Welan Gum-Modified Cellulose Bead as an Effective Adsorbent of Heavy Metal Ions (Pb2+, Cu2+, and Cd2+) in Aqueous Solution

A novel welan gum-modified cellulose adsorbent was prepared through emulsification, regeneration, and modification. SEM and FTIR were used to characterize the modified cellulose adsorbent. The adsorption isotherms of metal ions on the adsorbent were well fitted by Langmuir model, with the maximum adsorption capacities of 83.6, 77.0, and 67.4 mg/g for Cd2+, Pb2+, and Cu2+, respectively. The adsorption kinetics was well described using the pseudo-first-order model. Moreover, the adsorption capacities for the three metal ions increased with the increase of temperature, and the optimal pH was 5. Furthermore, the thermodynamic analysis indicated that the adsorption processes were spontaneous and endothermic.