Purification of 89Sr from FBTR irradiated Yttria target by extraction chromatography using HDEHP impregnated XAD-7 resin

89Sr is used in bone pain palliative care of cancer patients and the same is being produced presently via the 89Y(n, p)89Sr reaction by irradiating yttria target in Fast Breeder Test Reactor (FBTR). An efficient separation method was standardized for the removal of bulk yttrium target by extraction chromatography using di(2-ethylhexyl) phosphoric acid (HDEHP) impregnated on XAD-7 resin. In the present paper, the extraction behavior of Sr(II) and Y(III) was studied as a function of the concentration of nitric acid in the aqueous phase and concentration of HDEHP in the resin phase. The separation of Sr(II) and Y(III) was standardized using the above resins and the method was subsequently applied satisfactorily for the removal of yttrium from the dissolver solution of FBTR irradiated yttria pellet towards the purification of 89Sr. A baseline separation of 89Sr and Y was achieved. Leaching and breakthrough capacity studies were evaluated for the resins and it was established that the stability and capacity of the resins were satisfactory. The breakthrough capacity was found to be 12 mg Y(III) per gram of the HDHEP resin whereas the leaching studies established that the resins are stable for multiple cycle of operations.

Dry Scrubbing of Hydrogen Sulfide Gas Using Nano Zinc Oxide Coated Glass Beads

Hydrogen sulfide (H2S) is one of the most toxic and smelly gases emitted from animal production facilities, which also acts as a catalyst poison in many industrial processes. The principal objective of this research was to develop a dry scrubber to adsorb H2S gas efficiently from airstreams mimicking air exhausts of animal and poultry barns at the ambient atmospheric condition. Nano zinc oxide (nZnO) coated 3-mm sized glass beads were investigated to adsorb H2S gas in a vertical dry scrubber setting. Colloids of nZnO were prepared and thin films of nZnO were grown on the surfaces of commercially available glass beads following a sol-gel method. The sizes of nZnO on glass bead surfaces ranged from nm to µm and found to be clustered due to the repeated coatings on the same surfaces. The energy dispersion spectroscopy (EDS) analysis confirms the presence of sulfur (S) compound that indicated a conversion of H2S into zinc sulfide (ZnS) on nZnO coated bead surfaces. The highest H2S breakthrough capacity of 2.54 mg H2S g-1 sorbent was observed. Heating the beads at 550°C regenerated glass beads effectively but experienced a gradual loss of reactivity as a number of regeneration cycles progressed. This research demonstrated that nZnO supported on glass beads are promising adsorbents for capturing H2S gas from airstreams at ambient temperature. Keywords: Airstreams, Breakthrough capacity, Hydrogen sulfide, Nano zinc oxide, Regeneration.

Desulfurization Properties of Activated Carbon Fibers

Activated carbon fibers (ACFs) are one of the most promising adsorbents due to their outstanding properties, such as more exposed adsorption surface, narrower pore size distribution, fast adsorption rate and flexibility, in comparison with granular activated carbon and activated carbon powder. In this work, ACFs manufactured from various raw materials were studied and their pore structures and sulfur dioxide removal performance under dry and humid conditions were investigated. From the ACFs studied in this paper, larger surface area was found correspond to higher total pore volume and larger DA micropore diameter. In dry air, breakthrough capacity of ACFs with sulfur dioxide was found to be proportionately dependent on micropore ratio and pore size distribution. Although powdered activated carbon (PAC) showed higher breakthrough capacity, its adsorption rate was slower than ACFs due to the difference of the pore structure. The presence of water vapor in the air stream greatly increased SO2 adsorption capacities of ACFs but affected their utilization differently.

Adsorption Property of Cu-BTC for Dibenzothiophene Sulfide

Cu-BTC was synthesized by hydrothermal method. Adsorption desulfurization performance of Cu-BTC for dibenzothiophene sulfide was investigated. The adsorption property of Cu-BTC for dibenzothiophene and 4-methyldibenzothiophene in stimulated diesel were compared by equilibrium and dynamic experiments. The results show that when the equilibrium concentration is 0~50 mg S/L, the adsorption capacity of Cu-BTC for 4-methyldibenzothiophene is more than that of dibenzothiophene. When the equilibrium concentration is 50 mg S/L, the equilibrium adsorption capacity of Cu-BTC for 4-methyldibenzothiophene and dibenzothiophene are 17.54 mg S/gads and 15.64 mg S/gads, respectively. At the conditions of 30°C, 149.22h-1 and 0.1MPa, the initial concentration of dibenzothiophene and 4-methyldibenzothiophene is about 45.16~46.36 mg S/L, the adsorption property of 4-methyldibenzothiophene is superior than dibenzothiophene, the breakthrough capacity of Cu-BTC for 4-methyldibenzothiophehe is 1.73 times lager than dibenzothiophene. Cu-BTC shows an excellent prospect on diesel desulfurization process.

Enhanced Removal of Phenol by a Hyper-Cross-Linked Resin Functionalized with Composite Properties of Chemical Materials

A hyper-cross-linked polymeric adsorbent GQ-1 functionalized with acetamino groups and hydroxyl groups was synthesized to remove phenol. Results showed that the maximum adsorption capacity of GQ-1 emerged at the molecular state of phenol. More favorable adsorption of phenol onto GQ-1 than XAD-4 was further demonstrated by thermodynamic analysis. The breakthrough capacity of GQ-1 was 2.53 times that of XAD-4 when the effluent concentration reached 5mg/L.