Microfluidic generation of Prussian blue-laden magnetic micro-adsorbents for cesium removal

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 341; pp. 218 - 226
• Main Authors: Kang, Sung-Min, Rethinasabapathy, Muruganantham, Hwang, Seung Kuy, Lee, Go-Woon, Jang, Sung-Chan, Kwak, Cheol Hwan, Choe, Sang-Rak, Huh, Yun Suk
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2018
• Subjects: Cesium; Glass capillary device; Hydrogel; Micro-adsorbent; Prussian blue; Cesium; Glass capillary device; Prussian blue; Hydrogel; Micro-adsorbent
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2018.02.025

[Display omitted] •PB-MNPs-MAs were generated in microfluidic device using chemical co-precipitation.•The prepared PB-MNPs-MAs are monodispersed with uniform morphology.•PB-MNPs-MAs exhibited high Cs adsorption capacity (58.73 mg g−1).•100% recovery of PB-MNPs-MAs is possible under static magnetic field after Cs adsorption. Here, we designed and synthesized a recoverable multifunctional adsorbent using a microfluidic reaction system and evaluated the removal performance of the smart adsorbent toward radioactive cesium as a model sample. Prussian blue-laden magnetic micro-adsorbents (PB-MNPs-MAs) with uniform morphology and monodispersity were generated via two-step sequential procedures using a glass capillary microfluidic system, followed by chemical co-precipitation with a high production rate. The cesium removal efficacy of the PB-MNPs-MAs was analyzed based on Langmuir and Freundlich isotherms by controlling adsorption parameters such as adsorbent size, initial cesium concentration, and contact time. The adsorption isotherm of the PB-MNPs-MAs was better fitted to the Langmuir model with a maximum cesium adsorption capacity of 58.73 mg g−1, which was 40% higher than that of macro-adsorbents in a dynamic magnetic field. This result can be attributed to their large specific area, which increased the kinetic rate of cesium adsorption and achieved saturation within 20 min. Additionally, the PB-MNPs-MAs were recovered from wastewater within 5 s under a static magnetic field, indicating their great potential for magnetic actuation. We believe that our PB-MNPs-MAs can encapsulate nano-functional adsorbents and prevent actuation, making them promising for environmental remediation and especially for removal of radionuclides.