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

Conservation of Mass in Moving, Nondeforming Control Volume

Conservation of Mass in Moving, Nondeforming Control Volume

Stormwater detention basins are essential in managing runoff during heavy rainfall, particularly in urban areas where impervious surfaces increase the risk of flooding. Understanding the conservation of mass in these systems allows engineers to optimize basin performance, balancing inflow, outflow, and water storage.
In the context of a detention basin, the conservation of mass states that the total mass of water entering the basin must equal the mass leaving the basin plus any accumulation of...

Design Example: Creating a Hydraulic Model of a Dam Spillway

Design Example: Creating a Hydraulic Model of a Dam Spillway

Scaled hydraulic models of dam spillways provide a practical way to replicate and study the intricate flow dynamics of these structures. Often built to a 1:15 ratio, these models allow for observing critical water behavior, such as velocity distribution, flow patterns, and energy dissipation.

Noncompartmental Analysis: Mean Residence Time

Noncompartmental Analysis: Mean Residence Time

According to statistical moment theory, mean residence time (MRT) is an important measure in pharmacokinetics. MRT can be defined as the expected mean of a probability density function distribution. It provides valuable insights into drug disposition in the body.
After the administration of a drug through intravenous bolus injection, the drug molecules are distributed throughout the body and remain there for varying periods. The MRT represents the average time these drug molecules stay in the...

Retarders

Retarders

Retarders are chemical admixtures designed to extend the setting time, which is especially useful when there is a delay in sequential concrete pours to prevent cold joints and to achieve a cohesive structure. Retarders, when used in appropriate amounts, can also enhance the architectural appearance of exposed aggregate finishes.
The function of retarders is to delay the setting of concrete, and this effect can be measured using a penetration test. The retardation process involves adding...

Microbial Wastewater Treatment

Microbial Wastewater Treatment

Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water.

Design Example: Design of an Irrigation Channel

Design Example: Design of an Irrigation Channel

Trapezoidal channels are widely used in irrigation systems due to their cost-effectiveness and efficiency in conveying water. Trapezoidal channels feature a flat bottom and sloping sides, making them stable and easier to construct compared to other shapes. The bottom width and side slope ratio are determined based on the required flow capacity and site conditions. The side slope is kept gentle for unlined channels to prevent soil erosion.Hydraulic parameters in channel design include the flow...

You might also read

Related Articles

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

Sort by

Same author

Removal of recalcitrant organic matter content in wastewater by means of AOPs aiming industrial water reuse.

Environmental science and pollution research international·2016

Same author

Treatment of an industrial stream containing vinylcyclohexene by the H2O2/UV process.

Environmental science and pollution research international·2016

Same author

Nitrification of an industrial wastewater in a moving-bed biofilm reactor: effect of salt concentration.

Environmental technology·2011

Same author

Nitrification of industrial and domestic saline wastewaters in moving bed biofilm reactor and sequencing batch reactor.

Journal of hazardous materials·2010

Same author

Monitoring the bacterial community dynamics in a petroleum refinery wastewater membrane bioreactor fed with a high phenolic load.

Journal of microbiology and biotechnology·2010

Same author

Ozonation of azo dyes (Orange II and Acid Red 27) in saline media.

Journal of hazardous materials·2009

Search research articles

Related Experiment Video

Updated: Jul 10, 2026

Updated Protocol for the Assembly and Use of the Minibioreactor Array (MBRA)

Updated Protocol for the Assembly and Use of the Minibioreactor Array (MBRA)

Published on: September 5, 2025

Is hydraulic retention time an essential parameter for MBR performance?

Aline F Viero¹, Geraldo L Sant'anna

¹Chemical Engineering Program, COPPE/Federal University of Rio de Janeiro, P.O. Box 68502, CEP 21941-972, Rio de Janeiro, Brazil.

Journal of Hazardous Materials

|November 6, 2007

Summary

Hydraulic retention time (HRT) in membrane bioreactors (MBR) requires steady-state conditions for accurate results. Non-steady states and sludge adaptation significantly impact MBR performance and data interpretation.

More Related Videos

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

Published on: December 25, 2015

Related Experiment Videos

Last Updated: Jul 10, 2026

Updated Protocol for the Assembly and Use of the Minibioreactor Array (MBRA)

Updated Protocol for the Assembly and Use of the Minibioreactor Array (MBRA)

Published on: September 5, 2025

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

Published on: December 25, 2015

Area of Science:

Environmental Engineering
Biotechnology

Background:

Membrane bioreactors (MBR) are crucial for wastewater treatment.
Hydraulic retention time (HRT) is a key operational parameter in MBRs.

Purpose of the Study:

To discuss the effect of HRT on MBR operation.
To highlight the importance of steady-state conditions for reliable MBR data.

Main Methods:

Literature review on HRT effects in MBRs.
Analysis of factors influencing steady-state achievement.

Main Results:

Non-steady-state conditions can lead to biased conclusions.
Activated sludge adaptation is critical for stable MBR operation.
Wastewater composition affects steady-state and MBR performance.

Conclusions:

Accurate assessment of HRT's impact on MBRs necessitates steady-state operation.
Understanding sludge adaptation and wastewater characteristics is vital for optimizing MBR performance.