Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Precipitate Formation and Particle Size Control

Precipitate Formation and Particle Size Control

In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...

Coagulation

Coagulation

Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and...

Pore Size Distribution

Pore Size Distribution

In concrete, the pore size distribution significantly influences the material's properties. Capillary pores, markedly larger than gel pores, form a vast network within partially hydrated cement paste, reducing the concrete's strength and increasing its permeability. This heightened permeability leads to a greater risk of damage from environmental factors like freeze-thaw cycles and chemical attacks, with the extent of vulnerability also being tied to the water-to-cement ratio.
Adequate...

Typical Model Studies

Typical Model Studies

Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.

Recrystallization: Solid–Solution Equilibria

Recrystallization: Solid–Solution Equilibria

Recrystallization is a purification technique used to separate impurities from solid compounds. In this technique, no chemical reactions occur. Instead, it exploits physical properties only, specifically, the solubility differences between the desired compound and impurities, either at a single temperature or at different temperatures, and under other selected conditions. The solid-solution equilibrium (solubility equilibrium) of each component in the solution represents a binary phase...

Colloidal precipitates

Colloidal precipitates

The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Friability of pelletized biosolids thermally dried from various types of anaerobically digested sludges with and without thermal hydrolysis pretreatment.

Waste management (New York, N.Y.)·2026

Same author

Concentration, Antibacterial Effect, and Safety of Combining Intra-articular Epsilon-Aminocaproic Acid and Vancomycin in Primary Total Knee Arthroplasty: A Randomized Study.

The Journal of arthroplasty·2025

Same author

Rethinking Activated Sludge Modeling: A Critical Review of Modeling Strategies and the Role of Hybrid Integration.

Water environment research : a research publication of the Water Environment Federation·2025

Same author

Unveiling the bioprocess kinetics of leachate treatment at elevated temperatures: plant-wide dynamic simulation and experimental validation.

Waste management (New York, N.Y.)·2025

Same author

Retrospective Insights into the Clinicopathological Features and Treatment Outcomes of Thoracic SMARCA4-Deficient Tumors.

Technology in cancer research & treatment·2025

Same author

Efficacy and safety of aspirin in preventing venous thromboembolism after hip arthroplasty for femoral neck fracture: a noninferiority prospective cohort study.

BMC musculoskeletal disorders·2024

Search research articles

Related Experiment Video

Updated: Mar 11, 2026

Determination of the Settling Rate of Clay/Cyanobacterial Floccules

Determination of the Settling Rate of Clay/Cyanobacterial Floccules

Published on: June 11, 2018

Settling regimen transitions quantify solid separation limitations through correlation with floc size and shape.

William A S K Mancell-Egala¹, Chunyang Su², Imre Takacs³

¹Carollo Engineers, 3150 Bristol St, Costa Mesa, CA, 92626, USA; District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, 5000 Overlook Ave, SW Washington, DC, 20032, USA; Department of Civil and Environmental Engineering, Virginia Polytechnic and State University, Blacksburg, VA, 24061, USA.

|November 20, 2016

Summary

New metrics, Threshold of Flocculation (TOF) and Limit of Stokesian Settling (LOSS), effectively characterize activated sludge settling behavior and effluent quality, outperforming traditional Sludge Volume Index (SVI).

Keywords:

Activated sludge Effluent suspended solids Final clarifier Particle size distribution Settling velocity distribution Stokesian settling

More Related Videos

Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions

Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions

Published on: February 15, 2019

Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques

Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques

Published on: March 12, 2019

Related Experiment Videos

Last Updated: Mar 11, 2026

Determination of the Settling Rate of Clay/Cyanobacterial Floccules

Determination of the Settling Rate of Clay/Cyanobacterial Floccules

Published on: June 11, 2018

Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions

Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions

Published on: February 15, 2019

Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques

Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques

Published on: March 12, 2019

Area of Science:

Environmental Engineering
Wastewater Treatment
Water Quality

Background:

Activated sludge settling and flocculation behavior are critical for efficient wastewater treatment.
Traditional metrics like Sludge Volume Index (SVI) have limitations in characterizing settling dynamics.
Understanding sludge matrix limitations is key to improving effluent quality.

Purpose of the Study:

To explore the relationship between effluent quality and activated sludge settling/flocculation behavior.
To introduce and validate novel transitional metrics: Threshold of Flocculation (TOF) and Limit of Stokesian Settling (LOSS).
To assess the effectiveness of TOF and LOSS in characterizing sludge limitations impacting effluent quality.

Main Methods:

Monitored three activated sludge systems over one year.
Collected weekly measurements of hindered settling rates (ISV), SVI, TOF, and LOSS.
Utilized pilot clarifier and settling column studies with filming to analyze floc morphology.

Main Results:

SVI showed reduced sensitivity in characterizing ISV above 3 m/h.
ISV and LOSS demonstrated a strong correlation (r=0.71), though ISV varied with solids concentration.
TOF and LOSS effectively identified sludge matrix limitations: pinpoint floc formation (TOF > 400 mg TSS/L) and loose floc formation (TOF < 400 mg TSS/L, LOSS < 900 mg TSS/L).

Conclusions:

TOF correlates with particle size distribution, while LOSS correlates with settling velocity distribution.
TOF and LOSS provide a rapid and effective method for characterizing activated sludge limitations.
These novel metrics offer improved insights into factors affecting wastewater effluent quality compared to SVI.