GC-MS identification of odorous volatiles in wastewater

Abstract GC-MS analyses of water samples from all unit processes of a wastewater treatment plant resulted in the identification of hydrocarbons, oxygen, nitrogen and sulphur containing organic compounds. Sample preparation included a purge and trap method for apolar volatiles and solvent extraction for polar ones. Because odour nuisance was registered in the neighbourhood of the plant, attention was focused on the identification of malodorous volatiles. Sulphides, polysulphides, thiols, alkylthiophenes, alkylthiothiophenes, lower organic acids, phenol and p -cresol, were the most important odour stimuli identified in the samples. From these analyses it was shown that some organic malodorants were already present in the industrial wastewater. Most sulphur compounds however were formed during transport of the industrial wastewater in mains leading to the works.