Presence of fluoroquinolones and sulfonamides in urban sewage sludge and their degradation as a result of composting

The concentrations of some widely used pharmaceuticals, namely fluoroquinolones (ciprofloxacin C H FN O , norfloxacin C H FN O and ofloxacin C H FN O ) and sulfonamides (sulfadimethoxine C H N O S 17 18 3 3 16 18 3 3 18 20 3 4 12 14 4 4 and sulfamethoxazole C H N O S ) were determined in urban sewage sludge utilized for making compost. The 10 11 3 3 levels of degradation of these pharmaceuticals resulting from sludge treatment were assessed. The concentrations of the studied pharmaceuticals sufficiently varied both in sewage sludge and in compost and due to this phenomenon the possible danger resulting from the presence of pharmaceuticals in sewage sludge, used for composting, can not be ignored. The concentrations of the studied pharmaceuticals were lower in compost, if compared to the relevant concentrations in sewage sludge. The highest pharmaceutical concentration in sewage sludge 426 μg/kg was detected in the case of ciprofloxacin. The highest concentrations present in compost were 22 μg/kg of norfloxacin and 20 μg/kg of ciprofloxacin. Results show that before using the sewage sludge for making compost or before using the compost a fertilizer for food plants, they should be carefully tested against the content of commonly used