An OUR-based approach to determine the toxic effects of 2,4-dichlorophenoxyacetic acid in activated sludge

Süreyya Meriç*, Gülen Eremektar, Fehiman Çiner, Olcay Tünay

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)


This study uses the oxygen uptake rate (OUR) measurement to measure toxicity effects of 2,4-dichlorophenoxyacetic acid (2,4-D) on activated sludges fed with the wastewater from a small domestic wastewater treatment plant and peptone-based synthetic wastewater. Two 2l lab-scale batch reactors were run in parallel with the same F/M ratios (0.4mg COD per mg VSS per day) to assess the inhibition effects of 2,4-D concentrations between 25 and 75mgl-1 considering at least a 100% dilution rate, as compared with a pesticide industry effluent containing 20,000-40,000mgl-1 COD, reaches a central treatment plant. It was noted that the OUR was decreased to 15 and 30%, respectively, when adding 75mgl-1 of 2,4-D to the domestic and synthetic reactors,. Meanwhile, the addition of 25 plus 50mgl-1 of 2,4-D in sequence to the domestic wastewater reactor did not significantly affect the OUR profile. The OUR-based inhibition definition has been used in this research since the OUR methods have been frequently used and cited in the literature to study toxicity effects. However, the origin of the sludge used in the testing is also important. Synthetic wastewater may simulate the toxicity studies but with a higher response than actual systems, since the microorganisms are considerably becoming substrate-selective.

Original languageEnglish
Pages (from-to)147-155
Number of pages9
JournalJournal of Hazardous Materials
Issue number2
Publication statusPublished - 18 Jul 2003


This work was supported by a grant from the ITU Research and Development Center (Grant No: 1649).

FundersFunder number
ITU Research and Development Center1649


    • 2,4-D
    • Activated sludge
    • OUR
    • Synthetic wastewater
    • Toxicity


    Dive into the research topics of 'An OUR-based approach to determine the toxic effects of 2,4-dichlorophenoxyacetic acid in activated sludge'. Together they form a unique fingerprint.

    Cite this