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| Solids Separation Problems | |
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| Introduction | |
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| Solids Separation Problems | |
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| Activated Sludge Floc | |
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| Solids Separation Problems in Terms of Floc Structure | |
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| Dispersed Growth | |
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| Viscous Bulking | |
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| Pin Floc | |
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| Filamentous Bulking | |
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| Foam/Scum | |
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| Differentiation of Microbial and Process-Related Solids Separation Problems | |
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| Methods | |
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| Introduction | |
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| Microscopic Examination Methods | |
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| Filament Counting Methods | |
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| Total Extended Filament Length | |
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| Filament Count | |
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| Nocardioform Filament Organism Counting | |
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| Floc and Filamentous Microorganism Characterization | |
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| Introduction | |
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| Sampling Points | |
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| Sampling Frequency | |
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| Sample Transport and Storage | |
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| Microscope | |
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| Cameras | |
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| Staining Procedures | |
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| Sample Preparation | |
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| Floc Characteristics and Overall Filament Abundance | |
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| Floc Size | |
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| Floc Characteristics | |
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| Protozoa and Other Macroorganisms | |
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| Nonbiological Organic and Inorganic Particles | |
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| Bacterial Colonies | |
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| Cells Dispersed in Bulk Solution | |
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| Effects of Filamentous Organisms on Floc Structure | |
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| Filamentous Organism Abundance | |
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| Filamentous Organism Characteristics | |
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| Branching | |
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| Motility | |
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| Filament Shape | |
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| Location | |
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| Attached Bacteria | |
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| Sheath | |
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| Cross-Walls (Cell Septa) | |
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| Filament Width | |
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| Filament Length | |
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| Cell Shape | |
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| Cell Size | |
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| Sulfur Deposits | |
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| Other Granules | |
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| Staining Reactions | |
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| Additional Observations | |
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| Filamentous Organism Identification | |
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| Using the Dichotomous Key | |
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| Building Your Skills | |
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| Filamentous Organism Descriptions | |
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| Sphaerotilus natans (Figures 2.9c, 2.13b, 2.14f, and 2.21a) | |
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| Type 1701 (Figure 2.21b) | |
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| Haliscomenobacter hydrossis (Figure 2.21c) | |
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| Type 021N (Figures 2.11b, 2.13d, 2.14d, 2.14e, 2.15c, 2.18a, 2.19b, and 2.22a) | |
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| Thiothrix I (Figures 2.14b, 2.15a, 2.19c, and 2.23a) | |
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| Thiothrix II (Figures 2.19d, 2.23c, and 2.23d) | |
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| Type 0914 (Figures 2.15d, 2.24a, and 2.24b) | |
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| Beggiatoa sp. (Figures 2.15b, 2.22c, and 2.22d) | |
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| Nostocoida limicola I (Figure 2.25a) | |
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| Nostocoida limicola II (Figures 2.10e, 2.11c, 2.17b, 2.18e, and 2.25b) | |
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| Nostocoida limicola III (Figure 2.25c) | |
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| Type 0411 (Figure 2.26a) | |
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| Type 0961 (Figure 2.26b) | |
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| Type 0092 (Figures 2.18d and 2.26c) | |
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| Type 0581 (Figure 2.26d) | |
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| Type 0041 (Figures 2.10a, 2.12a, 2.13c, 2.14a, 2.17c, 2.18f, and 2.27a) | |
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| Type 0675 (Figure 2.27b) | |
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| Type 1851 (Figures 2.17d and 2.27c) | |
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| Type 0803 (Figure 2.27d) | |
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| Microthrix parvicella (Figures 2.17e, 2.18c, 2.28a, 5.1e, and 5.1f) | |
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| Nocardioforms (Figures 2.9b, 2.10f, 2.14g, 2.17f, 2.18b, 2.28b, 5.1a, 5.1b, 5.1c and 5.1d) | |
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| Type 1863 (Figures 2.10c, 2.14c, and 2.28c) | |
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| Type 0211 (Figure 2.28d) | |
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| Flexibacter sp. (Figure 2.29a) | |
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| Bacillus sp. (Figure 2.29b) | |
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| Cyanophyceae (Figure 2.29c) | |
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| Fungi (Figures 2.9a and 2.29d) | |
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| Progress in Identifying Filamentous Organisms | |
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| Protozoa And Metazoa | |
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| General | |
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| Microscopic Evaluation | |
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| Taxonomic Classification | |
