Batch culture biodegradation of methylhydrazine contaminated NASA wastewater

The batch culture degradation of NASA wastewater containing mixtures of cit ric acid, methylhydrazine, and their reaction product was studied. The orga nic contaminants present in the NASA wastewater were degraded by Achromobac ter sp., Rhodococcus B30 and Rhodococcus J10. While the Achromobacter sp. s howed a preference for the degradation of the citric acid, the Rhodococcus species were most effective in reducing the methylhydrazine and the reactio n product. Removals of more than 50% were observed for citric acid, methylh ydrazine and the reaction product when the NASA wastewater was inoculated w ith the microbes in batch cultures. Simulation and chemical characterizatio n of citric acid and hydrazine mixtures show that the interaction is partly of a chemical nature and leads to the formation of a conjugated UV/Visible absorbing compound. An 'azo' carbonyl derivative of the citric acid, consi stent with the spectral data obtained from the investigation, has been prop osed as the possible product.