Fibrous morphological cellulose-derived ternary composite filter for immobilizing heavy metal ions from wastewater

Abstract

Sewage containing heavy metal ions (HMIs) has caused serious damage to ecological environment and human health when discharged without treatment. In this work, a practical filter has been made with cellulose/zinc oxide/magnesium hydroxide (CelZnMg) ternary composite prepared via a simple hydrothermal method. The characterizations show that granular ZnO and lamellar Mg(OH)2 evenly distribute on cellulose. The electrostatic attraction drives the coupling of cellulose and ZnO/Mg(OH)2, and the formed CelZnMg is significantly stabilized by interfacial hydrogen bonds and dative bonds. On the other hand, the cellulose substrate also immobilizes the recovered HMIs and completely and easily separates them from wastewater. The ternary composite has outstanding bifunctional performance. Its Mg(OH)2 component offers high HMIs-removing capability; for instance, qmax of Cd2+ and Cu2+ in 400 mL 500 mg·L–1 solution reaches 693.2 and 764.6 mg·g–1 respectively. The ZnO moiety endows the antibacterial property, which inhibits the growth of Staphylococcus aureus and Escherichia coli. The inhibition effect indicates that cellulose in the composite is stable during application. Due to its multiple merits, the CelZnMg filter would be a perspective candidate for the use as water treatment agent.