Polycyclic aromatic hydrocarbons (PAHs) consist of a group of over 100 different organic compounds mainly generated by anthropogenic activities. Because of their low water solubility, they tend to be accumulated in sediment, where their degradation rate is very low. Few studies have been carried out so far to investigate the effects of PAHs on Artemia franciscana. Artemia is easy to manage at laboratory scale, but it is not a sensitive biological model considering the traditional endpoints (i.e., mortality). In addition to evaluating the lethality on nauplii and adults of A. franciscana after 24 and 48 h, we focused on the genotoxicity to investigate the potential effects of phenanthrene (PHE), naphthalene (NAP), fluoranthene (FLT), and benzo(k)fluoranthene (BkF). Results showed that FLT was the most toxic both for nauplii and adults after 48 h of exposure. Real-time qPCR showed that all toxicants, including BkF, which had no negative effects on the survival of the crustacean, were able to switch the gene expression of all nine genes. This work has important ecological implications, especially on contaminated sediment assessment considering that PAHs represent the most abundant organic group of compounds in marine environment, opening new perspectives in understanding the molecular pathways activated by crustaceans.

The removal of contaminants of emerging concern from urban wastewater treatment plants (WWTPs) remains a challenge to promote safe wastewater reuse practices. Macrolides are the most abundant antibiotics detected in untreated wastewater and their concentration in WWTPs effluents is only partially reduced by conventional treatments. Among several advanced oxidation processes (AOPs), photocatalysis has demonstrated the capability to effectively remove pharmaceuticals from different aqueous matrices. Recently, ZnO has emerged as an efficient, promising, and less expensive alternative to TiO₂, due to its photocatalytic capability and attitude to exploit better the solar spectrum than TiO₂. In this study, the behaviors of ZnO photocatalysis were evaluated using a representative macrolide antibiotic, spiramycin (SPY), in aqueous solutions and urban wastewater. After 80 min of photocatalysis, 95–99% removal of SPY was achieved at 1 g L⁻¹ ZnO concentrations in aqueous solutions and wastewater, respectively. After treatment, the effluent toxicity, evaluated using the bacterium Aliivibrio fischeri, the green alga Raphidocelis subcapitata, and the crustacean Daphnia magna ranged between slight acute and high acute hazard. Filterable and ultrafilterable Zn concentrations were quantified in treated effluents and shown to be high enough to contribute to the observed toxicity.