Screening for non-regulated organic compounds in municipal wastewater in Göteborg, Sweden

Organic compounds from influent and effluent wastewater were concentrated on C18 bonded phase cartridges and sequentially eluted with organic solvents of different polarity. About 80% of the toxicity (Microtox) arised from organic matter eluted with ether. Approximately 50% decrease in the overall toxicity of the influent was observed during the treatment process. More than 50 individual compounds were identified in the eluates for both influent and effluent by GC-MS and FIA-MS analysis. Perfume additives to washing powders and cleaning agents and a number of industrial volatile hydrophilic solvents were quantitatively removed by volatilization in the treatment process. Only a partial removal was observed for less volatile compounds (benzophenone, dibutyl formamide, dimethyl quinoline, benzothiazole, phosphate esters) of industrial origin. Substituted phenols, used as antioxidants in both industrial and domestic products were transformed to corresponding -ene-ones in the biological stage of the water treatment process. Polyglycols and polyglycol ether type surfactants are not removed in the activated sludge prosess, only partly transformed to highly persistant acids by oxidation of the terminal hydroxyl function. The treatability in municipal wastewater plants should be paid much more attention when introducing polar non-volatile constituents in new “environmentally friendly” water based products or processes.