Optimization of the Electron Donor Supply to Sulphate Reducing Bioreactors Treating Inorganic Wastewater PDF Download

Author: Luis Carlos Reyes-Alvarado
Publisher: CRC Press
ISBN: 0429799284
Category : Science
Languages : en
Pages : 350

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Book Description
The main objective of this research was to optimize the electron donor supply in sulphate reducing bioreactors treating sulphate rich wastewater. Two types of electron donor were tested: lactate and slow release electron donors such as carbohydrate based polymers and lignocellulosic biowastes. Biological sulphate reduction was evaluated in different bioreactor configurations: the inverse fluidized bed, sequencing batch and batch reactors. The reactors were tested under steady-state, high-rate and transient-state feeding conditions of electron donor and acceptor, respectively. The results showed that the inverse fluidized bed reactor configuration is robust and resilient to transient and high-rate feeding conditions at a hydraulic retention time as low as 0.125 d. The biological sulphate reduction was limited by the COD:sulphate ratio ( 82% either using carbohydrate based polymers or lignocellulosic bio-wastes, in batch bioreactors. The biological sulphate reduction was limited by the hydrolysis-fermentation rate and by the complexity of the slow release electron donors.

Author: Luis Reyes Alvarado
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Many industrial wastewaters, particularly from the mining, fermentation and food processing industry contain high sulphate (SO42-) concentrations. SO42- reduction (SR) is a serious environmental problem under non-controlled conditions, which can result in the release of toxic sulphide to the environment. Typical characteristics of SO42--rich wastewater are 0.4-20.8 g SO42-.L-1, low pH, high oxidative potential, low or negligible chemical oxygen demand (COD) and high heavy metals concentrations (acid mine drainage), that can dramatically damage the flora and fauna of water bodies. The aim of this PhD is to study the effect of electron donor supply on the biological SR process by sulphate reducing bacteria in bioreactors. The biological SR process was studied using carbohydrate based polymers (CBP) and lignocelulosic biowaste (L) as slow release electron donors (CBP-SRED and L-SRED, respectively) in batch bioreactors and continuously operated inverse fluidized bed bioreactors (IFBB). IFBB were vigorously tested for SR under high rate and transient (feast-famine) feeding conditions. In another bioreactor configuration, a sequencing batch bioreactor, the effect of the initial SO42- concentration on the reactor start-up was investigated. Besides, the effect of the initial concentration of electron donor, NH4+, and SO42- were evaluated in batch bioreactors as well. The robustness and resilience of SR was demonstrated in IFBB using lactate as the electron donor wherein the SO42- removal efficiency (SRE) was comparable in the feast period (67 ± 15%) of IFBB2 to steady feeding conditions (71 ± 4%) in the same IFBB2 and to IFBB1, the control reactor (61 ± 15%). From artificial neural network modeling and sensitivity analysis of data of IFBB2 operation, it was envisaged that the influent SO42- concentrations affected the COD removal efficiency, the sulphide production and pH changes. In another IFBB3 at a COD:SO42- ratio of 2.3, SR under high rate conditions (HRT=0.125 d) was 4,866 mg SO42-. L-1 d-1 and a SRE of 79% was achieved. Besides, the Grau second order and the Stover-Kincannon substrate removal models fitted the high rate reactor performance with r2 > 0.96. The COD:SO42- ratio was the major factor affecting the SR. In batch bioreactors, using filter paper as CBP-SRED, SR was carried out at > 98% SRE. Using scourer as L-SRED, a 95% SRE was achieved. However, when the scourer was used as the L-SRED carrier material in an IFBB4, the SR showed 38 (± 14) % SRE between 10-33 d of operation. The SR was limited by the hydrolysis-fermentation rate and, therefore, the complexity of the SRED. Concerning sequencing batch bioreactor operation, the SR process was affected by the initial SO42- concentration (2.5 g SO42-.L-1) during the start-up. The sequencing batch bioreactor performing at low SRE ( 70%) lead to propionate accumulation, however, acetate was the major end product when SRE was 90%. In batch bioreactors, the NH4+ feast or famine conditions affected the SR rates with only 4% and the electron donor uptake was 16.6% greater under NH4+ feast conditions. The electron donor utilization via the SR process improved simultaneously to the decreasing initial electron donor concentrations. This PhD research demonstrated that the SR process is robust to transient and high rate feeding conditions. Moreover, SR was mainly affected by the approach how electron donor is supplied, e.g. as SRED or as easy available electron donor, independently of the COD:SO42- ratio. Besides, the electron donor and SO42- utilization were affected by the lack or presence of nutrients like NH4+

Author: Joana Cassidy
Publisher:
ISBN: 9780138744861
Category : Sewage
Languages : en
Pages :

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Book Description
This work investigated two different approaches to optimize biological sulphate reduction in order to develop a process control strategy to optimize the input of an electron donor and to study how to increase the feasibility of using a cheap carbon source. Feast/famine regimes, applied to design the control strategy, were shown to induce the accumulation of storage compounds in the sulphate reducing biomass. This study showed that delays in the response time and a high control gain can be considered as the most critical factors affecting a sulphide control strategy in bioreactors. The delays are caused by the induction of different metabolic pathways in the anaerobic sludge, including the accumulation of storage products. On this basis, a mathematical model was developed and validated. This can be used to develop optimal control strategies. In order to understand the microbial pathways in the anaerobic oxidation of methane coupled to sulphate reduction (AOM-SR), diverse potential electron donors and acceptors were added to in vitro incubations of an AOM-SR enrichment at high pressure. Acetate was formed in the control group, probably resulting from the reduction of CO2. These results support the hypothesis that acetate may serve as an intermediate in the AOM-SR process.

