Extraction Equilibrium of Co(II) with Microcapsules of Cross-linked Gel of Poly(vinyl alcohol)/Alginic Acid Encapsulating Dispersed Droplets of 2-ethylhexyl Phosphonic Acid 2-ethylhexyl Ester

Abstract

Microencapsulation of 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) in the microcapsules with hydrophilic wall were carried out using two-step crosslinking of sodium alginate by Ca 2+ ion and polyvinyl alcohol by glutaraldehyde. The morphologies of the microcapsules prepared and during the preparation were investigated. The extraction properties of Co(II) in ammonium sulfate solution using the microcapsules were also investigated under various conditions. Spherical and oval microcapsules containing PC88-A droplets with the diameter around 3mm were successfully prepared. The inside of the microcapsules was observed darkly by a lot of small droplets of PC-88A. The extraction of Co(II) using the microcapsules containing PC-88A was sharply increased at pH higher than 4. It was confirmed that Co(II) ion was extracted by two molecules of PC-88A in the condition at high Co(II) concentration range from the analysis of the relationship between the maximum amount of Co(II) extracted and the PC-88A content in the microcapsule. The extraction of Co(II) was analyzed quantitatively by three-step reaction model that is stepwise reaction with the cluster of three PC-88A-dimer, and was able to explain successfully based on the analysis. Co(II) extracted in the microcapsules was successfully back-extracted at pH lower than 2. The microcapsules containing PC-88A could be used repeatedly for several times for the extraction and back-extraction processes of Co(II).

Preparation of Pellet Biopolymer Polyvinyl Alcohol/Alginate/Gluataraldehyde Impregnated with Banana Peel Activated Carbon (BPAC)

“…Banana peel activated carbon (BPAC), PVA and alginate are materials that are environmentally friendly materials. Furthermore, PVA/Alg pellet biopolymer impregnated with BPAC will be further crosslinked with glutaraldehyde (GA) (Komatsu, et al, 2015) by considering the results of Aprilia's research (2021) that the Gravitasi Journal available at: https://bestjournal.untad.ac.id/index.php/GravitasiFisika e-ISSN: 2654-4318 p-ISSN: 1412-2375 amount of banana peels, size 60 mesh, impregnated into the PVA/Alg pellet biopolymer affected the mechanical strength of the material wall. Glutaraldehyde (GA) has unique characteristics so that it is one of the most effective protein crosslinking agents.…”