Skip to main content
Article thumbnail
Location of Repository

Measuring Floc Structural Characteristics

By Peter Jarvis, Bruce Jefferson and Simon A. Parsons

Abstract

A review is presented of a range of techniques for the structural characterisation of flocs. Flocs may be considered as highly porous aggregates composed of smaller primary particles. The irregular size and shape of flocs makes them difficult to measure and quantify. A range of different equivalent diameters are often used to define the floc size and allow comparison with other floc systems. The application of a range of floc sizing methods has been described. Microscopy is time consuming, requiring large sample size and considerable preparation but gives good information on floc shape and form. Light scattering and transmitted light techniques have been used to good effect to measure floc size on-line whilst individual particle sensors have limited applicability to measuring floc size. Fractal dimension can be measured using one of three major techniques: light scattering, settling and two dimensional (2D) image analysis. Light scattering is ideally suited for small, open flocs of low refractive index whilst settling may be applied to most floc systems of low porosity. 2D image analysis requires flocs to have good contrast between the solid in the floc and the background

Publisher: Springer
Year: 2005
OAI identifier: oai:dspace.lib.cranfield.ac.uk:1826/985
Provided by: Cranfield CERES

Suggested articles

Citations

  1. (1999). A Laboratory Examination of Floc Characteristics with Regard to Turbulent Shearing. doi
  2. (2002). A Model to Describe the Settling Behaviour of Fractal Objects. doi
  3. (1989). A New Technique for Characterising Flocculated Suspensions. Dewatering Technology and Practice
  4. (1989). A Random Walk Through Fractal Dimensions. VCH Verlagsgesellschaft, doi
  5. (2000). Activated Sludge Flocculation: On-Line Determination of Floc Size and the Effect of Shear. doi
  6. (2001). Aggregate Size Distributions in Flocculation. Colloids and Surfaces A: Physicochemical and Engineering Aspects doi
  7. (2001). Aggregation Kinetics and Fractal Structure of γ-Alumina Assemblages. doi
  8. (2004). Breakup and Strength of Polystyrene Latex Flocs Subjected to a Converging Cell. Colloids and Surfaces A: Physicochemical and Engineering Aspects doi
  9. (2003). Changes in Fractal Dimension During Aggregation. doi
  10. (2001). Characterisation of activated sludge by automated image analysis. doi
  11. (2000). Characterisation of Alum Floc by Image Analysis. doi
  12. (1999). Characterisation of the Breaking Force of Latex Particle Aggregates by Micromanipulation. Particle Particle System Characterisation doi
  13. (1998). Comparison of Pelagic and Nephloid Layer Marine Snow: Implications for Carbon Cycling. doi
  14. (1983). Determining Velocity Gradients in Laboratory and Full Scale Systems.
  15. (2003). Dewatering of Alumino-Humic Sludge: Impacts of Hydroxide. doi
  16. (2001). Effects of pH and Dosage on Pollutant Removal and Floc Structure During Coagulation. doi
  17. (1998). Effects of Salinity on Physical Characteristics of Activated Sludge Flocs.
  18. (2001). Evidence of Shear Rate Dependence on Restructuring and Break-up of Latex Aggregates. doi
  19. (2002). Evolution of Size Distribution and Transfer of Mineral Particles Between Flocs in Activated Sludges: an Insight into Floc Exchange Dynamics. doi
  20. (1999). Flocculation Modelling: A Review. doi
  21. (1997). Flocs vs Granules: Differentiation by Fractal Dimension. doi
  22. (1994). Fractal Properties of Flocs Formed by Fluid shear and Differential Settling. doi
  23. (1989). Fundamentals of Flocculation. doi
  24. (2003). Impacts of Structural Characteristics on Activated Sludge Floc Stability. doi
  25. (1999). In:
  26. (1996). Laser-Based Techniques for Particle Size Measurement: a Review of Sizing Methods and their Industrial Applications. doi
  27. (1999). Measurement and Implications of Floc Structure in Water and Wastewater Treatment. Colloids and Surfaces A: Physicochemical and Engineering Aspects doi
  28. (1993). Measurement of the Size of Aggregates in Suspension. In:
  29. (1984). Methods for Determinination of Particle Size Distribution
  30. (1996). Microbial Floc Stabilisation and Preparation for Structural Analysis by Correlative Microscopy. doi
  31. (1997). Microbiological Aspects of Granular Methanogenic Sludge.
  32. (2003). Microscopic Observation of Particle Reduction in Slaughterhouse Wastewater by CoagulationFlocculation Using Ferric Sulphate as Coagulant and Different Coagulant Aids. doi
  33. (2002). Multilevel Structure of Sludge Flocs. doi
  34. (2002). On Techniques for the Measurement of the Mass Fractal Dimension of Aggregates.
  35. (1997). Optimising Natural Organic Matter Removal from Low Turbidity Waters by Controlled pH Adjustment of Aluminium Coagulation. doi
  36. (1997). Particle Size Measurement. In: Powder Sampling and Particle Size Measurement. doi
  37. (1986). Physical Characteristics of Activated Sludge Flocs. doi
  38. (1986). Predicting the Expansion Behaviour of Filter Media.
  39. (1999). Prediction of Fractal Properties of Polystyrene Aggregates. Colloids and Surfaces A: Physicochemical and Engineering Aspects doi
  40. (2001). Properties of Flocs Produced by Water Treatment Coagulants.
  41. (1998). Rapid Structure Characterization of Bacterial Aggregates. doi
  42. (1996). Settling Velocity of Fractal Aggregates. doi
  43. (1996). Shear-Induced Flocculation: the Evolution of Floc Structure and the Shape of the Size Distribution at Steady State. doi
  44. (1983). Strength of Ferric Hydroxide Flocs. doi
  45. (1999). Structure and Porosity of Alum Coagulation Flocs.
  46. (2002). Structure of Al-Humic Flocs and their Removal at Slightly Acidic and Neutral pH.
  47. (2003). Temperature Effects on Flocculation Using Different Coagulants. In:
  48. (1997). The Density of Particle Aggregates. doi
  49. (1998). The Influence of Tank Size and Impeller Geometry on Turbulent Flocculation: I Experimental. doi
  50. (2004). The Reversibility of Floc Breakage. doi
  51. (1998). The Role of Floc Density in Solid-Liquid Separation. doi
  52. (1985). Turbidity Fluctuations in Flowing Suspensions. doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.