The Sorption Performance of Cetyl Trimethyl Ammonium Bromide-Capped La(0.9)Sr(0.1)FeO(3) Perovskite for Organic Pollutants from Industrial Processes

La(0.9)Sr(0.1)FeO(3) perovskite, prepared by the microwave-assisted method, was capped with cetyl trimethyl ammonium bromide (CTAB) cationic surfactant, and applied as a sorbent for the removal of the anionic Congo red (CR) dye from aqueous solutions. X-ray diffraction (XRD) patterns showed that the perovskite structure was not affected by capping; however, the particle size increased. There was a hipsochromic shift in the value of λ(max) of the CR absorption spectrum in the presence of CTAB, which indicated the formation of an oppositely charged dye–surfactant complex. The adsorption efficiency of CTAB-capped La(0.9)Sr(0.1)FeO(3) was independent of the pH of the solution—equilibrium was reached after a few minutes. The value of the maximum adsorption capacity, q(m), was 151.52 mg·g(−1), which was 10-times higher than that of the pure perovskite. The proposed sorbent maintained its excellent sorption ability in the presence of the sample matrix; therefore, it can be regenerated and reused with unchanged performance.