Analysis of odor of treated wastewater by gas chromatography with olfactometry detection
ABSTRACT; T. Urase, H. Tsutsui, K. Nakamura. J. of Japan society on water environment, 41, 1, 11-17 (2018). doi: 10.2965/jswe.41.11
A gas chromatography – olfactometry analysis was conducted for biologically treated wastewater samples from seven different plants to clarify the compounds responsible for the odor of biologically treated wastewater. The odor of 2,4,6-trichloroanisole was detected with the highest or second-highest odor intensity for the treated wastewater samples from large-scale plants whose biological reactors are covered with a roof. The treated wastewater from these large-scale plants contained 11.6 – 21.2 ng/L of 2,4,6-trichloroanisole, and this range of concentration was approximately 100 times as high as the olfactory threshold. Earthy and musty odors, probably caused by geosmin and 2-methylisoborneol, were also detected with high odor intensities in all samples. A large contribution of an unidentified compound with a sweet odor was also observed in the analysis of treated water samples. In addition to earthy and musty odors, sulfuric and septic odors were detected in the samples from small-scale plants.
Keywords; Earthy and musty odors; Treated wastewater; 2,4,6-Trichloroanisole; Gas chromatography – olfactometry
Occurrence of earthy and musty odor compounds (geosmin, 2-methylisoborneol and 2,4,6-trichloroanisole) in biologically treated wastewater
ABSTRACT; T. Urase and Y. Sasaki. Water Science and Technology, 68, 9, 1969-1975 (2013). doi: 10.2166/wst.2013.451.
The concentrations of earthy and musty odor compounds (2-methylisoborneol (2-MIB), geosmin and 2,4,6-trichloroanisole (TCA)) in treated wastewater were measured. Concentrations of 2,4,6-TCA (4.3-37.7 ng/L) and geosmin (3.7-42.2 ng/L) higher than their odor thresholds were detected for effluents from large-scale treatment plants. The effluent from a small-scale wastewater plant treating toilet and kitchen wastewater contained the target earthy and musty odor compounds below the odor thresholds. The ozonation applied as an advanced wastewater treatment process was considerably more effective for the removal of 2,4,6-TCA than for the removal of 2-MIB and geosmin. The measured concentrations of 2,4,6-TCA in river environments without the influence of large-scale wastewater effluents were less than the odor threshold.
Keywords; geosmin, odor, treated wastewater, trichloroanisole