Biological Treatment Processes | Volume 3. Questo articolo non è disponibile.Biological Treatment Processes | Volume 3

The past few years have seen the emergence of a growing, widespread desire in this country, and indeed everywhere, that positive actions be taken to restore the quality of our environment, and to protect it from the degrading effects of all forms of pollution-air, noise, solid waste, and water. Since pollution is a direct or indirect consequence of waste, if there is no waste, there can be no pollution, and the seemingly idealistic demand for "zero discharge" can be construed as a demand for zero waste. However, as long as there is waste, we can only attempt to abate the consequent pollution by converting it to a less noxious form. In those instances in which a particular type of pollution has been recognized, three major questions usually arise: (1) How serious is the pollution? (2) Is the technology to abate it available? and (3) Do the costs of abatement justify the degree of abatement achieved? The principal intention of this series of books on environmental engineering is to help the reader formu­ late useful answers to the second and third of these questions, i. e. , to outline the best currently available engineering solutions, and to examine their costs in the light of the real level of benefits afforded. The traditional approach of applying tried-and-true solutions to specific pollution problems has been a major factor contributing to the success of environmental engineering, and in large measure has ac­ counted for the establishment of a "methodology of pollution control.

1 Bioscience Concepts for Environmental Control.- I. Introduction.- II. The Cell.- III. Biochemistry.- A. Important Compounds.- B. Photosynthesis.- C. Chemosynthesis.- D. Respiration.- E. Nutrition.- IV. Microbiology.- A. Bacteria.- B. Algae.- C. Protozoa.- D. Fungi.- E. Viruses.- F. Other.- V. Ecology.- A. Structure of the Ecosystem.- B. Biogeochemical Cycles.- C. Interspecies Relationships.- D. Population Dynamics.- VI. Physical and Biological Factors in Waste Treatment Ecosystems.- A. Chemical Composition of the Medium.- B. Indices of Pollution.- C. Flow Rates and Concentration.- D. Surfaces and Substrata.- E. Nutritional Shifts.- F. Biological Interactions.- G. Ecological Succession.- VII. Conclusions.- Suggested Reading.- 2 Treatment by Application Onto Land.- I. Introduction.- A. Scope.- B. Philosophy.- II. Types.- A. Surface Spreading.- B. Slow Rate.- C. Rapid Infiltration—Percolation.- D. Vegetative Cover vs Bare Ground.- E. Final Residence of Liquid.- F. Chlorination.- III. Processes.- A. Physical.- B. Physical—Chemical.- C. Chemical.- D. Biological.- E. Process Applications.- IV. Design.- A. Preliminary Studies.- B. Application Rates.- C. Distribution Facilities.- D. Monitoring.- V. Evaluation.- A. Effectiveness.- B. Applicability.- C. Cost.- D. Ease of Design for Various Conditions.- References.- 3 Treatment by Subsurface Application.- I. Introduction.- II. Theory.- A. Pretreatment in a Tank.- B. Subsurface Disposal.- III. Design.- A. General Considerations.- B. Septic Tank Design.- C. Aerobic Tank Design.- D. Conventional Tile Field.- E. Aerobic Tile Field.- F. Seepage Pit.- G. Institutional and Multiple Dwelling Systems.- H. Construction.- IV. State of the Art.- A. Tank Treatment.- B. Effluent Disposal.- C. Nutrient Removal.- V. Conclusions.- A. Cost Estimation.- B. Sample Design Problems.- References.- 4 Submerged Aeration.- I. Introduction.- II. Aeration Performance Evaluation.- A. Hydraulic Regimes of Performance Evaluation.- B. Means of Deoxygenation.- C. Oxygen Saturation Concentration.- D. Data Analysis and Interpretation.- III. Submerged Aeration Systems.- A. System Components.- B. Major Types of Submerged Aerators.- IV. Design Application.- A. Types of Design Problems.- B. Case Study Example.- Nomenclature.- References.- 5 Surface and Spray Aeration.- I. Introduction.- II. Fundamental Concepts.- A. Equilibrium.- B. Gas Solubility.- C. Molecular Diffusion.- D. Turbulent Mixing.- E. Air—Water Interface.- III. Theories of Gas Transfer.- A. Mass Transfer Equation.- B. Two-Film Theory.- C. Penetration Model.- D. Film-Penetration Model.- E. Surface Renewal—Damped Eddy Diffusion Model.- F. Turbulent Diffusion Model.- G. Other Models.- H. Comparison of Gas Transfer Coefficients.- I. Gas—Liquid Relation.- IV. Aeration Equation.- A. Significance of the Aeration Equation.- B. Influencing Factors.- C. Natural Reaeration.- V. Surface Aeration.- A. Introduction.- B. Types of Surface Aerators.- C. Techniques for Surface Aerator Performance Test.- D. Surface Aerator Design.- E. Artificial Instream Aeration.- VI. Spray Aeration.- A. Introduction.- B. Types of Spray Aerators.- C. Spray Aeration Applications.- D. Spray Aerator Design.- Nomenclature.- References.- 6 Activated Sludge Processes.