Rapid and selective removal of radiocesium from complex aquatic environments using a highly porous 3D AMP@GA bulk composite

Radioactive 137 Cs poses a severe threat in nuclear wastewater. Conventional powdered adsorbents suffer from poor recoverability and are ill-suited for large-scale continuous-flow operations. To address these limitations, a novel three-dimensional bulk ammonium phosphomolybdate-gelatin composite adsorbent (AMP@GA) was fabricated. Through this strategy, highly selective AMP particles were uniformly immobilized within a porous (92%) gelatin network. Rapid adsorption kinetics (reaching equilibrium within 30 min), a Langmuir-fitted theoretical maximum Cs + adsorption capacity of 142.17 mg·g −1 at 45 °C, and acceptable chemical stability across a broad pH range (2.0-11.0) were exhibited by the resulting AMP@GA. Most significantly, the material demonstrated outstanding selectivity over competing ions ( K d  = 7.48 × 10 4 mL·g −1 ). Its practical viability was confirmed by achieving over 88% removal efficiency in authentic seawater. Furthermore, in fixed-bed column tests, the material sustained continuous operation for 163.5 h. The mechanism is dominated by NH 4 + -Cs + ion exchange, assisted by electrostatic interactions. This work presents a scalable, easily recoverable bulk adsorbent that effectively helps address the engineering bottlenecks of traditional powdered materials.