Magnesium/aluminum layered double hydroxides intercalated with starch for effective adsorptive removal of anionic dyes

Aman Grover; Irshad Mohiuddin; Ashok Kumar Malik; Jatinder Singh Aulakh; Kumar Vikrant; Ki-Hyun Kim; Richard J C Brown

doi:10.1016/j.jhazmat.2021.127454

Magnesium/aluminum layered double hydroxides intercalated with starch for effective adsorptive removal of anionic dyes

J Hazard Mater. 2022 Feb 15;424(Pt B):127454. doi: 10.1016/j.jhazmat.2021.127454. Epub 2021 Oct 10.

Authors

Aman Grover¹, Irshad Mohiuddin¹, Ashok Kumar Malik¹, Jatinder Singh Aulakh¹, Kumar Vikrant², Ki-Hyun Kim³, Richard J C Brown⁴

Affiliations

¹ Department of Chemistry, Punjabi University, Patiala 147002, Punjab, India.
² Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seoul 04763, Republic of Korea.
³ Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seoul 04763, Republic of Korea. Electronic address: kkim61@hanyang.ac.kr.
⁴ Atmospheric Environmental Science Department, National Physical Laboratory, Teddington TW11 0LW, UK.

PMID: 34655876
DOI: 10.1016/j.jhazmat.2021.127454

Abstract

In this research, the adsorptive performance of a starch-magnesium/aluminum layered double hydroxide (S-Mg/Al LDH) composite was investigated for different organic dyes in single-component systems by conducting a series of batch mode experiments. S-Mg/Al LDH composite showed preferential adsorption of anionic dyes than cationic dyes. The marked impact of key process variables (e.g., contact time, adsorbent dosage, pH, and temperature) on its adsorption was investigated. Multiple isotherms, kinetics, and thermodynamic models were applied to describe adsorption behavior, diffusion, and uptake rates of the organic dyes over S-Mg/Al LDH composite. A better fitting of the non-linear Langmuir model reflects the predominance of monolayered adsorption of dye molecules on the composite surface. Partition coefficients (mg g^-1 μM^-1) for S-Mg/Al LDH were observed in the following descending order: Amaranth (665) > Tartrazine (186) > Sunset yellow (71) > Eosin yellow (65). Furthermore, comparative evaluation of the adsorption enthalpy, entropy, and Gibbs free energy values indicates that the adsorption process is spontaneous and exothermic. S-Mg/Al LDH composite maintained a stable adsorption/desorption recycling process over six consecutive cycles with the advantages of low cost, chemical/mechanical stability, and easy recovery. The results of this study are expected to expand the application of modified LDHs toward wastewater treatment.

Keywords: Adsorption; Dyes; Layered double hydroxides; Organic pollutants; Wastewater.