scholarly journals Effect of ion exchange resin particle size on homogeneity and leachability of Cs and Co in polymer waste form

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 2729-2732
Author(s):  
Jueun Kim ◽  
Bhupendra Kumar Singh ◽  
Wooyong Um
Keyword(s):  
Particle Size ◽  
Ion Exchange ◽  
Ball Mill ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Waste Form ◽  
Polymer Waste ◽  
Resin Particle

Ball mill ground IER waste form resulted in relatively better homogeneous waste distribution and displayed superior Cs leachability compared with the same polymer waste form prepared with non-ground IER.

scholarly journals Technique for Characterization and Clearance of the Resin Waste from the Greek Research Reactor (GRR-1)

2019 ◽  
Vol 25 ◽  
pp. 130
Author(s):  
E. Ntalla ◽  
A. Savvidou
Keyword(s):  
Ion Exchange ◽  
Research Reactor ◽  
Exchange Resin ◽  
Summation Formula ◽  
Ion Exchange Resin ◽  
Waste Form ◽  
Management Option ◽  
Management Options ◽  
Pavement Construction ◽  
Interim Storage

The present work concerns the examination of management options for VLLW drums [1] with ion exchange resin waste from the Greek Research Reactor (GRR-1). According to the general clearance criterion [2, 3], after cementation, 75 % of the VLLW could be cleared and for the remaining 25 % the summation formula result is lower than 1.6. The proposed management option for the total amount of the VLLW resin is the spread of the cemented resin, before thickening, over the ground around the interim storage facilities, inside the controlled area, for pavement construction. Additionally, a quantity of the cemented waste will be used for preparation of blocks for quality and homogeneity examination of the waste form.

scholarly journals Formulation and Characterization of Moxifloxacin Nanoparticles with Ion Exchange Resin

2020 ◽  
Vol 10 (1-s) ◽  
pp. 51-61 ◽  
Author(s):  
Jigar Vyas ◽  
Kapil Daxini ◽  
Jitendra Patel
Keyword(s):  
Particle Size ◽  
Ion Exchange ◽  
Zeta Potential ◽  
Exchange Resin ◽  
Diffusion Mechanism ◽  
In Vitro Release ◽  
Ion Exchange Resin ◽  
Fickian Diffusion ◽  
Stoichiometric Ratio ◽  
Media Milling

Moxifloxacin (MOX) is a fluoroquinolone anti-infective drug, indicated for the treatment of bacterial conjunctivitis. The drug is soluble in water but still produces low ocular bioavailability due to biological barriers and so it requires dosing for two/three times a day. The present study was designed to formulate, optimize and characterize polymeric Nanoparticles MOX for ocular administration using Ion Exchange Resin (IER). IER-nanoparticles were prepared by media milling method, formulation/process parameters were optimized based on evaluation parameters such as color of nanosuspension, sedimentation behaviour, particle size and zeta potential. MOX-IER nanosuspensions were prepared at different stoichiometric ratio of MOX and IER and characterized by entrapment efficiency, pH, particle size and zeta potential of nanosuspension. In vitro release study of optimized batch MNIER3 exhibited sustained release pattern which follows Korsmeyer-Peppas model with Fickian diffusion mechanism for drug release. Based on these results optimized batch of MOX-IER nanosuspension formulated in the laboratory was found suitable for ocular delivery. Keywords: Moxifloxacin; nanoparticles, nanosuspension; media milling; stoichiometric ratio; sedimentation behaviour.

Cementation of Radioactive Waste Resin by Calcium Sulfoaluminate Cement

2009 ◽  
Author(s):  
Junfeng Li ◽  
Jianlong Wang
Keyword(s):  
Compressive Strength ◽  
Ion Exchange ◽  
Radioactive Waste ◽  
Temperature Rise ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Waste Form ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate

