Mussel-inspired antifouling magnetic activated carbon for uranium recovery from simulated seawater

Undesirable bio-adhesion of microalgae on adsorbent can influence its adsorption capacity. In this report, we fabricated a novel mussel-inspired antifouling magnetic activated carbons which derived orange peel by integrated biosorption-pyrolysis process (MACs@PDA-Ag), via co-functionalization of poly-dopamine (PDA) and Ag nanoparticles (AgNPs), for the recovery of uranium (VI) from simulated seawater with antimicrobial adhesion performance; this process did not require an additional reducing agent. The effect of pH, concentration, contact time, fouling test against nitzschia closterium f.minutissima (GY-H8) were studied. Compared with MACs (632.91 mg/g at pH 7.0), the calculated maximum adsorption capacity of MACs@PDA-Ag increased to 657.89 mg/g at pH 8.0 and showed good recyclability. These data all fitted well with the Langmuir and pseudo-second order models. The possible removal mechanism by XPS is chelation (catechol hydroxyls, amine/imine units, the metal-oxygen and carboxylic) with uranium (VI). The antifouling tests indicated that the AgNPs-modified materials displayed the antimicrobial adhesion behavior, and the viability of the microorganism was not impacted. Thereby, the direct deposition of AgNPs onto the adsorbent has shown great potential for uranium (VI) recovery with an antifouling benefit and is environmentally friendly.