Activated Sludge Separation Problems

Name: Activated Sludge Separation Problems | Theory, Control Measures, Practical Experiences
Brand: IWA Publishing
Price: 132.99 EUR
Availability: OnlineOnly

Theory, Control Measures, Practical Experiences

Valter Tandoi David Jenkins Jiri Wanner(Editor)

IWA Publishing

Published on 1. January 2006

218 pages

E-Book

PDF with Adobe-DRM

System requirements

978-1-78040-306-9 (ISBN)

€132.99incl. 7% vat

System requirements

for PDF with Adobe-DRM

E-Book Single Licence

Available for download

Description

More details

Other editions

Content

Cover
Copyright
Contents
Abbreviations
List of contributors
1. Wastewater characterization
1.1 Introduction
1.2 Gross parameters
1.3 Physical properties
1.4 Organic matter
1.5 Inorganic matter
1.6 Biodegradability
1.6.1 COD, Nitrogen fractionation
1.6.2 Evaluation methods
1.6.2.1 Carbonaceous substrate (COD)
1.6.2.2 Nitrogen and phosphorus
1.7 References
2. The Microbiology of Activated Sludge Process
2.1 Introduction
2.2 Microorganisms in activated sludge
2.3 The identification of bacteria
2.4 Filamentous bacteria
2.5 Microthrix parvicella
2.6 Thiothrix
2.7 Nostocoida limicola
2.8 Polyphosphate Accumulating Organisms (PAO)
2.9 Glycogen Accumulating Organisms (GAO)
2.10 Nitrifiers
2.11 Denitrifiers
2.12 Quantitative estimation of filamentous bacteria in activated sludge
2.13 FISH Analysis
2.14 References
3. AS Separation problems
3.1 Introduction
3.2 "Well-settling" activated sludge
3.2.1 Requirements
3.2.2 Microscopic features of well settling activated sludge
3.3 Activated sludge separation problems
3.3.1 Poor floc microstructure
3.3.1.1 Dispersed growth
3.3.1.2 Unsettleable microflocs
3.3.1.3 Viscous bulking
3.3.2 Poor floc macrostructure
3.3.2.1 Filamentous bulking
3.3.2.2 Foaming caused by filamentous microorganisms
3.3.3 Other reasons
3.3.3.1 Rising sludge
3.4 Summary
3.5 References
4. Aeration tank and secondary clarifier as one system
4.1 Introduction
4.2 Aeration tank and secondary clarifier interactions
4.2.1 Activated sludge process
4.2.2 Secondary clarifier
4.2.2.1 General performance, thickening function
4.2.3 Separation function
4.2.4 BOD5
4.2.5 COD
4.2.6 Nitrogen and phosphorus
4.3 The impact of aeration basin equipment and operation on the performance of secondary clarifiers
4.3.1 Mechanical vs. diffused-air aeration
4.3.2 Mixed liquor mixing
4.3.3 Degasification and reflocculation in aeration tanks
4.4 Features of secondary clarifier construction
4.4.1 Inlet structure with a flocculation zone
4.4.1.1 Principles of a flocculation zone
4.4.1.2 Conventional flocculation zones with tangential flow regime
4.4.1.3 Novel flocculation zone with deflectors and a vertical flow regime
4.4.2 Outlet structure
4.4.2.1 Peripheral vs. internal effluent launders
4.4.3 Scum baffles
4.5 Efficient scum removal from the surface of secondary clarifiers
4.5.1 Conventional scum boxes
4.5.2 "Travelling" scum boxes
4.5.3 Pneumatic systems
4.6 Removal of settled and thickened sludge
4.6.1 Effect on the final effluent quality
4.6.2 Mechanical scrapers
4.6.3 Vacuum sludge removal
4.7 References
5. Bulking and Foaming Control Methods
5.1 Introduction
5.2 Specific control methods
5.2.1 Bulking due to low F/M
5.2.1.1 Continuous plug-flow reactors
5.2.1.2 Selectors
5.2.1.3 Sequencing batch reactors
5.2.1.4 Role of storage phenomena in microbial competition in substrate gradient processes
5.2.2 Bulking due to low nutrient concentration
5.2.3 Bulking due to low dissolved oxygen concentrations
5.2.4 Bulking due to fatty acids in the influent stream: control methods for Microthrix parvicella
5.2.5 Microbial and enzymatic preparations
