Fabrication of poly(itaconic acid)-g-potassium alginate aerogels as eco-friendly biosorbents for removal of cationic dyes

Abstract

Biosorbents derived from itaconic acid (IA) with abundant carboxyl groups are viewed as ideal materials for the removal of cationic dyes. However, it is still challenging to prepare IA-based biosorbents with satisfactory structural stability and adsorption ability. In this work, a novel poly(itaconic acid)-g-potassium alginate (PIA-g-PA) aerogel was prepared as a biosorbent and was then utilized to remove cationic dyes. The results presented that the as-prepared PIA-g-PA aerogel possessed outstanding adsorption capacities for cationic dyes based on the adsorption mechanism of electrostatic interaction. The adsorption process was well described by the pseudo-second-order model and the Freundlich model. The maximum adsorption capacities of the as-prepared aerogel toward methylene blue (MEB), malachite green (MG) and neutral red (NR) were 1892.07 mg·g−1, 786.96 mg·g−1 and 1169.23 mg·g−1, respectively. The adsorption capacity of aerogel toward cationic dyes significantly decreased with an increment of ionic strength. Meanwhile, the thermodynamic study indicated that the adsorption of cationic dyes onto the PIA-g-PA aerogel was spontaneous as an endothermic process. Additionally, the removal efficiency of as-prepared PIA-g-PA aerogel was still above 90.00% even after 10 cycles. Hence, the PIA-g-PA aerogel can be regarded as an eco-friendly adsorbent for the potential remediation of dye pollution in industrial effluents.