- I. Concepts and Physical Behavior.- A. Definition of Process.- B. Principles of Biological Oxidation.- C. Energy Flow.- D. Synthesis and Respiration.- II. System Variables and Control.- A. Kinetics of Sludge Growth and Substrate Removal.- B. Process Variables, Interactions, and Their Significance in Process Operation and Performance.- C. Aeration Requirements.- D. Temperature Effect.- III. System Modifications and Design Criteria.- A. The Conventional Activated Sludge Process.- B. Step Aeration Process.- C. Complete Mix Process.- D. Extended Aeration Process.- E. Contact Stabilization Process.- F. Kraus Process.- G. Design Criteria.- H. Other Process.- IV. Computer Aid in Process Design and Operation.- A. Prediction of Performance.- B. Computer Program for Process Design.- C. Computer Aid in Process Operation.- V. Practice and Problems in Process Control.- A. Wasting Sludge, Feedback, and Feed Forward Control.- B. Bulking of Sludge and Rising of Sludge.- VI. Capital and Operating Cost.- A. Traditional Cost Estimates.- B. Worksheet for Cost Estimates.- C. Improvements of Cost Estimation Techniques.- VII. Latest Process Development.- A. Step Sludge Process.- B. High Rate Adsorption—Biooxidation Process.- C. The Oxygenated Activated Sludge Process.- Appendixes.- A. Notation.- B. Definition of Terms, CASSO Program.- C. Sample Worksheet for Cost Estimates.- References.- 7 Waste Stabilization Ponds and Lagoons.- I. Concept and Physical Behavior.- A. Pond Ecology and Process Reactions.- B. Biology of Stabilization Ponds.- C. Classification of Stabilization Ponds.- II. System Variables and Control.- A. Kinetics of Substrate Removal.- B. Oxygen Supply.- C. Temperature Effect.- D. Detention Time.- III. Design Criteria.- A. Design Parameters.- B. Inlet Structures.- C. Outlet Structures.- D. Transfer Pipes.- E. Berm Design.- F. Bottom Preparation.- IV. Practice and Problems in Process Control.- A. Staging of Ponds.- B. Pond Recirculation.- C. Pond Mixing and Aeration.- D. Odor Control.- E. Algal Removal.- F. Insect Control.- V. Capital and Operation Costs.- VI. Latest Process Developments.- A. Nutrient Removal and Controlled Eutrophication.- B. Integrated Pond System.- VII. Examples of Process Design.- References.- 8 Trickling Filters.- I. Introduction.- A. Process Description of Attached Growth Systems.- B. Historical Development and Applicability of Attached Growth Systems.- C. Microbiology and Ecology.- II. Theories and Mechanisms.- A. Transfer of Oxygen in Slime Layer and Liquid Film.- B. Transfer of Substrate in Liquid Film and Slime Layer.- III. Types of Trickling Filters.- A. General Description.- B. Low-Rate, High-Rate, and Super-Rate Filters.- C. Single- and Multi-Stage Trickling Filter Plants.- IV. Performance Models and Design Procedures.- A. National Research Council Models.- B. Velz Model.- C. Upper Mississippi River—Great Lakes Board Model.- D. Howland Models.- E. Eckenfelder Models.- F. Galler and Gotaas Model.- G. Biofilm Model.- H. U.S. Army Design Formulas.- I. U.S. Environmental Protection Agency Model.- V. Design and Construction Considerations.- VI. Process Control Considerations.- VII. Energy Considerations.- VIII. Application, Performance, and Reliability.- IX. Limitations and Environmental Impact.- X. Design Examples.- Nomenclature.- References.- 9 Rotating Biological Contactors.- I. Introduction.- II. Factors Affecting Performance and Design.- A. Microorganisms and Environmental Factors.- B. Media Selection and Arrangement.- C. Loadings and Hydraulic Parameters.- III. Performance Models and Design Procedures.- A. US Environmental Protection Agency Model.- B. Modified US Environmental Protection Agency Model.- C. Manufacturer’s Design Procedures.- IV. Process Control Considerations.- V. Application, Performance, and Reliability.- VI. Limitations and Environmental Impact.- VII. Design Examples.- References.- Nomenclature.- 10 Anaerobic Sludge Digestion.- I. Introduction.- II. Theory.- A. Nature of Organic Wastes.- B. Biochemistry and Microbiology of the Anaerobic.- Process.- C. Reactor Configurations.- D. Organic Loading Parameters.- E. Time and Temperature Relationships.- F. Nutrient Requirements.- G. Gas Production and Utilization.- III. Design Practice.- A. Anaerobic Treatability Studies.- B. Anaerobic Reactor Design and Sizing.- C. Tank Construction and System Components.- D. System Equipment and Appurtenances.- E. Gas Utilization.- F. Sludge Pumping and Piping Considerations.- IV. Management of Digestion.- A. Control of Sludge Feed.- B. Withdrawal of Sludge and Supernatant.- C. Maintenance of Reactor Stability.- D. Digester Performance Criteria.- V. Capital and Operating Costs.- A. General.- B. Items Included in Cost Estimates.- VI. Design Examples.- A. Example Using Standards Design.- B. Example Using Solids Loading Factor.- C. Example Using Modified Anaerobic Contact.- Nomenclature.- References.