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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Hydrolysis of aluminum sulphate solutions at high temperatures

Nikolic, Cvetko January 1971 (has links)
Normal and acid aluminum sulphate solutions containing about 6.0 gr/1 of aluminum and up to 50 gr/1 SO₄⁼ were hydrolyzed until equilibrium was reached in the temperature region 125-250°C. Under the equilibrium conditions the only stable solid phase observed in equilibrium with a liquid phase of various compositions was basic aluminum sulphate with nominal formula 3A1₂0₃..4S0₃.9H₂O. A small portion of the ternary diagrams for the system A1₂O₃-SO₃-H₂O at 225°C and 250°C was constructed. A mixture of aluminum sulphate and other metal sulphates, K₂S0₄, Na₂S0₄, Li₂SO₄, FeSO₄ and CuSO₄ i.e. was hydrolyzed at 225°C in order to find the effect of these salts on hydrolysis. The overall hydrolysis reaction was found to occur according to the chemical equation: 6A1⁺⁺⁺+ 4HS0₄⁻ + 14H₂O ⃗ 3Al₂0₃.4S0₃.9H₂0 + 14H⁺ The equilibrium constants at 125, 150, 175, 200, 225 and 250°C were determined. Finally a mechanism for the hydrolysis of aluminum sulphate was proposed. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate
2

The influence of aluminum salts on the retention of titanium dioxide when using cationic polyelectrolyte as a retention aid

Proxmire, Paul R. 11 June 1988 (has links)
No description available.
3

Effect of poultry litter amended with aluminum sulfate on plant growth and soil properties

Lungu, Sosten 09 August 2008 (has links)
Amending litter with aluminum sulfate (Al-S) has proven to be effective in reducing water-soluble P but there are concerns that it could result in soil pH reduction and increase levels of extractable soil Al if applied to acidic soils. A glasshouse study with soybean (Glycine max, L Merr) and cotton (Gossypium hirsutum L) as test crops was conducted to determine the impact of applying litter amended with Al-S at 0, 10 and 20% to an acidic sandy loam soil. These treatments were applied to meet N needs of a crop grown in soil with pH levels of 4.5, 5.0, 5.5 and 6.5. The experimental design was a randomized complete block. Application of BL + 20% Al-S to soil with initial pH of 4.5 or 5.0 significantly decreased the pH compared to BL. The decrease in soil pH with application of BL + 20% Al-S was attributed to high concentrations of geochemically labile Al which released hydrogen ions upon hydrolysis. Both BL and BL + 10% Al-S increased the initial soil pH and decreased extractable soil Al. Application of BL + 20% Al-S resulted in significant higher levels of extractable soil Al than BL and the differences were greater in the lower pH soils. Mehlich-3 extractable soil P, K, Mg, Ca, and Cu decreased with BL + 10 or 20% Al-S relative to BL. Soybean or cotton biomass from BL + 20% Al-S fertilization was significantly decreased relative to BL fertilized soils with initial pH of 4.5 or 5.0. Biomass with BL + 10% Al-S application were not statistically different from those fertilized with BL. Fertilizing cotton or soybean with BL + Al-S decreased tissue Al, N and P concentration. BL and BL + 10% Al-S showed the potential to increase soil pH and reduce extractable soil Al in acid soils but need further field evaluation.
4

Effect of poultry litter amended with aluminum sulfate on plant growth and soil properties

Lungu, Sosten, January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Department of Plant and Soil Sciences. / Title from title screen. Includes bibliographical references.
5

An analysis of liquid aluminum sulfate (alum) use in broiler production houses to control in-house ammonia (NH₃) concentrations and naturally-occurring Salmonella and Campylobacter the development of an NH₃ emission factor for a typical Tennessee broiler house /

Armstrong, Kenneth A. January 2003 (has links) (PDF)
Thesis (M.S.)--University of Tennessee, Knoxville, 2003. / Title from title page screen (viewed Mar., 19, 2004). Thesis advisor: Robert T. Burns. Document formatted into pages (xiv, 148 p. : ill. (some col.)). Vita. Includes bibliographical references.
6

