The present study deals with the simultaneous removal of Binary Mixture of Basic Blue 41(BB) and Toluidinblue (TO) by Poly Dopamine modified Fe3O4. A first-order derivative spectrophotometric method is developed for the simultaneous determination of BB and TO in binary solutions. The influence of various parameters, such as pH, initial concentration of dyes and sorbent mass on the dye adsorption is investigated. A response surface methodology achieved through performing the Central Composite design is utilized to optimize the removal of dyes by magnetic nano particle modified by poly dopamine through a batch adsorption process.