Bed Volumes Of Solution Research Articles

Simple Method for Technetium Removal from Aqueous Solutions

Because of an increasing need for {sup 99}Tc removal from treatment solutions during waste processing and environmental cleanups, several inexpensive sorbents were investigated. Here, Packed-column experiments with iron dust of 40 to 60 mesh (Fisher I-57) showed an excellent uptake of pertechnetate ions from alkaline (pH {approximately} 8.5) high-nitrate (100 to 250 g/l) solutions at flow rates measured in bed volumes (BVs) of between 0.05 and 0.15 BV/min. The columns worked well until they became plugged by rusting after several hundred bed volumes of solution were flowed through (330 to 900 BV). Similar tests using organic ion-exchange resins, such as Dowex SRB-OH and Reillex HP and Reillex HPQ, and the same alkaline high-nitrate solutions showed breakthroughs after 20 to 50 BV were passed.

PRELIMINARY EVALUATION OF CHROMATOGRAPHIC TECHNIQUES FOR THE SEPARATION OF RADIONUCLIDES FROM HIGH-LEVEL RADIOACTIVE WASTE

ABSTRACT Three commercially available chromatographic materials were tested in a column mode for use in separating Am, Pu, and ™Sr from actual neutralized cladding removal waste (NCRW) taken from a Hanford waste tank. For these experiments, the NCRW was dissolved in HNO3/HF solutions. TRU-Spec™ was evaluated for the separation of transuranic elements. TRU-Spec™ removed Am and Pu from a dissolved NCRW solution, but not as effectively as the TRUEX solvent extraction process. Sr. Spec™ and SuperLig™ 601 were evaluated for the separation of Sr, Sr- Spec™ performed very well in the separation of SK from dissolved NCRW solution; Sr was not detectable in the column effluent after six bed volumes of solution had been passed through the column. SuperLig™ 601 was less effective than Sr- Spec™ at separating Sr from dissolved NCRW solution under the conditions used in this experiment. The poor performance of SuperLig Spec™ 601 has been attributed to slow kinetics of absorption of Sr.

27] Preparation of white resealable erythrocyte ghosts

Publisher Summary This chapter discusses that in biochemical labeling studies, in enzymatic digestion, and in optical studies of the membrane, the residual hemoglobin may cause an unwanted problem. Methods that deplete the membranes of all cytosolic materials through multiple washing steps generally form membranes that cannot be resealed tightly again. To overcome these problems, the following gel filtration procedure was developed. After collecting the membranes, it has been found convenient to reverse the flow to clear the column of the released hemoglobin. This is the fastest approach, since the hemoglobin front is down only about one-third the length of the column. The column may be cleaned by reverse flow with two to three bed volumes of isotonic saline, pH 7.6. The agarose should recover its white color. About once a week, depending on the frequency of use, the column is rinsed with two bed volumes of solution F to control bacterial growth.

Separation and Recovery of Cobalt from Copper Leach Solutions

Significant amounts of cobalt, a strategic and critical metal, are present in readily accessible copper recycling leach solutions. However, cost-effective technology is not available to separate and recover the cobalt from this low-grade domestic source. The Bureau of Mines has developed a procedure using a chelating ion-exchange resin from Dow Chemical Co. to successfully extract cobalt from a pH 3.0 copper recycling solution containing only 30 mg/1 cobalt. Cyclic tests with the commercial resin XFS-4195 in 4-ft-high by 1-in.-diameter columns gave an average cobalt extraction of 95% when 65 bed volumes of solution were processed at a flow rate of 4 gpm/ft.2 Elution of the cobalt using a 50 g/l H2SO4 solution yielded an eluate containing 0.5 gli Co. Selective elution of the loaded resin and solvent extraction procedures using di-2-ethylhexyl phosphoric acid (D2EHPA) and Cyanex 272 removed the impurities and produced a cobalt sulfate solution containing 25 g/l Co.