Fast and effective palladium adsorption from electronic waste using a highly macroporous monolith synthesized via rapid UV-irradiation

Abstract

Recovering palladium rapidly and effectively from electronic waste materials presents a challenging and essential task, mainly due to the harsh acidic conditions. This study developed a highly porous and lightweight monolith to address this issue by enabling rapid and efficient palladium adsorption under acidic conditions. The monoliths were fabricated through a quick UV-irradiation cryopolymerization process. The resulting monoliths exhibited significantly enhanced palladium adsorption capacity, measuring at 155.5 mg g−1, surpassing most previously reported data. The adsorbed concentrations of Pd(II) and other coexisting ions were determined using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES, VISTA-MPX, Varian). Various parameters such as pH, contact time, temperature, concentration, and selectivity were investigated to assess their impact on palladium adsorption. The material demonstrated superior selectivity for palladium ions in the presence of coexisting metal ions. Furthermore, the material's thermal stability was evaluated within the 25–100 °C range, revealing sufficient adsorption capacity at temperatures up to 100 °C, indicating its potential for implementation in harsh conditions. The synthesized monolith exhibited a shelf life of up to six months without degrading its adsorption performance. Moreover, the material retained its adsorption efficiency after multiple cycles of use. The effectiveness of palladium adsorption was also demonstrated in actual wastewater samples, further validating the material's practical application. Overall, this designed system showcases excellent adsorption performance and stability, making a valuable contribution to polymer chemistry and environmental science for recovering precious metals from wastewater.