title: Autotrophic denitrification for nitrate and nitrite removal using sulfur-limestone.
abstract: Sulfur-limestone was used in the autotrophic denitrification process to remove the nitrate and nitrite in a lab scale upflow biofilter. Synthetic water with four levels of nitrate and nitrite concentrations of 10, 40, 70 and 100 mg N/L was tested. When treating the low concentration of nitrate- or nitrite-contaminated water (10, 40 mg N/L), a high removal rate of about 90% was achieved at the hydraulic retention time (HRT) of 3 hr and temperature of 20-25 degrees C. At the same HRT, 50% of the nitrate or nitrite could be removed even at the low temperature of 5-10 degrees C. For the higher concentration nitrate and nitrite (70, 100 mg N/L), longer HRT was required. The batch test indicated that influent concentration, HRT and temperature are important factors affecting the denitrification efficiency. Molecular analysis implied that nitrate and nitrite were denitrified into nitrogen by the same microorganisms. The sequential two-step-reactions from nitrate to nitrite and from nitrite to the next-step product might have taken place in the same cell during the autotrophic denitrification process.
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiaotong University, No. 800, Dongchuan Road, Minhang District, Shanghai 200240, China. weilizhou@sjtu.edu.cn
authors.forename: Weili
authors.initials: W
authors.lastname: Zhou
authors.forename: Yejue
authors.initials: Y
authors.lastname: Sun
authors.forename: Bingtao
authors.initials: B
authors.lastname: Wu
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Huang
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Miyanaga
authors.forename: Zhenjia
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D052818:Autotrophic Processes; D002119:Calcium Carbonate; D058645:Denaturing Gradient Gel Electrophoresis; D058440:Denitrification; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000302:isolation & purification*; D009573:Nitrites / Q000302:isolation & purification*; D012150:Polymorphism, Restriction Fragment Length; D013455:Sulfur; D013696:Temperature; D013997:Time Factors; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification
chemical_list: D009566:Nitrates; D009573:Nitrites; D014874:Water Pollutants, Chemical; D013455:Sulfur; D002119:Calcium Carbonate