Occurrence of dissolved and particle-bound taste and odor compounds in Swiss lake waters

• Published in: Water research (Oxford) 2009-05, Vol.43 (8), p.2191-2200
• Main Authors: Peter, Andreas, Köster, Oliver, Schildknecht, Andrea, von Gunten, Urs
• Format: Article
• Language: English
• Subjects: 2-isobutyl-3-methoxypyrazine; 2-isopropyl-3-methoxypyrazine; 2-methylisoborneol; Algae; Applied sciences; beta-cyclocitral; beta-ionone; biomass; Bornanes - chemistry; Cyanobacteria; Cyanophyta; drinking water; eutrophication; Exact sciences and technology; Fresh Water - chemistry; Freshwater; gas chromatography; Gas Chromatography-Mass Spectrometry; GC–MS–olfactometry; geosmin; Lake water; lakes; mass spectrometry; Naphthols - chemistry; Norisoprenoids - chemistry; nutrients; Odorants; odors; Organic Chemicals - analysis; Organic Chemicals - chemistry; Other industrial wastes. Sewage sludge; particles; Particulate Matter - chemistry; phytoplankton; Phytoplankton - chemistry; Planktothrix; Planktothrix rubescens; Pollution; Pyrazines - chemistry; Reproducibility of Results; Solid phase micro extraction (SPME); Solubility; summer; Switzerland; Taste; Taste and odor; Wastes; water pollution; water quality; water treatment; Water treatment and pollution
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2009.02.016

The occurrence of algal taste and odor (T&O) compounds was investigated in three Swiss lakes which exhibit different nutrient levels from eutrophic to oligotrophic (Lake Greifensee, Lake Zurich and Lake Lucerne). Apart from dissolved T&O compounds, the study also encompassed particle-bound compounds, i.e., compounds that can be released from damaged algal cells during drinking water treatment. A combined instrumental (SPME–GC–MS) and sensory method was applied that allowed to detect and quantify T&O compounds in natural waters in the sub ppt to low ppt-range. In addition to the prominent T&O compounds geosmin and 2-methyl-isoborneol (MIB), four other T&O compounds could be detected in the lake waters, though all at relatively low concentrations (maximum concentrations of geosmin 19 ng L −1, MIB 3 ng L −1, β-ionone 27 ng L −1, β-cyclocitral 7 ng L −1, 2-isobutyl-3-methoxypyrazine 2 ng L −1, 2-isopropyl-3-methoxypyrazine 16 ng L −1). The concentration peaks typically occurred in the epilimnion during summer concurrent with a high phytoplankton biomass. Consistently, the concentration levels for most of the compounds varied substantially between the three lakes and generally decreased in the order eutrophic Lake Greifensee > mesotrophic Lake Zurich > oligotrophic Lake Lucerne. Furthermore, our data revealed that the occurrence of β-ionone was largely influenced by Planktothrix rubescens. This is the first time that a correlation between β-ionone and this cyanobacterium has been reported for natural waters.