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Related Experiment Video

Updated: Jul 14, 2025

Microfluidic Platform with Multiplexed Electronic Detection for Spatial Tracking of Particles

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Published on: March 13, 2017

A COD measurement method with turbidity compensation based on a variable radial basis function neural network.

Renhao Fan^1,2,3, Senlin Wang^1,4,3, Hao Chen^1,4,3

¹Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fujian, 350005, China. senlin16888@fjirsm.ac.cn.

Analytical Methods : Advancing Methods and Applications

|October 6, 2023

Summary

This study introduces a novel method for measuring chemical oxygen demand (COD) in wastewater using ultraviolet-visible (UV-vis) spectroscopy. The technique effectively compensates for turbidity, improving accuracy and speed in COD analysis.

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Area of Science:

Environmental Science
Analytical Chemistry
Spectroscopy

Background:

Ultraviolet-visible (UV-vis) spectrometry is commonly used for measuring chemical oxygen demand (COD) in sewage.
Existing UV-vis methods struggle to eliminate turbidity's influence, affecting measurement accuracy.

Purpose of the Study:

To develop a new, accurate, and efficient method for measuring sewage COD using UV-vis spectroscopy.
To address the challenge of turbidity interference in spectroscopic COD analysis.

Main Methods:

A novel turbidity compensation algorithm utilizing principal component analysis (PCA) to identify characteristic wavelengths.
Development of a turbidity compensation model to remove spectral interference from turbidity.
Application of a variable radial basis function (VRBF) neural network for COD concentration measurement.

Main Results:

The proposed method significantly improved the coefficient of determination (R²) from 0.27 to 0.88 compared to traditional partial least squares regression.
Root-mean-square deviation decreased from 5.56 to 1.69, indicating enhanced accuracy.
The VRBF neural network approach demonstrated faster, more direct, and accurate COD measurements than improved bagging and MLP algorithms.

Conclusions:

The new UV-vis spectroscopy method with turbidity compensation and VRBF neural network provides a superior approach for sewage COD measurement.
This method overcomes the limitations of existing techniques by effectively handling turbidity.
The findings suggest a promising advancement for real-time and reliable water quality monitoring.