title: Xenobiotic substrate reduces yield of activated sludge in a continuous flow system.
abstract: The biomass yield of a continuous flow activated sludge system varied when the system treated influent containing different compositions of biogenic and xenobiotic substrates. Both the biogenic substrate and a test xenobiotic 2,4-dichlorophenoxyacetic acid (2,4-D) were degraded at steady-state activated sludge operations. The true yields, determined from steady-state activated sludge treatment performances, were at the maximum and the minimum when the activated sludge treated the influent of sole biogenic substrate and sole 2,4-D, respectively. The minimum yield was 56% of the maximum. Yield reduction between the maximum and the minimum was proportional to the concentration of 2,4-D in the influent. This trend of yield reduction suited a model that describes the metabolic uncoupling effect of 2,4-D on the sludge's degradation of the substrates. The model function variable was defined as the ratio of 2,4-D to biogenic COD concentrations in the influent.
authors.affiliation: Department of Environmental Engineering, DaYeh University, No. 168, University Rd., Dacun, Changhua 51591, Taiwan, ROC. chong@mail.dyu.edu.tw
authors.forename: Nyuk-Min
authors.initials: NM
authors.lastname: Chong
authors.forename: Chih-Hsiang
authors.initials: CH
authors.lastname: Wang
authors.forename: Chun-Hsien
authors.initials: CH
authors.lastname: Ho
authors.forename: Ching-Shyung
authors.initials: CS
authors.lastname: Hwu
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D006540:Herbicides / Q000378:metabolism*; D008954:Models, Biological; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods*; D015262:Xenobiotics / Q000378:metabolism*
chemical_list: D006540:Herbicides; D012722:Sewage; D015262:Xenobiotics; D015084:2,4-Dichlorophenoxyacetic Acid