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Gu L.,Shanghai JiaoTong University | Nie J.-Y.,Shanghai Municipal Engineering Design Institute | Zhu N.-W.,Shanghai JiaoTong University | Wang L.,CAS Shanghai Advanced Research Institute | And 2 more authors.
Chemical Engineering Journal | Year: 2012

The production of dye intermediates made from naphthalene compounds such as 6-nitro-1-diazo-2-naphthol-4-sulfonic acid (6-nitro-1,2,4-Acid) caused a major environmental concern, mainly due to their nature of being highly toxic concentrated organics. In this work, an enhanced Fenton process integrating the multi-staged Fenton reaction with inner circulation was practiced in a pilot scale. This creative design exhibited a particular advantage in treating the wastewater with high amount of organic substances. Experiments showed a higher COD removal efficiency (93%) and oxidation efficiency (62%) when two-staged Fenton reaction with inner circulation (flow-to-influent ratio of 5) was applied, whereas only 40.9% of COD reduction was obtained when using the single-staged Fenton without any circulation. It was demonstrated experimentally that the wastewater color went through a fast change via different stages of the reaction. The main intermediates generated along the two-staged reaction have been identified as aromatic and aliphatic acids, but their concentrations demonstrated regular changes in each stage, indicating an enhanced oxidation effect of staged Fenton process. © 2012 Elsevier B.V..

Qian Z.,Nanjing Southeast University | Chen L.,Nanjing Southeast University | Wang Y.,Nanjing Southeast University | Shen J.,Nanjing Southeast University | Shen J.,Shanghai Municipal Engineering Design Institute
Journal Wuhan University of Technology, Materials Science Edition | Year: 2012

In order to understand the strength developing law of the epoxy asphalt mixture, a curing reaction model of the epoxy asphalt binder was proposed based upon the thermokinetic analysis. Given some assumptions, the model was developed by applying the Kissinger law as well as Arrhenius equation, and the differential scanning calorimetry was performed for estimating the model parameters. To monitor the strength development of the epoxy asphalt mixture, a strength test program was employed and then results were compared to those produced from the proposed model. The comparative evaluation shows that a good consistency exists between the outputs from test program and the proposed model, indicating that the proposed model can be used effectively for simulating the curing reaction process for the epoxy asphalt binder and predicting the strength development for the epoxy asphalt mixture. © 2012 Wuhan University of Technology and Springer-Verlag Berlin Heidelberg.

Lu B.,Tsinghua University | Lu B.,Shanghai Municipal Engineering Design Institute | Zhu Y.,Tsinghua University
Physical Chemistry Chemical Physics | Year: 2014

A new type of layered oxy-acid salt of bismuth oxynitrate was synthesized by a simple hydrothermal method. The obtained bismuth oxy-nitrates consist of a Bi2O2 2+ layered module inserted into the interlamellar anion modules of NO3 - and OH-. Varying amounts of NO3 - and OH- complexes on the surface of the bismuth oxynitrate were also obtained by adjusting the precursor pH before hydrothermal treatment. It was found that the sample prepared with the precursor pH = 5.00 presented the highest photocatalytic activity, with a rate constant of 0.05 min-1, which is 2 and 6.7 times higher than those presented by the samples with the precursor pH = 7.00 and 1.22, respectively. The largest cathodic to anodic photocurrent switching was also presented by the sample with the precursor pH = 5.00, which can be reasonably attributed to NO3 - complexes on the surface of the bismuth oxynitrate. The NO3 - complexes could efficiently migrate the photo-induced holes to the surface of the semiconductor. This journal is © the Partner Organisations 2014.

