Preparation of nylon based magnetic adsorption materials and their adsorption properties for heavy metal ions

Wastewater containing heavy metal ions poses great harm to human health and the environment. The adsorption materials used in traditional adsorption methods, such as starch and cellulose, are prone to hydrolysis, causing secondary pollution to water bodies. Nylon@Fe₃O₄@PAA adsorption material was obtained by using nylon as a substrate, activating nylon with sodium carbonate/hydrochloric acid, depositing a Fe₃O₄ magnetic layer by coprecipitation, and grafting polyacrylic acid. The adsorption material was used to explore the effects of different conditions (adsorption material dosage, Cu²⁺ concentration, pH value, and adsorption time) on the adsorption efficiency, adsorption capacity, and total adsorption amount of copper ions through changing the adsorption conditions. The research results showed that the adsorption material dosage was 31.25 mg (suspension solution with a concentration of 62.5 mg/mL was added with 300 μL), the concentration of Cu²⁺ solution was 20.48 mg/L, the adsorption time was 60 min, and the pH value was 9. The optimal adsorption efficiency was 82.29%, the optimal adsorption capacity was 154.87 mg/g, and the optimal total adsorption amount was 343.91 mg. After fitting thermodynamic and kinetic equations, the adsorption process of nylon@Fe₃O₄@PAA for Cu²⁺ ions dominated by chemical adsorption, with good adsorption rate and adsorption performance.