A Biomass Cationic Adsorbent Prepared From Corn Stalk: Low-Cost Material and High Adsorption Capacity

In this research, corn stalk fibers (CSF) grafted polyacrylic acid (PAA) on their surfaces (CSF-g-PAA) were successfully prepared via heterogeneous esterification in the case of maintaining inherent fiber framework and shape. It can be used to removal cationic contaminants from aqueous solution. Four dyes and three metal ions were employed as models of cationic adsorbates to survey its adsorption performance. All of them showed high adsorption capacities, even the lowest RhB reached 179 mg/g. The CSF-g-PAA not only has a high adsorption capacity but also maintains inherent fiber framework, showing features of easy separation. The adsorption capacity reached 370 mg/g for methylene blue (MB), which was significantly far higher than that of original CSF (<30 mg/g). MB adsorption followed pseudo-second-order kinetic and the Langmuir isotherm model. The adsorbent can be separated easily and rapidly from wastewater through a sieve of 200 mesh. Adsorption and desorption were also evaluated. The CSF-g-PAA might be used as a promising adsorbent for practical application because of its low cost and high performance.