1st Edition

The Membrane-Coupled Activated Sludge Process in Municipal Wastewater Treatment

By Berthold Guender Copyright 2001

    This book represents a milestone. It is the first overall presentation that summarizes the membrane-coupled activated sludge process (MCASP) in its entirety. The volume offers a thorough survey of current know-how, an explanation of the operational MCASP in municipal plants with full-scale membrane modules, and a description of its advantages and disadvantages. A new approach for calculating excess sludge production and oxygen consumption for the oxidation of carbon compounds is discussed. This approach details correct values for various wastewater streams-from very small to very high sludge loads. Derived values are then related to regulatory criteria and process design alternatives. This book also addresses the relationships between the alpha factor and the concentration of mixed liquor suspended solids (MLSS), as well as engineering issues such as: membrane performance, energy requirements, and the removal performance of membrane systems. The findings in The Membrane Coupled Activated Sludge Process in Municipal Wastewater Treatment support the practical applicability of the MCASP to smaller wastewater operations ranging from modest-sized municipal treatment plants to facilities serving only one structure. In addition, the MCASP process is shown to be applicable in water reuse operations. The Membrane Coupled Activated Sludge Process in Municipal Wastewater Treatment demonstrates that sewage treatment problems for various types of waste streams-from rural to suburban-can be solved with MCASP. All the required design and operational data for implementing this technology in wastewater treatment can be found in this book.

    Preface
    1. The Conventional Activated Sludge Process
    1.1 Some General Information about the Activated Sludge Process
    o Historical Evolution
    o Construction and Function of the Activated Sludge Process
    o Composition and Determination of Activated Sludge
    o Separation of Activated Sludge in Final Clarifiers
    o Capability of the Activated Sludge Process
    o Energy Requirement of the Activated Sludge Process
    1.2 Excess Sludge Production and Oxygen Consumption
    o Introduction and Definition
    o Growth of Heterotrophic Bacteria
    o Model Considerations and Specific Values within the Activated Sludge Process
    o Approach for the Calculation of the Excess Sludge Production and the Oxygen Consumption
    1.3 Aeration of the Activated Sludge
    o Preliminary Note
    o Oxygen Transfer in Clear Water and in Activated Sludge
    o Problems and Aims during the Description of Oxygen Transfer in Activated Sludge
    1.4 Rheology of the Activated Sludge
    o General Information
    2. Basics of Membranes and Membrane Procedures
    2.1 General Comments to Membranes and Membrane Procedures
    2.2 Classification of Membrane Processes
    2.3 Cut-Offs of Pressure Driven Membrane Processes
    2.4 Basics of Microfiltration
    o Description of Microfiltration
    o Material, Structure and Characterization of Porous Membranes for Microfiltration
    o Procedures for Microfiltration
    o Definitions and Operating Parameters
    o Model Ideas for Crossflow Microfiltration
    o Fouling
    o Modules for Crossflow Microfiltration
    o Application and Performance of Crossflow Microfiltration
    3. The Membrane Coupled Activated Sludge Process (MCASP)
    3.1 Definitions and Basics
    3.2 Construction and Function
    3.3 Evolution of the MCASP
    4. Aim of the Work

    5. Experimental Setups and Testing Procedures
    5.1 General View of Pilot Plants and Experimental Conception
    5.2 Experiments with MCASP Pilot Plants with Submerged Plate and Hollow Fiber Modules
    5.3 Experiments with MCASP Pilot Plants with External Tubular Membranes
    o Construction and Description of the Experimental Plants
    o Experimental Program and Testing Procedures
    o Measuring and Analysis
    o Average Wastewater Composition
    o Operation Parameters
    5.4 Procedure to Depict the Hydraulic Performance of the Membrane Units
    o Calculation of the Transmembrane Pressure Difference
    o Influence of the Temperature on the Membrane Filtration
    6. Presentation and Discussion of the Results
    6.1 MCASP Plants with Submerged Membrane Modules
    o Performance and Reliability
    o Effluent Quality and Removal Efficiency
    o Hydraulic Performance of the Submerged Membranes
    o Oxygen Transfer and a-Factor
    o Energy Requirements for Membrane Filtration and Oxygen Supply
    6.2 MCASP-Plants with External Tubular Membranes
    o Preliminary Notes
    o Effluent Parameters and Removal Efficiency
    o Hydraulic Performance of the Tubular Membranes
    6.3 Excess Sludge Production
    o Procedure for the Calculation of Excess Sludge Production
    o Withdrawal of Excess Sludge and Increase in Activated Sludge
    o Treated Wastewater Volume and Excess Sludge Production
    o Sludge Loading and Sludge Age
    o Specific Excess Sludge Production
    o Approach for the Calculation of the Specific Excess Sludge Production
    6.4 Characterization of the Activated Sludge from MCASP-Plants
    o Volatile Solids (MLVSS/MLSS-ratio)
    o Oxygen Uptake Rate (Carbonaceous)
    o Chemical Composition
  • Microscopic Sludge Picture
    6.5 Rheological Qualities of Activated Sludge from MCASP-Plants
    o Problem Description and Aim
    o Measuring Scope and Method of Measurement
    o Results of the Rheological Investigations
    o Causes for Rheological Behavior
    o Effects of Rheological Qualities
    7. Application of the MCASP
    7.1 Preliminary Notes
    7.2 Performance Features of MCASP compared to the Conventional Activated Sludge Process
    7.3 Design of the MCASP
    o Activated Sludge Process Step
    o Membrane Filtration
    7.4 Decision Criteria for the Application of the MCASP in Municipal Wastewater Treatment
    8. Summary

    Bibliography
    Index
  • Biography

    Berthold Guender