During the last two decades, nanomaterials based on nanoscale zero-valent iron (nZVI) have ranked among the most utilized remediation technologies for soil and groundwater cleanup. The high reduction capacity of elemental iron (Fe⁰) allows for the rapid and cost-efficient degradation or transformation of many organic and inorganic pollutants. Although worldwide real and pilot applications show promising results, the effects of nZVI on exposed living organisms are still not well explored. The majority of the recent studies examined toxicity to microbes and to a lesser extent to other organisms that could also be exposed to nZVI via nanoremediation applications. In this work, a novel approach using amoebocytes, the immune effector cells of the earthworm Eisenia andrei, was applied to study the toxicity mechanisms of nZVI. The toxicity of the dissolved iron released during exposure was studied to evaluate the effect of nZVI aging with regard to toxicity and to assess the true environmental risks. The impact of nZVI and associated iron ions was studied in vitro on the subcellular level using different toxicological approaches, such as short-term immunological responses and oxidative stress. The results revealed an increase in reactive oxygen species production following nZVI exposure, as well as a dose-dependent increase in lipid peroxidation. Programmed cell death (apoptosis) and necrosis were detected upon exposure to ferric and ferrous ions, although no lethal effects were observed at environmentally relevant nZVI concentrations. The decreased phagocytic activity further confirmed sublethal adverse effects, even after short-term exposure to ferric and ferrous iron. Detection of sublethal effects, including changes in oxidative stress-related markers such as reactive oxygen species and malondialdehyde production revealed that nZVI had minimal impacts on exposed earthworm cells. In comparison to other works, this study provides more details regarding the effects of the individual iron forms associated with nZVI aging and the cell toxicity effects on the specific earthworms’ immune cells that represent a suitable model for nanomaterial testing.

Titanium dioxide nanoparticles (TiO₂ NPs) are manufactured worldwide. Once they arrive in the soil environment, they can endanger living organisms. Hence, monitoring and assessing the effects of these nanoparticles is required. We focus on the Eisenia andrei earthworm immune cells exposed to sublethal concentrations of TiO₂ NPs (1, 10, and 100 µg/mL) for 2, 6, and 24 h. TiO₂ NPs at all concentrations did not affect cell viability. Further, TiO₂ NPs did not cause changes in reactive oxygen species (ROS) production, malondialdehyde (MDA) production, and phagocytic activity. Similarly, they did not elicit DNA damage. Overall, we did not detect any toxic effects of TiO₂ NPs at the cellular level. At the gene expression level, slight changes were detected. Metallothionein, fetidin/lysenin, lumbricin and MEK kinase I were upregulated in coelomocytes after exposure to 10 µg/mL TiO₂ NPs for 6 h. Antioxidant enzyme expression was similar in exposed and control cells. TiO₂ NPs were detected on coelomocyte membranes. However, our results do not show any strong effects of these nanoparticles on coelomocytes at both the cellular and molecular levels.

The transformation of dewatered sewage sludge into vermicompost provides an advantageous solution in cases where the sludge is not too contaminated with inorganic pollutants, especially heavy metals. In addition to the conversion of the sludge to a product with a higher-added value, undesirable organic pollutants and micropollutants are partially eliminated. Anaerobically stabilized dewatered sewage sludge from a medium-sized WWTP was subjected to the vermicomposting process under field conditions. Straw was used as the bedding material in the form of two mixing ratios. The almost 1 year of the monitoring of the process focused on the hazardous substances present, the concentrations of which are regulated by legislation on the use of sludge on agricultural land. In addition, the contents of macro- and micro-nutrients such as N, P, K, Mo, Ca, Mg, and the wintering of the earthworm inocula were monitored. The potential of the vermicomposting process to reduce the content of emergent pollutants from the PPCP group was described with respect to 34 detected substances, including five endocrine disruptors. The study suggested that the bio-stabilization of dewatered sewage sludge using earthworms provides an effective technology for converting noxious wastewater treatment products into nutrient-rich bio-fertilizers.

The use of some organic fertilizers may raise concerns about the transfer of hazardous substances to soil and plants. This study examined the impact of soil amendment with compost and vermicompost derived from sewage sludge and straw pellets in different ratios on the accumulation of pharmaceuticals and personal care products (PPCPs) by hemp (Cannabis sativa L.). The concentrations of fifty different PPCPs were measured in compost-treated soil, and in the roots and above-ground biomass of cannabis grown on the soil. The highest bioaccumulation of PPCPs was recorded in plants from previously unfertilized soils low in organic matter, while the lowest concentrations were measured in soil amended with compost or vermicompost made from straw pellets only, without sewage sludge. The effect of sludge-derived compost and vermicompost application on the absorption of PPCPs was statistically determined by measurements in soil samples, roots and shoots of carbamazepine, cetirizine, lamotrigine, telmisartan, paraxanthine, tramadol, triclosan, and venlafaxine. The above-ground biomass exhibited lower PPCP content than roots, suggesting a potential plant defense mechanism for limiting contaminant translocation. Only tramadol and carbamazepine showed significantly increased content in above-ground biomass.

This study evaluates the removal efficiency of 15 estrogenic endocrine-disrupting compounds in two operational constructed wetlands with different designs: a hybrid system (constructed wetland A) and a horizontal system (constructed wetland B). The assessment involved analyzing composite water samples obtained from passive samplers through liquid chromatography-mass spectrometry coupled with yeast assays. Additionally, grab samples of sludge and sediment were examined to determine the endocrine-disrupting compound's adsorption efficacy. The application of the full logistic model enabled the discernment and ranking of the chemicals contributing to mixture toxicity. The findings revealed constructed wetland A's superior efficacy in the removal of individual endocrine-disrupting compounds (with an average efficiency of 94%) compared to constructed wetland B (60%). Furthermore, constructed wetland A displayed a higher estimated estrogenic activity removal efficiency (83%) relative to constructed wetland B (52%). Estrogenic activity was adequately accounted for (58–120%) in half of the analyzed samples, highlighting estrone as the primary estrogenic agent. The investigation underscores constructed wetlands’ effectiveness in purging endocrine-disrupting compounds, suggesting that their integration as secondary or tertiary treatment systems for such pollutants removal merits further exploration.