作者：
Yuling ZhaoXiaomin LiuSchool of Chemistry and Environmental Science
Key Laboratory of Green Chemical Media and ReactionsMinistry of Education Henan Normal University Xinxiang Henan 453007 China Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex Systems Beijing Key Laboratory of Ionic Liquids Clean Process
State Key Laboratory of Multiphase Complex SystemsInstitute of Process Engineering Chinese Academy of Science Beijing 100190 China
Dissimilatory metal reducing bacteria were domesticated with MnO2 in acidic conditions, and then the MnO2 color changed from black to white, even colorless. X-ray diffraction analysis indicated that dissimilatory redu...
详细信息
Dissimilatory metal reducing bacteria were domesticated with MnO2 in acidic conditions, and then the MnO2 color changed from black to white, even colorless. X-ray diffraction analysis indicated that dissimilatory reductive microbes could reduce MnO2 effectively after domestication. Manganese leaching from pyrolusite was investigated by using dissimilatory metal reducing bacteria under acid conditions, with the effluent of bio-hydrogen production as a reducing agent. Single-factor experiments were employed to examine the effects of anaerobic conditions and pH values on the leaching rate of Mn. The removal rate of chemical oxygen demand (COD) and the mechanism were also studied. It was shown that dissimilatory metal reducing bacteria reduced pyrolusite using the effluent of fermentative hydrogen production. The leaching rate of manganese under anaerobic conditions was higher than that under aerobic conditions, and it could reach 98% under the conditions of pH 3.0-3.5 and the leaching time of 3 d. For degrading the effluent of bio-hydrogen production under subacid conditions, the COD removal rate could reach 84% when COD in the effluent of bio-hydrogen production was 2612 mg·L-1, and it would be higher with more pyrolusite.
In order to study the behavior of microbial dissimilatory reduction in the process of bioleaching metal oxide, dissimilatory metal reducing microorganism (DMRM) was isolated from deep sea floor sediment of the pacific...
详细信息
In order to study the behavior of microbial dissimilatory reduction in the process of bioleaching metal oxide, dissimilatory metal reducing microorganism (DMRM) was isolated from deep sea floor sediment of the pacific ocean. The DMRM was adopted to the bioleaching process of the metals in marine manganese nodules of deep sea bed under anaerobic leaching condition. The leaching rates of Mn, Co, Cu and Ni are 98.6%, 96.4%, 95.8% and 89.6%, respectively. Microbialfuel cell was set up with the bacteria of Geobacter metallireducens, and the mechanism of microbial dissimilatory metal reduction was studied. The results show that metal oxide is the final electron acceptor of microbial respiration. The biofilm formed by the way of directly adsorption on the surfaces of the metal oxide mineral plays a key role during the metal dissimilatorilly reduction process.
Acid leaching of ocean polymetallic nodules was investigated, CO and N2 mixture was used as reducing gas and fluid medium. The effects of operation parameters on metal leaching rate such as reducing temperature, time ...
详细信息
Acid leaching of ocean polymetallic nodules was investigated, CO and N2 mixture was used as reducing gas and fluid medium. The effects of operation parameters on metal leaching rate such as reducing temperature, time and atmosphere were analyzed. The results show that under the condition of reducing temperature of 700-850°C, reducing time of 10 min and CO volume ratio of 20%, an average leaching rate higher than 95% can be achieved, which indicates the ocean polymetallic nodules can be reduced efficiently in fluidized bed.
A novel enzyme membrane reactor with sandwich structure has been developed by confining glucosidase between two sheets of ultrafiltration membranes to effectively convert maltose to isomaltooligosaccharides (IMOs). Th...
详细信息
A high-performance gas-liquid transmission device (HPTD) was described in this paper. To investigate the HPTD mass transfer characteristics, the overall volumetric mass transfer coefficients, KLa,CO2A for the absorpti...
详细信息
A sequential procedure of alkaline treatment followed by SiCl4 or hydrothermal treatment has been investigated to obtain a tailored ZSM-5 catalyst for the synthesis of pyridine bases. The major function of alkaline tr...
详细信息
A sequential procedure of alkaline treatment followed by SiCl4 or hydrothermal treatment has been investigated to obtain a tailored ZSM-5 catalyst for the synthesis of pyridine bases. The major function of alkaline treatment is desilication; however, it is accompanied by the extraction of framework aluminum, which formed the extra-framework alumina and amorphous alumina by realumination. Moreover, a large number of intracrystalline meso- and macropores and silanol groups are created. The desilication and realumination cause the ratio of Lewis acid sites to Brönsted acid sites (L/B) to increase. The subsequent SiCl4 or hydrothermal dealumination increases both L/B ratio and acid strength. The introduced hierarchical pores and changed acid strength distribution by the alkaline treatment improve the stability of the catalysts; the generated stronger acid sites by dealumination benefits the yields of pyridine bases; and the increased L/B by the sequential treatment promotes the selectivity of pyridine over 3-picoline.
Biodiesel is an important renewable energy. Supercritical methanol transesterification for biodiesel has recently been concerned because of its obvious advan-tages. The tubular reactor is an ideal reactor for continuo...
详细信息
Biodiesel is an important renewable energy. Supercritical methanol transesterification for biodiesel has recently been concerned because of its obvious advan-tages. The tubular reactor is an ideal reactor for continuous preparation of biodiesel via supercritical methanol trans-esterification. A methanol preheating tube is necessary for the tubular reaction system because the reaction tempera-ture for supercritical methanol transesterification is usually 520-600 K. Therefore, in the range of 298-600 K, changes of the density, isobaric capacity, viscosity and thermal conductivity of sub/supercritical methanol with tempera-ture are first discussed. Then on the basis of these thermophysical properties, an integration method is adopted for the design of sub/supercritical methanol preheating tube when methanol is preheated from 298 K to 600K at 16MPa and the influencing factors on the length of the preheating tube are also studied. The computational results show that the Reynolds number Re and the local convection heat-transfer coefficient a of sub/supercritical methanol flowing in Φ6×1.5mm pre-heating tube change drastically with temperature. For the local overall heat transfer coefficient K and the average overall heat transfer coefficient Km, temperature also has an important influence on them when the inlet velocity of methanol is lower than 0.5 m/s. But when the inlet velocity of methanol is higher than 0.5 m/s, K and Km almost keep invariable with temperature. Additionally, both the outlet temperature and the inlet velocity of methanol are the key affecting factors for the length of the preheating tube, especially when the outlet temperature is over the critical temperature of methanol. At the same time, the increase of tin bath's temperature can shorten the required length of the preheating tube. At the inlet flow rate of 0.5 m/s, the required length of the preheating tube is 2.0m when methanol is preheated from 298 K to 590 K at 16 MPa with keeping the tin bath's
暂无评论