Facile and green construction of carboxymethyl cellulose-based aerogel to efficiently and selectively adsorb cationic dyes

With sodium p-styrene sulfonate (SSS) and acrylic acid (AA) as the organic monomers, a carboxymethyl cellulose (CMC)-based aerogel (named as CMC/PSA) was successfully synthesized by a facile and green method as evidenced by a series of characterizations. The adsorption behaviors of the resulting aerogel were systematically investigated with methylene blue (MB) as the cationic dye model. CMC/PSA aerogel exhibited excellent adsorption performance toward MB with a maximum theoretical adsorption capacity of 925.9 mg/g at 323 K, and the adsorption process could be well simulated by quasi-secondary kinetic model as well as Langmuir model. The aerogel possessed better efficient adsorption capacity toward MB under neutral and alkaline conditions than under acidic environment. In addition, the CMC-based aerogel could achieve the selective removal of cationic dye from a mixture of cationic and anionic dyes. Adsorption capacity of the aerogel decreased only by 3.25 % compared to the initial one even after 6 adsorption-desorption cycles, indicating the excellent recyclable performance. At the practical application level, the dynamic adsorption revealed that the aerogel was highly effective in treating wastewater at the operating time of 2250 min when flow rate of the wastewater was 0.4 L/h. In conclusion, CMC/PSA aerogel could be considered as an ideal adsorbent with green, efficient, selective, and regenerative properties.