Resorcinol-Formaldehyde Resins for Cesium Removal from Solutions Produced after Processing Spent Ion-Exchangers

2020 ◽  
Vol 842 ◽  
pp. 107-114
Author(s):  
Eduard Tokar' ◽  
Marina Palamarchuk ◽  
Mikhail Tutov ◽  
Anna Matskevich ◽  
Andrei Egorin
Keyword(s):  
Chemical Stability ◽  
Contact Time ◽  
Sorption Properties ◽  
Molar Ratio ◽  
Ion Exchangers ◽  
Resorcinol Formaldehyde ◽  
Dynamic Conditions ◽  
Cesium Removal ◽  
Dynamic Sorption ◽  
Short Contact Time

A series of resorcinol-formaldehyde resins (RFR) has been prepared and studied in terms of Cs-137 uptake efficiency from solutions (0.75М NaOH-2.25M NaNO3) intended for processing spent ion-exchangers. Sample synthesized at molar ratio of resorcinol to formaldehyde of 1.8:2.2 and solidified at 210 °C (sample RFR-3-1-210) has shown the best sorption-selective performance and chemical stability. Implementing RFR in dynamic sorption scheme enables to reduce its decay due to short contact time. In dynamic conditions, after feeding 1000 bed volumes of the solution, RFR 3-1-210 maintains its sorption properties after 6 sorption-desorption cycles.

scholarly journals Effect of the Resorcinol/Formaldehyde Ratio and the Temperature of the Resorcinol–Formaldehyde Gel Solidification on the Chemical Stability and Sorption Characteristics of Ion-Exchange Resins

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 239
Author(s):  
Eduard Tokar ◽  
Mikhail Tutov ◽  
Pavel Kozlov ◽  
Arseni Slobodyuk ◽  
Andrei Egorin
Keyword(s):  
Ion Exchange ◽  
Chemical Stability ◽  
Model Solution ◽  
Alkaline Media ◽  
Molar Ratio ◽  
Ion Exchange Resins ◽  
Solidification Temperature ◽  
Resorcinol Formaldehyde ◽  
Exchange Resins ◽  
Sorption Characteristics

A series of resorcinol–formaldehyde resins (RFR) samples for Cs-137 removal from liquid alkaline media have been synthesized. It has been demonstrated that the chemical stability as well as sorption characteristics are determined by the resorcinol/formaldehyde molar ratio and the solidification temperature. It has been also demonstrated that the sample synthesized at the resorcinol/formaldehyde molar ratio of 1.8/2.2 and solidified at 210 °C is characterized by the best sorption-selective characteristics and chemical stability. Under dynamic conditions, at feeding >1000 bed volumes of a model solution with pH > 13, the RFR 3-1 goes through six sorption cycles without noticeable changes in the sorption characteristics. The results are presented that demonstrate the possibility of RFR application in the decontamination of real LRW from Cs-137.

scholarly journals Impact of Neodymium and Scandium Ionic Radii on Sorption Dynamics of Amberlite IR120 and AB-17-8 Remote Interaction

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5402
Author(s):  
Talkybek Jumadilov ◽  
Bakytgul Totkhuskyzy ◽  
Zamira Malimbayeva ◽  
Ruslan Kondaurov ◽  
Aldan Imangazy ◽  
...  
Keyword(s):  
Atomic Emission ◽  
Sorption Process ◽  
Sorption Properties ◽  
Molar Ratio ◽  
Ion Exchangers ◽  
Ionic Radii ◽  
Average Growth ◽  
Optimal Conformation ◽  
Neodymium Sulfate ◽  
Exchange Resins

The aim of the work is to provide a comparative study of influence of ionic radii of neodymium and scandium ions on their sorption process from corresponding sulfates by individual ion exchangers Amberlite IR120, AB-17-8 and interpolymer system Amberlite IR120-AB-17-8. Experiments were carried out by using the following physicochemical methods of analysis: conductometry, pH-metry, colorimetry, and atomic-emission spectroscopy. Ion exchangers in the interpolymer system undergo remote interactions with a further transition into highly ionized state. There is the formation of optimal conformation in the structure of the initial ion exchangers. A significant increase of ionization of the ion-exchange resins occurs at molar ratio of Amberlite IR120:AB-17-8 = 5:1. A significant increase of sorption properties is observed at this ratio due to the mutual activation of ion exchangers. The average growth of sorption properties in interpolymer system Amberlite IR120:AB-17-8 = 5:1 is over 90% comparatively to Amberlite IR120 and almost 170% comparatively to AB-17-8 for neodymium ions sorption; for scandium ions sorption the growth is over 65% comparatively to Amberlite IR120 and almost 90% comparatively to AB-17-8. A possible reason for higher sorption of neodymium ions in comparison with scandium ions is maximum conformity of globes of internode links of Amberlite IR120 and AB-17-8 after activation to sizes of neodymium sulfate in an aqueous medium.

