Highly efficient removal of heavy metal ions by carboxymethyl cellulose-immobilized FeO nanoparticles prepared via high-gravity technology.

The aim of this study is to explore facile and large-scale method for the preparation of magnetic adsorbent materials with high-efficient heavy metal removal performance. Here, based on the process intensification of high-gravity technology, the carboxymethyl cellulose-immobilized FeO nanoparticles (CMC-FeO) were continuously synthesized via impinging stream-rotating packed bed. With a theoretical production rate of 2.35 kg h, the as-prepared CMC-FeO exhibited better adsorption capacity and faster rate for Pb(II) than those of pure FeO, and the maximum adsorption capacity of Pb(II) reached up to 152.0 mg g. It was found that the adsorption data of Pb(II) onto CMC-FeO fit well to pseudo-second order kinetic model and Langmuir isotherm model. Moreover, the as-prepared adsorbent exhibited good reusability after five adsorption-desorption cycles. Overall, the high-gravity technology can be employed for the preparation of high-performance nano-adsorbent and has a great potential in the application of heavy metal removal.