Emerging pollutants in sewage, surface and drinking water in Galicia (NW Spain)

A monitoring programme was carried out on wastewater, surface and drinking water on the NW area of Spain during the four seasons of a year period (November 2007–September 2008). This study covered a series of emerging pollutants of different classes, including pharmaceuticals, neutral and acidic organophosphorus flame retardant/plasticizers (OPs), triclosan, phenoxy-herbicides, insect repellents and UV filters. From the total set of 53 compounds, 19 were found in raw wastewater with median concentrations higher than 0.1 μg L−1. Among them, salicylic acid, ibuprofen and the UV filter benzophenone-4 (BP-4) were the most concentrated, exceeding the 1 μg L−1 median value. Subsequently, 11 of these contaminants are not efficiently enough removed in the small WWTPs tested and their median concentrations in effluents still surpassed the 0.1 μg L−1, so that they can spread through surface water. These chemicals are the pharmaceuticals naproxen, diclofenac and atenolol; the OPs tri(2-chloroethyl) phosphate (TCEP), tri(chloropropyl) phosphate (TCPP), tri-n-butyl phosphate (TnBP), diphenyl phosphate (DPhP) and diethylhexyl phosphate (DEHP); and the sulphonate UV filters BP-4 and 2-phenylbenzimidazole-5-sulphonic acid (PBSA). These OPs were then the dominant emerging pollutants occurring in surface and drinking water, where they are detected in the 20–200 ng L−1 range. Pharmaceuticals and UV filters are typically below the 10 ng L−1 level. Finally, herbicides were only detected in the last sampling campaign under the 100 ng L−1 drinking water European Union limit.

► Fifty-three emerging pollutants measured in sewage, surface and drinking water. ► Nineteen compounds detected in sewage at median values higher than 0.1 μg L. ► Eleven of them not properly eliminated and still higher than 0.1 μg L−1 in effluent. ► Pharmaceuticals, UV filters and organoP flame retardants prevail in surface water. ► BP-4, TnBP, TCEP and several organoP diesters found in drinking water at 10–100 ng L−1.