title: Impact of aluminum chloride on process performance and microbial community structure of granular sludge in an upflow anaerobic sludge blanket reactor for natural rubber processing wastewater treatment.
abstract: In this study, granular sludge formation was carried out using an aluminum chloride supplement in an upflow anaerobic sludge blanket (UASB) reactor treating natural rubber processing wastewater. Results show that during the first 75 days after the start-up of the UASB reactor with an organic loading rate (OLR) of 2.65 kg-COD·m(-3)·day(-1), it performed stably with a removal of 90% of the total chemical oxygen demand (COD) and sludge still remained in small dispersed flocs. However, after aluminum chloride was added at a concentration of 300 mg·L(-1) and the OLR range was increased up to 5.32 kg-COD·m(-3)·day(-1), the total COD removal efficiency rose to 96.5 ± 2.6%, with a methane recovery rate of 84.9 ± 13.4%, and the flocs began to form granules. Massively parallel 16S rRNA gene sequencing of the sludge retained in the UASB reactor showed that total sequence reads of Methanosaeta sp. and Methanosarcina sp., reported to be the key organisms for granulation, increased after 311 days of operation. This indicates that the microbial community structure of the retained sludge in the UASB reactor at the end of the experiment gave a good account of itself in not only COD removal, but also granule formation.
authors.affiliation: School of Biotechnology and Food Technology, Hanoi University of Science and Technology, No.1, Dai Co Viet, Hai Ba Trung District, Hanoi, Vietnam E-mail: huong.ibft@gmail.com; huong.nguyenlan@hust.edu.vn.
authors.forename: Nguyen Thi
authors.initials: NT
authors.lastname: Thanh
authors.affiliation: Department of Civil and Environmental Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Watari
authors.affiliation: School of Biotechnology and Food Technology, Hanoi University of Science and Technology, No.1, Dai Co Viet, Hai Ba Trung District, Hanoi, Vietnam E-mail: huong.ibft@gmail.com; huong.nguyenlan@hust.edu.vn.
authors.forename: Tran Phuong
authors.initials: TP
authors.lastname: Thao
authors.affiliation: Department of Civil and Environmental Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Hatamoto
authors.affiliation: Department of Civil and Environmental Engineering, National Institute of Technology, Kure College, 1-2-11 Agaminami, Kure, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tanikawa
authors.affiliation: Center for Regional Environmental Research, National Institute for Environmental Studies, 6-2 Onogawa, Tsukuba, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Syutsubo
authors.affiliation: Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Fukuda
authors.affiliation: School of Chemical Engineering, Hanoi University of Science and Technology, No.1, Dai Co Viet, Hai Ba Trung District, Hanoi, Vietnam.
authors.forename: Nguyen Minh
authors.initials: NM
authors.lastname: Tan
authors.affiliation: School of Biotechnology and Food Technology, Hanoi University of Science and Technology, No.1, Dai Co Viet, Hai Ba Trung District, Hanoi, Vietnam E-mail: huong.ibft@gmail.com; huong.nguyenlan@hust.edu.vn.
authors.forename: To Kim
authors.initials: TK
authors.lastname: Anh
authors.affiliation: Department of Civil and Environmental Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: School of Biotechnology and Food Technology, Hanoi University of Science and Technology, No.1, Dai Co Viet, Hai Ba Trung District, Hanoi, Vietnam E-mail: huong.ibft@gmail.com; huong.nguyenlan@hust.edu.vn.
authors.forename: Nguyen Lan
authors.initials: NL
authors.lastname: Huong
mesh_terms: D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000032:analysis*; D000693:Anaerobiosis; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors; D002712:Chlorides / Q000032:analysis*; D007220:Industrial Waste / Q000032:analysis*; D064307:Microbiota / Q000187:drug effects; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism; D012408:Rubber; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D014877:Water Pollution, Chemical / Q000032:analysis*
chemical_list: D017607:Aluminum Compounds; D002712:Chlorides; D007220:Industrial Waste; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D000077410:Aluminum Chloride; D012408:Rubber