The dye that is widely used in the textile industry is congo red dye which is carcinogenic and toxic to many organisms so that processing is needed. Fe3O4-SDS (2:1) and (2:3) composites were used as adsorbents in the adsorption of congo red dye by synthesis using the coprecipitation method and then characterized by XRD, BET, VSM and FTIR. The XRD characterization results of Fe3O4-SDS (2:1) and …