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Microbial pathways of nitrogen removal in aerobic granular sludge treating domestic wastewater
Author(s) -
Guimarães Lorena B,
Mezzari Melissa P,
Daudt Gilberto C,
da Costa Rejane HR
Publication year - 2017
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.5176
Subject(s) - nitrification , wastewater , denitrification , nitrite , sequencing batch reactor , effluent , environmental chemistry , chemistry , pulp and paper industry , sewage treatment , ammonium , nitrogen , environmental engineering , nitrate , environmental science , organic chemistry , engineering
Abstract BACKGROUND Aerobic granular sludge ( AGS ) technology has been widely investigated for wastewater treatment. The morphological and structural characteristics of granules and nitrogen pathways have not been fully clarified using real domestic wastewater. To address this issue, microbial community distribution, diversity and functional pathways towards nitrogen conversions in a sequencing batch reactor were investigated. RESULTS Granules (d ∼ 300 µm) were formed with low‐strength domestic wastewater ( COD influent < 200 mg COD soluble L −1 ). COD and ammonium effluent concentrations (55 mgCOD L −1 , 14 mgNH 4 − ‐N L −1 ) achieved national treatment standards. Nitrite accumulation was observed (16.5 mgNO 2 − ‐N L −1 ) and N 2 O emissions (2.8% of nitrogen load) were detected. Granules were composed of protozoa and bacteria, with an outer layer dominated by ammonium‐oxidizing bacteria ( AOB ) and deeper layers with nitrite‐oxidizing bacteria ( NOB ) and denitrifiers. Partial nitrification, denitrification via nitrite, nitrifier denitrification, complete and incomplete denitrification pathways were assessed by qPCR . CONCLUSIONS AGS process showed the establishment of partial nitrification in a low‐strength real wastewater condition. The granular system showed N 2 O emission in a lower range than others known partial nitrification processes. In order to achieve nitrogen removal saving costs in terms of energy and space, engineering wastewater designers can consider AGS as an attractive technology. © 2016 Society of Chemical Industry