Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6585965 | Chemical Engineering Journal | 2015 | 9 Pages |
Abstract
Simultaneous nitrification and denitrification (SND) was evidently observed in a full-scale multi-channel oxidation ditch (OD), especially occurring within the outer channel under microaerophilic conditions. The optimum average dissolved oxygen (DO) concentration for SND was 0.25 mg Lâ1 with 79% SND efficiency and 5.09 mg Lâ1 hâ1 SND rate, leading to 74.9% overall TN removal efficiency. Small sized flocs consisting of more nitrifying bacteria enhanced nitrification in favor of SND due to less oxygen diffusion limitation inside flocs than larger flocs under micro-aerated conditions. SND was also identified by co-existing of nitrifying and denitrifying bacteria as well as some microaerophilic microorganisms based on molecular biology analysis. Nitrogen mass balances (NMB) quantitatively demonstrated that the highest SND efficiency accounted for 44.1% of influent nitrogen mass. Above valuable findings might deeply reveal SND as a principal mechanism of nitrogen removal in a multi-channel OD from macro- to micro-scale.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Xin Zhou, Yunping Han, Xuesong Guo,