The Eriochrome Black-T (EBT) azo dye was removed from aqueous solution using TMAB (tetramethyl ammonium bromide) stabilised NiFe2O4 (TMAB@NFO) nanoparticles, which have been synthesized through polymeric precursor method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectra (FTIR) were used to analyse the TMAB@NFO nanoparticles. Adsorption studies were conducted under a variety of conditions, including pH, adsorbent dosage, and contact time, intraparticle diffusion, pseudo-first- and pseudo-second-order kinetic models were used to analyse the kinetic data. According to the systematic study of adsorption isotherms and kinetics models, TMAB@NFO nanoparticles will adsorb EBT dye utilising the Freundlich model and pseudo-second-order kinetics. The intraparticle diffusion model revealed a linear relationship (R2 - 0.98, 0.97, and 0.94 for TMAB@NiFe2O4 and bare NiFe2O4-NPs), demonstrating how surface modification influences the overall EBT adsorption process and the pore diffusion rate. Additionally, the manufactured nano adsorbents of NiFe2O4 were effectively regenerated and reused after the treatments up to four times following the elimination of 89% of EBT dye by TMAB@NiFe2O4-NPs. The results have demonstrated the enormous potential of TMAB @NiFe2O4-NPs to eliminate EBT in a practical way. KEY WORDS: Tetramethyl ammonium bromide, NiFe2O4, EBT, Surface capping, Adsorption, Kinetics Bull. Chem. Soc. Ethiop. 2024, 38(6), 1569-1581. DOI: https://dx.doi.org/10.4314/bcse.v38i6.6