Pharmaceuticals are nowadays generally recognized as environmental micropollutants owing to their ubiquitous occurrence in water bodies at concentrations ranging from ng to ìg L-1. Since they are molecules designed to be biologically active at very low concentrations, their presence cause concern for both human and ecosystem health. Incomplete removal during wastewater biological treatments is the main source of surface water contamination. Some of the detected molecules are rapidly degraded, while others are reported to be persistent in surface water. In some cases, although they are not intrinsically persistent, being continuously introduced into the aquatic ecosystem, they can be considered pseudo-persistent compounds. Degradation of a chemical in the aquatic ecosystem depends on a variety of factors, including compound properties and environmental factors and above all the presence of a natural microbial community able to degrade it via metabolic and/or co-metabolic pathways. Although pharmaceutical and therapeutic products are widely found in the natural environment, the ecological effects on receiving ecosystems remain largely unknown. Naproxen, a nonsteroidal anti-inflammatory drug and gemfibrozil, a fibrate drug used as lipid regulator, have been found in several natural waters. Our recent investigations pointed out their occurrence in influent-effluent from municipal WWTPs close to the city of Rome in and in the receiving river Tiber. For this reason we studied the degradation of these pharmaceuticals in microcosm studies using natural river water. The biotic and abiotic degradation (in terms of the disappearance of the 50% of the initial concentration) of naproxen and gemfibrozil were evaluated in microbiologically active river water versus sterilized one. The overall results show that gemfibrozil is more persistent than naproxen and that the microbial community has a significant role in promoting naproxen (DT50 = 27 d) and gemfibrozil degradation (DT50 > 70d).
Degradation of gemfibrozil and naproxene in a river water ecosystem
Barra Caracciolo A;Patrolecco L;Falconi F;Grenni P
2011
Abstract
Pharmaceuticals are nowadays generally recognized as environmental micropollutants owing to their ubiquitous occurrence in water bodies at concentrations ranging from ng to ìg L-1. Since they are molecules designed to be biologically active at very low concentrations, their presence cause concern for both human and ecosystem health. Incomplete removal during wastewater biological treatments is the main source of surface water contamination. Some of the detected molecules are rapidly degraded, while others are reported to be persistent in surface water. In some cases, although they are not intrinsically persistent, being continuously introduced into the aquatic ecosystem, they can be considered pseudo-persistent compounds. Degradation of a chemical in the aquatic ecosystem depends on a variety of factors, including compound properties and environmental factors and above all the presence of a natural microbial community able to degrade it via metabolic and/or co-metabolic pathways. Although pharmaceutical and therapeutic products are widely found in the natural environment, the ecological effects on receiving ecosystems remain largely unknown. Naproxen, a nonsteroidal anti-inflammatory drug and gemfibrozil, a fibrate drug used as lipid regulator, have been found in several natural waters. Our recent investigations pointed out their occurrence in influent-effluent from municipal WWTPs close to the city of Rome in and in the receiving river Tiber. For this reason we studied the degradation of these pharmaceuticals in microcosm studies using natural river water. The biotic and abiotic degradation (in terms of the disappearance of the 50% of the initial concentration) of naproxen and gemfibrozil were evaluated in microbiologically active river water versus sterilized one. The overall results show that gemfibrozil is more persistent than naproxen and that the microbial community has a significant role in promoting naproxen (DT50 = 27 d) and gemfibrozil degradation (DT50 > 70d).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