Lu B.,Tsinghua University | Lu B.,Shanghai Municipal Engineering Design Institute | Ma X.,Tsinghua University | Pan C.,Tsinghua University | Zhu Y.,Tsinghua University
Applied Catalysis A: General | Year: 2012

In situ hybridization of carbon with BiPO 4 films were performed through calcination of amorphous complex precursor films on the Ti substrate under various temperatures. The BiPO 4 crystallites were in situ grown into BiPO 4 particles on the surface of the Ti substrate. The formed BiPO 4 particles in situ hybridized with the residual carbon from precursor calcination to form carbon hybridized BiPO 4 films. The extent of hybridization depended on the calcination temperatures. The photocatalytic activities of carbon hybridized BiPO 4 films under different calcination temperatures were estimated through photocatalytic degradation of methylene blue. The results indicated that the film prepared at 400 °C presented the highest photocatalytic activity, which was about 1.5 times than that of the film at 550 °C. This phenomenon could be attributed to the higher carbon hybridization extent, higher transfer efficiency of photo-induced electrons between carbon and BiPO 4 crystalline nanoparticles in films, and corresponding separation efficiency of photo-induced electrons and holes. The electronic interaction was also systematically investigated by the photoelectrochemical measurements. © 2012 Elsevier B.V.

Lu B.,Tianjin University | Lu B.,Shanghai Municipal Engineering Design Institute | Ji M.,Tianjin University
Plasma Chemistry and Plasma Processing | Year: 2012

Plasma oxidation of ethanethiol in air was investigated using three plasma regimes: surface dielectric pulsed corona discharge, surface dielectric barrier discharge and pulsed corona discharge (PCD) in the plasma reactor. Catalytic plasma degradation of ethanethiol was also performed on the singular or binary metals doped γ-Al2O3. The ethanethiol removal rate increased with increasing energy density but energy efficiency was first increased and then decreased with increasing energy density under three various types of discharges. PCD plasma required the lowest energy density at the similar ethanethiol removal performance compared with the other two plasma discharges. The main intermediate by-products of ethanethiol oxidation by plasma are CH3CHO, HCHO, CO and CO2. The sum of these intermediate products selectivities is 19-43 %, implying that some other intermediates containing carbon were undetermined. When using PCD plasma combined with catalysts, ethanethiol removal rate and energy efficiency were all evidently improved. The maximum energy efficiency was achieved about 200 g kWh-1 using Fe-Mn/γ-Al2O3 assisted PCD plasma, which was about 4.4 times when using PCD plasma alone. The mechanism of ethanethiol oxidation is also discussed. © Springer Science+Business Media, LLC 2012.

Zhou P.,Dalian University of Technology | Zhang Z.,Dalian University of Technology | Yu Y.,Shanghai Municipal Engineering Design Institute
International Journal of Advancements in Computing Technology | Year: 2012

This paper is concerned with the optimization method of hanger forces in reasonable finished state of diagonal-span arch bridge. Based on the energy principle and considered the spatial effect the unconstrained and constrained optimization method is studied. The results show that the unconstrained and constrained optimization method described in this paper are simple, convenient and reliable, and can be used in engineering design.

Li J.,Tongji University | Xiang N.,Tongji University | Tang H.,Shanghai Municipal Engineering Design Institute | Guan Z.,Tongji University
Soil Dynamics and Earthquake Engineering | Year: 2016

Damage investigation of small to medium-span highway bridges in Wenchuan earthquake revealed that typical damage of these bridges included: sliding between laminated-rubber bearings and bridge girders, concrete shear keys failure, excessive girder displacements and even span collapse. However, the bearing sliding could actually act as a seismic isolation for piers, and hence, damage to piers for these bridges was minor during the earthquake. Based on this concept, an innovative solation system for highway bridges with laminated-rubber bearings is developed. The system is comprised of typical laminated-rubber bearings and steel dampers. Bearing sliding is allowed during an earthquake to limit the seismic forces transmitting to piers, and steel dampers are applied to restrict the bearing displacements through hysteretic energy dissipation. As a major part of this research, a quarter-scale, two-span bridge model was constructed and tested on the shake tables to evaluate the performance of this isolation system. The bridge model was subjected to a Northridge and an artificial ground motion in transverse direction. Moreover, numerical analyses were conducted to investigate the seismic performance of the bridge model. Besides the test bridge model, a benchmark model with the superstructure fixed to the substructure in transverse direction was also included in the numerical analyses. Both the experimental and the numerical results showed high effectiveness of this proposed isolation system in the bridge model. The system was found to effectively control the pier-girder relative displacements, and simultaneously, protect the piers from severe damage. Numerical analyses also validated that the existing finite element methods are adequate to estimate the seismic response of bridges with this isolation system. © 2016 Elsevier Ltd.

