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101.
Anyun Zhang Yuezhou Wei Mikio Kumagai Yoshikazu Koma 《Journal of Alloys and Compounds》2005,390(1-2):275-281
To separate the long-lived minor actinides (MA(III) = Am(III), Cm(III)) and some specific fission products (FP) such as Pd(II), Mo(VI), Cs(I) and Sr(II) from high-level liquid waste (HLLW), we have been studying a new partitioning process by extraction chromatography using several novel silica-based extraction resins. In this work, we examined the separation behavior of the elements contained in a simulated MA-effluent by the CMPO/SiO2P packed column. In addition, as an attempt to further isolate Am(III) and Cm(III) from the heavy RE(III) such as Eu(III), Gd(III) and Dy(III) contained in the MA-effluent, we investigated the possibility of separation by using a silica-based cationic exchange resin. Furthermore, to isolate Sr(II) from the HLLW, adsorption and separation performances of Sr(II) and some other FP elements were studied by using a novel silica-based crown ether extraction resin, DtBuCH18C6/SiO2P. The experimental results demonstrated that the elements in the simulated MA-effluent can be successfully separated to (1) Pd, (2) MA-hRE and (3) Zr–Mo, by CMPO/SiO2P packed column using water and a dilute DTPA solution as eluents. Am(III) and Cm(III) are expected to be effectively separated from light RE(III) and Y(III) by the SiSCR cationic resin. However, more effective separation between Am(II), Cm(III) and heavy RE(III) such as Eu(III), Gd(III) and Dy(III) needs further approach. DtBuCH18C6/SiO2P showed a highly selective adsorption for Sr(III) so that the Sr(II) could be completely separated from other FPs except a portion of Ba(II). 相似文献
102.
Sheng-lian LUO Lin YUAN Li-yuan CHAI Xiao-bo MIN Yun-yan WANG Yan FANG Pu WANG 《中国有色金属学会会刊》2006,16(6):1431-1435
Biosorption of heavy metal ions, such as Cu2+, Cd2+ and Zn2+, was carried out using waste activated sludge from municipal sewage treatment plant as adsorption material, and the effects of parameters, such as pH value, temperature, reaction time and sorption duration, were studied in detail. The results indicate that the removal rates of Cu2+, Zn2+ and Cd2+ with low concentration are 96.47%, 80% and 90%, respectively, adsorbed by waste activated sludge. Little effect of dosage of activated sludge on the adsorption of Cu2+ and more effects on the adsorption of Zn2+ and Cd2+ are observed. Little effect of temperature is observed, while pH value and adsorption time exert important influence on the sorption process. The adsorption behaviors of heavy metal ions all have parabolic relationships with pH value. The optimum pH value is between 6 and 10, and the optimum adsorption time is 1 h. In single heavy metal ion system, the sorption processes of Cu2+, Zn2+ and Cd2+ are in accordance with Freundlich model, which indicates that it is suitable for the treatment of these three heavy metal ions using intermittent operation. In addition, the sorption capacity of the sludge for Cu2+ is preferential to the other two ions. 相似文献
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Ground rubber powder (GRP) and devulcanized rubber (Dev.R) waste through a continuous shear‐flow reaction were used as fillers for virgin natural rubber. A Horikx plot and the gel fraction proved that both main‐chain scission and crosslink scission occurred during the devulcanization. The cure characteristics, swelling behavior, crosslink density, and mechanical properties were studied. GRP and Dev.R, generated from passenger car and light truck tires, showed applicable mechanical properties in the new rubber compounds, and the compounds containing Dev.R demonstrated better properties than those containing GRP. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 208–217, 2005 相似文献
108.
ABSTRACT The mixture of citrus fruits (orange, grapefruit, mandarin, and lemon) wastes was utilized to obtain high surface area activated carbon (AC) by H3PO4 activation. The production conditions were optimized and the optimum conditions were determined. The optimal-activated carbon (CFWAC) was characterized by various physicochemical techniques. CFWAC was also used as a sorbent for Pb (II) ions from water. Batch experiments were performed to explore the adsorption capacity and mechanism. The Langmuir isotherm and pseudo-second-order kinetic model showed good fitness to the experimental data. The maximum Pb (II) adsorption capacity of CFWAC was found to be 163.93 mg/g. 相似文献
109.
Methane Transport Capacity of Rice Plants. II. Variations Among Different Rice Cultivars and Relationship with Morphological Characteristics 总被引:3,自引:0,他引:3
M.S. Aulakh J. Bodenbender R. Wassmann H. Rennenberg 《Nutrient Cycling in Agroecosystems》2000,58(1-3):367-375
Of the total methane (CH4) emitted from a rice field during the growing season 60–90% is emitted through the rice plants. We determined the methane transport capacity (MTC) of rice plants at different physiological growth stages using an automatic measuring system under greenhouse conditions. A total of 12 cultivars (10 inbred varieties and 2 hybrids) were studied in sets of two experiments and was distinguished into three groups according to the patterns of MTC development. MTC is generally increasing from seedling stage to panicle initiation (PI), but differs in the development from PI to maturity. While the hybrid showed a gradual increase in MTC, the inbred cultivars showed either minor changes in MTC or a drastic decrease from flowering to maturity. Among tall cultivars, Dular showed the highest MTC, followed by B40; the lowest MTC was found in Intan. High-yielding dwarf cultivars showed MTC in the descending order of IR72 > IR52 > IR64 > PSBRc 20. New plant type cultivars showed very low MTC with IR65600 exhibiting the smallest MTC at PI, flowering, and maturity. Hybrids (Magat and APHR 2) showed the largest MTC that continued to increased with plant growth. The MTC patterns were attributed to growth parameters and the development of morphological characteristics of the aerenchyma. These results suggest that in tall, dwarf, and NPT cultivars, increase in root or aboveground biomass during initial growth determines a corresponding increase in MTC. Once aerenchyma has fully developed, further increase in plant biomass would not influence MTC. However, in the case of hybrids, a positive relationship of MTC with root + shoot biomass (r = 0.672, p 0.05) and a total plant biomass including grain (r = 0.849, p 0.01) indicate continuous development of aerenchyma with plant growth, resulting in enhanced MTC. In all cultivars, tiller number, but not height, was linearly related to MTC, indicating that the number of outlets/channels rather than plant size/biomass determines the transport of CH4. These results clearly demonstrate that rice cultivars differ significantly in MTC. Therefore, the use of high-yielding cultivars with low MTC (for example, PSBRc 20, IR65598, and IR65600) could be an economically feasible, environmentally sound, and promising approach to mitigate CH4 emissions from rice fields. 相似文献
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