Dissertation > Excellent graduate degree dissertation topics show

Domestication of Acidithiobacillus Ferroxidans and Its Application to Bio-desulfuration of Coal

Author: ZhangDeWei
Tutor: WangShiMei;ZhouLiXiang
School: Nanjing Agricultural College
Course: Environmental Engineering
Keywords: Acidithiobacillus ferrooxidans Pyrite Domestication Extracellular polymeric substance Coal desulfurization Conditions optimization
CLC: X701.3
Type: Master's thesis
Year: 2011
Downloads: 19
Quote: 0
Read: Download Dissertation

Abstract


As one of the most important energy resources, coal occupies a critical position in the energy structure of China. China consume huge amount of coal every year, of which 90% is used for combusting directly. Consequently, China has become the country which discharges the largest amount of SO2 in the world since 1998 and acid deposition accounts for 40% of its land. So we study the bio-desulfurizing of coal, not only to avoid the acid rain caused by emission of SO2 at root, but also to get to know the mechanism of the bio-desulfurizing of the coal in theory, which can provide theoric basis to the industrialization and scalization of bio-desulfurizing.In this study, Acidithiobacillus ferrooxidans LX5 was cultured in 9K medium with pyrite and ferrous sulfate as the substrate, respectively. Biomass was enhanced by the presence of ferrous sulfate, for example, the LX5 number was 3.0×107cell/mL cultured for 20d in the presence of pyrite, and 108cell/mL cultured for 48h in presence of ferrous sulfate. After A. ferrooxidans LX5 acclimated by pyrite, the isoelectric point of A.ferrooxidans LX5 was bigger than that of A. ferrooxidans LX5 acclimated by ferrous sulfate, more easy to adhere to the surface of the pyrite. Compared the different of A.ferrooxidans LX5 acclimated by pyrite and ferrous sulfate as the substrates, the results showed that concentration of SO42-were 2241.6mg/Land 516.2mg/L more than that of the the A. ferrooxidans LX5 acclimated by FeSO4, indicating the oxidation activity of A.ferrooxidans LX5 in pyrite was stronger than it in ferrous sulfate.Incubation experiments under shaking conditions were used to investigate the response of A. ferrooxidans LX5 to additions of pyrite and ferrous sulfate, two substrates that might be expected to influence EPS in amount and configuration. It was found that the EPS generation rate of pyrite was 2973.2μg/1010 cells and was as three times as that of ferrous sulfate. With pyrite and ferrous sulfate as substrates, the polysaccharides and proteins in EPS were 46.6% and 34.6%, and 44.6% and 36.2%, respectively. It was presented that the composition of the EPS was almost same by the FTIR spectra, for example, either of EPS containing -OH、-NH2 and -COOH functional groups, respectively. The increase rate of SO42- in the flasks with A. ferrooxidans LX5 and EPS were markedly higher than those in the flasks with A. ferrooxidans LX5 only throughout the incubation. The EPS played a key role on the oxidation activity of LX5 during the desulfurization of coal.500-mL conical flasks containing freely suspended biomass were shaken with a high-strength coal liquors to determine the desulfurization rates at various initial pH, inoculation of LX5 and sulfur loadings. In view of desulfurization rate, an intermittent mode, with initial pH 2.5, additions of 10% bacterial suspension and 10% high-sulfur coal, showed the best results, and the coal desulfurization rate was up to 72.4% after bioleaching for 13d. Under these optimal conditions, a maximum coal desulfurization rate of 69.2% was achieved in a laboratory-scale continuously stirred tank reactor (5.0-L working volume) after the inoculation lasting 15 days, indicating great potential of A. ferrooxidans LX5 for future full-scale applications.

Related Dissertations

  1. Mapping Quantitative Trait Loci and Domestication Analysis for Seed Size and Shape Traits in Soybean (Glycine Maxl.Merr.),S565.1
  2. Mechanisms Involved in Lmwoas-Caused Inhibition on Ferrous Iron Oxidation by Acidithiobacillus Ferrooxidans,X703
  3. An Analysis of Interpretative Force of Relevance Theory on Cultural Factors in the Translation of Thunderstorm,I046
  4. Foreignization and Domestication in the Translation of English Proverbs,H315.9
  5. A Postcolonial Approach to the Hybridity in C-E Soft News Translation,H315.9
  6. Domestication and Foreignization in Cultural Translation,H059
  7. On Howard Goldblatt’s Translation Thoughts,H059
  8. Pyrite residue desulfurization and arsenic,X705
  9. Studies on Domesticating of Bifidobacterium Bifidum and Optimizing Its Growth Conditions,TS201.3
  10. Bioleaching of Low-grade Phosphate Ore with the Mixed Acidophilic Bacteria and Pseudomonas Aeruginosa,TF18
  11. The New Flotation Technique Research of the Sulphide Ore in Chengmenshan Copper Mine,TD952
  12. Breeding of L-Glutamic Acid Producer and Study of Its Metabolic Control,TQ922.1
  13. The Biological Characteristics of Taishan-coriolus Versicolor TN-1 and Study on Domestication & Cultivation,S646
  14. Domestication and Foreignization in the Translation of Tourism English,H315.9
  15. Domestication: The First Choice in Literary Translation,H315.9
  16. The Translation Strategies Combination of Foreignization and Domestication from the Perspective of Culture,H059
  17. Separation and Screening of Glucose Oxidase Producing Strain and Study on the Enzyme Producing Conditons Optimization,TP212.3
  18. Experimental Study of Pyrite Growth Mechanism,P618.31
  19. Expression, Purification and Activity of Ferredoxin NADP~+ Reductase from Acidithiobacillus Ferrooxidans,Q814
  20. Study on the Influencing Factors of Membrane Fouling in a Submerged Membrane Bio-Reactor,X703

CLC: > Environmental science, safety science > Processing and comprehensive utilization of waste > General issues > Exhaust gas processing and utilization > Desulfurization and desulfurization
© 2012 www.DissertationTopic.Net  Mobile