title: Effects of salinity on performance and microbial community structure of an anoxic-aerobic sequencing batch reactor.
abstract: The effects of salinity on the performance and microbial community structure of activated sludge were investigated in an anoxic-aerobic sequencing batch reactor (SBR). The removal efficiencies of chemical oxygen demand (COD) and [Formula: see text]-N decreased as the influent salinity increased from 0.5% to 6%. The specific oxygen utilization rate of activated sludge increased from 22.47 to 43.16 mg O2 g(-1) mixed liquid suspended solids (MLSS) h(-1) with the increase in salinity from 0.5% to 4% and subsequently decreased to 18.3 mg O2 g(-1) MLSS h(-1) at 6% salinity. The specific ammonium oxidation rate (SAOR) and specific nitrite oxidation rate (SNOR) decreased slowly at 0.5-1% salinity and then decreased rapidly with the increase in salinity from 1% to 6%. The SNOR diminished at a faster rate than the SAOR with the increase in salinity from 0.5% to 6%. The specific nitrate reduction rate (SNRR) decreased with the increase in salinity, whereas the SNRR was higher than the sum of SAOR and SNOR at 0.5-6% salinity. The denaturing gradient gel electrophoresis profiles revealed obvious changes in microbial community structure at different salinities. Some microbes were capable of tolerating up to 6% salinity in the SBR, such as Planomonospora sphaerica, Nitrosomonas sp. Is32, and Denitromonas sp. D2-1.
authors: a Key Lab of Marine Environment and Ecology, Ministry of Education , Ocean University of China , Qingdao 266100 , People's Republic of China.
authors: Zichao
authors: Z
authors: Wang
authors: Mengchun
authors: M
authors: Gao
authors: Sen
authors: S
authors: Wang
authors: Qingbo
authors: Q
authors: Chang
authors: Zhe
authors: Z
authors: Wang
mesh_terms: D001420:Bacteria, Aerobic / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D049109:Cell Proliferation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D059013:Microbial Consortia / Q000502:physiology*; D056265:Microbial Interactions / Q000502:physiology; D010100:Oxygen / Q000378:metabolism; D012965:Sodium Chloride / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D012965:Sodium Chloride; D010100:Oxygen
keywords: SBR; microbial community; salinity; specific ammonium oxidation rate (SAOR); specific oxygen utilization rate (SOUR)