The environmental occurrence of antimicrobial pharmaceuticals and antibiotic resistant bacteria and antibiotic resistant genes has become a global phenomenon and a multifaceted threat. Integrated actions of many parties are needed to prevent further aggravation of the problem. Well-directed actions require clear understanding of the problem, which can be ensured by frequent revaluation of the existing knowledge and disseminating it among relevant audiences. The goal of this review paper is to discuss the occurrence and abundance of antimicrobial pharmaceuticals in the aquatic environment in context of adverse effects caused directly by these substances and the threat associated with the antibiotics resistance phenomenon. Several classes of antimicrobial pharmaceuticals (aminoglycosides, β-lactams, glycopeptides, macrolides, fluoroquinolones, sulfonamides and trimethoprim, tetracyclines) have been selected to illustrate their sources, environmental abundance, degradation routes (transformation products) and environmental implications including their ecotoxic effect and the spread of antibiotic resistance within the compartments of the aquatic environment and wastewater treatment plants. Wastewater treatment plants are indeed the main source responsible for the prevalence of these factors in the aquatic environment, since predominantly the plants have not been designed to retain antimicrobial pharmaceuticals. In order to limit the prevalence of these impurities into the environment, better source control is recommended as well as the establishment of stricter environmental quality standards. Counteracting all the above-mentioned threats requires to undertake integrated activities based on cooperation of professionals and scientists from various fields of science or industry, such as environmental sciences, medicine, veterinary, pharmacology, chemical engineering and others.

The ability to measure and control the composition of activated sludge is an important issue, aiming at evaluating the effectiveness of changes occurring in the sludge, what determines its usefulness to treat wastewater. In this research, diffuse reflectance infrared Fourier transform (FTIR–DRIFT) technique was used, which relies on measuring the reflectance of the powdered substance’s surface layer and capturing spectra in range of infrared wave. First, spectra correlation table of the substances mostly occurring in wastewater was developed to assess the main components of the tested samples of activated sludge. The simplest compounds containing functional groups characteristic for particular chemical classes were chosen: peptides (peptone and albumin), fats (glycerin and fatty acids), carbohydrates (glucose and sucrose), nitrogen compounds (NaNO₃ and NH₄SO₄), sulfur compounds (Na₂SO₄ and Na₂S₂O₃), silicate, etc. The spectra of those substances were captured and characteristic absorption bands for respective bonds in the function groups were assigned. Second, samples of activated sludge from lab-scale membrane bioreactors (MBRs), which purifies petroleum wastewater, were taken. Samples were properly prepared (lyophilization and homogenization) and their spectra were captured. During spectra analysis, previously developed correlation table was used. In obtained spectra of activated sludge, absorption bonds characteristic for amides, peptides, carbohydrates, fats, and aliphatic was identified. The spectra profile of the sludge sample from MBR feed with petroleum wastewater was slightly different from the control MBR sample’s spectra. Intensity of bands in the area characteristic for aliphatic compounds and phenols was clearly higher. This study proves the usefulness of FT-IR technique to observe changes in the chemical composition of activated sludge.