Microplastics (MPs) pollution has become a persisting problem over the last decades and is a critical issue for environmental protection and human health. In this context, scientific data able to reveal MPs presence and improve the characterization and identification of this pollution via different systems are valuable. The aim of this paper is to assess available techniques for determining MPs in real freshwater samples and subsequently to highlight the occurrence and type of MPs in the study case area (Somesul Mic River). The MPs sampling was performed from fresh water and sediment using planktonic nets and sieves with different mesh sizes (from 20 to 500 µm). Using both classical microscopic techniques as well as scanning electron microscopy (SEM), large (1–5 mm) and small (1 µm to 1 mm) MPs were observed in the shape of fibers, fragments, foam, foils and spheres in various colors (red, green, blue, purple, pink, white, black, transparent, and opaque). Raman and FT-IR spectroscopic methods were used for MPs identification. The presence of polyethylene (PE), polypropylene (PP), and polystyrene (PS) was registered for all sampling points. The MPs laboratory investigations have raised some issues regarding the identification of MPs particles smaller than 500 µm, these being characterized especially under microscope. Some small MPs particles were identified using micro-Raman spectroscopy that highlighted the same type of polymers. No differences were registered between the sampling points due to the widespread presence of MPs. The sediment samples presented a greater abundance as compared to the water samples. Overall, it is necessary to continue the optimization of MPs separation protocol and identification according to the complexity of samples, mainly due to the limitation and lack of spectral databases.

Global consumption led to increased and persistent plastic pollution in aquatic environments, affecting aquatic biota. Polystyrene (PS) is a synthetic polymer and one of the most widely used plastics. This study aims to investigate the acute and chronic effects of PS microplastics on Cyprinus carpio using an adapted OECD methodology. For the acute test, PS was tested in different particle sizes (20, 200, and 430 µm), each at concentrations of 0, 1, 10, and 100 mg PS/L. Mortality and clinical signs were monitored after 96 h of exposure. No acute effects were recorded. In the chronic test, a mix of PS particles of different sizes (20, 200, and 430 µm) at a total concentration of 1.2 mg PS/L was used for a 75-day fish exposure. Mortality, biometric parameters, physiological indices, and antioxidant enzyme activities, including catalase (CAT), glutathione reductase (GRed), glutathione S-transferase (GST), 7-ethoxyresorufin-O-deethylase (EROD), lipid peroxidation (MDA), hepatic enzymes (alanine aminotransferase—ALT and aspartate aminotransferase—AST), vitellogenin (VTG), and acetylcholinesterase (ACh), were assessed. Fish exposed to the PS mix exhibited a 40% change in hepatosomatic indices after 75 days. Additionally, the PS mix induced oxidative stress in fish organs. CAT activity increased fourfold in the intestine, GRed activity increased thirtyfold in the gonads, and GST activity doubled in the brain. GRed activity also increased in the gills but was not statistically significant compared to the control. Lipid peroxidation was observed in the kidney (twofold increase) and was also detected in the gills and intestine; however, these changes were not statistically significant. EROD activity increased by 15% compared to the control group, indicating an amplification of stress enzyme expression. The activity of hepatic enzymes ALT and AST increased nine to tenfold compared to the control. VTG activity increased by 47%, and ACh activity showed more than 80% inhibition in the brain and muscle. Furthermore, an overall amplification of protein expression in the intestine and liver was observed compared to the control group. Our study revealed the incidence and severity of PS microplastic effects on freshwater fish and emphasized the urgent need for prevention, monitoring, and mitigation measures to combat microplastic pollution.

Continuous human population growth, industrialization, and technical progress have increased the demand for a new design and synthesis of chemical compounds. Developing eco-friendly chemical compounds has been a priority for fostering a sustainable and healthy environment, which is directly linked to human well-being. In this context, green chemistry and circular economy principles have been applied to generate valuable new chemicals, such as surfactants, with high market value. Surfactants play a crucial role in various products for both domestic and industrial applications, leading to their large-scale production a diverse array of chemical structures. However, the advantages of their use must be balanced against their negative environmental impact as pollutants. Thus, there is an increasing demand for the development of new eco-friendly surfactants. Additionally, life cycle assessment (LCA) studies of new surfactants are essential for evaluating their environmental impact, enhancing energy efficiency and facilitating the transition toward sustainable energy resources. In this work, we present the chemical synthesis of oligomeric and polymeric thiophene-based surfactants with potential applications in biosensors, organic transistors, and various other fields. The newly synthesized oligomeric and polymeric thiophene-based surfactants demonstrated medium-to-high biodegradation potential and showed no significant ecotoxicological effects on bacterial communities. However, the LCA of their synthesis revealed a negative impact on the environment and human health, particularly concerning polymeric thiophene-based surfactants. The LCA identified specific chemical steps that could be optimized to develop a new generation of eco-friendly surfactants.

