Rapid removal of methyl orange from aqueous media by modified Mg–Al layered double hydroxides

Abstract

The current work deals with the synthesis of polymer modified synthetic clay, composed of Mg–Al layered double hydroxides (LDHs) and using a non-toxic organic polymer polyethylene glycol-400 (PEG400). A series of polymer-composites of Mg–Al LDH (LDHP-400) are prepared by changing concentrations of PEG-400 from 4% to 20 %, to find out the maximum adsorption efficiency for the adsorption of an industrially important anionic azo dye, MO from aqueous. The results depicted that LDH-P400, with 16 % PEG-400 shown the removal efficiency of 99.49 % for 100 ppm solution of MO (20 min). Effect of different factors such as dose of adsorbate, temperature, contact time, and pH of the solution, etc. are systematically investigated using batch experiments and thermodynamics parameters as well as kinetic studies are also carried out for the quick and instantaneous removal of MO from aqueous media. Maximum adsorption capacity of 198 mg/g has been achieved at pH4.2 and at temperature 313K for 100 ppm (mg/l) of MO in aqueous media using 0.5 g/l of adsorbent dose. Desorption studies reveal that prepared LDHP-400 can be reused and recycle up to three successive cycles with achieving 88.23 % recovery of MO, which confirmed that prepared LDHP-400 can be reused effectively for laboratory or industrial wastewater which has MO concentrations up to 100 ppm.