Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5740433 | International Biodeterioration & Biodegradation | 2017 | 10 Pages |
â¢Aerobic granules cultivated by feeding acetate plus 2,4-dinitrotoluene for the first time.â¢2,4-dinitrotoluene was rapidly removed when fed along with acetate or lactate.â¢2-amino-4-nitrotoluene was formed in minor amounts during 2,4-DNT removal.â¢Aerobic granules removed 2,4-DNT by both oxidative and reductive pathways.â¢Nutrient removal by aerobic granules was not impacted by 10 mg Lâ1 2,4-DNT.
Aerobic granules were cultivated in sequencing batch reactor (SBR) by feeding 2,4-dinitrotoluene (2,4-DNT) along with acetate. Aerobic granules with an SVI10 of 34.57 ± 2.6 mL gâ1 and average diameter of 0.78 ± 0.3 mm were formed during 30 d of SBR start-up period. In an alternative approach, aerobic granules cultivated using acetate as carbon source were acclimatized and evaluated for 2,4-DNT removal. In both the approaches, the aerobic granules exhibited rapid 2,4-DNT removal wherein >90% of 10 mg Lâ1 2,4-DNT was removed within 24 h cycle period. The aerobic granules also exhibited ammonium-nitrogen and phosphorus removal in addition to organic carbon removal, indicating that presence of 2,4-DNT did not negatively affect nutrient removal. In aerobic granular biomass reactors, most of the organic carbon was consumed within the first 6 h while, majority of the 2,4-DNT was removed during the 24 h cycle period. HPLC analysis detected smaller amounts of 2-amino-4-nitrotoluene, a biotransformation product of 2,4-DNT. 2,4-DNT removal by granules under anaerobic conditions was observed to be much smaller compared to the aerobic SBR. Thus, 2,4-DNT removal by aerobic granules was likely mediated by combination of both oxidative and reductive pathways. Although, the mechanisms of 2,4-DNT removal requires further investigations, effective and stable removal of 2,4-DNT in aerobic granular biomass reactors offers practical possibilities for treatment of wastewaters from ammunition factories.