Chapter 14 - Fate and Occurrence of Pharmaceuticals in the Aquatic Environment (Surface Water and Sediment)

Abstract

Abstract Many classes of pharmaceuticals are administered in humans and animals to treat and prevent diseases. Due to in complete removal of pharmaceuticals in wastewater treatment plants, they have been widely detected in effluents and receiving aquatic environments at the nanogram/liter to microgram/liter concentration levels. The residue levels of these pharmaceuticals in the environment are related to their usages, removal rates, and physiochemical properties and environmental factors. The fate of pharmaceuticals in the environment is determined by various processes such as partitioning (sorption and desorption), photolysis, hydrolysis, and biodegradation. The partitioning of a pharmaceutical compound between aqueous phase and sediment phase in the aquatic environment is mainly influenced by the properties of the compound and the environmental factors such as pH and organic matter. Some pharmaceutical compounds such as acidic drugs tend to remain in aqueous phase, while others such as tetracyclines and quinolones tend to partition into sediment. Furthermore, some pharmaceuticals such as carbamazepine are resistant to degradation, while some other compounds such as ibuprofen are labile to degradation. The presence of pharmaceuticals in the aquatic environment may pose risks to aquatic organisms; therefore, there is a need to gain reliable knowledge and understanding of the occurrence and fate of pharmaceutical active compounds in the environment.