Li J.,Tongji University | Tang H.,Shanghai Municipal Engineering Design Institute | Guan Z.,Tongji University
Journal of Earthquake Engineering | Year: 2016

Elastomeric pad bearings are widely applied in short- to medium-span girder bridges in China, with the superstructure restrained by reinforced concrete (RC) shear keys in the transverse direction. Field investigations after the 2008 Wenchuan earthquake reveal that bearing systems had suffered the most serious damage, such as span falling, bearing displaced, and shear key failure, while the piers and foundations underwent minor damage. As part of a major study on damage mechanism and displacement control method for short- to medium-span bridges suffered in Wenchuan earthquake, a 1:4 scale, two-span bridge model supported on elastomeric pad bearings were recently tested on shake tables at Tongji University, Shanghai. The bridge model was subjected to increasing levels of four seismic excitations possessing different spectral characteristics. Two restraint systems with and without the restraint of RC shear keys were tested. A comprehensive analytical modeling of the test systems was also performed using OpenSees. The experimental results confirmed that for the typical bridges on elastomeric pad bearings without RC shear keys, the sliding effect of the elastomeric pad bearings plays an important role in isolation of ground motions and, however, lead to lager bearing displacement that consequently increases the seismic risk of fall of span, especially under earthquakes that contain significant mid-period contents or velocity pulse components. It is suggested from the test results that RC shear keys should be elaborately designed in order to achieve a balance between isolation efficiency and bearing displacement. Good correlation between the analytical and the experimental data indicates that the analytical models for the bearing and RC shear key as well as other modeling assumptions were appropriate. © 2016, Taylor & Francis. All rights reserved.

Su Q.-T.,Tongji University | Wu C.,Tongji University | He W.-C.,Shanghai Municipal Engineering Design Institute
Gongcheng Lixue/Engineering Mechanics | Year: 2010

Steel-anchor-box structure is used in the connection between cable and girder of Shanghai Yangtze River Bridge. Due to large quantities of plates being used in this structure, complex configuration and severe stress concentration, the fatigue behavior of the steel-anchor-box subjected to service live loads need a careful investigation. Full scale test model which can represent the mechanical behavior of anchor-zone is obtained by finite element method, and fatigue testing method is introduced. Combining the traffic condition and the design quantity of variable vehicles, referring the foreign code and relative research, the fatigue load range for the test is determined by the theory of cumulative damage in fatigue, and the calculation shows the light rail loadings is the major causes of fatigue effects in cable-stayed bridge burdened the vehicle loadings and light rail loadings on same layer. Based on the theoretical analysis and the result obtained from fatigue test, resistance fatigue behavior of steel-anchor-box structure in the connection of cable-girder subjected to cycle loading is studied. The results show the cable-girder anchorage of Shanghai Yangtze River Bridge is safe enough.

Lu B.,Shanghai Municipal Engineering Design Institute
Chinese Journal of Environmental Engineering | Year: 2015

Oxidation of acetaldehyde in water was investigated using ozone produced by dielectric barrier discharge. Ozone was produced using dielectric barrier discharge plasmas in pure oxygen. Ozonation of acetaldehyde was carried out after transferring ozone into the water solutions containing acetaldehyde. It was found that acetaldehyde was oxidized into CO and CO2. The selectivity of CO2 was in range of 66%-80%. The ozonation reaction of acetaldehyde presented a first-order reaction of ozone concentration and a first-order reaction of acetaldehyde concentration. The energy efficiency decreased with increasing injected energy density. It was also suggested that the recycle of unreacted ozone into the solution containing acetaldehyde could contribute to reducing the operating cost for wastewater treatment using ozone. © 2015, Science Press. All right reserved.

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