Phytic acid-modified carboxymethyl cellulose-based hydrogels for efficient removal of methylene blue dye

With the rapid development of science and technology, the discharge of industrial wastewater, especially dye wastewater, has caused great harm to the ecological environment. In response to the pollution caused by cationic organic dyes in industrial wastewater, this study employed free radical polymerization to prepare a new hydrogel adsorbent, PAA-PA-CMC, which exhibits both reusability and a large adsorption capacity. Phytic acid (PA) and carboxymethyl cellulose (CMC) were introduced into the acrylic acid-based polymer network using N, N ‘-methylene-bisacrylamide (MBA) and glycidyl methacrylate (GMA) as cross-linking agents. Phytic acid serves as both a cross-linking agent and an active component in the adsorption of methylene blue cationic dyes. Methylene blue (MB) adsorption experiments demonstrated that PAA-PA-CMC possesses a porous structure and abundant functional groups, primarily utilizing hydrogen bonds and electrostatic interactions for efficient MB adsorption. The adsorption capacity of PAA-PA-CMC for MB can reach 1005.41 mg/g and has good reusability. After 5 cycles, its adsorption efficiency remains at about 85 %. The adsorption behavior of PAA-PA-CMC conforms to the pseudo-second-order kinetic model and the Langmuir isotherm adsorption model, which is a monolayer chemical adsorption. In summary, the PAA-PA-CMC hydrogel prepared in this investigation shows great potential for treating MB dye wastewater.