In the last years, there is great attention paid to the determination of polycyclic aromatic hydrocarbons (PAHs) in different environmental matrices. Extensive reviews on PAHs presence and toxicity were published recently. However, PAHs formation and transformation in the environment lead to the production of PAHs derivatives containing oxygen (O-PAHs), nitrogen (N-PAHs and aazarenes AZA) or sulfur (PASHs) in the aromatic ring. The development of new analytical methods enabled the determination of these novel contaminants. The presence of oxygen, nitrogen, or sulfur in PAHs aromatic rings increased their toxicity. The most common primary sources of PAHs derivatives are biological processes such as microbial activity (in soil, water, and wastewater treatment plants (O-PAHs)) and all processes involving combustion of fuel, coal, and biomass (O-PAHs, N-PAHs, AZA, PASHs). The secondary resources involved i) photochemical (UV light), ii) radical-mediated (OH, NO₃), and iii) reactions with oxidants (O₃, NO_x) (O-PAHs, N-PAHs, AZA). Furthermore, N-PAHs were able to transform to their corresponding O-PAHs, while other derivatives were not. It indicated that N-PAHs are more vulnerable to photooxidation in the environment. 85% of O- and N-PAHs were detected with particle matter below 2.5 μm suggesting their easier bioaccessibility. More than 90% of compounds with four and more aromatic cycles were present in the particle phase in the air. Although the concentrations of N-PAHs or O-PAHs may be similar to PAHs concentration or even 1000 times lower than parent PAHs, PAHs derivatives accounted for a significant portion of the total mutagenicity. The present review is describing the results of the studies on the determination of PAHs derivatives in different environmental matrices including airborne particles, sediments, soil, and organisms. The mechanisms of their formation and toxicity were assessed.

The photocatalytic oxidation of diclofenac, metoprolol, estrone and chloramphenicol was tested in the tube reactor using different commercially available TiO₂. The photocatalysts were characterized using BET, XRD and SEM. The studied photocatalysts differed in S_BET, pore volume and rutile presence. It was observed that generally anatase TiO₂ possessed the highest activity in the photocatalytic oxidation of diclofenac, chloramphenicol and estrone. The presence of rutile enhanced the photooxidation of metoprolol. In case of the other pollutants, however, rutile diminished the photooxidation efficiency. The most effective in the reduction of the COD parameter of treated water was anatase with 21 nm crystals. The photooxidation of all studied pollutants can be described by the pseudo-first order kinetics with the values ranging from 0.46 × 10⁻² min⁻¹ in case of estrone removal over Tytanpol (Z.A. Police, Poland) to 1.87 × 10⁻² min⁻¹ for the removal of chloramphenicol over TiO₂ 21 nm (Sigma-Aldrich). The highest initial reaction rates were obtained for metoprolol removal over TiO₂ 21 nm (Sigma-Aldrich) 1.9 × 10⁻⁶ mol dm³ min⁻¹ being three times higher than that determined for estrone photocatalytic oxidation over TiO₂ (Sigma-Aldrich).

Phthalic acid esters (PAEs) are dialkyl or alkyl/aryl ester derivatives of phthalic acid. PAEs are colorless, odorless, and flavorless oily liquids. PAEs are the main plasticizers used in industry and households. DEHP (di-(2-ethyl hexyl) phthalate) is the main plasticizer used in the polymer industry, whereas DMP (dimethyl phthalate) and DEP (diethyl phthalate) are used mainly as solvents or fixatives in cosmetics and personal care products. PAEs are synthetic organic compounds poorly soluble in water but soluble in organic solvents. Into the environment, they are introduced during the production, use and degradation, packaging, and transportation of plastic products. In the environment, PAEs are degraded in three ways: by hydrolysis, photodegradation, and microbial degradation, whereas the biodegradation and hydrolysis of PAEs in the environment are very slow. PAEs are pollutants of soil, water, groundwater, river water, marine water, air, sediments, vegetables, and biota. Due to the great interest in the subject of environmental pollution by PAEs and the emergence of new information in this area, it is extremely important to systematically review the current knowledge. In the presented paper, the occurrence of PAEs in different environmental matrices was reviewed. The toxicity to plants, animals, and humans was also described.