On time discretizations for the simulation of the batch settling-compression process in one dimension

Area of Science:

• Environmental Engineering
• Chemical Engineering
• Fluid Dynamics

Background:

• Secondary settling tanks are crucial in wastewater treatment.
• Existing Bürger-Diehl models face computational challenges with hindered settling, compression, and dispersion.
• Efficient simulation methods are needed to reduce long computational times.

Purpose of the Study:

• To investigate time-integration methods for more efficient simulations of secondary settling tanks.
• To compare a new time-discretization method with existing tailored and standard methods.
• To evaluate implementation complexity and robustness alongside efficiency.

Main Methods:

• Development and testing of a new linearly implicit time-discretization method.
• Comparison of the new method with semi-implicit and standard methods using batch settling simulations.
• Analysis of computational time, implementation complexity, and robustness.

Main Results:

• The new linearly implicit method offers easier implementation compared to semi-implicit methods.
• The new method is less computationally efficient than other tested methods in batch sedimentation tests.
• Both advantages and disadvantages were identified for each evaluated time-integration method.

Conclusions:

• The developed linearly implicit method presents a trade-off between implementation ease and computational efficiency.
• Further research into time-integration techniques is necessary for optimizing secondary settling tank simulations.
• The study provides valuable insights for selecting appropriate numerical methods in wastewater treatment modeling.