Related Experiment Video
Updated: May 8, 2026
09:49
Visualizing Hyporheic Flow Through Bedforms Using Dye Experiments and Simulation
Published on: November 18, 2015
pH dynamics in sewers and its modeling.
Keshab Sharma1, Ramon Ganigue, Zhiguo Yuan
1Advanced Water Management Centre, Building 60, Research Road, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
Water Research
|August 22, 2013
Summary
Accurate prediction of sewer pH is crucial for managing hydrogen sulfide emissions. This study reveals that nitrogen content significantly influences pH, and a charge balance model using ammonium concentration effectively predicts sewer pH variations.
Area of Science:
- Environmental Engineering
- Wastewater Treatment
- Water Chemistry
Background:
- Sewer pH fluctuations impact hydrogen sulfide (H2S) production and emissions.
- Accurate pH prediction is vital for optimizing H2S mitigation strategies in sewer systems.
Purpose of the Study:
- To investigate the nature and dynamics of pH variation in sewer systems.
- To develop and validate a predictive methodology for sewer pH based on wastewater characteristics.
Main Methods:
- Monitoring of pH in three domestic wastewater sewer systems.
- Analysis of diurnal pH variations and correlation with sewage flow rate.
- Development of a charge balance-based pH prediction model calibrated with total ammonium concentration.
Main Results:
- Significant diurnal pH variations were observed in all monitored sewer systems.
- Fresh sewage pH trends correlated with sewage flow rate, indicating influence of household water use.
- Total ammonium concentration was the most influential factor for pH variation in fresh sewage and adequately calibrated the predictive model.
Conclusions:
- Sewer pH dynamics are strongly influenced by nitrogen content, particularly ammonium.
- A charge balance-based methodology, calibrated with total ammonium concentration, provides an effective means for predicting sewer pH variations.
- This predictive capability is essential for optimizing H2S emission control strategies.
Related Concept Videos
01:21Design 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.
01:30Typical 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.
01:12Modeling and Similitude
Scaled modeling is a fundamental technique in engineering, enabling the study of large and complex systems by creating smaller, manageable replicas that recreate critical characteristics of the original. In hydrology and civil infrastructure, for example, scaled models of dams help analyze water flow, turbulence, and pressure. This method allows for accurate predictions of real-world behavior within a controlled environment, significantly reducing the cost and time involved in full-scale...
01:25Modeling with Differential Equations
Population dynamics can be described mathematically by considering the population size P(t) as a function of time. The rate of change of the population is then represented by the derivative of P(t). A simple assumption is that the rate of growth is proportional to the size of the population itself. This leads to an exponential growth model, where the population increases rapidly without bound. While this is a useful first approximation, it does not reflect realistic long-term...
01:25Design Example: Designing a Residential Plumbing System
The design of residential plumbing systems requires carefully evaluating water demand, flow rates, and pressure dynamics to ensure both efficiency and reliability. The nature of water flow within pipes is defined by its Reynolds number, which classifies flow as either laminar (smooth) or turbulent.
01:24Rapidly Varying Flow
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...