Scale-down studies of membrane bioreactor degrading anionic surfactants wastewater: Isolation of new anionic-surfactant degrading bacteria

摘要

Sodium lauryl ether sulfate (SLES) is an anionic surfactant used in the formulation of several detergent products. The high concentration of organic materials and SLES present in the industrial wastewater poses a real problem. In the previous study, Dhouib et al. (Dhouib et al., 2003) showed that Citrobacter braakii has a large capacity to degrade anionic surfactants in the wastewater treatment of a cosmetics industry. The scale-down has made possible to isolate, from the aerobic membrane bioreactor (MBR) inoculated with Citrobacter braakii since after one year, four strains A4, A10, A13 and A14 which were identified as Pseudomonas aeruginosa, Pseudomonas stutzeri, Bacillus safensis and Staphylococcus arlettae, respectively. These isolates are able to degrade 100% of SLES at a concentration of 1000 mg l(-1) in the BSM medium. Physical-chemical parameters have been followed during 104 days in the influent, bioreactor and effluent. Biomass concentration increased slightly in the reactor and reached 13 g VSS l(-1). The COD and surfactants average removals were about 92% and 99.6%, respectively. (C) 2016 Elsevier Ltd. All rights reserved.