Zero-valent iron treatment of RDX-containing and perchlorate-containing wastewaters from an ammunition-manufacturing plant at elevated temperatures

2006 ◽  
Vol 54 (10) ◽  
pp. 47-53 ◽  
Author(s):  
S.-Y. Oh ◽  
D.K. Cha ◽  
P.C. Chiu ◽  
B.J. Kim
Keyword(s):  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Treatment Plant ◽  
Ph Control ◽  
Zero Valent Iron ◽  
Batch Reactors ◽  
Subsequent Oxidation ◽  
Iron Treatment ◽  
The Usa ◽  
Pressure Controlled

The use of zero-valent iron for treating wastewaters containing RDX and perchlorate from an army ammunition plant (AAP) in the USA at elevated temperatures and moderately elevated temperature with chemical addition was evaluated through batch and column experiments. RDX in the wastewater was completely removed in an iron column after 6.4 minutes Increasing the temperature to 75 °C decreased the required retention time to 2.1 minutes for complete RDX removal. Perchlorate in the wastewater was completely removed by iron at an elevated temperature of 150 °C in batch reactors in 6 hours without pH control. Significant reduction of perchlorate by zero-valent iron was also achieved at a more moderate temperature (75 °C) through use of a 0.2 M acetate buffer. Based on the evaluation results, we propose two innovative processes for treating RDX-containing and perchlorate-containing wastewaters: a temperature and pressure-controlled batch iron reactor and subsequent oxidation by existing industrial wastewater treatment plant; and reduction by consecutive iron columns with heating and acid addition capabilities and subsequent oxidation.

A Batch Activated Sludge Study of Pineapple Wastewater Using a Bioaugmentation Process

1991 ◽  
Vol 24 (5) ◽  
pp. 233-240 ◽  
Author(s):  
Nik Fuaad Nik Abllah ◽  
Aik Heng Lee
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Ammonia Nitrogen ◽  
Batch Reactors ◽  
Organic Loading ◽  
Suitable Alternative ◽  
Organic Removal ◽  
Sludge Production

A laboratory study was conducted to determine the feasibility of batch activated sludge reactor for treating pineapple wastewater and to examine the effects of bioaugmentation on treatment performance. The experimental set-up consists of eleven batch reactors. Activated sludge obtained from a wastewater treatment plant treating domestic wastewater was used as seed for the reactors. Synthetic pineapple wastewater was used as feed for the reactors. The eleven reactors were arranged to evaluate the total organic removal, nitrification, and sludge production by bioaugmentation process. Three major factors considered were influent organic loading, ammonia-nitrogen, and dosage of bacterial-culture-product addition. Removal of TOG (total organic carbon), sludge production in terms of SS(suspended solids), and ammonia-nitrogen removal variation are used as evaluation parameters. The TOC removal efficiency after the end of a 48 hour reactor run, for influent TOC of 350.14 to 363.30 mg/l, and 145.92 to 169.66 mg/l, was 94.41 to 95.89%, and 93.72 to 94.73% respectively. Higher organic removal was observed in the bioaugmented reactors with higher organic loading. The better organic removal efficiency in the bioaugmented reactors was probably due to activities of bacteria added. The test results also indicated that sludge yield was enhanced by the bacteria additive and high bacteria dosage produced less sludge. Bioaugmentation was observed to be a suitable alternative for enhancing the biological treatment of pineapple wastewater.

Experimental procedures characterizing transformations of wastewater organic matter in the Emscher river, Germany

1995 ◽  
Vol 31 (7) ◽  
pp. 201-212 ◽  
Author(s):  
H. Løkkegaard Bjerre ◽  
T. Hvitved-Jacobsen ◽  
B. Teichgräber ◽  
D. te Heesen
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Treatment Plant ◽  
Subsequent Treatment ◽  
Treated Wastewater ◽  
Batch Reactors ◽  
River Rhine ◽  
Quality Changes ◽  
Ruhr District ◽  
Wastewater Quality

The Emscher river in the Ruhr district, Germany, is at present acting as a large wastewater collector receiving untreated and mechanically treated wastewater. Before the Emscher flows into the river Rhine, treatment takes place in a biological wastewater treatment plant. The transformations of the organic matter in the Emscher affect the river catchment, the subsequent treatment and the river quality. This paper focuses on evaluation of methods for quantification of the microbial transformations of wastewater in the Emscher with emphasis on characterization of wastewater quality changes in terms of biodegradability of organic matter and viable biomass. The characterization is based on methods taken from the activated sludge process in wastewater treatment. Methods were evaluated on the basis of laboratory investigations of water samples from the Emscher. Incubation in batch reactors under aerobic, anoxic and anaerobic conditions were made and a case study was performed. The methods described will be used in an intensive study of wastewater transformations in the Emscher river. This study will be a basis for future investigations of wastewater quality changes in the Emscher.