5.3 Non specific control methods
5.3.1 Oxidising agents
5.3.2 Weighting or flocculating agents
5.3.3 New findings: use of alluminum salts to control Microthrix parvicella
5.4 Control of non-filamentous bulking ("viscous bulking")
5.5 Avoiding poor settling properties: alternative separations of activated sludge
5.6 References
6. Experiences in Various Countries
6.1 Introduction
6.2 Australia
6.2.1 General situation
6.2.2 Foaming filamentous bacteria in Australian Activated Sludge Plants
6.2.3 Foaming and Bulking Filamentous Bacteria in Activated Sludge Plants
6.2.4 Do the filamentous populations in activated sludge plants change with time?
6.2.5 Which operational factor affect filamentous populations and consequently determine incidents of bulking and foaming
6.2.6 Control Measures for Bulking and Foaming
6.2.7 An Australian Case Study
6.2.7.1 Plant Design Features
6.2.7.2 Microscopic Features of the Biomass
6.2.7.3 Bulking and Foaming Incidents
6.2.8 Conclusions
6.3 Czech Republik
6.3.1 Separation problems - situation up to 1980s
6.3.2 Separation problems - situation up to mid-1990s
6.3.3 WWTPs screening - 1995 - 2000
6.3.3.1 Methodology
6.3.3.2 Microscopic analysis and sedimentation properties evaluation
6.3.4 Results of separation problems and filamentous micro-organisms screening
6.3.4.1 Filamentous micro-organism abundance
6.3.4.2 Dominant filamentous microorganisms in sludge and foam
6.3.5 Development of filamentous population in Czech activated sludge plants between 1997 - 1998
6.3.5.1 SVI and total abundance of filaments
6.3.5.2 Dominant filamentous microorganisms in activated sludge mixed liquor and foams
6.3.6 Screening of eight nutrient removal plants in 2000
6.3.6.1 Characterization of monitored WWTPs
6.3.6.2 Activated sludges and settling properties
6.3.6.3 Dominant filamentous microorganisms in activated sludge mixed liquor
6.3.6.4 Biological foams
6.3.7 Foam control strategies
6.3.7.1 Water sprays
6.3.7.2 Skimming (mechanical removal) of foam
6.3.7.3 Return activated sludge manipulation
6.3.7.4 Manipulation of SRT
6.3.7.5 Additional installation of baffles
6.3.7.6 Initial contact zones ("selectors")
6.3.7.7 Chlorination of foam
6.4 Denmark, Greece and Netherlands
6.4.1 General situation
6.4.2 Wastewater composition
6.4.3 Process configurations
6.4.4 Magnitude of bulking and foaming problems in Denmark, Greece and The Netherlands
6.4.5 Settling properties in nutrient removal plants
6.4.6 Effect of different process conditions on SVI and the size of the filamentous population
6.4.7 Composition of the filamentous population
6.4.8 Influence of wastewater composition, process configuration and operating parameters on filamentous microorganisms growth
6.4.9 Effects of wastewater composition
6.4.10 Effects of process configuration
6.4.11 Experience with control measures applied
6.4.12 Non specific control measures
6.4.13 Specific control measures
6.4.14 Conclusions
6.5 France
6.5.1 General situation
6.5.2 Bulking and foaming characterization
6.5.3 Bulking and foaming situation
6.5.4 Dominant filamentous microorganisms in bulking and foaming sludges
6.5.5 Filamentous microorganisms and relationship with plant operation
6.5.6 Successful solutions for bulking and foaming control
6.5.7 Contact zone as preventive solution
6.5.7.1 Key points of contact zone design
6.5.8 Control of bulking by Cl2 addition
6.6 Germany/Austria
6.6.1 General situation
6.6.2 Bulking and scum in municipal and industrial wastewater treatment plants
6.6.3 Biology and specific troubleshooting measures of filamentous bacteria
6.6.4 Sulfur bacteria
6.6.5 Gram-negative filamentous bacteria in highly load plants
