An analytical methodology was developed for the first time in this work enabling the simultaneous enantiomeric separation of the fungicide fenpropidin and its acid metabolite by Capillary Electrophoresis. A dual cyclodextrin system consisting of 4 % (w/v) captisol with 10 mM methyl-beta-cyclodextrin was employed in a 100 mM sodium acetate buffer at pH 4.0. Optimal experimental conditions (temperature 25 degrees C, separation voltage -25 kV, and hydrodynamic injection of 50 mbar x 10 s) allowed the simultaneous separation of the four enantiomers in <10.7 min with resolutions of 3.1 (fenpropidin) and 3.2 (its acid metabolite). Analytical characteristics of the method were evaluated and found adequate for the quantification of both chiral compounds with a linearity range from 0.75 to 70 mg L-1, good accuracy (trueness included 100 % recovery, precision with RSD<6 %), and limits of detection and quantification of 0.25 and 0.75 mg L-1, respectively, for the four enantiomers. No significant differences were found between the concentrations determined and labelled of fenpropidin in a commercial agrochemical formulation. The stability over time (0-42 days) of fenpropidin enantiomers using the commercial agrochemical formulation was evaluated in two sugar beet soils, revealing to be stable at any time in one sample, while in the other a decrease of 45 % was observed after 42 days. Individual and combined toxicity of fenpropidin and its metabolite was determined for the first time for marine organism Vibrio fischeri, demonstrating higher damage caused by parent compound. Synergistics and antagonists' interactions were observed at low and high effects levels of contaminants.
Microplastics derived from biobased and biodegradable materials will increase their presence in soils as their use becomes more widespread. Research into their effects on soil fauna will help to ensure a better understanding of their environmental impacts. The aim of this work was to study the effects on the development of the earthworm Eisenia andrei (ingestion capacity, survival, growth, cocoon, and hatchling production), earthworm lysosomal stability through the neutral red retention time (NRTT), and substrate enzymatic activity of dehydrogenase (DHA) and fluorescein diacetate-hydrolysing activity (FDA) in the presence of polylactic acid (PLA), polyhydroxybutyrate (PHB) and polyethylene (PE) microplastics in laboratory tests. Three different tests were designed, one feeding test of 4 days, and two medium-term tests with 49 and 112 days. The 4-day test and the 49-day growth test were carried out using OECD artificial soil, while in the 112-day growth test, vermicompost was used as the substrate. PLA and PHB particle ingestion was demonstrated. No concentration or polymer-dependent lysosomal damage or effects on earthworm growth were observed. However, reproductive effects, such as a decrease in cocoon production and the number of juveniles, were reported upon exposure to PE and PLA during medium-term assays. These findings indicated that the toxicity of PLA bioplastic exposure is comparable to that of conventional plastic PE concerning the negative effects on the reproductive efficiency of the detritivorous earthworm E. andrei.
Emerging contaminants in estuarine sediments, such as bis(2-ethylhexyl) phthalate (DEHP) and titanium dioxide nanoparticles (nTiO2), pose ecotoxicological risks that may be exacerbated by co-contamination. This study investigated the impacts of DEHP, nTiO2, and their combinations at environmentally relevant concentrations (1, 10, and 100 mu g/g) on the soil nematode Caenorhabditis elegans in estuarine-like sediment (14.25 parts per thousand salinity). Life history traits and bioenergetics endpoints were examined, with a sample size of >= 45 worms or 9 technical repeats per treatment. While individual exposures did not affect growth, the combination of DEHP (1 mu g/g) and nTiO2 (100 mu g/g) significantly reduced body length by 19%. Single exposure reduced total offspring by 18-41%, whereas the combination of DEHP and nTiO2 synergistically worsened reproductive toxicity (52-74% inhibition), as revealed by Loewe's additivity model and Bliss's independence. DEBtox modeling revealed a shift in physiological mode of action from increased reproductive costs in singular exposures to increased growth and reproductive cost in co-exposure. Moreover, co-exposure significantly intensified the impacts on bioenergeticsrelated endpoints, including ATP level (single exposure: 33-34%; co-exposure: 56%), mitochondrial damage (single exposure: 15-17%; co-exposure: 40%), and oxidative stress (single exposure: 5-7%; co-exposure: 13%). Risk quotients based on reproductive toxicity EC10 and DEBtox-derived zb suggested that environmental concentrations of DEHP and nTiO2 pose high risks in global estuarine sediments, with a 2-fold increase during co- exposure. This study demonstrates that co-contamination of DEHP and nTiO2 synergistically aggravates ecotoxicities through disrupted energy allocation, highlighting the importance of assessing mixture toxicity in environmental risk assessment of estuarine sediments.