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| Flagellates | |
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| Amoebae | |
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| Free-Swimming Ciliates | |
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| Attached Ciliates | |
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| Rotifers | |
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| Higher Invertebrates | |
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| Use of Protozoa and Metazoa as Indicator Organisms | |
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| Physical and Chemical Methods | |
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| Settling Tests | |
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| Foaming Tests | |
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| Methods for Differentiating Microbiological and Process-Related Solids Separation Problems | |
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| Dispersed SS (DSS) | |
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| Flocculated SS (FSS) | |
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| Secondary Effluent SS (ESS) | |
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| Applications and Results of Microscopic Examination of Activated Sludge | |
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| Introduction | |
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| Filament Counting | |
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| Filamentous Organism Identification in Activated Sludge | |
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| Results of Filamentous Organism Surveys | |
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| Diagnosis of Causes of Solids Separation Problems through Microscopic Examination | |
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| General | |
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| Nonmicrobial Particles | |
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| Other Microbiological Features | |
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| General | |
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| Limited Diversity | |
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| Dispersed Growth | |
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| Neisser-Positive Cell Clumps | |
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| Yeast | |
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| Zoogloeas | |
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| Selector Flocs | |
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| Nitrifying Bacteria | |
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| Denitrifying Bacteria | |
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| Spirochaetes, Spirillum, and Flexibacter | |
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| Exocellular Material | |
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| Algae | |
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| Filamentous Organisms | |
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| Relationship to Causes of Bulking | |
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| Nutrient Balance | |
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| Readily Metabolizable Soluble Organics | |
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| Sulfide | |
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| Lipids | |
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| Other Particulate Substrates | |
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| Case Study | |
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| Net Growth Rate (MCRT, F/M) | |
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| Aeration Basin Configuration and Redox Conditions | |
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| Wastewater Feeding Regime | |
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| Foam Trapping Features | |
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| Upstream Biological Treatment Units, Sewer Surfaces, and In-Plant Surfaces | |
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| DO Concentration | |
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| pH | |
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| Temperature | |
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| Summary | |
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| Control of Activated Sludge Bulking and Other Settling Problems | |
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| Introduction | |
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| General Approach | |
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| Rapid, Nonspecific Bulking Control Methods | |
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| Manipulation of RAS Flow Rates and Aeration Basin Feed Points | |
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| Secondary Clarifier Operating Principles | |
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| Activated Sludge Process Schematic and Definitions | |
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| Secondary Clarifier Process Operating Relationships | |
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| Degree of Thickening Achieved by Secondary Clarifier | |
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| Required RAS Flow Rate | |
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| Secondary Clarifier Capacity | |
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| Sludge Thickening Theory | |
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| Secondary Clarifier Analysis and Operation | |
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| System Analysis and Operation | |
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| Addition of Chemicals and Inert Solids to Enhance Activated Sludge Settling Rates | |
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| Addition of Disinfectants to Selectively Kill Filamentous Organisms | |
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| General | |
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| Use of Chlorination for Bulking Control | |
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| Chlorination Criteria | |
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| General Guidelines | |
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| Chlorination System Design | |
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| Monitoring Effects of Chlorine Addition | |
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| Case Histories of Bulking Control Using Chlorination | |
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| General | |
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| City of Albany, GA | |
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| City of San Jose/Santa Clara Water Pollution Control Plant, CA | |
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| Stroh Brewing Co., Longview, TX | |
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| Plastics Manufacturing Wastewater Activated Sludge System, WV | |
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| Use of Hydrogen Peroxide for Bulking Control | |
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| General | |
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| City of Petaluma, CA | |
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| Use of Ozone for Bulking Control | |
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| Filamenticides | |
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| Specific Methods of Bulking Control | |
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| Nutrient Deficiency | |