Author: Guang-Hao Chen
Publisher: IWA Publishing
ISBN: 1789060354
Category : Science
Languages : en
Pages : 867

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Book Description
The first edition of this book was published in 2008 and it went on to become IWA Publishing’s bestseller. Clearly there was a need for it because over the twenty years prior to 2008, the knowledge and understanding of wastewater treatment had advanced extensively and moved away from empirically-based approaches to a fundamental first-principles approach based on chemistry, microbiology, physical and bioprocess engineering, mathematics and modelling. However the quantity, complexity and diversity of these new developments was overwhelming for young water professionals, particularly in developing countries without readily available access to advanced-level tertiary education courses in wastewater treatment. For a whole new generation of young scientists and engineers entering the wastewater treatment profession, this book assembled and integrated the postgraduate course material of a dozen or so professors from research groups around the world who have made significant contributions to the advances in wastewater treatment. This material had matured to the degree that it had been codified into mathematical models for simulation with computers. The first edition of the book offered, that upon completion of an in-depth study of its contents, the modern approach of modelling and simulation in wastewater treatment plant design and operation could be embraced with deeper insight, advanced knowledge and greater confidence, be it activated sludge, biological nitrogen and phosphorus removal, secondary settling tanks, or biofilm systems. However, the advances and developments in wastewater treatment have accelerated over the past 12 years since publication of the first edition. While all the chapters of the first edition have been updated to accommodate these advances and developments, some, such as granular sludge, membrane bioreactors, sulphur conversion-based bioprocesses and biofilm reactors which were new in 2008, have matured into new industry approaches and are also now included in this second edition. The target readership of this second edition remains the young water professionals, who will still be active in the field of protecting our precious water resources long after the aging professors who are leading some of these advances have retired. The authors, all still active in the field, are aware that cleaning dirty water has become more complex but that it is even more urgent now than 12 years ago, and offer this second edition to help the young water professionals engage with the scientific and bioprocess engineering principles of wastewater treatment science and technology with deeper insight, advanced knowledge and greater confidence built on stronger competence.

Author: Joana Cassidy
Publisher: IHE Delft PhD Thesis Series
ISBN: 9781138373440
Category :
Languages : en
Pages : 158

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Book Description
This work investigated two different approaches to optimize biological sulphate reduction in order to develop a process control strategy to optimize the input of an electron donor and to study how to increase the feasibility of using a cheap carbon source. Feast/famine regimes, applied to design the control strategy, were shown to induce the accumulation of storage compounds in the sulphate reducing biomass. This study showed that delays in the response time and a high control gain can be considered as the most critical factors affecting a sulphide control strategy in bioreactors. The delays are caused by the induction of different metabolic pathways in the anaerobic sludge, including the accumulation of storage products. On this basis, a mathematical model was developed and validated. This can be used to develop optimal control strategies. In order to understand the microbial pathways in the anaerobic oxidation of methane coupled to sulphate reduction (AOM-SR), diverse potential electron donors and acceptors were added to in vitro incubations of an AOM-SR enrichment at high pressure. Acetate was formed in the control group, probably resulting from the reduction of CO2. These results support the hypothesis that acetate may serve as an intermediate in the AOM-SR process.

Author: Joana Cassidy
Publisher: CRC Press
ISBN: 0429606168
Category : Technology & Engineering
Languages : en
Pages : 114

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Book Description
This work investigated two different approaches to optimize biological sulphate reduction in order to develop a process control strategy to optimize the input of an electron donor and to study how to increase the feasibility of using a cheap carbon source. Feast/famine regimes, applied to design the control strategy, were shown to induce the accumulation of storage compounds in the sulphate reducing biomass. This study showed that delays in the response time and a high control gain can be considered as the most critical factors affecting a sulphide control strategy in bioreactors. The delays are caused by the induction of different metabolic pathways in the anaerobic sludge, including the accumulation of storage products. On this basis, a mathematical model was developed and validated. This can be used to develop optimal control strategies. In order to understand the microbial pathways in the anaerobic oxidation of methane coupled to sulphate reduction (AOM-SR), diverse potential electron donors and acceptors were added to in vitro incubations of an AOM-SR enrichment at high pressure. Acetate was formed in the control group, probably resulting from the reduction of CO2. These results support the hypothesis that acetate may serve as an intermediate in the AOM-SR process.

