Adsorption of methylene blue using sodium carboxymethyl cellulose-g-poly (acrylamide-co-methacrylic acid)/Cloisite 30B nanocomposite hydrogel.

A new adsorbent of CMC-g-Poly(MAA-co-AAm)/Cloisite 30B (Hyd/C30B) nanocomposite hydrogel was synthesized by the free radical polymerization approach to eliminate methylene blue (MB) dye from wastewater samples. The BET value for C30B, Hyd, and Hyd/C30B was determined 5.00, 0.83, and 2.42 m²/g, respectively, while, based on the MB removal method, the surface area for the mentioned adsorbents was calculated 133.12, 129.53, and 149.61 m²/g, respectively. The generated nano-hydrogel belonged to a type IV isotherm and had a pore size of 2–50 nm. In the MB adsorption process using the desired adsorbents, the maximum adsorption was attained at pH 8, temperature of 45 °C, time of 30 min, adsorbent dose of 0.8 g/L, and dye concentration of 10 mg/L. The swelling rate of the studied hydrogel depended on pH and temperature. The adsorption process increased with increasing temperature. The Gibbs free energy parameter and enthalpy had negative values, indicating that the degree of the spontaneity of the adsorption process increased at high temperatures. The data followed pseudo-second-order kinetic and Langmuir isotherm. The maximum MB adsorption using Hyd, Hyd/C30B, and C30B was computed to be 67.11 mg/g, 77.51 mg/g, and 70.42 mg/g, respectively. The adsorbents had a good ability to reduce industrial wastewater pollutants. [ABSTRACT FROM AUTHOR]