Abstract
In this research, fabrication and functionalization of MnO
2
nanoparticles with cetyltrimethylammonium bromide (MnO
2
NPs-CTAB) were confirmed for removal of two reactive anionic sulfonated azo dyes: remazol red (RR) and reactive black 5 (RB5). The modified nanosorbent was characterized via X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, BET analysis, SEM and HRTEM studies. Various adjustable parameters, for instance nanosorbent mass, pH, reaction contact time, dyes concentration, reaction medium temperature and interfering compounds, were also explored. The adsorption processes for both dyes were favorable fitted with the Langmuir adsorption isotherm model. The highest adsorption capacities were 40.00 and 38.46 mg g
−1
for RR and RB5, respectively. Various kinetic models were employed, and the results manifested the preferable fitting for the
pseudo
-second-order one. The standard thermodynamic parameters (Δ
H
°, Δ
S
° and Δ
G
°) have been calculated, and the outcomes illustrated that RR and RB5 dyes adsorption was exothermic and spontaneous. Finally, the potential applications of MnO
2
NPs-CTAB under optimum conditions for adsorptive decolorization and detoxification of RB5 and RR from various water samples, for instance tap water, raw water and seawater, were investigated.