# Contamination with Pharmaceuticals in Aquatic Environment: Focus on Analytical Methodologies
## 1 Introduction  
Pharmaceutical substances are indispensable components of contemporary medicine and veterinary practice. They are primarily used to treat and prevent disease in humans and animals, and their beneficial effects on food production and economic prosperity are widely recognized. The growing global population, advances in research, investments in the pharmaceutical industry, and the ubiquitous availability of pharmaceuticals on the global market contribute to a significant increase in drug consumption [1]. According to a report by the Organization for Economic Co-operation and Development (OECD), global antibiotic consumption for livestock is expected to rise by 67% by 2030. Furthermore, drug consumption in industrialized nations such as Germany could rise by up to 67% by 2045 due to demographic changes [2]. Pharmaceuticals do not represent a new group of contaminants; their research in the environment has been dealt with worldwide and for a long time by many development researchers and workers; however, their specific occurrence according to actual medical situations, concentration levels, and variability in effluents is changing. Although pharmaceuticals are not a novel class of contaminants, their presence in aquatic environments is becoming increasingly prevalent. These substances enter these ecosystems via a number of different pathways, including direct discharge from wastewater treatment plants (WWTPs) [3], agricultural runoff, and the improper disposal of unused medications [4]. The persistence and extensive distribution of these compounds give rise to concerns regarding their potential environmental and health impacts--the full extent of which is yet to be determined. It is estimated that between 70 and 80 percent of this pollution originates from treated wastewater, while the remaining 20 to 30 percent is attributable to industrial waste [5], the improper disposal of unused or expired medications, and agricultural runoff. The pervasive occurrence of these contaminants underscores the inadequacy of conventional wastewater treatment processes in effectively removing pharmaceutical compounds. Despite numerous endeavors, current wastewater treatment methods frequently prove incapable of degrading or eliminating pharmaceutical substances, their metabolites, and byproducts [6]. Another significant source of contamination is the runoff from livestock farms and aquaculture, which utilize pharmaceuticals such as antibiotics and hormones [7]. The improper disposal of pharmaceuticals from households, hospitals, and healthcare facilities, in addition to landfill leachates, contributes further to the issue [8]. Despite the advent of novel advanced treatment methods, including biological processes and electrocoagulation, their overall efficiency remains constrained [9; 10; 11]. On the other hand, the occurrence and concentration of drugs in wastewater depend on the physicochemical properties of the pharmaceutical compounds (logK\({}_{\text{ow}}\), volatility, etc. ), the characteristics of the wastewater influent (i.e., alkalinity and acidity), the sorption of drugs onto suspended particles, and the treatment processes used [8]. Recently, novel treatment methods were introduced for the elimination of pharmaceuticals using advanced materials, such as micromotors and solar evaporation techniques [12; 13], and Phoslock TM as a P&N-inactivation agent was also applied [14]. A selection of the most frequently occurring groups of monitored pharmaceutical substances in environmental water samples is shown in Figure 1. The pharmaceuticals that were identified in the aquatic environment belong to a number of different chemical classes. These include non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, antiepileptic, \(\beta\)-blockers, steroid estrogens, and psychiatric medications [15; 16; 17; 18; 19; 20].