Conditions contributing to poor coagulation and sedimentation performance in municipal water treatment

Jenkins, Andre' L., Kramer, Timothy L. January 2006 (has links)
Thesis--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.71-72).
7

Uso de suspensões preparadas com sementes de moringa oleifera associada a coagulantes químicos no tratamento da água residuária de usinas de concreto / Use of suspensions prepared with moringa oleifera seeds associated with chemical coagulants in the treatment of wastewater concrete plants

Paula, Heber Martins de, 1980- 12 December 2014 (has links)
Orientador: Marina Sangoi de Oliveira Ilha / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-26T09:43:25Z (GMT). No. of bitstreams: 1 Paula_HeberMartinsde_D.pdf: 3249461 bytes, checksum: 6923aa798c1f5a019c40de1328b74651 (MD5) Previous issue date: 2014 / Resumo: A operação de usinas de concreto gera água residuária que necessita de tratamento antes da disposição ou reuso. O processo de coagulação/floculação com o uso de coagulantes químicos associados à decantação pode gerar resíduos nocivos à saúde humana. Inserido nesse contexto, este trabalho tem como objetivo avaliar a eficiência da Moringa oleifera (MO) como coagulante natural para o tratamento da água residuária do concreto produzido em usinas. A pesquisa foi composta por cinco etapas: (a) caracterização da qualidade da água residuária coletada em uma usina de concreto; (b) avaliação da eficiência, em laboratório, do uso combinado do sulfato de alumínio e da MO em pó no tratamento da água residuária do concreto coletada em campo, com a determinação da concentração e as possíveis combinações entre eles; (c) avaliação da eficiência, em laboratório, do uso combinado de Sulfato de alumínio e da MO na forma solúvel e também do emprego do Cloreto férrico, outro coagulante químico, associado à MO, ambos na forma solúvel, no tratamento das águas residuárias de usinas de concreto; (d) otimização das dosagens de MO e de coagulantes químicos no tratamento da água residuária por meio do Delineamento de Composto Central Rotacional, avaliando os dados via Metodologia de Superfície de Resposta e desejabilidade global e (e) avaliação da eficiência do tratamento proposto, considerando as dosagens ótimas determinadas nos estudos anteriores, em amostras coletadas no início e no final da semana de produção, durante o período de um mês. Os resultados indicaram que os coagulantes em pó e solúvel, isolados e associados, obtiveram uma dosagem de 20% MO e 80% Al2(SO4)3 (concentração total de 1,85 g L 1), reduzindo o pH a 9,2 e removendo de 99% da turbidez. O processo foi otimizado e reduziu a concentração total dos coagulantes para 1,01 g L-1, removendo à turbidez em até 99,9%, aumentando o uso da MO para 46,5%. Simulando o ciclo de produção da usina, a dosagem otimizada foi capaz de tratar a água independente de suas características iniciais, deixando a turbidez sempre abaixo de 2 UNT. Assim, os resultados apontam para a possibilidade do reuso da água tratada em diferentes atividades, como lavagem de veículos, rega de jardins, descarga de bacias sanitárias e até mesmo na própria produção do concreto / Abstract: The operations of concrete plants generate wastewater that requires treatment before disposal or reuse. The process of coagulation / flocculation using chemical coagulants associated with decantation can generate waste harmful to human health. Inserted in this context, this work aims at evaluating the efficiency of Moringa oleifera (MO) as a natural treatment of wastewater produced in the concrete plant coagulant. The research was divided into five steps: (a) characterization of the quality of the wastewater collected in a concrete plant; (b) evaluation of the efficiency in the laboratory, the combined use of aluminum sulfate and MO powder in the treatment of wastewater collected in the concrete field, with the determination of the concentration and the possible combinations between them; (c) evaluation of the efficiency in the laboratory, the combined use of aluminum sulfate and MO in soluble form and also the use of ferric chloride, other chemical coagulant, associated with MO, both in soluble form, in the treatment of wastewater concrete plants; (d) optimization of dosages of MO and chemical coagulants in the treatment of wastewater through the Central Composite Rotational Design of evaluating the data via Response Surface Methodology and overall desirability and (e) evaluation of the effectiveness of the proposed treatment, considering optimal dosages determined in previous studies on samples collected at the beginning and end of week production during the period of one month. The results indicated that the coagulant soluble or powder, isolated and associates obtained a dosage MO 20% and 80% Al2 (SO4) 3 (1.85 g L-1 total concentration) reducing the pH to 9.2 and removing 99% of the turbidity. The process was optimized and reduced the total concentration of the coagulant to 1.01 g L-1 turbidity removing up to 99.9%, increasing the use of MO to 46.5%. Simulating the production cycle of the concrete plant, the optimum dosage was able to treat independent water from their initial characteristics, leaving the turbidity always below 2 UNT. Thus, the results point to the possibility of reuse of treated water in different activities such as washing cars, watering gardens, flushing toilets and even in production of the concrete / Doutorado / Arquitetura e Construção / Doutor em Engenharia Civil
8

