Performance of surfactant-modified BEA-type zeolite nanosponges for the removal of nitrate in contaminated water: Effect of the external surface

[Display omitted] •Surfactant-modified zeolites were obtained by surface modification of *BEA-type zeolites.•The nitrate removal capacity increases with the increase of the zeolite external surface.•The highest ever observed nitrate removal capacity using surfactant-modified zeolite. Hierarchical *BEA-type nanosponges zeolite with a high external surface area (116 m2.g−1) and small crystal size, synthesized in the presence of a dual-porogenic organic compound, were modified with a cationic surfactant (HDTMA+Br−: hexadecyltrimethyl ammonium bromide) in order to create a new anion exchanger system: the surfactant-modified zeolite nanosponges (SMZNS). For comparison, two other surfactant-modified *BEA-type zeolite materials, SMZMC and SMZNC, were obtained by modifying the synthesized conventional micron-size microcrytals and nanocrystals *BEA-type zeolite with HDTMA+Br−, respectively. Textural and structural properties were determined for the three prepared materials using N2 adsorption/desorption analysis, XRD, SEM, and TEM. Nitrate adsorption isotherms were drawn in a large concentration range [0.8–24.2 mmol.L−1] and fitted with Langmuir isotherm model. The maximum nitrate removal capacity (1338 mmol.Kg−1/83 mg.g−1) was obtained for SMZNS material. This value is the highest ever observed for nitrate removal using surfactant-modified zeolite. The nitrate removal kinetics were fitted with the pseudo second-order model for both materials SMZNS and SMZNC.