scholarly journals Effect of Elevated Temperature on Mechanical Properties of High-Volume Fly Ash-Based Geopolymer Concrete, Mortar and Paste Cured at Room Temperature

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1473
Author(s):  
Jun Zhao ◽  
Kang Wang ◽  
Shuaibin Wang ◽  
Zike Wang ◽  
Zhaohui Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
High Volume ◽  
Sem Analysis ◽  
Geopolymer Concrete ◽  
Ordinary Concrete ◽  
Exposure Temperature

This paper presents results from experimental work on mechanical properties of geopolymer concrete, mortar and paste prepared using fly ash and blended slag. Compressive strength, splitting tensile strength and flexural strength tests were conducted on large sets of geopolymer and ordinary concrete, mortar and paste after exposure to elevated temperatures. From Thermogravimetric analyzer (TGA), X-ray diffraction (XRD), Scanning electron microscope (SEM) test results, the geopolymer exhibits excellent resistance to elevated temperature. Compressive strengths of C30, C40 and C50 geopolymer concrete, mortar and paste show incremental improvement then followed by a gradual reduction, and finally reach a relatively consistent value with an increase in exposure temperature. The higher slag content in the geopolymer reduces residual strength and the lower exposure temperature corresponding to peak residual strength. Resistance to elevated temperature of C40 geopolymer concrete, mortar and paste is better than that of ordinary concrete, mortar and paste at the same grade. XRD, TGA and SEM analysis suggests that the heat resistance of C–S–H produced using slag is lower than that of sulphoaluminate gel (quartz and mullite, etc.) produced using fly ash. This facilitates degradation of C30, C40 and C50 geopolymer after exposure to elevated temperatures.

Effects of Elevated Temperatures on the Compressive Strength of HFCC

2011 ◽  
Vol 261-263 ◽  
pp. 416-420 ◽  
Author(s):  
Fu Ping Jia ◽  
Heng Lin Lv ◽  
Yi Bing Sun ◽  
Bu Yu Cao ◽  
Shi Ning Ding
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Relative Strength ◽  
Ordinary Concrete ◽  
Residual Compressive Strength ◽  
Fly Ash Concrete ◽  
The Relationship

This paper presents the results of elevated temperatures on the compressive of high fly ash content concrete (HFCC). The specimens were prepared with three different replacements of cement by fly ash 30%, 40% and 50% by mass and the residual compressive strength was tested after exposure to elevated temperature 250, 450, 550 and 650°C and room temperature respectively. The results showed that the compressive strength apparently decreased with the elevated temperature increased. The presence of fly ash was effective for improvement of the relative strength, which was the ratio of residual compressive strength after exposure to elevated temperature and ordinary concrete. The relative compressive strength of fly ash concrete was higher than those of ordinary concrete. Based on the experiments results, the alternating simulation formula to determine the relationship among relative strength, elevated temperature and fly ash replacement is developed by using regression of results, which provides the theoretical basis for the evaluation and repair of HFCC after elevated temperature.

Microstructure Evolution and Mechanical Properties of an Al-Cu-Mg Alloy at Elevated Temperature

2014 ◽  
Vol 1004-1005 ◽  
pp. 148-153
Author(s):  
Min Hao ◽  
Ji Gang Ru ◽  
Ming Liu ◽  
Kun Zhang ◽  
Liang Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Shear Fracture ◽  
S Phase ◽  
Mg Alloy ◽  
Transmission Electron ◽  
Fracture Features ◽  
Scanning Electron

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to study the microstructure and mechanical behavior of an Al-Cu-Mg alloy after tensile test at 125°C, 150°C, 175°C and 200 °C, respectively. The yield strength and ultimate tensile strength decreased with the increase of temperature, while the elongation increased firstly and then decreased. The S and S′ precipitate after tension at elevated temperatures. When the temperature was higher than 175°C, the precipitate coarsens rapidly. The alloys displayed a shear fracture features at elevated temperature. The larger S′ and S phase coarsened and dropped which forming crack in the grain boundaries and precipitate interfaces, resulting in the decrease of the elongation of the alloy.

