title: Effect of pH on elemental sulfur conversion and microbial communities by autotrophic simultaneous desulfurization and denitrification.
abstract: pH has an important influence on the elemental sulfur accumulated in an autotrophic simultaneous desulfurization and denitrification process. The influent nitrate to sulfide (N/S) mole ratio was set to 0.5, 0.67, 1.0, 1.33 and 2.0 with a 200 mg/L sulfide concentration. The effect of pH on elemental sulfur conversion and microbial communities was studied. Sulfide removal was achieved to the extent of 98% under near-neutral and weak base conditions after 24 h of reaction. The conversion rate of elemental sulfur was 29.41% under the near-neutral condition. The weak base condition led to greater formation of sulfate, and the nitrate used by the microorganisms was transformed mainly to N2 with a removal rate of 96%. Increasing the retention time from 24 to 48 h caused the removal rate of nitrate increased from 63.58% to 90% under the near-neutral condition. Sulfurovum sp. was the functioning bacterial species, and bands 1 and 2 represent different species of Sulfurovum sp. in the system according to the PCR-DGGE analysis of the microbial community structure. The functional bacteria represented by band 1 produced mainly sulfate, but the functional bacteria represented by band 2 produced mainly elemental sulfur.
authors.affiliation: a School of Environmental and Municipal Engineering , Xi'an University of Architecture & Technology , Xi'an , People's Republic of China.
authors.forename: Jinlan
authors.initials: J
authors.lastname: Xu
authors.affiliation: a School of Environmental and Municipal Engineering , Xi'an University of Architecture & Technology , Xi'an , People's Republic of China.
authors.forename: Yimin
authors.initials: Y
authors.lastname: Fan
authors.affiliation: a School of Environmental and Municipal Engineering , Xi'an University of Architecture & Technology , Xi'an , People's Republic of China.
authors.forename: Zhixu
authors.initials: Z
authors.lastname: Li
mesh_terms: D019149:Bioreactors / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D058440:Denitrification; D020565:Epsilonproteobacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D012722:Sewage; D013440:Sulfides / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D009566:Nitrates; D012722:Sewage; D013440:Sulfides; D014874:Water Pollutants, Chemical; D013455:Sulfur; D009584:Nitrogen
keywords: Autotrophic simultaneous desulfurization and denitrification process; N/S mole ratio; elemental sulfur; microbial community; pH