Application of fuzzy logic control for Benchmark simulation model.1

Mahmoud Nasr, Medhat Moustafa, Hamdy Seif, Galal El-Kobrosy

Research output: Contribution to journalArticle

14 Citations (Scopus)


Wastewater treatment processes are difficult to control because of their complex and nonlinear bio-chemical reactions. This study compared a fuzzy logic control (FLC) to classical (on/off and Proportional-Integral) methods in order to maintain the effluent quality within specified limits, as well as acceptable aeration energy (AE) consumption. Data were collected from the COST Benchmark simulation model.1 that comprises anoxic/aerobic modules for a combined biological carbon and nitrogen removal. Fuzzy logic toolbox in MATLAB was used to develop the fuzzy logic rule based system. The data of variables were implemented into the fuzzy inference system with Mamdani's method. Results showed that, good performance was achieved under dynamic influent characteristics, especially concerning the nitrogen-related species. In the anoxic section (denitrification process), nitrate was utilized by the heterotrophic organisms, and decreased from 4.8 ± 1.2 to 2.8 ± 0.9 mg L−1. In the subsequent aerobic section, ammonium was oxidized by the autotrophs and dropped from influent value of 30 ± 7 to 5 ± 4 mg L−1 (nitrification process). Degradation of the readily biodegradable substrate (98% removal) was associated with the utilization of nitrate in the anoxic tanks and oxygen in the aerated reactors. Moreover, fuzzy controller was able to handle variations in the system, and showed lower AE consumption, by 18.5 and 8.3%, as compared to uncontrolled and Proportional-Integral controlled systems, respectively. Additionally, FLC was able to self-adapt the aeration supply to handle different influent wastewater characteristics, i.e., rain and storm weather. The results showed that, FLC could be effectively used to control wastewater treatment process with good effluent quality and adequate AE consumption.

Original languageEnglish
Pages (from-to)235-243
Number of pages9
JournalSustainable Environment Research
Issue number4
Publication statusPublished - 2014
Externally publishedYes



  • Activated sludge
  • Benchmark
  • Biological process
  • Fuzzy logic

ASJC Scopus subject areas

  • Environmental Engineering
  • Renewable Energy, Sustainability and the Environment
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

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