title: The heterotrophic-combined-with-autotrophic denitrification process: performance and interaction mechanisms.
abstract: In this work, the interaction mechanisms between an autotrophic denitrification (AD) and heterotrophic denitrification (HD) process in a heterotrophic-autotrophic denitrification (HAD) system were investigated, and the performance of the HAD system under different S/Ac(-) molar ratios was also evaluated. The results demonstrated that the heterotrophic-combined-with-autotrophic denitrification process is a promising technology which can remove chemical oxygen demand (COD), sulfide and nitrate simultaneously. The reduction rate of NO(3)(-) to NO(2)(-) by the HD process was much faster than that of reducing NO(2)(-) to N₂, while the reduction rate of NO(3)(-) to NO(2)(-) by the AD process was slower than that of NO(2)(-) to N₂. Therefore, the AD process could use the surplus NO(2)(-) produced by the HD process. This could alleviate the NO(2)(-)-N accumulation and increase the denitrification rate. In addition, the inhibition effects of acetate on AD bacteria and sulfide on HD were observed, and the inhibition was compensated by the promotion effects on NO(2)(-). Therefore, the processes of AD and HD seem to react in parallel, without disturbing each other, in our HAD system.
authors.affiliation: Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China E-mail: shchen@iue.ac.cn.
authors.forename: Guihua
authors.initials: G
authors.lastname: Xu
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China E-mail: shchen@iue.ac.cn.
authors.forename: Cuijie
authors.initials: C
authors.lastname: Feng
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China E-mail: shchen@iue.ac.cn.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China E-mail: shchen@iue.ac.cn.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Chen
authors.affiliation: Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
authors.forename: Yuanjian
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
authors.forename: Xingzu
authors.initials: X
authors.lastname: Wang
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000378:metabolism; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D052836:Heterotrophic Processes; D009566:Nitrates; D013440:Sulfides; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D009566:Nitrates; D013440:Sulfides