| Description |
1 online resource : text file, PDF |
| Contents |
Cover; Title; Joint PhD degree in Environmental Technology; Thesis committee; Copyright; Dedication; Table of Contents; Acknowledgement; Summary; Sommaria; Samenvatting; CHAPTER 1 General introduction; 1.1. Background; 1.2. Problem description; 1.3. Research objectives; 1.4. Structure of the thesis; References; CHAPTER 2 Literature review; 2.1. Introduction; 2.2. Quantum dots and their properties; 2.3. Metal Chalcogenide QDs; 2.4. Biological metal chalcogenides; 2.5. Sulfur based chalcogenides; 2.5.1. Sulfur oxyanion reduction mechanisms; 2.5.2. Biological synthesis of metal sulfides QDs |
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2.5.2.1. MeS QDs synthesis using bacteria2.5.2.2. MeS QDs synthesis using yeast/fungi; 2.6. Selenium based chalcogenides; 2.6.1. Selenium oxyanion reduction mechanisms; 2.6.2. Biological synthesis of metal selenide QDs; 2.6.2.1. MeSe QDs synthesis using bacteria; 2.6.2.2. MeSe QDs synthesis using yeast/fungi; 2.7. Tellurium based chalcogenides; 2.7.1. Tellurium oxyanion reduction mechanisms; 2.7.2. Biological synthesis of cadmium telluride QDs; 2.7.2.1. CdTe QDs synthesis using bacteria; 2.7.2.2. CdTe QDs synthesis using fungi/yeast |
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2.8. Mechanisms of biological synthesis of metal chalcogenides2.8.1. Localization of metal chalcogenides; 2.8.2. Size and shape of biogenic metal chalcogenides; 2.9. Applications of chalcogenide QDs; 2.9.1. Cell imaging and tracking; 2.9.1.1. In-vitro Imaging; 2.9.1.2. In-vivo imaging; 2.9.1.3. Cell tracking; 2.9.2. Cancer imaging; 2.9.3. Cytotoxicity of MeCh QDs; References; CHAPTER 3 Biological removal of selenate and ammonium by activated sludge in a sequencing batch reactor; 3.1. Introduction; 3.2. Materials and Methods; 3.2.1. Source of biomass and synthetic wastewater |
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3.2.2. Synthetic wastewater3.2.3. Sequencing batch reactor operation; 3.2.4. Batch experiments -- effect of ammonium on selenium removal; 3.2.5. Analytical methods; 3.3. Results; 3.3.1. Performance of the SBR; 3.3.1.1. COD removal performance of the SBR; 3.3.1.2. Selenate removal performance of the SBR; 3.3.1.3. Ammonium-N removal in the SBR; 3.3.2. Simultaneous nitrogen and selenium removal profiles in SBR cycles; 3.3.3. Effect of NH4+-N concentrations on selenium reduction; 3.4. Discussion; 3.4.1. Selenate bioreduction by activated sludge in the presence of NH4+-N |
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3.4.2. Fate of biogenic selenium in the SBR system3.4.3. Simultaneous nitrification and denitrification; 3.5. Conclusion; References; CHAPTER 4 Effect of heavy metal co-contaminants on selenite bioreduction by anaerobic granular sludge; 4.1. Introduction; 4.2. Materials and methods; 4.2.1. Source of biomass; 4.2.2. Selenite reduction experiments; 4.2.3. Effect of heavy metals on selenite reduction; 4.2.4. Kinetics of heavy metal removal; 4.2.5. Analytical methods; 4.3. Results; 4.3.1. Effect of Cd, Zn and Pb on selenite reduction by anaerobic granular sludge |
| Summary |
"Recent years have seen a growing interest in the application of chalcogenide nanoparticles (NPs) (e.g. Se, Te, CdSe) in various industrial sectors including energy, petroleum refining and also in the field of biology and medicine. Moreover, due to the high toxicity of chalcogen oxyanions, their release in the environment is of great concern. Thus, emphasize was given in this book on the development of a novel microbial synthesis process of chalcogenide NPs by combining biological treatment of Se/Te-containing wastewaters with biorecovery in the form of Se/Te chalcogenides NPs. Anaerobic granular sludge capable of reducing selenite to selenide in the presence of Cd was enriched for the microbial synthesis of CdSe NPs. It was evident that when Cd is present along with selenite, it reacts with aqueous selenide (HSe- ) after selenite bioreduction to form CdSe. The formation of an alloyed layer of CdSxSe1-x at the interface between the CdSe core and CdS shell in the sludge was also observed. Distinct fingerprints of extracellular polymeric substances (EPS) extracts by size exclusion chromatography indicated a compositional change in the EPS matrix of anaerobic granular sludge performing selenite reduction in the presence of cadmium and synthesizing CdSe NPs. Studies also shows that EPS on the surface of chalcogenide NPs plays a major role in lowering the toxicity of NPs and make biogenic Se(0) NPs 10 times less toxic than chemogenic Se(0) NPs. An UASB reactor was used for the first time for continuous removal of tellurite from synthetic wastewater and the recovery of Te as biogenic Te(0). As the majority of the biogenic Te(0) nanocrystals was trapped predominantly in the EPS surrounding the biomass, make it easier to separate and recovery by centrifugation."--Provided by publisher |
| Subject |
Hydrology.
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Waterworks.
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waterworks.
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TECHNOLOGY & ENGINEERING -- Environmental -- Water Supply.
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anaerobic granular sludge.
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biogenic chalcogenide nanoparticles.
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bioreactors.
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chalcogen.
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EPS.
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extracellular polymeric substances.
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Hydrology
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Waterworks
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| Form |
Electronic book
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| ISBN |
9780429470943 |
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0429470940 |
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9780429895258 |
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0429895259 |
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9780429895241 |
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0429895240 |
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