Congo red dye is widely used in industry, one of them is textile industry. Congo red dye waste if it enters the environment without proper processing will cause environmental pollution. Fe3O4 and Fe3O4-SDS (1:1) composite were used for the adsorption of congo red dye by synthesizing using the coprecipitation method and characterized using XRD, FTIR, VSM and BET. The XRD characterization results…