Simultaneous Adsorption of Chromium (VI) and Phosphate by Calcined Mg-Al-CO₃Layered Double Hydroxides

Abstract

The adsorption characteristics of chromium (VI) and phosphate on calcined Mg-Al-CO 3 layered double hydroxides (CLDH) were investigated in single and binary systems. A series of batch experiments were performed to study the influence of various experimental parameters. In this study, CLDH exhibited a high adsorption capacity for Cr (VI) and P in a single system. The experimental data were close to the theoretical adsorption capacity given by the Langmuir isotherm, the calculating adsorption capacities of Cr (VI) and P were up to 70.42 mg/g and 97.09 mg/g, respectively. It was found that the initial pH was approximately 6 and it took 24 h to reach equilibrium when P and Cr (VI) were added simultaneously. The experimental data were best fitted by a pseudo-second-order kinetics model. Competitive adsorption between Cr (VI) and P existed in the binary system. The presence of Cr (VI) had no significant influence on P adsorption. However, the suppression of Cr (VI) adsorption was obvious when the initial concentration of P was up to 10 mg/L with a concentration of 0.5 g/L of CLDH.

Enhanced Removal of Sulfonated Lignite from Oil Wastewater with Multidimensional MgAl-LDH Nanoparticles

“…Adsorbents with large specific surface areas and low costs were used for the removal of sulfonated lignite, such as activated carbon, fly ash, resin and hydrotalcite. Layered double hydroxide (LDH) nanoparticles comprise a class of anionic clay minerals and have always been a research focus of scientific researchers in the application of adsorption materials [ 15 , 16 ]. Currently, various methods including structural reconstruction, in situ growth, exfoliation, and assembly have been used to prepare hierarchical hydrotalcites with various morphologies [ 17 ].…”