title: Microbial communities and their performances in anaerobic hybrid sludge bed-fixed film reactor for treatment of palm oil mill effluent under various organic pollutant concentrations.
abstract: The anaerobic hybrid reactor consisting of sludge and packed zones was operated with organic pollutant loading rates from 6.2 to 8.2 g COD/L day, composed mainly of suspended solids (SS) and oil and grease (O&G) concentrations between 5.2 to 10.2 and 0.9 to 1.9 g/L, respectively. The overall process performance in terms of chemical oxygen demands (COD), SS, and O&G removals was 73, 63, and 56%, respectively. When the organic pollutant concentrations were increased, the resultant methane potentials were higher, and the methane yield increased to 0.30 L CH₄/g COD(removed). It was observed these effects on the microbial population and activity in the sludge and packed zones. The eubacterial population and activity in the sludge zone increased to 6.4 × 10⁹ copies rDNA/g VSS and 1.65 g COD/g VSS day, respectively, whereas those in the packed zone were lower. The predominant hydrolytic and fermentative bacteria were Pseudomonas, Clostridium, and Bacteroidetes. In addition, the archaeal population and activity in the packed zone were increased from to 9.1 × 10⁷ copies rDNA/g VSS and 0.34 g COD-CH₄/g VSS day, respectively, whereas those in the sludge zone were not much changed. The most represented species of methanogens were the acetoclastic Methanosaeta, the hydrogenotrophic Methanobacterium sp., and the hydrogenotrophic Methanomicrobiaceae.
authors.affiliation: The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
authors.forename: Kanlayanee
authors.initials: K
authors.lastname: Meesap
authors.forename: Nimaradee
authors.initials: N
authors.lastname: Boonapatcharoen
authors.forename: Somkiet
authors.initials: S
authors.lastname: Techkarnjanaruk
authors.forename: Pawinee
authors.initials: P
authors.lastname: Chaiprasert
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000235:genetics; D001419:Bacteria / Q000235:genetics; D001483:Base Sequence; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D058645:Denaturing Gradient Gel Electrophoresis; D008697:Methane / Q000032:analysis; D059013:Microbial Consortia / Q000235:genetics; D000073878:Palm Oil; D010938:Plant Oils / Q000737:chemistry*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D010938:Plant Oils; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D014874:Water Pollutants, Chemical; D000073878:Palm Oil; D008697:Methane