Emerging pollutants in sewage sludge

Trabajo presentado en TERRAenVISION Environmental Issues Today: Scientific Solutions for Societal Issues, celebrado en Barcelona (España) del 27 de enero al 2 de febrero de 2018The sewage sludge is generated in the wastewater treatment plants (WWTPs) because of wastewater treatment. This water contains several anthropogenic contaminants, and part of these end up in the sludge. The occurrence of emerging contaminants in the influents and effluents of the treatment plants has been widely studied, but not in sewage sludge, which due to its high organic matter content is use as organic amendment in agricultural soils. In fact, in Spain, the 80% of the sewage sludge is used as a fertilizer for the crops, being of great interest to know the different compounds present in them and asses the environmental risk of their utilization. The sludge samples are from 8 WWTPs with different treatments. Samples were extracted using a Methanol-McIlvaine Buffer (4.1) mixture and assisted by ultrasound, the supernatant was cleaned up with solid phase extraction (SPE) using StrataTMX cartridges and then the analytes were eluted with methanol at gravity flow. To identify as many compounds as possible and obtain high quality information, non-target identification was used with a liquid chromatograph triple quadrupole time-of-flight (LC-QqTOF). As overall results, 50 different compounds were identified with high degree of confidence belonging 31 of them to the group of the pharmaceuticals. Several human metabolites (nucleotides, amino acids, etc.) were also detected. Other compounds were tentative identify but further study is still needed to increase the degree of confidence in their identification. In conclusion, this method is suitable to identify emerging contaminants in sewage sludge, which could suppose and environmental risk in the areas where they are utilized.This work has been supported by the Spanish Ministry of Economy and Competitiveness and the ERDF (European Regional Development Fund) through the project CGL2015-64454-C2-1. R. Álvarez also knowledge the same institutions for his FPI grant BES-2016-078612.Peer reviewe