title: An Autopsy of Nanofiltration Membrane Used for Landfill Leachate Treatment.
abstract: Komurcuoda leachate treatment plant, Istanbul, which consists of membrane bioreactor (MBR) and nanofiltration (NF) system, faced rapid flux decline in membranes after 3-year successful operation. To compensate rapid flux decline in membranes, the fouled membranes were renewed but replacement of the membranes did not solve the problem. To find the reasons and make a comprehensive analysis, membrane autopsy was performed. Visual and physical inspection of the modules and some instrumental analysis were conducted for membrane autopsy. Membranes were found severely fouled with organic and inorganic foulants. Main foulant was iron which was deposited on surface. The main reason was found to be the changing of aerator type of MBR. When surface aerators were exchanged with bottom diffusers which led to increasing of dissolved oxygen (DO) level of the basin, iron particles were oxidized and they converted into particulate insoluble form. It was thought that probably this insoluble form of the iron particles was the main cause of decreased membrane performance. After the diagnosis, a new pretreatment alternative including a new iron antiscalant was suggested and system performance has been recovered.
authors.affiliation: Environmental Engineering Department, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Demir
authors.affiliation: Environmental Engineering Department, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey ; National Research Center on Membrane Technologies (MEM-TEK), Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
authors.forename: Ismail
authors.initials: I
authors.lastname: Koyuncu
authors.affiliation: Environmental Engineering Department, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey ; National Research Center on Membrane Technologies (MEM-TEK), Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
authors.forename: Serkan
authors.initials: S
authors.lastname: Guclu
authors.affiliation: ISTAC, Istanbul Environmental Management in Industry and Trade Inc., 34379 Istanbul, Turkey.
authors.forename: Senol
authors.initials: S
authors.lastname: Yildiz
authors.affiliation: ISTAC, Istanbul Environmental Management in Industry and Trade Inc., 34379 Istanbul, Turkey.
authors.forename: Vahit
authors.initials: V
authors.lastname: Balahorli
authors.affiliation: ISTAC, Istanbul Environmental Management in Industry and Trade Inc., 34379 Istanbul, Turkey.
authors.forename: Suphi
authors.initials: S
authors.lastname: Caglar
authors.affiliation: Environmental Engineering Department, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey ; National Research Center on Membrane Technologies (MEM-TEK), Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
authors.forename: Turker
authors.initials: T
authors.lastname: Turken
authors.affiliation: Environmental Engineering Department, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey ; National Research Center on Membrane Technologies (MEM-TEK), Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
authors.forename: Mehmet E
authors.initials: ME
authors.lastname: Pasaoglu
authors.affiliation: Environmental Engineering Department, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey ; National Research Center on Membrane Technologies (MEM-TEK), Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
authors.forename: Recep
authors.initials: R
authors.lastname: Kaya
authors.affiliation: National Research Center on Membrane Technologies (MEM-TEK), Istanbul Technical University, Maslak, 34469 Istanbul, Turkey ; Nanoscience and Nanoengineering Department, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey.
authors.forename: Reyhan
authors.initials: R
authors.lastname: Sengur-Tasdemir