In this study, the Acid Black 1 dye containing effluent collected from a dyeing unit was examined with the alginate extracted from the marine brown algae, Sargassum sp. for its removal. Batch experiments were carried out using standard Jar test apparatus. Fourier Transform InfraRed (FT-IR) Spectroscopy and Scanning Electron Microscopy (SEM) techniques were used to characterize the raw alginate and dye loaded alginate after the coagulation process. The optimum condition for maximum colour removal of 96.8% was found to be at 40mg/L of alginate dose, 6g/L of calcium dose and 30 minutes of settling time for the pH of 4.2. The experimental data were analyzed with the first and second order kinetic model and kinetic study on the coagulation process reveals that it follows second order kinetic model. The results revealed that alginate extracted from marine brown algae Sargassum sp has the coagulation potential for effective removal of Acid Black 1 dye. © 2018, Iranian Institute of Research and Development in Chemical Industries. All rights reserved.