Papers by Keyword: Metal Membrane

Abstract: In order to study changes in the quantity of different denitrifying bacteria during the process of the metal membrane bioreactor, and to determine the relationship between different types of bacteria’s quantity and the treating water quality, the fluorescence in situ hybridization (FISH) dominant molecular biological technologies were used in this study to explore different denitrifying bacteria populations in the active sludge in the denitrification tank on the immersed plate-type metal membrane bioreactor. The study result implies that the addition involvement of the denitrification tank is enormous beneficial to the growth of all bacteria and nitrifying bacteria, meanwhile the removal rate of total nitrogen and ammonia nitrogen is improved as well.

Abstract: To study the amount changes of different denitrifying bacteria in the process of the metal membrane bioreactor, and to confirm the relationship between the amount of different bacteria and the quality of the treating water, the fluorescence in situ hybridization (FISH) dominant molecular biological technologies were applied in this study to preliminary explore the time and space distribution of different denitrifying bacteria populations in the active sludge on the immersed plate-type metal membrane bioreactor. The result indicates that the involvement of the denitrification tank is beneficial to the growth of all bacteria and nitrifying bacteria, meanwhile the eliminate rate of the total nitrogen and ammonia nitrogen is also improved.

Abstract: An anodized TiO2 membrane has enhanced photocatalytic properties of anatase phase and small crystal size. From the photocatalytic results, the prepared anodized nano-structured TiO2 membrane had an effective organics decomposition capacity and high water permeability. This anodization method enabled the prepared nano-structured TiO2 membrane to have high photocatalytic activity and desired pore structure.

Abstract: With the aim of replacing Pd coating layer currently used for the dissociation and recombination of hydrogen molecules, the performance of Nb and Ta thin layers as catalystforhydrogen permeationwas evaluated at 673 K.Although not as efficient as Pd, Nb and Ta coating layers can nevertheless provide a reasonable H2 dissociation and recombination rates. Thereduced values of hydrogen permeabilityin comparison to that of Pd were explained by the reduced catalytic properties of Nb and Ta and the formation of hydrides on the surface.

Abstract: The hydrogen permeation properties of the Pd-coated Ni37.5Nb27.5Zr25Co5Ta5 amorphous membranes have been investigated at 673 and 723K for 720 hours (1 month). Values of the hydrogen permeability during these long term tests were found to be reduced of about 50 and 30 % at 673 and 723K, respectively. The reduction in the hydrogen permeability could be correlated to the change in the composition of the coating as well as at the interface between Pd coating and Ni-based amorphous membrane.

Abstract: The objective of this study is to evaluate the performance of photocatalysis/hydrogen peroxide/metal membrane system. Metal membrane for the separation of TiO2 particles was used in an experiment and nominal pore size is 0.5 μm. Hydrogen peroxide was tested as oxidants. The removal efficiency of CODCr and color for initial hydrogen peroxide concentration increases rapidly with an increase in the hydrogen peroxide concentration up to 50 mg/L. The removal efficiency of of CODCr and color for 50 mg/L of initial hydrogen peroxide concentration was about 95 % and 98 %, respectively. However, the addition of hydrogen peroxide over 50 mg/L inhibits the system efficiency. The addition of hydrogen peroxide in UV/TiO2 system enhanced removal efficiency of CODCr and color compared to no addition of hydrogen peroxide. This may be ascribed to capture the electrons ejected from TiO2 and to produce OH radicals. The application of metal membrane in UV/ TiO2/H2O2 system enhanced removal efficiency of CODCr and color due to the adsorption of metal membrane surface as well as the production of OH radical. In application of metal membrane with nominal pore size 0.5 μm, TiO2 particles were effectively separated from the treated water by metal membrane rejection. Photocatalytic metal membrane was much smaller resistance than these of humic acid, TiO2 and humic acid/ TiO2 due to humic acid degradation of photocatalytic reaction.

Abstract: This study was conducted to evaluate the applicability of photocatalytic metal membrane system for the treatment of humic acid and heavy metals in aqueous solution. The catalysts, TiO2 powder P25 Degussa and metal membrane with 0.5 μm nominal pore size were used for experiments. Removal efficiency of humic acid and heavy metals increased with the increase of TiO2 dosage, however decreased over 0.3 g/L of TiO2 dosage. The addition of H2O2 as an oxidation reagent had a positive effect for the removal rate of humic acid and heavy metals. Metal membrane with stainless steel seemed to be quite stable to UV light with oxidation reagent in long-term operational periods over 6 months. Moreover, TiO2 particles can be effectively separated from the treated water by membrane rejection and the permeation flux was also enhanced by the combination of photocatalytic reaction.