The principal objective of the present research involved the achievement of high biodegradation degrees of perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS) using pure individual bacterial strains. The use of such microorganisms can contribute to the improvement of the wastewater treatment process in sewage treatment plants through bioaugmentation or other bioremediation processes. Thus, in this study, we investigated the biodegradation potential of PFOA and PFOS. Bacterial strains tested in this study were from the Pseudomonas genus, namely: Pseudomonas aeruginosa and Pseudomonas putida, due to their known capacity to degrade xenobiotic compounds. The results indicated that Pseudomonas aeruginosa was able to transform 27.9% of PFOA and 47.3% of PFOS in 96 h, while Pseudomonas putida managed to transform 19.0% of PFOA and 46.9% of PFOS in the same time frame. During the biodegradation tests, PFHxA was recognized as the principal biotransformation product of PFOA in the presence of Pseudomonas aeruginosa, and PFPeA, PFPxA and PFHpA were recognized as the biotransformation products in the presence of Pseudomonas putida. For PFOS, only two biotransformation products (PHHxA and PFHpA) were observed as a consequence of biodegradation by both bacterial strains.

Drinking and wastewater are to be treated for safe human consumption and for keeping surface waters clean. There are multiple water purification procedures, but the use of ion-exchange resins significantly enhances water purification efficiency. This review was targeted on highlighting the concept and classification of polymeric ion-exchange resins as well as pointing out their real-world applications. Their successful use for purification purposes has been linked to their chemical structure, simplicity of operation, accessibility, and reusability. Therefore, polymeric ion-exchange resins have been used for the removal of a wide range of organic and inorganic pollutants such as pharmaceutical compounds, dyes, organic matter, metals, and many others. Ion-exchange resins are obtained directly by synthesis methods or grafting ionizable groups on polymer matrix in order to ensure continuous improvement. Furthermore, the newly designed ion-exchange resins take into consideration biodegradability potential towards obtaining ecofriendly compounds.

One cationic surfactant with a wide spectrum of microbiocidal activity is benzethonium chloride (BEC). Despite being widely used, the toxicity data on vertebrate organisms are limited. Therefore, we aimed to evaluate within this study the acute toxicity of BEC on the gills and kidneys of Cyprinus carpio (European carp). An alteration of the antioxidant enzymes activities (glutathione reductase, glutathione peroxidase and glutathione S-transferase) was noticed after 96 h of exposure, along with an elevation of lipid peroxidation and decreased concentration of reduced glutathione, which confirmed that BEC was able to induce toxicity to these tissues. These metabolic effects were correlated with unspecific structural changes observed in gills and kidneys, having moderate degree of severity (such as an increase of melanomacrophages aggregation incidence and cytoplasm vacuolation of goblet cells in collecting tubules) and generally being compatible with life for the exposure time studied. The most severe structural effects were observed in gills after 96 h, noticing a lamellar aneurysm, hemorrhages and lamellar epithelium disruption due to the blood vessels and pillar cells damages and increased blood flow inside the lamellae. By our research we can confirm the utility of biochemical and histological analyses in the fish organs as tools for monitoring the water quality and ecotoxicological potential of chemicals.

The aim of this article is to present a nonconventional method for the efficient removal of lead ions from industrial wastewater. For this purpose, magnetite nanomaterial was used, which was very easily separated from the wastewater at the end of the treatment due to its magnetic properties. Currently, nanotechnology is an efficient and inexpensive manner that is being researched for wastewater treatment. Additionally, iron oxide nanoparticles are widely used to remove heavy metal ions from water due to their special properties. The experimental results detailed in this article show the influence of pH and contact time on the process of adsorption of lead ions from wastewater. The magnetite nanomaterial had its maximum efficiency of speed when the wastewater had pH 6. At a lower pH, the highest treatment efficiency was over 85%, and the required contact time has doubled. When the pH increases above 6, the precipitation process occurs. Langmuir and Freundlich models were used to describe the adsorption process.

Background: Romania is one of the European countries reporting very high antimicrobial resistance (AMR) rates and consumption of antimicrobials. We aimed to characterize the AMR profiles and clonality of 304 multi-drug resistant (MDR) Acinetobacter baumannii (Ab) and Pseudomonas aeruginosa (Pa) strains isolated during two consecutive years (2018 and 2019) from hospital settings, hospital collecting sewage tanks and the receiving wastewater treatment plants (WWTPs) located in the main geographical regions of Romania. Methods: The strains were isolated on chromogenic media and identified by MALDI-TOF-MS. Antibiotic susceptibility testing and confirmation of ESBL- and CP- producing phenotypes and genotypes were performed. The genetic characterization also included horizontal gene transfer experiments, whole-genome sequencing (WGS), assembling, annotation and characterization. Results: Both clinical and aquatic isolates exhibited high MDR rates, especially the Ab strains isolated from nosocomial infections and hospital effluents. The phenotypic resistance profiles and MDR rates have largely varied by sampling point and geographic location. The highest MDR rates in the aquatic isolates were recorded in Galați WWTP, followed by Bucharest. The Ab strains harbored mostly bla_OXA-23, bla_OXA-24, bla_SHV, bla_TEM and bla_GES, while Pa strains bla_IMP, bla_VIM, bla_NDM, bla_VEB, bla_GES and bla_TEM, with high variations depending on the geographical zone and the sampling point. The WGS analysis revealed the presence of antibiotic resistance genes (ARGs) to other antibiotic classes, such as aminoglycosides, tetracyclines, sulphonamides, fosfomycin, phenicols, trimethoprim-sulfamethoxazole as well as class 1 integrons. The molecular analyses highlighted: (i) The presence of epidemic clones such as ST2 for Ab and ST233 and ST357 for Pa; (ii) The relatedness between clinical and hospital wastewater strains and (iii) The possible dissemination of clinical Ab belonging to ST2 (also proved in the conjugation assays for bla_OXA-23 or bla_OXA-72 genes), ST79 and ST492 and of Pa strains belonging to ST357, ST640 and ST621 in the wastewaters. Conclusion: Our study reveals the presence of CP-producing Ab and Pa in all sampling points and the clonal dissemination of clinical Ab ST2 strains in the wastewaters. The prevalent clones were correlated with the presence of class 1 integrons, suggesting that these isolates could be a significant reservoir of ARGs, being able to persist in the environment.

Benzenthonium chloride (BEC, Hyamine 1622) is a quaternary ammonium surfactant with cationic properties widely used in cleaning, sanitation, and medical products that can become harmful to humans and also to the environment. This study aimed to evaluate its acute effects on Cyprinus carpio fish in terms of oxidative stress and morphological changes on hepatic tissue in order to show the sub-lethal toxicity of BEC. Fish were exposed to 1 mg/L BEC for 24, 48, and 96 h, and the liver samples were collected. The most significant changes were noticed after 96 h of exposure when the entire antioxidant enzyme system was affected. The activities of catalase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase decreased by 44%, 31%, 30%, and 45%, respectively, compared to control. Glucose-6-phosphate dehydrogenase activity decreased by 29% after 96 h of control, inducing a reduction of NADPH formation which decreased by half the level of reduced glutathione, the main non-enzymatic antioxidant. These effects correlated with the raised value of lipid peroxidation after 96 h and the morphology changes on hepatic tissue, such as cytoplasmic vacuolization and nuclear hypertrophy that could affect the normal function of the liver. All of these results showed acute toxicity of BEC on C. carpio after 96 h of exposure, causing oxidative stress response at the hepatic level.