Efficient and selective adsorption of multi-metal ions using sulfonated cellulose as adsorbent

• Sulfonated cellulose can remove metal ions with excellent selectivity and high efficiency.
• Sulfonated cellulose is a kind of renewable adsorbent.
• Adsorption equilibrium can be reached within as short as 2 min.
• Sulfonic group was proved to play a major role in adsorption process.

Contamination of heavy metal in wastewater has caused great concerns on human life and health. Developing an efficient material to eliminate the heavy metal ions has been a popular topic in recent years. In this work, sulfonated cellulose (SC) was explored as efficient adsorbent for metal ions in solution. Thermo gravimetric analyzer (TGA), X-ray diffraction (XRD) and Fourier-transform infrared spectrometer (FTIR) first analyzed the characterizations of SC. Subsequently, effects of solution pH, adsorbent loading, temperature and initial metal ion concentration on adsorption performance were investigated. The results showed that sulfonated modification of cellulose could decrease the crystallinity and thermostability of cellulose. Due to its excellent performance of adsorption to metal ions, SC could reach adsorption equilibrium status within as short as 2 min. In multi-component solution, SC can orderly removes Fe3+, Pb2+ and Cu2+ with excellent selectivity and high efficiency. In addition, SC is a kind of green and renewable adsorbent because it can be easily regenerated by treatment with acid or chelating liquors. The mechanism study shows that the sulfonic group play a major role in the adsorption process.