Potassium cobalthexacyanoferrate–gel beads for cesium removal: kinetics and sorption studies

Abstract

The hydrogel-sorbent composite beads of potassium cobalthexacyanoferrate (KCoHCF) were synthesized for separation of cesium from waste generated in the nuclear industry. Cross-linked sodium alginate, containing PVA, was used as a binding matrix for the synthesis of spherical beads of 2 mm diameter.The characterization of these beads was carried out, using TGA, SEM and BET surface area analysis techniques, which indicated the highly porous and hydrophilic nature of the beads. The sorption of cesium ions onto these synthesized beads was studied, using a radiotracer technique. To determine equilibrium sorption and kinetic parameters for different initial cesium ion concentrations, all the studies were conducted by a batch method. The experimental data were analyzed, using the different sorption isotherms, and found to be described the best by a Langmuir sorption isotherm. The monolayer capacity of KCoHCF-gel beads is found to be 15 mg g À1 of the dry beads. Sorption kinetics data were analysed, using different kinetic models. The results show that the sorption follows pseudo second-order reaction kinetics. The initial sorption rate and the rate constants for the pseudo first-order, pseudo second-order and intraparticle diffusion were evaluated, and discussed for different initial concentrations in the range 1-20 mg L À1 . The mechanism of the sorption of cesium ions onto the synthesized beads was also investigated and film diffusion was found to be the rate determining step.

Investigating the adsorption of cesiun ion (Cs+) on cobalt hexacyanoferrate coated magnetite nanoparticles

“…Quá trình hấp phụ và phản ứng được thực hiện tại giá trị pH=4, trong quá trình khảo sát tốc độ phản ứng của thí nghiệm này dùng nồng độ Cs + trong dung dịch loãng, kết quả được thể hiện tại Hình 6B. Từ kết quả cho thấy phản ứng đạt cân bằng trong thời gian khoảng 15 phút và ion Cs + bị loại khỏi dung dịch lên đến 98% tương ứng với nghiên cứu của Dwivedi C. và cộng sự [19].…”

“…Lượng ion Cs + thay đổi đáng kể khi so sánh phổ đồ từ Hình 7A và B; lượng ion Co 2+ cũng thay đổi một cách tương ứng trước và sau phản ứng. Quá trình hấp phụ ion Cs + của vật liệu Co2[Fe(CN)6]/Fe3O4 theo cơ chế trao đổi ion tương tự công bố của Dwivedi, C. và cộng sự [19], phản ứng được đề nghị là: CHUYÊN SAN KHOA HỌC TỰ NHIÊN, TẬP 2, SỐ 6, 2018…”

“…sự[9] đã sử dụng hạt gel có thành phần là Cobalt hexacyanoferate gắn trên các hạt alginate với kích thước micromet làm vật liệu hấp phụ để tách loại cesium ra khỏi nước.…”

Eco-friendly one-pot synthesis of Prussian blue-embedded magnetic hydrogel beads for the removal of cesium from water

“…One involves the immobilization of PB on various support materials. For example, the surfaces of mesoporous silica 14 , 15 and carbon materials 16 , 17 were functionalized with PB, and various polymer matrices, such as chitin 18 , 19 , alginate 20 , 21 , polyacrylonitrile 22 , and polyacrylic acid 23 , were used to encapsulate PB. The other approach is to use magnetic particles to magnetically separate the adsorbent after 137 Cs sorption.…”

Amazing selectivity for Am(iii) uptake by composite graphene oxide-PES polymeric beads prepared by phase inversion

“…There have been reports on the use of polymeric resin beads with the extractants blended with the polymer and the resin beads prepared by a phase inversion technique to yield highly porous beads to have faster mass transfer rates. [12][13][14][15] It was thought of interest to prepare such beads containing GO in polyethersulphone (PES) as the polymer. In the present paper, the GO containing PES beads were prepared and characterized by various techniques including thermal analysis, SEM and were subsequently tested for the uptake of actinide ions viz., UO 2 2+ , Th 4+ , Pu 4+ and Am 3+ from acidic pH feed solutions.…”