BARC/PUB/2017/0206

 
 

2,4-Dinitrotoluene removal in aerobic granular biomass sequencing batch reactors

 
     
 
Author(s)

Reddy, K. K. G.; Sarvajith, M.; Nancharaiah, Y. V.; Venugopalan, V. P.
(W&SCD)

Source

International Biodeterioration and Biodegradation, 2017. Vol. 119: pp. 56-65

ABSTRACT

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 g1 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 L-1 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.

 
 
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