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| General | |
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| Macronutrient Deficiency | |
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| General | |
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| Factors Affecting Macronutrient Requirements | |
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| Availability of Macronutrients | |
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| Satisfying Macronutrient Demands | |
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| Required Residual Macronutrient Concentrations | |
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| Micronutrients | |
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| Low Dissolved Oxygen (DO) Concentrations | |
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| General | |
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| Case Histories | |
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| Orange County Sanitation District Plant, Fountain Valley, CA | |
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| Pulp and Paper Wastewater Activated Sludge Plant | |
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| City of Woonsocket, RI | |
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| Effect of Aeration Basin Configuration, Wastewater Feeding Method, and Redox Conditions on Activated Sludge Settling Characteristics | |
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| Effect of Aeration Basin Configuration | |
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| Selectors | |
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| Selector Effect | |
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| General Observations | |
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| Selector Mechanisms | |
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| Effects of Selectors | |
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| Selector Design (Sizing) | |
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| General | |
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| Initial Contact Zones | |
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| Aerobic Selectors | |
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| Anoxic Selectors | |
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| Anaerobic Selectors | |
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| Main Aeration Basin | |
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| Selector Case Histories | |
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| Leopoldsdorf Sugar Mill, Austria | |
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| Hamilton, OH | |
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| Davenport, IA | |
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| Tri-City, Clackamas County, OR | |
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| Fayetteville, AR | |
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| Hyperion Treatment Plant, Los Angeles, CA | |
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| 23rd Avenue Plant, Phoenix, AZ | |
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| Situations Where Selectors Are Not Effective | |
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| High Effluent SS Due to Clarification Problems | |
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| General | |
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| Problem Definition | |
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| Method of Investigation | |
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| Results | |
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| Problem Resolution | |
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| Inadequate Flocculation, Floc Break-Up (High ESS, High DSS[subscript i], Low FSS) | |
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| Clarifier Hydraulic Problems (High ESS, Low DSS, Low FSS) | |
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| Bioflocculation Problems (High DSS[subscript i], High FSS, High ESS) | |
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| Activated Sludge Foaming and Control | |
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| Activated Sludge Foaming | |
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| Types of Activated Sludge Foam | |
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| Nocardioform Foaming | |
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| Extent and Significance of Problems | |
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| Foaming Organism Surveys | |
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| Foaming Problems | |
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| Activated Sludge | |
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| Anaerobic Digesters | |
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| Pathogenic Nocardioforms | |
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| Proposed Mechanisms of Foaming | |
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| Introduction | |
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| Physical/Chemical Factors | |
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| Nature of Foam | |
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| Solids-Containing Foams | |
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| Roles of Surfactants | |
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| Anaerobic Digester Foaming | |
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| Foam Trapping and Recycling | |
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| Foaming Tests | |
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| Microbiological Factors | |
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| Factors Affecting Growth | |
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| MCRT and Temperature | |
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| pH | |
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| Nocardioform Control | |
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| Nocardioform Growth in Activated Sludge | |
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| Introduction | |
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| Aerobic Selectors | |
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| Anoxic Selectors | |
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| Anaerobic Selectors | |
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| Classifying Selectors and Selective Foam Wasting | |
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| Chlorination | |
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| Cationic Polymer Addition | |
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| Automatic MCRT Control | |
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| Microthrix parvicella | |
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| Factors Affecting M. parvicella Growth | |
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| General | |
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| Substrates | |
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| Operating Conditions | |
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| Control | |
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| Case Histories | |
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| Upper Occoquan Sewage Authority (UOSA), VA | |
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| Northside Wastewater Treatment Plant, Tulsa, OK | |
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| Anaerobic Digester Foaming | |
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| Bibliography and References | |
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| Index | |