共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
Coal fly ash (CFA) catalyzed Fenton-like process was studied under microwave (MW) irradiation for the decolorization of Rhodamine B (RhB) wastewater. The physical-chemical properties of CFA were characterized, including the specific surface area, micromorphology, chemical and crystal components, and the distribution and chemical valence of metallic elements. The metallic oxidants in the CFA indicate CFA can work as Fenton-like catalyst and MW-absorbent simultaneously. The results reveal OH is more significant in the decolorization of RhB than HO2 and O2?. The generation of more OH in the MW-Fenton-like process (293–326 K) than that in the conventional heated Fenton-like process (326 K) reflects the function of hot spot effect and possible non-thermal effect of MW. Under the optimum condition ([H2O2] 2 mmol L?1, [CFA] 15 g L?1, pH 3, PMW 0.1 kW), the decolorization rate reaches 91.6% after 20 min. The intrinsic kinetic model of RhB decolorization is . The loss of catalytic metallic elements causes the decline of catalytic capacity of CFA. The energy consumption (4313.3 kW·h kg?1 RhB) is a limitation for the MW-Fenton-like process, which can be overcame by the safe application of nuclear energy. The intermediates and the path of RhB decolorization were detected and proposed, respectively. 相似文献
9.
10.
《Advanced Powder Technology》2022,33(8):103629
We experimentally examined the history dependence of the rotation-induced granular deformation. As an initial state, we prepared a quasi-two-dimensional granular pile whose apex is at the rotational axis and its initial inclination is at the angle of repose. The rotation rate was increased from 0 to 620 (rpm) and then decreased back to 0. During the rotation, deformation of the rotated granular pile was captured by a camera. From the acquired image data, granular friction coefficient was measured as a function of the ratio between centrifugal force and gravity, . To systematically evaluate the variation of both in the increasing (spinning up) and decreasing (spinning down) rotation-rate regimes, surface profiles of the deformed granular piles were fitted to a model considering the force balance among gravity, friction, and centrifugal force at the surface. We found that value grows in the increasing regime. However, when was reduced, cannot recover its initial value. A part of the history-dependent behaviors of the rotated granular pile can be understood by the force balance model. 相似文献
11.
12.
13.
14.
15.
16.
18.
The effect of a linearly heated left sidewall on natural convection flows in a cavity filled with nanofluid-superposed porous layers is investigated numerically using the Galerkin finite element method. Two cases, which use the vertical and horizontal directions for the porous–nanofluid layers, are considered to investigate the natural convection in the flow inside a square enclosure. In both cases, the left wall is linearly heated, whereas the right wall is isothermally cooled. The horizontal walls are assumed to be thermally insulated. The Darcy–Brinkmann model is used to solve the governing equations in the porous layer. The results show that the nanofluid produces more enhancement of heat transfer compared to the base fluid. Increasing the Rayleigh number values caused the intensity of the streamlines in case 2 to be stronger than that in case 1. Lower values of the thermal conductivity ratio ( imply greater heat transfer enhancement than for the high thermal conductivity ratios. At the low values of the thermal conductivity ratio ( and Darcy number values , the heat transfer is more enhanced for case 2 compared to case 1 while higher Darcy number produced case 1 overcome case 2. 相似文献