To improve the adsorptive mineralization efficiency of Fe-Ni nanoparticles (Fe-Ni NP's), we demonstrate a facile, rational and highly efficient approach by intercalating Fe-Ni NP's onto montmorilonite (MMT). XRD analysis suggested formation of MMT-composites with Fe-Ni NP's having spherical shape of 30-40 nm size. Kinetics of basic magenta (BM) demonstrated it to be of pseudo-second order with 2% in-situ and 10% loaded nanocomposites exhibiting better adsorption tendency. The adsorption properties of BM are analyzed with isotherms like Redlich-Peterson, Dubinin-Radushkevich, Temkin and Flory-Huggins besides Langmuir and Freundlich for understanding the adsorption dynamics. Pseudo-multilayer exothermic chemisorption is predominant with significant amount of free energy change (Delta G degrees) involved in adsorption on the nanocomposite surface. Employing Webber-Morris and Boyd intra-particle diffusion models, it is observed that diffusion is within micro- and meso-pores that subsequently favors pore-diffusion controlled process. These features have significantly contributed towards successful utilization of these composites for continuous removal capabilities. From the adsorption capacity, kinetics and diffusion controlled characteristics: it is observed that in-situ formed Fe-Ni nanocomposites possess enhanced adsorption capacity towards BM remediation. Present work clearly demonstrates that tailor-made nanocomposites may exhibit potential applications towards continuous removal of organic pollutants from aqueous streams with high efficiency. (C) 2013 Elsevier B.V. All rights reserved.