ABSTRACT Competitive adsorption of Pb 2+ and Cu 2+ in a binary system was investigated using a copolymer hydrogel and its nanocomposite counterparts prepared by the incorporation of MWCNT or functionalized form (F‐MWCNT). Poly(methacrylic acid‐co‐itaconic acid) (P(MAA‐co‐IA)), poly(methacrylic acid‐co‐itaconic acid)/multi‐walled carbon nanotube (P(MAA‐co‐IA)/MWCNT) and poly(methacrylic acid‐co‐itaconic acid)/functionalized multi‐walled carbon nanotube (P(MAA‐co‐IA)/F‐MWCNT) were prepared by using free radical polymerization method. Fourier transform infrared spectroscopy (FT‐IR), thermal gravimetric analysis (TGA), X‐ray diffraction (XRD), and scanning electron microscopy (SEM) were used for characterization. To determine the relationships between metal ions and carboxyl groups (─COOH), an investigation was conducted on the effects of the pH point of zero charge (pH pzc ). The adsorption behavior was investigated using adsorption kinetic models and adsorption isotherms. The findings indicated that the data are best explained by pseudo‐second‐order kinetic model, and Langmuir isotherm, which describes the monolayer adsorption. The maximum adsorption capacities of P(MAA‐co‐IA), P(MAA‐co‐IA)/MWCNT, and P(MAA‐co‐IA)/F‐MWCNT were founded as 277.8, 263.2 and 196.1 mg/g for Pb 2+ and 125.0, 126.6, and 123.5 mg/g for Cu 2+ , respectively. The adsorption experiments demonstrated that a higher removal efficiency was observed for Pb 2+ in comparison to Cu 2+ . A key finding of the present study was the comparison of experimental results obtained from nanocomposite hydrogels incorporating MWCNT or F‐MWCNT.
Altun et al. (Sun,) studied this question.