A Research on the Use of Aluminum Sulphate in Parchment Production and its Effects on Ageing and Color

Kolan, Nilgün Kayahan, Bayramoğlu, Eser Eke 24 June 2019 (has links)
Content: In this study, different proportions 2.5%, 5%, 10% of aluminum sulfate were used as tanning agents during parchment production. The research was carried out on goat skin and also there were no usage of any tanning agents as control groups. Finished leathers have been exposed to ageing conditions. Before and after ageing color measurements on all finished leathers have been conducted with Konica Minolta CM-3600d brand spectrophotometer. The impacts of the aluminum sulfate utilized in the research on light fastness were also inspected by using an ATLAS-XENOTEST ALPHA+ test instrument. Visible whitening on the color of parchment was observeded when tanning process with aluminum sulphate was performed. Take-Away: -Aluminum sulfate has tanning effects -Aluminium gave white color to the parchment -Aluminum sulfate changed collagen structure.
9

Polyvinyl alcohol (PVA) adhesives reinforced by microfibrillated cellulose (MFC) – adhesive properties and reinforcement mechanisms

Wloch, Daniela January 2019 (has links)
The aim of the project was to investigate a green and sustainable replacement for boric acid in polyvinyl alcohol (PVA) adhesives for solid paperboard production. Boric acid acts as a cross-linker and tackifier in the adhesive but is classified as a harmful substance. Microfibrillated cellulose (MFC) was therefore investigated as a possible replacement for boric acid since it is produced from renewable and sustainable resources. In addition, it has hydroxyl groups available for interaction with the PVA, can be used to modulate the viscosity and can function under a variety of pH-values.  For the industrial process, there are three basic characteristics which must be met by the newly developed adhesive, which have to be the same as for the boric acid-containing reference. These three are the viscosity, the pH-value, and the dry content. Furthermore, it is important that the initial wet tack and the final adhesive strength are at least as high as the reference’s.  In this context, eight types of samples were investigated in total. Two were references, one prepared on industrial and the second on a laboratory scale according to a current industrial recipe. In the other six samples, the boric acid from the recipe was replaced by three different weight percentages of MFC of two different industrial grades. Both the dry content and the pH-value were not noticeably influenced by the addition of MFC. The viscosity however increased drastically with the increasing amount of MFC. The addition of MFC was enough to reach the three basic characteristics. In addition it was observed positive effects on a couple of other parameters that is beneficial for the glue.   A test method for evaluating the initial wet tack of the adhesive was developed. It was shown, that the tack of the adhesive containing MFC is 40 % lower than the one of the reference material. Therefore, five additives were tested in the formulation, in combination with MFC. The most promising result led to a comparable initial tack and final strength as the reference.
10

Coagulation Treatment to Remove Denatonium Benzoate from Water

Alaydamee, Hussein Hantoosh 24 May 2017 (has links)
No description available.

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