This project applied non-targeted and suspect screening to activated sludge from five Danish wastewater facilities. In addition, the concentrations of 61 elements were also determined in the sludge.
The sludge concentrations showed relatively high levels of mercury (0.4-1.4 mg/kg) and cadmium (0.4-1.4 mg/kg), compared to natural levels in arable soils. Also, a high copper (203-571 mg/kg) and zinc (502-1616 mg/kg) concentrations in sludge relative to arable soil show that the use of sludge is likely to increase the level of copper and zinc over time in sludge amended fields.
Five non-targeted screening platforms were applied to analyse the sewage sludge. After data analysis, thousands of substances were discovered in the non-targeted dataset. Searching the data against in-house and international databases 41 substances were determined at the highest annotation level (1), 1,751 molecules were identified at the second highest level (2), 7,091compounds at level 3, and a total of 15,471 combined at level four and five. Examples of confirmed substances are 1H-benzotriazole, 2,6-dichlorophenol, bisphenol S, methylparaben, terbutryn and prosulfocarb.
By applying novel semi-quantitative concepts, it was possible to predict concentrations of 513 substances, e.g. PFOS was detected at all five sites with concentrations ranging from 2.4-47.4 µg/kg sludge, while 6PPD-quinone was only found in three sites (14-74 µg/kg). Endogenous or natural metabolites were found, e.g. bile acids as deoxycholate (58-3247 µg/kg) and peptides as Gly-Leu-Lys (53-938 µg/kg).
Non-targeted and suspect screening of sewage sludge
This project applied non-targeted and suspect screening to activated sludge from five Danish wastewater facilities. In addition, the concentrations of 61 elements were also determined in the sludge. The sludge concentrations showed relatively high levels of mercury (0.4-1.4 mg/kg) and cadmium (0.4-1.4 mg/kg), compared to natural levels in arable soils. Also, a high copper (203-571 mg/kg) and zinc (502-1616 mg/kg) concentrations in sludge relative to arable soil show that the use of sludge is likely to increase the level of copper and zinc over time in sludge amended fields.Five non-targeted screening platforms were applied to analyse the sewage sludge. After data analysis, thousands of substances were discovered in the non-targeted dataset. Searching the data against in-house and international databases 41 substances were determined at the highest annotation level (1), 1,751 molecules were identified at the second highest level (2), 7,091compounds at level 3, and a total of 15,471 combined at level four and five. Examples of confirmed substances are 1H-benzotriazole, 2,6-dichlorophenol, bisphenol S, methylparaben, terbutryn and prosulfocarb.By applying novel semi-quantitative concepts, it was possible to predict concentrations of 513 substances, e.g. PFOS was detected at all five sites with concentrations ranging from 2.4-47.4 µg/kg sludge, while 6PPD-quinone was only found in three sites (14-74 µg/kg). Endogenous or natural metabolites were found, e.g. bile acids as deoxycholate (58-3247 µg/kg) and peptides as Gly-Leu-Lys (53-938 µg/kg).