Reusable and cross-linked cellulose nanofibrils aerogel for the removal of heavy metal ions

Reusable and porous aerogel was fabricated using natural cellulose nanofibrils (CNFs) cross-linked with acrylic acid (AA) for the removal of heavy metal ions. CNFs with diameters of 5-50 nm were obtained and the cross-linking mechanism of CNFs with AA (CA aerogel) was analyzed. The CNFs based aerogel formed highly porous networks after cross-linking with AA and carboxyl groups were introduced onto the molecular chain of CNFs. The maximum adsorption capacities of CA aerogel for Cu(II) and Pb(II) were 40.01 and 130.36 mg/g and the adsorption closely followed the pseudo-second-order kinetic and Langmuir isothermal model for both Cu(II) and Pb(II). Chemical adsorption combined with porous physical adsorption endowed CA aerogel excellent adsorption properties. The prepared CA aerogel showed desirable reusability and could remove various heavy metal ions in industrial sewage. This resulted CA aerogel was considered to be promising alternative for conventional adsorbents in fields of sewage recovery, water purification, and soil remediation. POLYM. COMPOS., 39:4442-4451, 2018. (c) 2017 Society of Plastics Engineers