Treatment of ferrous-NTA-based NO x scrubber solution by an up-flow anaerobic packed bed bioreactor.

A bench scale system consisting of an up-flow packed bed bioreactor (UAPBR) made of polyurethane foam was used for the treatment and regeneration of aqueous solution of ferrous-NTA scrubbed with nitric oxide (NO). The biomass in the UAPBR was sequentially acclimatized under denitrifying and iron reducing conditions using ethanol as electron donor, after which nitric oxide (NO) gas was loaded continuously to the system by absorption. The system was investigated for different parameters viz.

Reduction of NOx in Fe-EDTA and Fe-NTA solutions by an enriched bacterial population.

An enriched biomass was developed from municipal sewage sludge consisting of three dominant bacteria, representing the genera of Enterobacter, Citrobacter and Streptomyces. The biomass was used in a series of batch experiments in order to determine kinetic constants associated with biomass growth and NOx reduction in aqueous Ferrous EDTA/NTA solutions and Ferric EDTA/NTA solutions using ethanol as organic electron donor. The maximum specific reduction rates of NOx in Ferrous EDTA and Ferrous NTA solutions were 0.