Global consumption has led to an increased and persistent plastic pollution in the aquatic environments. Due to their small size, plastic particles are omnipresent, affecting aquatic biota. Polystyrene is a synthetic polymer and one of the most widely used plastics. Its accumulation in the environment endangers the health of aquatic organisms. This study aims to investigate the acute (7 days) and chronic (75 days) toxicity of spherical polystyrene particles (20, 200, 430 µm) on Cyprinus carpio fish using OECD methodology. No mortality or behavioral changes were recorded after acute or chronic tests conducted on 1, 10, 100 mg/L polystyrene particles. Polystyrene showed bioavailability mainly through ingestion with food, causing weight loss in fish. Fish lots exposed to the polystyrene mix (particle sizes of 20, 200, 430 µm and 1.2 mg PS/L total concentration) showed changes in physiological indices but without major significance compared to control lots. After 75 days of chronic exposure of fish to a mix of polystyrene particles, organs were collected for sub-lethal effect investigation. Polystyrene was found to cause oxidative stress in fish organs. A very significant increase in the activity of the enzymes catalase and glutathione reductase, correlated with lipid peroxidation in gills, were observed. In the liver, catalase and glutathione S transferase activity increased, but there were no lipid peroxidation effects. Also, alanine transferase and aspartate transferase activity showed significant changes. Regarding the vitellogenesis initiated in the liver, vitellogenin activity increased by 40%. EROD activity saw a 20% increase compared to control fish, indicating stress enzyme expression. Instead, acetylcholinesterase showed significant inhibition (>80%) in the brain and muscle. The protein profile showed new stress protein expression compared to the control in the gills and liver. Based on the results of our study, the introduction of new regulations monitoring the accumulation of microplastics in surface water is an urgent matter.

CO₂, a major industrial (waste)water treatment process byproduct, significantly contributes to climate change, desertification and overall water depletion. Therefore, there is a significant interest in decreasing CO₂ amounts, generated by various technological processes, through a wide range of methods from geological sequestration to biological sequestration. The CO₂ (waste)water treatment byproduct sequestration into agricultural CO₂-enhanced irrigation water offers several benefits by enhancing crop yield and repurposing emissions. This sustainable approach supports climate neutrality via biological sequestration, promotes circular economy principles, and strengthens the link between agriculture and climate change. In this study, the effect of CO₂-enriched water irrigation was analyzed in a complex network of plants germination, soil bacterial populations’ dynamics and soil composition. Results showed that germination rates of plants irrigated with CO₂-enriched water were species specific. Sage plants increased their germination and growth when irrigated with CO₂-enriched water compared with plants irrigated with plain water. Moreover, CO₂ addition favored the development of soil anaerobic bacteria in detriment of aerobic bacteria and subsequently changing organic and nitrogenous compounds soil composition compared to plain water irrigation. For the first time, the germination process influenced by CO₂ was correlated with on overall possible CO₂ effects on bacterial population growth dynamics and soil quality metabolites availability.

Microplastics (MPs) pollution has become a persisting problem over the last decades and a critical issue for environmental protection and human health. In this context any scientific data able to reveal the MPs presence and to improve the characterization and identification in different systems is valuable. The aim of this paper was to assess available techniques for determining MPs in real freshwater samples and subsequently to highlight the occurrence and type of MPs in the study case area (Somesul Mic River). The specific objectives of the study were: i) MPs separation and visual characterization; ii) microscopic analyses and morphological characterization of MPs; iii) Raman and FT-IR spectroscopic identification of MPs. MPs sampling was performed from the fresh water and sediment using planktonic nets and sieves with different mesh sizes (20 to 500µm). After digestion with hydrogen peroxide, the MPs characterization was performed using both classical microscopic techniques as well as scanning electron microscopy (SEM). For the MPs identification, Raman and FT-IR spectrometry techniques were used. Large (1-5 mm) and small (1 µm to 1 mm) MPs were observed in the shape of fibers, fragments, foam, foils and spheres in various colors (red, green, blue, purple, pink, white, black, transparent, opaque). Polymers were identified related to scientific literature and reference spectra. The presence of polyethylene (PE), polypropylene (PP) and polystyrene (PS) was registered for all sampling point. The MPs laboratory investigations have raised some issues regarding the identification of MPs particles with the size smaller than 500µm, being characterized especially under microscope. Small MPs particle dispersed on cellulose filter were identified using micro-Raman spectroscopy highlighting the same type of polymers. The results showed that both spectrometric methods Raman or FT-IR confirm the identification of the same type of polymers. No differences were registered between the sampling points due to the widespread presence of MPs. The sediments samples presented a greater abundance compared to the water samples. Overall, it is necessary to continue the optimization of the MPs separation protocol and identification according to the complexity of samples, mainly due to the limitation and lack of spectral databases.