Magnetic Alginate Carbon Aerogel Adsorbents for Water-/Oil-Soluble Dyes

The discharge of dye wastewater and waste-oil has brought serious harm to the ecological environment and human health. Unfortunately, bifunctional adsorbents towards aqueous dyes in water- and oil-soluble dyes in organic media are still rare to date. In this research, magnetic ferric alginate carbon aerogel (FeACA) was prepared from sodium alginate by wet spinning, Fe 3+ -ion cross-linking, and pyrolysis in N 2 atmosphere. FeACA obtained a specific surface area of 215.3 m 2  g −1 with a mean pore size of 3.1 nm and exhibited near superparamagnetic character. The adsorption capacities of FeACA for methylene blue, Congo red, and oil red O were 123.7, 141.1, and 65.7 mg g −1 , respectively. FeACA revealed a good broad-spectrum adsorption performance for other eleven various types of dyes. This study demonstrates a fast adsorption strategy by combining the magnetic separation and ethanol desorption. Utilizing the strategy, the adsorption time of MB was reduced from 12 h to 205 min with half dosage of adsorbent. This research provides new insights for achieving multifunctional dye adsorption.