Preparation of Modified Corn Straw Cellulose by the Dry Method and Its Adsorption of Anionic Dye from Aqueous Solution

The presence of organic dyes in the aquatic environment poses a significant threat to ecosystems and human health, thereby necessitating the development of effective and green adsorbents for their removal. To address this concern, modified corn straw cellulose was prepared from corn straw and betaine hydrochloride by a dry method. The adsorbent’s structure was characterized by FTIR, SEM, XRD, zeta potential, and TG-DTG. The adsorption capacity for Acid Red 1 (AR1) was evaluated, and the effects of initial pH, adsorbent dosage, initial dye concentration, and NaCl concentration on the adsorption capacity were investigated. The adsorption of the anionic dye AR1 onto the adsorbent followed the pseudo-second-order kinetic model and the Langmuir isotherm, with a maximum monolayer adsorption capacity of 315.2 mg/g at 298 K. The adsorption process was predominantly governed by electrostatic interactions between the adsorbent surface and the dye molecules. This study provides a viable strategy for the dry preparation of adsorbent from waste biomass for anionic dye adsorption.