Aerobic biodegradation of nitroglycerin in a sequencing batch reactor

Biological treatment of nitroglycerin (glycerol trinitrate [GTN]) by a mixed microbial culture was examined under aerobic conditions in a bench-scale sequencing batch reactor with GTN present as a minor component in the feed. Initial operation demonstrated the. resistance of GTN and glycerol dinitrates (GDNs) to microbial attack. The presence of GTN and GDNs adversely affected microbial activity, reflected by erratic mixed liquor suspended solids concentrations and low chemical oxygen demand removal efficiencies. Complete removal of GTN and GDNs was contingent on addition of a GTN-adapted inoculum. Transient accumulation and subsequent removal of 1,2-GDN, 1,3-GDN, and nitrite were measured during individual reaction cycles. Complete mineralization of GTN was confirmed and GDN denitration was the rate limiting step governing GTN mineralization.