Settleability Problems and Loss of Solids in the Activated Sludge Process

Preface.

PART I: OVERVIEW.

The Activated Sludge Process.

Floc Formation.

A Floc Formation Model.

Interruption of Floc Formation.

PART II: SETTLEABILITY PROBLEMS AND LOSS OF SOLIDS.

Introduction.

Undesired Filamentous Growth.

Nutrient-Deficient Floc Particles.

Denitrification.

Sheared Floc Particles.

Dispersed Floc Particles.

Heavy Metals and Congealed Floc Particles.

Low Dissolved Oxygen Concentration.

Young Sludge Age.

Floc Particles Lost Through Sludge Aging.

Slug Discharge of Soluble cBOD.

Viscous Bulking or Zoogloeal Growth.

Increase in Percent MLVSS.

Colloidal Floc Particles.

Temperature.

PART III: FOAM AND SCUM.

Production and Accumulation of Foam and Scum.

Identification of Foam.

Controlling Foam Production and Accumulation.

PART IV: SETTLEABILITY TESTING.

Settleability Testing and Settling Rate.

Settleability Testing: Microscopic Analyses.

Appendix I: F/M, HRT, MCRT, MLVSS, Sludge Age, SVI.

Appendix II: Microscopic Techniques.

References.

Abbreviations and Acronyms.

Chemical Compounds and Elements.

Glossary.

Index.