Broad-Spectrum Adsorption Property of Chondrus crispus Activated Carbon for Ionic and Solvent Dyes

There are few activated carbons that are capable of adsorbing both ionic and solvent dyes. In this paper, activated carbon was prepared from Chondrus crispus as a marine material by a high-temperature carbonization procedure for the first time. The Chondrus crispus activated carbon (CCAC) can effectively adsorb methylene blue (MB) as a cationic dye, methyl orange (MO) as an anionic dye, oil red O (ORO) as a solvent dye, and other eight dyes. The adsorption capacities for MB and MO in water, and ORO in n -hexane are 132.81, 49.48, and 33.17 mg g −1 , respectively. CCAC was characterized by scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller (BET) method, and zeta potential analysis. CCAC was proved to have a porous and gully structure with a specific surface area of 60.0687 m 2  g −1 . The effects of initial dye concentration, dosage, pH, contact time, and temperature on the adsorption were investigated. The adsorption kinetic data proved that the adsorption process accorded with pseudo-second-order model. The adsorption isotherms fit to both the Langmuir and Freundlich models. The broad-spectrum dye adsorption mechanism is attributed to the π-π interaction between CCAC and dye.