Magnesium/Silica/Lanthanum@Activated Carbon for the Remediation of As(III) from Water

Abstract

In this study, activated carbon was suitably modified with Mg/Si/La and its effectiveness in removing As(III) was investigated. The structure of Magnesium/Silica/Lanthamum@Activated Carbon (Mg-Si-La@AC) was fully characterized and several parameters, such the dosage, pH, contact time, and initial As(III) concentration, were studied. Thus, the BET surface area, total pore volume, and micropore volume of Mg-Si-La@AC were measured to be 271.46 m2/g, 0.006 cm3/g and 0.52 cm3/g, respectively. The results showed that the optimal condition for the reduction in As(III) from the initial concentration of 100 μg/L to below 10 μg/L was the addition of 1.5 g/L of adsorbent at pH 7.0. Furthermore, 4 h of contact time showed >90% removal. The Langmuir isotherm model was best fitted to the experimental results, exhibiting a maximum adsorption capacity of 322 μg/g, and the PSO kinetic model was found to be the most applicable according to kinetics. Consecutive regeneration studies were carried out and the results showed that the adsorbent was effectively used up to four cycles.