3:1 LDH/silica mass ratio. Thus, adsorptionexperiments were carried out with respect to adsorbent dosage, phosphate andarsenate concentration at initial pH 4. Phosphate concentrations weredetermined using spectrophotometer and arsenate concentrations weredetermined using atomic absorption spectrometer. The results showed that themaximum sorption capacities for phosphates was 62.2 mg g-1, and for arsenatewas 59.0 mg g-1. Kinetic study confirmed intra-particle diffusion asrate-limiting step, while thermodynamic study indicates feasible andspontaneous process.</jats:p>

Topics

• Deposition
• x-ray diffraction
• layered
• precipitate
• precipitation
• infrared spectroscopy
• field-emission scanning electron microscopy