title: Phosphorus removal performance and population structure of phosphorus-accumulating organisms in HA-A/A-MCO sludge reduction process.
abstract: We developed a new sludge reduction HA-A/A-MCO (Hydrolysis-Acidogenosis-Anaerobic/Anoxic -Multistep Continuous Oxic tank) process, which has improved phosphate (P) and nitrogen (N) removal. Its biological treatment unit uses an A2/O P & N removal process with hydrolysis acidification, multistep continuous aeration, and continuous flow, coupled with sidestream P removal by draining out anaerobic P-bearing wastewater. The process has advanced synchronization of P and N removal and sludge reduction. The improved performance is closely associated with the population structure of P-accumulating organisms (PAOs). This study investigated the relationship between P removal performance and the population structure of PAOs. The results show that the average effluent P content of HA-A/A-MCO process was only 0.44 mg/L, when the influent P concentration was 8∼12 mg/L. The effluent met the A standard set by GB18918-2002. PAOs were able to effectively release 1 mg of P and absorb 2.8 mg of P. The system removed P by draining out anaerobic P-rich wastewater, as P had been reduced in the aerobic absorption process. This reduced the need for excess P uptake ability of the PAOs. The bacterial pure culture method was applied to isolate 5 PAOs with typical P absorption and removel features. 16SrDNA amplification and sequence analysis revealed that Acinetobacter sp. and Lampropedia sp played dominant roles in anaerobic P-releasing process. Moreover, Devosia sp. and Bdellovibrio sp were the primary strains in the aerobic tank, and, they were the major stains for P absorption. Uncultured Bacterium and other uncultured strains were detected in the anoxic tank.
authors.affiliation: a Southwest Research Institution for Water Transport Engineering, Chongqing Jiaotong University , Chongqing , China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zuo
authors.affiliation: a Southwest Research Institution for Water Transport Engineering, Chongqing Jiaotong University , Chongqing , China.
authors.forename: Jinchao
authors.initials: J
authors.lastname: He
authors.affiliation: a Southwest Research Institution for Water Transport Engineering, Chongqing Jiaotong University , Chongqing , China.
authors.forename: Xiqin
authors.initials: X
authors.lastname: Ma
authors.affiliation: a Southwest Research Institution for Water Transport Engineering, Chongqing Jiaotong University , Chongqing , China.
authors.forename: Yongqin
authors.initials: Y
authors.lastname: Peng
authors.affiliation: a Southwest Research Institution for Water Transport Engineering, Chongqing Jiaotong University , Chongqing , China.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
mesh_terms: D000150:Acinetobacter / Q000378:metabolism; D000332:Aerobiosis; D000693:Anaerobiosis; D001419:Bacteria / Q000302:isolation & purification / Q000378:metabolism*; D001501:Bdellovibrio / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D004867:Equipment Design; D009584:Nitrogen / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus / Q000302:isolation & purification*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000737:chemistry*
chemical_list: D004269:DNA, Bacterial; D010710:Phosphates; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D010758:Phosphorus; D009584:Nitrogen
keywords: anaerobic phosphorus release; nitrogen and phosphorus removal; phosphorus-accumulating organisms; population structure; sludge reduction