Emerging contaminants (ECs) are not monitored nor regulated consistently, but may have negative effects on human health and ecosystem balance. Although pharmaceuticals and personal care products are among the main ECs found in surface and wastewater, their toxicity and fate are currently not sufficiently studied. In this study, we analyzed for the first time a group of 46 ECs in the secondary effluent of the wastewater treatment plants (WWTP) of Prague. Thirty-seven compounds were identified in the discharge to surface water. Three compounds had no toxicology information on Artemia salina: furosemide, hydrochlorothiazide, and tramadol. We performed acute toxicity (LC50) tests and enzyme assays after 24 and 48 h at room temperature and 28 °C for these three compounds. LC50 ranged from 225.01 mg/L for furosemide, the most toxic, up to above 14,000 mg/L for tramadol. Changes in enzymatic activity for GST, GPx, AChE, and LDH when A. salina were exposed to LC25 for each contaminant were conspicuous and significant in a contaminant-, exposure time-, and temperature-dependent manner. These biochemical markers complement the toxicity profile of these contaminants in aquatic ecosystems and highlight the need for further research on other ECs and their implications, and the regulations required to protect human and ecological health.

• A. salina as aquatic study model for BZ, PTD, PPD and TBBPA toxicity. • Toxicity and response to oxidative stress depend on temperature and exposure time. • TBBPA and BZ were the most lethal substances at the different tested conditions. • The dyes PTD and PPD induced significant detrimental effects in brine shrimp. • The toxicity of PTD and PPD in A. salina is possibly caused by their by-products.

Background: Tetrabromobisphenol (TBBPA), a flame retardant compound, is considered a ubiquitous pollutant, with potential impact on the environment and human health. Several technologies have been applied to accelerate its degradation and minimize environmental impacts. Due to its aromaticity character, peroxidase enzymes may be employed to carry out its transformation in mild conditions. Therefore, the purpose of this work was to determine the capacity of the enzyme chloroperoxidase (CPO) to oxidize TBBPA in several water samples. Methods: The oxidation capacity of CPO was evaluated in catalytic conditions using water samples from surface and groundwater, as well as effluents from wastewater treatment plants. The biocatalytic performance of CPO was improved due to its immobilization on nanofibers composed of polyvinyl alcohol and chitosan (PVA/chitosan). Results: Free and immobilized CPO were able to transform more than 80% in short reaction times (60 min); producing more biodegradable and less toxic products. Particularly, the immobilized enzyme was catalytically active in a wider range of pH than the free enzyme with the possibility of reusing it up to five times. Conclusions: The biocatalytic oxidation of TBBPA under environmental conditions is highly efficient, even in complex media such as treated effluents of wastewater treatment plants.

Apparent digestibility coefficients (ADC) for dry matter, energy, crude protein (CP), and amino acids (AA) were evaluated for 4 feedstuffs used to feed juvenile white shrimp (Penaeus vannamei): fish meal (73.5% CP), potato protein concentrate (89.3% CP), brewer’s yeast (42.5% CP), and crustacean meal (47.2% CP). Experimental diets included 30% of the test ingredient and 69% of a commercial diet supplemented with 1% chromium oxide as inert marker. Amino acid contents in the ingredients, experimental diets, leached diets, and feces were analyzed by high-performance liquid chromatography. Nutrient loss in water was highest in the fishmeal diet (25%). The AA with the highest losses in water were lysine, methionine, and arginine (25%, 23%, and 21%, respectively). The ADC for dry matter oscillated between 79.2% and 90.6%, for CP between 78.1% and 91.8%, and for AA between 75.4% and 96.6%. In all cases the lower limit corresponded to the meal with potato protein concentrate and the upper limit to the crustacean meal. The ADC for energy fluctuated between 89.1% and 95.2%, with the lower limit for the crustacean meal and the upper limit for the meal with potato protein concentrate.