This work is reported on the synthesis of Fe3O4/eggshell nanocomposites in the absence of any stabilizer or surfactant. Fe3O4 magnetic nanoparticles were established on the egg shell. The adsorption of Malachite green (MG) and Crystal violet (CV) as cationic dyes and Eriochrome Black T (EBT) as an anionic dye by magnetite nanoparticles loaded egg shell (MNLES) and magnetite nanoparticles loaded egg membrane (MNLEM) were studied. FT-IR, XRD and SEM were used for specification of adsorbents. XRD pattern of MNLES and MNLEM were corresponded to pure magnetite at 2θ= 30.2o, 35.6o, 43.3o and 57.2o. FTIR showed that main peak similar magnetite in 580, 1620 and 3407cm-1. SEM pictures showed that Fe3O4 nanoparticles in nm size loaded on natural adsorbents. Adsorbents dose, pH and contact time as parameters that have effect on dyes removal were investigated. Pseudo-first order, pseudo-second order, intraparticle diffusion and Elovich models were used for study of kinetic of adsorption. The sorption of the MG, EBT, CV on the MNLEM were pseudo second-order model. The sorption of the MG and EBT on MNLES were described by Elovich and pseudo second-order model. Value of qmax from the Langmuir model for adsorption of CV, EBT and MG were 61.72, 21.69 and 38.31mg g -1 for MNLEM and qmax for adsorption of EBT, MG on the MNLES was 40.0 and 25.12mg g -1. It was found MNLES and MNLEM can be used as efficient adsorbents for removal of EBT more than cationic dyes (MG, CV). Manuscript profile

This study was focused on the adsorption of malachite green as a cationic dye on magnetite nanoparticles loaded green tea waste (MNLGTW), peanut husk (MNLPH), Azolla (MNLA) and Fig leave (MNLFL) as naturally cheap sources of adsorbent. MNLGTW, MNLPH, MNLA and MNLFL were prepared with chemical precipitation method and they were characterized with Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Energy Dispersive X- ray (EDX) analysis. Different parameters affecting the dye removal efficiency were optimized. At optimum conditions, the sorption of the malachite green on the MNLGTW, MNLPH, MNLA and MNLFL adsorbents was best described by a pseudo second-order kinetic model with R2 =1, qeq= 12.51 mg g-1 , R2 =0.9996, qeq=625 mg g-1 , R2 =0.9842, qeq=0.5772 mg g-1 and R2 =0.9912, qeq=0.517 mg g-1 respectively. Equilibrium data were fitted well to the Langmuir isotherm more than Freundlich and Temkin isotherm. The synthesized sorbent showed complete dye removal with 112.359, 98.039, 23.1 and 73.2 mg g-1 for MNLGTW, MNLPH, MNLA and MNLFL, respectively. The results showed MNLGTW, MNLPH, MNLA and MNLFL can be used as efficient adsorbents for removal of malachite green from aqueous solutions. Manuscript profile