Spent radioactive ion-exchange resin (SIER) is a long-standing issue for radioactive waste management safety. Performance of radioactive waste form is featured with extra long-term and non-repairable. Calcium sulfoaluminate cement (SAC) was used in radioactive spent resins solidification in China. A prescription of X SAC cement + 0.5X waste resins (50%water hold) + 0.35X water was obtained first. In order to control the temperature rise caused by hydration of cement in 200L solidification matrix, various supplementary materials were tried. Based on compressive strength tests and center temperature rise, super powered zeolite was selected. In addition, more resins were added to reduce the center temperature rise. A superior combination was obtained as SAC 35wt.%, zeolite 7wt.% to mix 42wt.% of resins (50%water hold) with 16wt.% of water. The microstructures of hydrated Ordinary Portland Cement (OPC), SAC and SAC with different zeolite addition were compared by means of Scanning Electron Microscopy (SEM). From the SEM pictures, the structures of the needles or spines can be seen in SAC matrices and the needles structure of SAC change into flake structure gradually with more zeolite added. The simulated leaching tests showed that inclusion of zeolite in SAC reduced the leaching rates of radionuclides significantly. From 200L matrix test, the centre temperature curve was measured, and the highest temperature was lower than 90°C. No thermal cracks were found in the final solidified products. The effect of radiation on compressive strength and radiolysis gas generation was studied for cement solidified form of various content of ion exchange resin with Co-60 irradiator. Variation of compressive strength, as well as the compressive strength of the waste form both with and without irradiation all within the standards requirement under irradiation of 106 Gy. However, the data obtained for ion exchange resin shows that hydrogen generation under irradiation of 105 Gy reached up to 3.5% of the total gas generated. This implies that the radioactivity of spent ion exchange resin shall be limited for long term storage and disposal with High-Integrity-Container. Calculation demonstrates that cement solidification of spent radioactive ion exchange resin existing in China so far should not result in radiation stability concern. It is concluded that SAC is one of the preferential binding material for ion exchange resins, the resin loading can be up to 75 (vol%) (wet resin). It is recommended that the performance requirement for cement solidified radioactive form shall be amended and guidelines for performance characterization in certain detail should be established. Biodegradation of cement solidified resin waste would be a safety concern and shall be investigated. Modeling of leaching should be promoted.

OPTIMIZATION OF DNA EXTRACTION METHODS FROM BIOLOGICAL MATERIALS OF HONEY BEES IN A DIFFERENT METAMOTPHOSIS PHASE

2016 ◽  
Vol 52 ◽  
pp. 171-176
Author(s):  
M. Palkina ◽  
O. Metlitska
Keyword(s):  
Ion Exchange ◽  
Dna Extraction ◽  
Honey Bees ◽  
Biological Material ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Extraction Methods ◽  
Chelex 100 ◽  
Drone Brood ◽  
Dna Extraction Methods

The aim of the research – adaptation, optimization and using of existing DNA extraction methods from bees’ biological material with the reagent «Chelex-100" under complex economic conditions of native laboratories, which will optimize labour costs and improve the economic performance of DNA extraction protocol. Materials and methods. In order to conduct the research the samples of honey bees’ biological material: queen pupae exuviae, larvae of drone brood, some adult bees’ bodies (head and thorax) were selected. Bowl and drone brood were obtained from the experimental bee hives of Institute of Apiculture nd. a. P. I. Prokopovich of NAAS. DNA extraction from biosamples of Apis mellifera ssp. was carried out using «Chelex-100®» ion exchange resin in different concentrations and combinations. Before setting tests for determination of quantitative and quality indexes, dilution of DNA samples of the probed object was conducted in ratio 1:40. The degree of contamination with protein and polysaccharide fractions (OD 260/230), quantitative content of DNA (OD 260/280) in the extracted tests were conducted using spectrophotometer of «Biospec – nano» at the terms of sample volume in 2 µl and length of optical way in 0,7 mm [7]. Verification of DNA samples from biological material of bees, isolated by «Chelex-100®», was conducted after cold keeping during 24 hours at 20°C using PСR with primaries to the fragment of gene of quantitative trait locus (QTL) Sting-2 of next structure [8]:  3' – CTC GAC GAG ACG ACC AAC TTG – 5’; 3' – AAC CAG AGT ATC GCG AGT GTT AC – 5’ Program of amplification: 94 °C – 5 minutes – 1 cycle; 94 °C – 1 minute, 57°C – 1 minute, 72 °C – 2 minutes – 30 cycles; elongation after 72°C during 2 minutes – 1 cycle. The division of obtained amplicons was conducted by gel electrophoresis at a low current – 7 µÀ, in 1,5 % agarose gel (Sigma ®) in TAE buffer [7]. The results. At the time of optimization of DNA isolation methods, according to existing methods of foreign experts, it was found optimal volume of ion exchange resin solution was in the proposed concentration: instead of 60 µl of solution used 120 µl of «Chelex-100®», time of incubation was also amended from 30 minutes to 180 minutes [9]. The use of the author's combination of method «Chelex-100®» with lysis enzymes, proteinase K and detergents (1M dithiothreitol), as time of incubation was also amended, which was reduced to 180 minutes instead of the proposed 12 hours [10]. Changes in quality characteristics of obtained DNA in samples after reduction in incubation time were not found. Conclusions. The most economical method of DNA isolation from bees’ biological material is 20% solution of «Chelex-100» ion exchange resin with the duration of the incubation period of 180 minutes. It should also be noted that the best results can be obtained from exuviae, selected immediately after the queen’s exit from bowl, that reduces the likelihood of DNA molecules destruction under the influence of nucleases activation, but not later than 12 hours from release using the technology of isolated obtain of queens.

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