title: Activated sludge treatment of a xenobiotic with or without a biogenic substrate during start-up and shocks.
abstract: Lab-scale continuous flow activated sludge systems that were acclimated to 2,4-dichlorphenoxyacetic acid (2,4-D) under sole 2,4-D influent and without sludge wastage, were able to maintain successful 2,4-D treatment when both 2,4-D and a biogenic substrate were fed and the systems operated with finite mean cell residence times (theta(c)). When the systems were fed dual 2,4-D and biogenic substrates and operated with finite theta(c) from the start, treatment of 2,4-D fluctuated noticeably long after acclimation. At the reintroduction of 2,4-D after its absence from the influent for a period of time (2,4-D shock), the systems under both the sole and dual substrate conditions suffered similar treatment losses; the extent of treatment losses was related to the length of 2,4-D absence time. When shocked, systems with sole 2,4-D influent had a slight advantage over dual substrates by showing a faster recovery from shocks with the help of re-acclimation.
authors.affiliation: Department of Environmental Engineering, DaYeh University, 112 Shan-Jiau Rd., Da-Tsuen, Changhua 515, Taiwan. chong@mail.dyu.edu.tw
authors.forename: Nyuk-Min
authors.initials: NM
authors.lastname: Chong
authors.forename: Yi-Shin
authors.initials: YS
authors.lastname: Chen
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000737:chemistry / Q000378:metabolism; D000064:Acclimatization; D001419:Bacteria / Q000378:metabolism; D019149:Bioreactors; D012722:Sewage / Q000737:chemistry*; D015262:Xenobiotics / Q000737:chemistry*
chemical_list: D012722:Sewage; D015262:Xenobiotics; D015084:2,4-Dichlorophenoxyacetic Acid