Mesoporous silicon extracted from rice husk for remediation of different sorts of dyestuffs from simulated textile effluent: kinetic, isotherm, and mechanism study

Due to their significant differences in physicochemical properties, it is still challenging to remediate complex wastewater containing more than one kind of dyes via convenient adsorption. Herein, rice-husk-extracted mesoporous silicon (RH@MCM-41) was facilely synthesized, systematically characterized, and used as a versatile adsorbent to remediate methylene blue (MB) from simulated textile effluent. The influences of adsorption kinetics, isotherms, thermodynamics, pH, and mixed dyestuff toward MB remediation were studied. Results demonstrated that RH@MCM-41 possessed well MB sorption capacity in the single dyestuff solution with maximum sorption capacity of 213.31 mg/g at Sips model. Moreover, RH@MCM-41 could selectively sequestrate MB from rhodamine B (RB)/MB mixed systems. Interestingly, the sorption capacity of RH@MCM-41 to MB (methyl orange (MO)/MB, acid fuchsin (AF)/MB, and xylenol orange (XO)/MB) were significantly enhanced in mixed system while no obvious MO and AF as well as XO adsorption were detected in its individual system. It was elucidated that the uptake of other dyestuff and MB by RH@MCM-41 were due to the synergistic effects between multiple sorption mechanisms. Therefore, the source of green, simple preparation method, well sorption capacity, removal selectivity, and unique adsorption potential reveal RH@MCM-41 possessed tremendous potential for MB-containing wastewater sequestration in practical applications.