Author: Suthee Janyasuthiwong
Publisher: CRC Press
ISBN: 0429605838
Category : Nature
Languages : en
Pages : 104

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Book Description
Metal contamination in the environment is a persisting global issue. The metal reservoirs in the earth have declined due to society’s needs and due to uncontrolled mining activities. Therefore, the idea to recover metals from waste streams has emerged. In this thesis, cost competitive technologies such as adsorption using agro-wastes and precipitation using an inverse fluidized bed (IFB) reactor were investigated, with special emphasis on the recovery of base metals. Groundnut shell showed good potential for metal (Cu, Pb and Zn) removal. From artificial neural network modeling, the performance of the sulfate reducing bacteria (SRB) was found to be strongly pH dependent; the removal efficiency of Cu and Zn in the IFB at pH 5.0 was >97%. Electronic waste is a good candidate as secondary metal resource. The recovery of Cu from computer printed circuited boards (PCBs) using biogenic sulfide precipitation was investigated as well. Using this technology, Cu could be recovered at ~0.48 g Cu/g PCBs.

Author: Piet Lens
Publisher: IWA Publishing
ISBN: 1900222094
Category : Science
Languages : en
Pages : 565

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Book Description
Environmental Technologies to Treat Sulfur Pollution: Principles and Engineering provides a definitive and detailed discussion of state-of-the-art environmental technologies to treat pollution by sulfurous compounds of wastewater, off-gases, solid waste, soils and sediments. Special attention is given to novel bioremediation techniques that have been developed over the last 10 years. Information density is unique owing to the many figures and graphs (150), tables (over 80) and over 1500 cited literature references. A detailed subject index helps the reader to find their way through the different technological applications, making it the perfect reference work for professionals and consultants dealing with sulfur-related environmental (bio)-technologies. Contents Part I - The sulfur cycle Part II - Technologies to Desulfurise Resources Part III - Treatment of Waters Polluted by Sulfurous Compounds Part IV - Treatment of Gases Polluted by Sulfurous Compounds Part V - Treatment of Soils and Sediments Polluted by Sulfurous Compounds Part VI - Other Applications of Sulfur Cycle: Bioconversions in Environmental Engineering Part VII - Problems Related to Sulfur Cycle: Bioconversions

Author: Edward F. DeLong
Publisher: Springer
ISBN: 9783642301421
Category : Science
Languages : en
Pages : 662

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Book Description
The Prokaryotes is a comprehensive, multi-authored, peer reviewed reference work on Bacteria and Achaea. This fourth edition of The Prokaryotes is organized to cover all taxonomic diversity, using the family level to delineate chapters. Different from other resources, this new Springer product includes not only taxonomy, but also prokaryotic biology and technology of taxa in a broad context. Technological aspects highlight the usefulness of prokaryotes in processes and products, including biocontrol agents and as genetics tools. The content of the expanded fourth edition is divided into two parts: Part 1 contains review chapters dealing with the most important general concepts in molecular, applied and general prokaryote biology; Part 2 describes the known properties of specific taxonomic groups. Two completely new sections have been added to Part 1: bacterial communities and human bacteriology. The bacterial communities section reflects the growing realization that studies on pure cultures of bacteria have led to an incomplete picture of the microbial world for two fundamental reasons: the vast majority of bacteria in soil, water and associated with biological tissues are currently not culturable, and that an understanding of microbial ecology requires knowledge on how different bacterial species interact with each other in their natural environment. The new section on human microbiology deals with bacteria associated with healthy humans and bacterial pathogenesis. Each of the major human diseases caused by bacteria is reviewed, from identifying the pathogens by classical clinical and non-culturing techniques to the biochemical mechanisms of the disease process. The 4th edition of The Prokaryotes is the most complete resource on the biology of prokaryotes. The following volumes are published consecutively within the 4th Edition: Prokaryotic Biology and Symbiotic Associations Prokaryotic Communities and Ecophysiology Prokaryotic Physiology and Biochemistry Applied Bacteriology and Biotechnology Human Microbiology Actinobacteria Firmicutes Alphaproteobacteria and Betaproteobacteria Gammaproteobacteria Deltaproteobacteria and Epsilonproteobacteria Other Major Lineages of Bacteria and the Archaea

Author: Paola Foladori
Publisher: IWA Publishing
ISBN: 184339278X
Category : Science
Languages : en
Pages : 381

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Book Description
Sludge Reduction Technologies in Wastewater Treatment Plants is a review of the sludge reduction techniques integrated in wastewater treatment plants with detailed chapters on the most promising and most widespread techniques. The aim of the book is to update the international community on the current status of knowledge and techniques in the field of sludge reduction. It will provide a comprehensive understanding of the following issues in sludge reduction: principles of sludge reduction techniques; process configurations; potential performance; advantages and drawbacks; economics and energy consumption. This book will be essential reading for managers and technical staff of wastewater treatment plants as well as graduate students and post-graduate specialists.