In this study; sludge; from a water treatment plant that takes care of wastewater from pharmaceutical and explosives industries; was biologically treated. Transformation and degradation of the explosives and nitroaromatics in the sludge during the different treatments was studied. The sludge was treated under aerobic or anaerobic conditions. LC/MS and GC/MS were used to analyse the explosives and nitroaromatics in the sludge; before and during the treatments. Mass spectrometric detectors can be used for identifying unknown substances by specific fragmentation patterns. LC-MS is used for polar and thermally unstable compounds while GC-MS has the advantage of available spectral libraries for comparison and identification of unknown compounds.
This study showed a decrease in the amount of explosives and nitroaromatics during both the aerobic and anaerobic treatments; except for some pharmaceutical compounds that seem to accumulate in the treated sludge. The degradation of nitroaromatics seems to have been successful for both the aerobic and the anaerobic system.