ELIMINATION OF TERPENOID ODOROUS COMPOUNDS BY SLOW SAND AND RIVER BANK FILTRATION OF THE RUHR RIVER, GERMANY

The elimination of odorous compounds by river bank and slow sand filtr ation was studied at the Ruhr River in Germany. The aquifer of the riv er bank filtration was anoxic and exhibited intense dissimilatory nitr ate reduction; the aquifer of the slow sand filter was oxic. Polar mon oterpenes, such as linalool, menthol, isobonlyl acetate, lipoxygenase products (oct-1-en-3-ol) and geosmin exhibited a much higher percentag e elimination than monoterpene hydrocarbons and other lipophilic compo unds (dimethyldisulphide, aliphatic and aromatic hydrocarbons). The ef ficiency of river bank filtration was slightly better than that of slo w sand filtration. The schmutzdecke and upper layers of the slow sand filters were responsible for most of the removal of VOC. The deeper la yers exhibited only small effects.