Study on the Formability of Aluminium Alloy Sheets at Room and Elevated Temperatures

2016 ◽  
Vol 877 ◽  
pp. 393-399
Author(s):  
Jia Zhou ◽  
Jun Ping Zhang ◽  
Ming Tu Ma
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Elevated Temperature ◽  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
Elevated Temperatures ◽  
Hot Stamping ◽  
Natural Aging ◽  
Alloy Sheet ◽  
Aluminum Alloy Sheet

This paper presents the main achievements of a research project aimed at investigating the applicability of the hot stamping technology to non heat treatable aluminium alloys of the 5052 H32 and heat treatable aluminium alloys of the 6016 T4P after six months natural aging. The formability and mechanical properties of 5052 H32 and 6016 T4P aluminum alloy sheets after six months natural aging under different temperature conditions were studied, the processing characteristics and potential of the two aluminium alloy at room and elevated temperature were investigated. The results indicated that the 6016 aluminum alloy sheet exhibit better mechanical properties at room temperature. 5052 H32 aluminum alloy sheet shows better formability at elevated temperature, and it has higher potential to increase formability by raising the temperature.

Experimental Investigation of Ti-6Al-4V with a Biaxial Tensile Test Setup at Elevated Temperature

2014 ◽  
Vol 622-623 ◽  
pp. 273-278 ◽  
Author(s):  
Marion Merklein ◽  
Sebastian Suttner ◽  
Adam Schaub
Keyword(s):  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Advanced Materials ◽  
Uniaxial Tensile ◽  
Plastic Yielding ◽  
Characterization Methods ◽  
Specific Strength ◽  
Biaxial Tensile ◽  
Stress States

The requirement for products to reduce weight while maintaining strength is a major challenge to the development of new advanced materials. Especially in the field of human medicine or aviation and aeronautics new materials are needed to satisfy increasing demands. Therefore the titanium alloy Ti-6Al-4V with its high specific strength and an outstanding corrosion resistance is used for high and reliable performance in sheet metal forming processes as well as in medical applications. Due to a meaningful and accurate numerical process design and to improve the prediction accuracy of the numerical model, advanced material characterization methods are required. To expand the formability and to skillfully use the advantage of Ti-6Al-4V, forming processes are performed at elevated temperatures. Thus the investigation of plastic yielding at different stress states and at an elevated temperature of 400°C is presented in this paper. For this reason biaxial tensile tests with a cruciform shaped specimen are realized at 400°C in addition to uniaxial tensile tests. Moreover the beginning of plastic yielding is analyzed in the first quadrant of the stress space with regard to complex material modeling.

Polycrystal Simulations Investigating the Effect of Additional Slip System Availability in a 6063 Aluminum Alloy at Elevated Temperature

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Antoinette M. Maniatty ◽  
David J. Littlewood ◽  
Jing Lu
Keyword(s):  
Aluminum Alloy ◽  
Elevated Temperature ◽  
Compression Test ◽  
Elevated Temperatures ◽  
Material Model ◽  
Grain Structure ◽  
Slip Systems ◽  
Modeling Framework ◽  
Element Analysis ◽  
6063 Aluminum Alloy

In order to better understand and predict the intragrain heterogeneous deformation in a 6063 aluminum alloy deformed at an elevated temperature, when additional slip systems beyond the usual octahedral slip systems are active, a modeling framework for analyzing representative polycrystals under these conditions is presented. A model polycrystal that has a similar microstructure to that observed in the material under consideration is modeled with a finite element analysis. A large number of elements per grain (more than 1000) are used to capture well the intragranular heterogeneous response. The polycrystal model is analyzed with three different sets of initial orientations. A compression test is used to calibrate the material model, and a macroscale simulation of the compression test is used to define the deformation history applied to the model polycrystal. In order to reduce boundary condition effects, periodic boundary conditions are applied to the model polycrystal. To investigate the effect of additional slip systems expected to be active at elevated temperatures, the results considering only the 12 {111}⟨110⟩ slip systems are compared to the results with the additional 12 {110}⟨110⟩ and {001}⟨110⟩ slip systems available (i.e., 24 available slip systems). The resulting predicted grain structure and texture are compared to the experimentally observed grain structure and texture in the 6063 aluminum alloy compression sample as well as to the available data in the literature, and the intragranular misorientations are studied.

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