title: Operational performance, biomass and microbial community structure: impacts of backwashing on drinking water biofilter.
abstract: Biofiltration has been widely used to reduce organic matter and control the formation of disinfection by-products in drinking water. Backwashing might affect the biofilters' performance and the attached microbiota on filter medium. In this study, the impacts of backwashing on the removal of dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and N-nitrosamine precursors by a pilot-scale biological activated carbon (BAC) filtration system were investigated. The impacts of backwashing on biomass and microbial community structure of BAC biofilm were also investigated. Phospholipid fatty acid (PLFA) analysis showed that backwashing reduced nearly half of the attached biomass on granular activated carbon (GAC) particles, followed by a recovery to the pre-backwashing biomass concentration in 2 days after backwashing. Backwashing was found to transitionally improve the removal of DOC, DON and N-nitrosamine precursors. MiSeq sequencing analysis revealed that backwashing had a strong impact on the bacterial diversity and community structure of BAC biofilm, but they could gradually recover with the operating time after backwashing. Phylum Proteobacteria was the largest bacterial group in BAC biofilm. Microorganisms from genera Bradyrhizobium, Hyphomicrobium, Microcystis and Sphingobium might contribute to the effective removal of nitrogenous organic compounds by drinking water biofilter. This work could add some new insights towards the operation of drinking water biofilters and the biological removal of organic matter.
authors.affiliation: School of Environment, Tsinghua University, Beijing, 100084, China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Liao
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.forename: Jingxu
authors.initials: J
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Dai
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Zhang
authors.forename: Shuguang
authors.initials: S
authors.lastname: Xie
mesh_terms: D018441:Biofilms; D018533:Biomass; D002606:Charcoal; D060766:Drinking Water; D005374:Filtration; D059013:Microbial Consortia; D009584:Nitrogen / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis; D010865:Pilot Projects; D017421:Sequence Analysis; D018508:Water Purification
chemical_list: D060766:Drinking Water; D009930:Organic Chemicals; D002606:Charcoal; D009584:Nitrogen
references.citation: J Environ Biol. 2013 Apr;34(2 Spec No):321-4
references.pmid: 24620600
references.citation: Environ Technol. 2003 Mar;24(3):277-87
references.pmid: 12703853
references.citation: Water Res. 2009 Dec;43(20):5075-86
references.pmid: 19783028
references.citation: Water Res. 2011 Nov 1;45(17):5695-704
references.pmid: 21903236
references.citation: Water Res. 2008 Jun;42(12):2839-48
references.pmid: 18405938
references.citation: Appl Environ Microbiol. 2007 Aug;73(16):5261-7
references.pmid: 17586664
references.citation: J Appl Microbiol. 2009 Nov;107(5):1457-67
references.pmid: 19457026
references.citation: Water Sci Technol. 2007;55(8-9):173-80
references.pmid: 17546984
references.citation: J Environ Monit. 2010 Jun;12(6):1302-6
references.pmid: 20532383
references.citation: Biodegradation. 2010 Jul;21(4):513-23
references.pmid: 19960233
references.citation: Water Res. 2007 May;41(9):1949-59
references.pmid: 17368504
references.citation: Water Res. 2013 Feb 1;47(2):535-46
references.pmid: 23164216
references.citation: Water Res. 2011 Dec 1;45(19):6355-61
references.pmid: 21982679
references.citation: Water Res. 2013 Mar 1;47(3):1101-10
references.pmid: 23245544
references.citation: J Hazard Mater. 2003 Jan 31;96(2-3):291-303
references.pmid: 12493214
references.citation: Appl Environ Microbiol. 2009 Dec;75(23):7537-41
references.pmid: 19801464
references.citation: J Environ Sci Health B. 2013;48(2):101-7
references.pmid: 23305277
references.citation: Appl Microbiol Biotechnol. 2012 Jun;94(6):1647-56
references.pmid: 22105542
references.citation: Appl Microbiol Biotechnol. 2011 Jul;91(2):425-34
references.pmid: 21538111
references.citation: J Microbiol Biotechnol. 2013 Dec;23(12):1774-8
references.pmid: 24002451
references.citation: ISME J. 2012 Aug;6(8):1621-4
references.pmid: 22402401
references.citation: J Bacteriol. 2011 Jun;193(12):3057-63
references.pmid: 21498645
references.citation: Water Res. 2001 Feb;35(2):397-404
references.pmid: 11228991
references.citation: Sci Total Environ. 2012 Jan 1;414:508-14
references.pmid: 22169394
references.citation: Water Res. 2001 Jan;35(1):211-23
references.pmid: 11257875