Non-Premixed Reactive Volatilization Reactor for Catalytic Partial Oxidation of Low Volatility Fuels at a Short Contact Time

2021 ◽  
Author(s):  
Ying Lin ◽  
Xuesong Li ◽  
Martyn Twigg ◽  
William F Northrop
Keyword(s):  
Partial Oxidation ◽  
Contact Time ◽  
Catalytic Partial Oxidation ◽  
Liquid Hydrocarbons ◽  
Short Contact ◽  
Short Contact Time ◽  
Opposed Flow

This work presents a novel non-premixed opposed-flow reactive volatilization reactor that simultaneously vaporizes and partially oxidizes low volatility liquid hydrocarbons at a short contact time (<12 ms). In the reactor,...

Short contact time oxidative dehydrogenation of propane

2001 ◽  
Vol 64 (1-2) ◽  
pp. 113-120 ◽  
Author(s):  
M Fathi ◽  
R Lødeng ◽  
E.S Nilsen ◽  
B Silberova ◽  
A Holmen
Keyword(s):  
Oxidative Dehydrogenation ◽  
Contact Time ◽  
Oxidative Dehydrogenation Of Propane ◽  
Short Contact ◽  
Short Contact Time

scholarly journals Application of Ozone and Oxygen to Reduce Chemical Oxygen Demand and Hydrogen Sulfide from a Recovered Paper Processing Plant

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Patricia A. Terry
Keyword(s):  
Hydrogen Sulfide ◽  
Chemical Oxygen Demand ◽  
Contact Time ◽  
Oxygen Demand ◽  
Gas Production ◽  
Injection System ◽  
Processing Plant ◽  
Short Contact Time ◽  
Production Of Hydrogen ◽  
Fox River

A pilot study was performed at the Fox River Fiber recovered paper processing company in DePere, Wisconsin, to determine the extent to which injection of oxygen and ozone could reduce the high chemical oxygen demand, COD, in the effluent and the effectiveness of the ozone/oxygen stream in suppressing production of hydrogen sulfide gas in downstream sewage lines. Adaptive Ozone Solutions, LLC, supplied the oxygen/ozone generation and injection system. Samples were analyzed both before and after oxygen/ozone injection. Hydrogen sulfide gas was continuously monitored at sewer stations downstream of Fox River Fiber. Results showed that with a very short contact time, effluent COD was reduced by over 15%. A simple kinetic model predicts that a contact time of fewer than 30 minutes could reduce COD by as much as 60%. In addition, downstream hydrogen sulfide gas production in the sewage mains was also better controlled, such that costly Bioxide applications could be reduced.

Fabrication of Carbon Aerogels

2006 ◽  
Vol 11-12 ◽  
pp. 19-22 ◽  
Author(s):  
Y.N. Feng ◽  
Lei Miao ◽  
Yong Ge Cao ◽  
T. Nishi ◽  
Sakae Tanemura ◽  
...  
Keyword(s):  
Pore Size ◽  
Sol Gel ◽  
Supercritical Drying ◽  
Limited Range ◽  
Molar Ratio ◽  
Carbon Aerogels ◽  
Resorcinol Formaldehyde ◽  
Catalyst Content ◽  
Fabrication Parameters ◽  
Pyrolysis Processes

RF (Resorcinol-Formaldehyde) aerogels and carbon aerogels were prepared through the sol-gel method following the routes of polymerization, gelation, supercritical drying and pyrolysis processes. The influence of fabrication parameters on the textural structure of the samples, e.g., specific surface area, pore size, and pore size distribution, etc., were systematically investigated. With a decrease in the R/F molar ratio, or an increase in the catalyst content within a limited range, the porosity of the nanostructure materials increases. The optimal temperature of pyrolysis for RF aerogel was investigated by TGA (Thermogravimetric Analysis).

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