Contribution of filamentous fungi to the musty odorant 2,4,6-trichloroanisole in water supply reservoirs and associated drinking water treatment plants

Chemosphere. 2017 Sep;182:223-230. doi: 10.1016/j.chemosphere.2017.04.138. Epub 2017 May 6.


In this study, the distribution of 2,4,6-trichloroanisole (2,4,6-TCA) in two water supply reservoirs and four associated drinking water treatment plants (DWTPs) were investigated. The 2,4,6-TCA concentrations were in the range of 1.53-2.36 ng L-1 in water supply reservoirs and 0.76-6.58 ng L-1 at DWTPs. To determine the contribution of filamentous fungi to 2,4,6-TCA in a full-scale treatment process, the concentrations of 2,4,6-TCA in raw water, settled water, post-filtration water, and finished water were measured. The results showed that 2,4,6-TCA levels continuously increased until chlorination, suggesting that 2,4,6-TCA could form without a chlorination reaction and fungi might be the major contributor to the 2,4,6-TCA formation. Meanwhile, twenty-nine fungal strains were isolated and identified by morphological and molecular biological methods. Of the seventeen isolated fungal species, eleven showed the capability to convert 2,4,6-trichlorophenol (2,4,6-TCP) to 2,4,6-TCA. The highest level of 2,4,6-TCA formation was carried out by Aspergillus versicolor voucher BJ1-3: 40.5% of the original 2,4,6-TCP was converted to 2,4,6-TCA. There was a significant variation in the capability of different species to generate 2,4,6-TCA. The results from the proportions of cell-free, cell-attached, and cell-bound 2,4,6-TCA suggested that 2,4,6-TCA generated by fungi was mainly distributed in their extracellular environment. In addition to 2,4,6-TCA, five putative volatile by-products were also identified by gas chromatography and mass spectrometry. These findings increase our understanding on the mechanisms involved in the formation of 2,4,6-TCA and provide insights into managing and controlling 2,4,6-TCA-related problems in drinking water.

Keywords: 2,4,6-Trichlorophenol; Biomethylation; Identification; Taste and odor.

MeSH terms

  • Anisoles / analysis*
  • Chlorophenols
  • Chromatography, Gas
  • Drinking Water / analysis*
  • Fungi / chemistry*
  • Halogenation
  • Odorants / analysis*
  • Water Purification / methods*
  • Water Supply / standards


  • Anisoles
  • Chlorophenols
  • Drinking Water
  • 2,4,6-trichloroanisole
  • 2,4,6-trichlorophenol