Waste generation has been a source of environmental concern in case of inadequate management. However, the potential for resource recovery from waste has been highlighted, and circular economy strategies have been greatly promoted to achieve sustainability goals. Municipal solid waste incineration bottom ash (IBA) and mine tailings represent two relevant waste streams under study for geotechnical applications. The present work aims at investigating the physical, mechanical, chemical, and ecotoxicological characteristics of two mixtures of 90 % bottom ash and 10 % of two different mine tailings (one of iron and another of tungsten, tin, and copper) to evaluate their safe utilization. The results indicated that mixtures of IBA and mine tailings have good compressibility, permeability, and shear strength properties, comparable to granular soils. Additionally, adding 10 % mine tailings in the mixtures had minimal effect on the mechanical behaviour of IBA alone. No substantial concentration of potentially toxic metals or relevant ecotoxic effects were found in any of the analysed materials and their eluates. These results suggest that mixing IBA with mine tailings for geotechnical use, e.g., in embankments or road base/subbase may be a safe option. This represents a promising alternative for valorising both waste streams while promoting sustainable and circular solutions.
Herbicides are important for weed control but can severely impact ecosystems, causing soil and water contamination, biodiversity loss, and harm to non-target organisms. Tebuthiuron, widely used in sugarcane cultivation, is highly soluble and persistent, posing significant environmental risks. Microbial inoculation has emerged as a sustainable strategy to mitigate such damage. This study investigated the phytoremediation potential of Mucuna pruriens and Canavalia ensiformis in tebuthiuron-contaminated soils, enhanced by fungal and bacterial inoculants. Crotalaria juncea served as a bioindicator plant, and Lactuca sativa was used in ecotoxicological bioassays. During a 140-day greenhouse experiment from September 2021 to March 2022, M. pruriens showed faster growth than C. ensiformis in uncontaminated soils but was more affected by tebuthiuron. Bacterial inoculants improved M. pruriens growth under stress, while fungal inoculants mitigated tebuthiuron's effects on C. ensiformis. C. juncea exhibited high sensitivity to tebuthiuron but grew beyond 100 cm with bacterial inoculants. Ecotoxicological assays showed that bacterial bioaugmentation significantly reduced soil toxicity. Natural attenuation further decreased tebuthiuron toxicity, and prior cultivation of M. pruriens enhanced soil detoxification. This integrated approach combining phytoremediation and bioaugmentation offers a sustainable method to degrade tebuthiuron, foster safer agriculture, and reduce environmental and health risks.
A novel diester monomer synthesized from 4-hydroxybenzoic acid, a compound which can be derived from lignin, was used to obtain aliphatic-aromatic copolyesters (P1-P4) by melt polymerization with 1,4-cyclohexanedimethanol, and either 1,4-butanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, or 1,12-dodecanedioic acid as aliphatic diacid. Structure-property relations for the copolyesters were established using FTIR and 1H NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis and tensile testing. The weight-average molecular weight (Mw) of the samples ranged from 41,400 to 48,300 g/mol. As the spacer length in the aliphatic diacid was increased, the glass transition temperature (Tg) decreased from 90 to 51 degrees C, the melting point (Tm) from 175 to 147 degrees C, the tensile modulus from 1800 to 980 MPa, and the yield strength from 76 to 54 MPa, while the elongation at break increased from 270 to 320%. The thermal stability of the copolyesters also decreased for longer aliphatic diacid spacers. The copolyester derived from 1,12-dodecanedioic acid displayed the highest degradation rate in artificial soil, with 4.4% degradation after 30 weeks, and low ecotoxicity in an earthworm viability test. These findings contribute to understanding structure-property relationships and the environmental impact of aliphatic-aromatic copolyesters as potential sustainable materials.
A novel diphenyl monomer, dimethyl 2,2'-(((ethane-1,2-diylbis(oxy))bis(4-acetyl-3,1-phenylene))bis(oxy))diacetate (EDPD), was synthesized from methyl 2-(4-acetyl-3-hydroxyphenoxy)acetate (MAHA), a 2,4-dihydroxyacetophenonederivative, and combined with 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol or p-phenylenedimethanolto afford a series of biodegradable polyesters via melt polymerization. The polyesters were characterized by Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The weight-average molecular weight (M-w) of the polyesters varied from 3.2-4.4 x 10(4) g/mol, the glass transition temperature (T-g) from 52 to 80 degrees C, and the 5% decomposition temperature (T-d,T-5%) was in the 334-362 degrees C range. All the samples exhibited high yield strength (53-68 MPa) and elongation at break (230-330%) values, comparable with poly(ethylene terephthalate) (PET), owing to their aromatic character. Degradability testing of the polyesters in soil yielded mass losses reaching up to 7% after 32 weeks. In ecotoxicity testing, earthworms had a survival rate of more than 80% after 14 d of incubation, indicating relatively low toxicity. Overall, the good thermal and mechanical properties, biodegradability and low ecotoxicity of the polyesters make them promising materials for packaging applications, in replacement for PET, thereby promoting carbon neutrality and sustainable development.