6.6.6 Experience with selectors for industrial wastes in Austria
6.6.6.1 Dimensioning and construction of an aerobic selector
6.6.6.2 Storage capacity and substrate removal after shock loads, maximum storage capacity
6.6.6.3 Influence of SRT and F/M ratio on the substrate elimination in the selector
6.6.6.4 Nutrient supply and substrate elimination
6.6.6.5 Adaptation of mixed liquor to a selector
6.6.6.6 Microbial growth and storage of substrate in the selector
6.6.7 Gram-positive filamentous bacteria in low load WWTP
6.6.7.1 M. parvicella
6.6.7.2 Nocardioform actinomycetes
6.6.8 Eikelboom morphotypes Nostocoida limicola, Types 0041/0675, 1851, and 0092
6.6.9 Non-specific control measures for sludge bulking and scum
6.6.9.1 Addition of aluminum salts for phosphate precipitation
6.6.9.2 Addition of layered silicates
6.6.9.3 Addition of lime
6.6.10 Decreasing the biomass of filamentous bacteria
6.7 Italy
6.7.1 General situation
6.7.2 Filament surveys
6.7.2.1 Puglia Region, Southern Italy
6.7.2.2 Lazio Region, Central Italy
6.7.2.3 Industrial wastes, Northern Italy
6.7.2.4 Survey on 167 Domestic plants
6.7.3 Control methods
6.7.3.1 Non specific methods
6.7.3.2 Specific methods
6.7.4 Case studies at full-scale plants
6.7.4.1 Reduction of Type 021N by chlorination at the Bagnuolo (Reggio Emilia) Municipal Plant
6.7.4.2 Controlling growth of Nocardia and M. parvicella by selectors at the Moncasale (Reggio Emilia) Treatment Plant
6.7.4.3 Experiences at Varese - Olona Plant (northern Italy) for controlling Nocardia and M. parvicella growth by reducing sludge age
6.7.4.4 Type 021N and Thiothrix reduction by an anoxic selector at Area Nolana Treatment Plant
6.7.4.5 Selector investigations on four large WWTP in Central Italy
6.7.4.6 M. parvicella elimination by poly aluminium chloride at Fusina Treatment Plant
6.8 Japan
6.8.1 General situation
6.8.2 Major Filaments Responsible for problems
6.8.3 Research on Fundamental Aspects of Filamentous Bulking in Japan/Thailand
6.8.4 Control Measures Applied
6.8.5 Case Studies
6.9 South Africa
6.9.1 General situations
6.9.1.1 Extended aeration plants
6.9.1.2 Conventional activated sludge
6.9.1.3 Plants treating industrial wastes
6.9.2 Plants specifically designed for biological nutrient removal (BNR)
6.9.2.1 First generation plants
6.9.3 Filamentous organisms in South African activated sludge plants
6.9.4 Reasons for the growth of filamentous organisms in SA plants
6.9.5 Methods used for the control of bulking and foaming in South Africa
6.9.5.1 Physical removal
6.9.5.2 Use of toxicants
6.9.5.3 Reduction of sludge age
6.9.5.4 Elimination and prevention of surface trapping
6.9.5.5 Increase in clarification capacity
6.9.5.6 Adjustments of dissolved oxygen levels
6.9.5.7 Improvements of reactor configuration
6.9.6 A case study
6.10 United Kingdom
6.10.1 General situation
6.10.2 Current situation
6.10.3 Control measures
6.10.4 Case history
6.10.4.1 Background
6.10.4.2 Solution Process
6.10.5 Conclusion
6.11 USA
6.11.1 General situations
6.11.2 Control of filaments in activated sludge systems
6.11.3 Other solids separation problems
6.11.4 Foaming
6.11.5 Viscous bulking and dispersed growth
6.11.6 Conclusions
6.12 References
7. Modelling of bulking phenomena
7.1 Introduction
7.2 Chudoba's theory
7.3 Chiesa and Irvine model
7.4 AEROFIL model
7.4.1 Hypotheses and fundamentals
7.4.2 Processes in model
7.5 Conclusions
7.6 References
Index

System requirements

Save as PDF Copy link into clipboard

Schweitzer Fachinformationen

Activated Sludge Separation Problems

Description

More details

Other editions

Additional editions

Content

System requirements