Functional wastepaper-montmorillonite composite aerogel for Cd²⁺ adsorption

In this study, a composite aerogel (WP-MMT) composed of wastepaper (WP) and montmorillonite (MMT) was prepared by ambient pressure drying technology to adsorb Cd²⁺. The study of compression performance indicated that the composite aerogel had ideal mechanical strength when the mass ratio of WP to MMT was 1:1. The specific surface areas of the aerogels modified by hydrogen peroxide (WP-MMT-H₂O₂) and sodium hydroxide (WP-MMT-NaOH) were increased greatly. The sorption isotherms and kinetics of Cd²⁺ sorption on WP-MMT-H₂O₂ and WP-MMT-NaOH were investigated. The Cd²⁺ sorption data could be well described by a simple Langmuir model, and the pseudo-second-order kinetic model best fitted the kinetic data. The maximum sorption capacity obtained from the Langmuir model was 232.50 mg/g for WP-MMT-NaOH. The adsorption mechanism of WP-MMT was chemical adsorption of a single-molecule layer. In general, it was proved that the composite aerogel with high adsorption capacity of Cd²⁺ could be synthesized from modified WP and MMT by ambient pressure drying. The composite aerogel fabricated by wastepaper and montmorillonite showed bright application prospect in the aqueous heavy metal pollution control.