Polymer chain extenders, commonly used in plastic production, have garnered increasing attention due to their potential environmental impacts. However, a comprehensive understanding of their ecological risks remains largely unknown. In this study, we employed the model organism Caenorhabditis elegans to investigate toxicological profiles of ten commonly -used chain extenders. Exposure to environmentally relevant concentrations of these chain extenders (ranging from 0.1 mu g L-1 to 10 mg L-1) caused significant variations in toxicity. Lethality assays demonstrated the LC50 values ranged from 92.42 mu g L-1 to 1553.65 mg L-1, indicating marked differences in acute toxicity. Sublethal exposures could inhibit nematodes' growth, shorten lifespan, and induce locomotor deficits, neuronal damage, and reproductive toxicity. Molecular analyses further elucidated the involvement of the DAF-16 and SKN-1 signaling pathways, as evidenced by upregulated expression of genes including ctl-1,2,3, sod -3, gcs-1, and gst-4. It implicates these pathways in mediating oxidative stress and toxicities induced by chain extenders. Particularly, hexamethylene diisocyanate and diallyl maleate exhibited markedly high toxicity among the chain extenders, as revealed through a comparative analysis of multiple endpoints. These findings demonstrate the potential ecotoxicological risks of polymer chain extenders, and suggest the need for more rigorous environmental safety assessments.
Rainwater is susceptible to pollutants such as sulphur dioxide, nitrogen oxides, heavy metals, and particles, posing challenges to water quality protection and soil degradation, impacting ecosystems and agriculture. The study focuses on the effectiveness of combined ozonation and photocatalysis in improving physicochemical parameters and reducing toxic substances. Integrated analyses, including ecotoxicological assessments, evaluate the impact of treatment on actual rainwater samples. The results indicate significant reductions in color, heavy metals, and organic pollutants after treatment. Microbiological analyses reveal the inactivation of E. coli, which is crucial for safe water reuse. Ecotoxicity studies show no toxicity to crustaceans, but slight toxicity to algae and bioluminescence bacteria in post-treatment samples. Genotoxicity assessments indicate that there is no detectable DNA damage. Overall, the study highlights the complex nature of rainwater pollution and the efficacy of photocatalytic ozonation in reducing contaminants, underscoring the need for more research to ensure sustainable water resource management.
Soils represent crucial sinks for pharmaceuticals and microplastics, making them hotspots for pharmaceuticals and plastic pollution. Despite extensive research on the toxicity of pharmaceuticals and microplastics individually, there is limited understanding of their combined effects on soil biota. This study focused on the earthworm Eisenia fetida as test organism to evaluate the biotoxicity and bioaccumulation of the typical pharmaceutical naproxen and microplastics in earthworms. Results demonstrated that high concentrations of naproxen (100 mg kg - 1 ) significantly increased the malondialdehyde (MDA) content, inducing lipid peroxidation. Even though the low exposure of naproxen exhibits no significant influence to Eisenia fetida , the lipid peroxidation caused by higher concentration than environmental relevant concentrations necessitate attention due to temporal and spatial concentration variability found in the soil environment. Meanwhile, microplastics caused oxidative damage to antioxidant enzymes by reducing the superoxide dismutase (SOD) activity and MDA content in earthworms. Metabolome analysis revealed increased lipid metabolism in naproxen-treated group and reduced lipid metabolism in the microplastic-treated group. The co -exposure of naproxen and microplastics exhibited a similar changing trend to the microplastics-treated group, emphasizing the significant influence of microplastics. The detection of numerous including lipids like 17-Hydroxyandrostane-3-glucuronide, lubiprostone, morroniside, and phosphorylcholine, serves to identify potential biomarkers for naproxen and microplastics exposure. Additionally, microplastics increased the concentration of naproxen in earthworms at sub -organ and subcellular level. This study contributes valuable insights into the biotoxicity and distribution of naproxen and microplastics in earthworms, enhancing our understanding of their combined ecological risk to soil biota.