Organic pollutants in the effluents of large wastewater treatment plants in Sweden

Effluents from the three largest WWTPs in Sweden were analysed for the presence of organic pollutants by GC-MS. From a total of 137 identified compounds only 10 were priority pollutants. A broad spectrum of non-regulated organic pollutants found in the effluents included aromatic hydrocarbons, food and household related compounds, solvents, plasticisers, flame retardants, preservatives, antioxidants and washing and cleaning related compounds. The concentrations of individual compounds in effluents of all three WWTPs were in the range of 0.5–50 μg/l. Rather few point-discharged pollutants from specific industries were present in the effluents. The majority of pollutants detected in the effluents were attributable to the overall usage and discharge of chemical products in modern society. These pollutants originate from diffuse sources and represent “a background chemical pollution load” of the receiving waters through the discharge from WWTPs in large cities.