Preparation of corn stalk adsorbent and its adsorption performance for Pb2+ in aqueous solution

In this paper, corn stalk adsorbents are prepared by pretreated corn stalks and carboxymethylation reaction. Then the adsorbents are used to remove Pb2+ in the aqueous solution, and the effect of the pH value of the solution, adsorption time, adsorbent dosage, the initial concentration of Pb2+ on the adsorption performance, and the adsorption kinetics and adsorption isotherm are discussed. The results show that when the pH is 4.50, the adsorption time is 150 min, the amount of adsorbent is 0.45 g, the adsorption capacity of the adsorbent is as high as 928 mg/g, and the Pb2+ removal rate reaches 99.78 %. The adsorption kinetics showed that the adsorption of Pb2+ by the adsorbent reached adsorption equilibrium within 150 minutes, the adsorption process conformed to the quasi-second-order kinetic model, and the adsorption mechanism was chemical adsorption. The adsorption isotherm shows that the adsorption process of Pb2+ by the adsorbent conforms to the single-layer adsorption of the Langmuir model.