Activated Sludge Aeration Forecasting for Stable Dissolved Oxygen

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Solution Overview

Problem

Existing methods for adjusting aeration quantity in activated sludge systems to maintain stable dissolved oxygen concentration are lagging, leading to energy waste and unstable system operation due to manual adjustments based on experience, and existing control prediction models fail to address immediate DO concentration fluctuations.

Innovation Solution

A method involving data measurement, lag compensation, and a random forest model is employed to predict aeration airflow rate, using historical data to adjust airflow rates in advance to maintain stable DO concentration, incorporating influent flow rate, organic matter, ammonia nitrogen, and sludge concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual adjustment of aeration quantity based on experience is used, then operation simplicity is maintained, but DO concentration stability deteriorates and energy consumption increases

Engineering Contradiction:
Improveaeration adjustment simplicityVSAvoidDO concentration stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces manual experience-based adjustment with an automated control system that uses sensors to detect DO concentration and a controller to automatically adjust aeration quantity, eliminating the need for manual intervention while improving DO concentration stability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a closed-loop feedback control system where DO concentration is continuously monitored and the measured value is fed back to the controller, which then adjusts the aeration quantity accordingly to maintain stable DO levels

Inventive Principle:
Principle #23Feedback

2Reliability

If real-time aeration adjustment is implemented, then DO concentration stability improves, but response time lag worsens

Engineering Contradiction:
ImproveDO concentration stabilityVSAvoidDO concentration response time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent uses historical data and machine learning models to predict future DO concentration trends and adjusts aeration quantity in advance before DO concentration actually deviates from the target range, compensating for the inherent time lag in the system

Inventive Principle:
Principle #10Preliminary action

3Reliability

If excessive aeration is applied to ensure DO concentration, then DO concentration stability improves, but energy consumption increases

Engineering Contradiction:
ImproveDO concentration stabilityVSAvoidaeration energy consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies precise partial aeration by using machine learning predictions to determine the exact aeration quantity needed, avoiding excessive aeration while ensuring DO concentration remains stable through optimized control strategies

Inventive Principle:
Principle #16Partial or excessive action

4Reliability

If automated control systems are introduced, then DO concentration stability improves, but system complexity increases

Engineering Contradiction:
ImproveDO concentration stabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions including DO detection, data storage, historical data analysis, prediction modeling, and control execution into a unified automated control system, managing complexity through functional integration

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS12421144B1Method for predicting aeration quantity required to maintain stable dissolved oxygen concentration in activated sludge system
Publication Date: 2025.09.23 NANJING UNIV
  • US12421144B1 patent drawing
  • US12421144B1 patent drawing

AI summary

Disclosed is a method for predicting aeration quantity required to maintain a stable dissolved oxygen concentration in an activated sludge system, including measuring operating parameters of a biochemical tank of a wastewater treatment plant at intervals of a t1 time period over a certain period of time; replacing the DO concentration data with DO concentration data after a t2 time period from the time of measurement; filtering the DO concentration data after being replaced to form a dataset; building a random forest model, and building a machine learning matrix using data in the dataset to train the random forest model; evaluating prediction performance of the trained random forest model; and using the trained random forest model to predict an aeration airflow rate required to achieve the target DO concentration value after the t2 time period, thereby adjusting an aeration airflow rate.