Effective Adsorptive Removal of Methylene Blue from Water by Didodecyldimethylammonium Bromide-Modified Brown Clay

Muhammad Munir; Muhammad Faizan Nazar; Muhammad Nadeem Zafar; Muhammad Zubair; Muhammad Ashfaq; Ahmad Hosseini-Bandegharaei; Salah Ud-Din Khan; Ashfaq Ahmad

doi:10.1021/acsomega.0c01613

Effective Adsorptive Removal of Methylene Blue from Water by Didodecyldimethylammonium Bromide-Modified Brown Clay

ACS Omega. 2020 Jun 29;5(27):16711-16721. doi: 10.1021/acsomega.0c01613. eCollection 2020 Jul 14.

Authors

Muhammad Munir¹, Muhammad Faizan Nazar¹, Muhammad Nadeem Zafar¹, Muhammad Zubair¹, Muhammad Ashfaq¹, Ahmad Hosseini-Bandegharaei^{2

3}, Salah Ud-Din Khan⁴, Ashfaq Ahmad⁵

Affiliations

¹ Department of Chemistry, University of Gujrat, Gujrat 50700, Pakistan.
² Department of Environmental Health Engineering, Faculty of Health, Sabzevar University of Medical Sciences, Sabzevar, Iran.
³ Department of Engineering, Kashmar Branch, Islamic Azad University, P.O. Box 161, Kashmar, Iran.
⁴ Sustainable Energy Technologies Center, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.
⁵ Department of Chemistry, King Saud University, P.O. Box 2425, Riyadh 11451, Saudi Arabia.

Abstract

In the present investigation, brown clay (BC) was modified with didodecyldimethylammonium bromide (DDAB) to produce a sorbent (DDAB-BC), which was characterized and applied for sorption of methylene blue (MB) from aqueous media. BC was functionalized using DDAB by cation exchange of the DDAB moiety with positive ions existing inside the interlayer spaces of the BC. X-ray diffraction (XRD) studies confirmed that the d-spacing of DDAB-BC became wider (3.39 Å) than that of BC (3.33 Å). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were exploited to explore the functional groups and morphological structure of sorbents, respectively. The Brunauer-Emmett-Teller (BET) surface area, pore volume, and pore diameter of DDAB-BC were determined as 124.6841 m²/g, 0.316780 cm³/g, and 8.75102 nm, respectively. Batch sorption investigations were carried out to determine the optimum experimental conditions, using the one-factor one-time procedure. The sorption of MB on DDAB-BC strongly obeyed the Langmuir isotherm and agreed well with pseudo-second-order kinetics. Sorption of MB onto DDAB-BC showed maximum efficiency (∼98%) and maximum sorption capacity (∼164 mg/g) at optimal values of pertinent factors: dye concentration (100 mg/L), pH (7), and temperature (55 °C). Sorption isothermal studies predicted that removal of MB on DDAB-BC follows multilayer sorption at higher MB dye concentrations and monolayer sorption at lower MB dye concentrations.