Preparation of Nanocomposite Hydrogel with High Mechanical Strength and Reusability for Cu(Ii) and Pb(Ii) Removal from Water

The adsorbent with the characteristics of good reusability, rapid adsorption kinetics, cost-effective, and high adsorption capacity is extremely demanded in practical adsorption process but has been proven challenging. Herein, a new strategy was raised by combining the nano-biochar (NBC) and double network to synthesize nanocomposite hydrogel. The nano-biochar/carboxymethylcellulose/polyacrylic acid (NBC/CMC/PAA) nanocomposite hydrogel was prepared using one-step method, the carboxymethylcellulose (CMC) and polyacrylic acid (PAA) were used to form double networks then immobilize and crosslink with NBC. The NBC/CMC/PAA possessed higher allowable compression force of 133.52 N. The FTIR and XPS results confirmed that -COOH, -OH, and -NH- functional groups were the main adsoption sites. The excellent reusability of NBC/CMC/PAA remained a stable removal efficiency of Cu2+ and Pb2+ was 100% within five cycles. Thomas mode have a better description for the Cu2+ and Pb2+ in the individual dynamic adsorption process. In the alternate fixed-bed column experiments, the treatment volume of Cu2+ contained water reached 13.7 L and produced 300 mL eluent. This work not only developed a new strategy for nanocomposite hydrogel preparation but also verified that the NBC/CMC/PAA have a great application potential for Cu2+ and Pb2+ removal in practical.