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.

This study investigated the occurrence and transport of four isothiazolinone-type biocides from commercial products to wastewater treatment plants (influents, sludges, and effluents) and to natural emissaries (upstream and downstream the wastewater treatment plants) in Romania. All four biocides were determined in personal care and household products, with the highest concentration of 76.4 µg/L OIT (2-octyl-4-isothiazolin-3-one). For environmental samples, three of the four isothiazolinones were determined, CMI (5-chloro-2-methyl-4-isothiazolin-3-one) being the prominent compound for water samples. The maximum concentration of 84.0 µg/L in influent, 122 µg/L upstream, and 144 µg/L downstream the wastewater treatment plants were obtained for CMI. Unlike water samples, in the sewage sludge samples, OIT proved to be the dominant compound, with concentration up to 5.80 µg/g d.w. The extremely high levels of isothiazolinone determined in different WWTPs from Romania may be due to the COVID-19 pandemic situation, during which a much larger amount of cleaning, hygiene, and personal care products was used. The isothiazolinone-type biocides were readily removed from the influents of the five WWTPs, with the mean removal rate up to 67.5%. The mean mass loading value for the targeted biocides based on influent was 20.4 μg/day/1000 people, while the average environmental emissions were 6.93 μg/day/1000 people for effluents. The results obtained for riverine water combine with statistical analysis showed that the anthropogenic activities are the major contamination sources of the surface waters. Preliminary ecological risk evaluation showed that BIT (1,2-benzisothiazol-3(2H)-one), OIT, and CMI could pose a very high risks to different aquatic species living in the receiving aquatic environments.

Adsorption of toxic compounds from water using zeolites and magnetite was developed due to the various advantages of their applicability. In the last twenty years, the use of zeolite-based compositions in the form of zeolite/inorganic or zeolite/polymer and magnetite has been accelerated for the adsorption of emergent compounds from water sources. The main adsorption mechanisms using zeolite and magnetite nanomaterials are high surface adsorption, ion exchange capacity and electrostatic interaction. This paper shows the capacity of Fe₃O₄ and ZSM-5 nanomaterials of adsorbing the emerging pollutant acetaminophen (paracetamol) during the treatment of wastewater. The efficiencies of the Fe₃O₄ and ZSM-5 in the wastewater process were systematically investigated using adsorption kinetics. During the study, the concentration of acetaminophen in the wastewater was varied from 50 to 280 mg/L, and the maximum Fe₃O₄ adsorption capacity increased from 25.3 to 68.9 mg/g. The adsorption capacity of each studied material was performed for three pH values (4, 6, 8) of the wastewater. Langmuir and Freundlich isotherm models were used to characterize acetaminophen adsorption on Fe₃O₄ and ZSM-5 materials. The highest efficiencies in the treatment of wastewater were obtained at a pH value of 6. Fe₃O₄ nanomaterial presented a higher removal efficiency (84.6%) compared to ZSM-5 nanomaterial (75.4%). The results of the experiments show that both materials have a potential to be used as an effective adsorbents for the removal of acetaminophen from wastewater.

This study presents an adsorbent material (activated carbon) used in the treatment of wastewater with the role of removing ibuprofen, acetaminophen, diclofenac and ketoprofen pollutants. The wastewater treatment efficiencies of the activated carbon were systematically investigated using adsorption kinetics. The parameters studied were: pH (4 and 6 values of pH), initial concentration of wastewater (1, 5, and 10 mg/L), contact time (10 min), adsorbent quantity (0.1, 0.5, and 1 g), and isotherm models (Langmuir and Freundlich). The highest wastewater treatment efficiency was obtained at the 6 pH value. The determination of four anti-inflammatory drugs, frequently monitored in wastewater, was performed by a simple and fast method using the HPLC-technique-type DAD (diode array detector). The method was linear when the concentration ranged between 0.5 and 20 m/L for all compounds. The equilibrium concentration was obtained after 8 min. The octanol/water coefficient influenced the removal efficiency of the four drugs by the adsorbent material (activated carbon). The dose of activated carbon (0.1 to 1 g) significantly influenced the efficiency of wastewater treatment, which increased considerably when the dose of the adsorbent material increased. Using 1 g of the adsorbent material for the treatment of wastewater containing 1 mg/L initial concentration of pollutant compounds, the efficiencies were 98% for acetaminophen, 92% for diclofenac, 88% for ketoprofen and 96% for ibuprofen.

Per- and polyfluoroalkyl substances (PFAS) are a global concern due to their persistence, ubiquity, and accumulation in living organisms. Found in soils, biosolids, water, and the food chain, they pose health risks such as hormone disruption, immune damage, reproductive issues, and cancer. Regulations mainly target older PFAS like PFOA and PFOS, while many newer PFAS, including breakdown products, are poorly understood in terms of distribution, behavior, and toxicity. To address this complex issue, this review offers a detailed overview of human exposure to PFAS and their toxic effects. It highlights biosolids as a key, understudied source of PFAS in the environment. The review also discusses limitations of testing, missing long-term cleanup data, and regulatory issues that neglect total exposure and vulnerable populations. Additionally, it evaluates, in the specific context of biosolids management, the effectiveness, scalability, benefits, and drawbacks of various treatment technologies, such as thermal processes (pyrolysis, incineration, smoldering combustion), advanced oxidation, adsorption, hydrothermal liquefaction, and biological degradation. This work combines environmental science, toxicology, and engineering to outline PFAS management in biosolids and proposes a research and policy plan. Focusing on regulating PFAS as a group, validating real-world results, and employing adaptable treatment strategies underscores the need for a coordinated, science-based effort to reduce PFAS risks worldwide.