Behavior of γ-Al2O3-bonded-3-chloropropyltrimethoxysilane nanosorbent toward potential binding and removal of 4-nitroaniline and 2-amino-3-nitro-pyridine from water

Abstract

Nitro compounds are widely used in military and industrial activities including explosives dyes, pesticides, polymers and other active species. The main goal of this work is to present an efficient nanosorbent to remove mgL−1 of 4-nitroaniline (4NA) and 2-amino-3-nitropyridine (2A3NP) from aqueous solutions and real water matrices. To accomplish this study, γ-Al2O3 nanomaterial was synthesized by the hydrothermal method and covalent bonded with 3-chloropropyltrimethoxysilane using microwave-assisted synthesis approach to produce γ-Al2O3-Silane-Cl nanosorbent. The particle size of this material was identified in the range 14–28nm using SEM imaging and confirmed by the TEM study in the range 19.59–40.18nm. The designed nanosorbent, γ-Al2O3-Silane-Cl, was also characterized by the HR-TEM, FT-IR, XRD, TGA and surface area analysis. The adsorptive behaviors of 4NA and 2A3NP by γ-Al2O3-Silane-Cl from aqueous solutions were investigated using the batch technique and optimized in presence of different conditions of initial pH, contact time, nanosorbent dosage, initial concentration of nitro compounds and coexisting metal salts. The mechanisms of adsorption processes of 4NA and 2A3NP by γ-Al2O3-Silane-Cl were investigated and illustrated using four different kinetics models and four different adsorption isotherm theories. Excellent recovery values in the range 96.85–99.06mgg−1 of 4NA and 2A3NP from tap water, sea water and wastewater were established by γ-Al2O3-Silane-Cl as an efficient and promising nanosorbent.