This study aimed at evaluation of air pollution control residues (APCR) and flue gas desulfurization residues (FGDR) from copper foundry in Southwestern Poland as adsorbents of Cu(II) and Pb(II) from simulated wastewater. Studies of the impact of pH and adsorbent dose, as well as sorption isotherms, and kinetic and thermodynamic studies were conducted in a series of batch experiments. The maximum adsorption capacities were equal to 42.9 mg g⁻¹ Cu(II) and 124.4 mg g⁻¹ Pb(II) for APCR and 98.8 mg g⁻¹ Cu(II) and 124.7 mg g⁻¹ Pb(II) for FGDR, which was comparable to mineral adsorbents examined in other studies. Adsorption isotherms followed the Langmuir model, except for Pb(II) for FGDR, which followed Freundlich model. Sorption kinetics for both materials was properly expressed by pseudo-second-order equation. Mean adsorption energy parameter suggested that the adsorption might have occurred via physical bonding. Thermodynamic study revealed that adsorption was spontaneous and endothermic for Cu(II) and not spontaneous and exothermic for Pb(II), with lower temperature favoring the process. The results suggested that both materials had high affinity towards Cu(II) and Pb(II) ions and could be conducted industrial scale research for consideration as potential adsorbents from aqueous solutions.

The aim of this study was to assess the degradation and mineralization of hydroquinone (HQ) by the Fenton’s process in a bubble column reactor (BCR). The effect of the main operating variables, namely, air flow rate, effluent volume, hydrogen peroxide (H₂O₂) concentration, catalyst (Fe²⁺) dose, initial pH, and temperature, were assessed. For all air flow rates tested, no concentration gradients along the column were noticed, evidencing that a good mixing was reached in the BCR. For the best conditions tested ([H₂O₂] = 500 mg/L, [Fe²⁺] = 45 mg/L, T = 24 °C, Q ₐᵢᵣ = 2.5 mL/min, pH = 3.0, and V = 5 L), complete HQ degradation was reached, with ~ 39% of total organic carbon (TOC) removal, and an efficiency of the oxidant use—η H₂O₂—of 0.39 (ratio between TOC removed per H₂O₂ consumed normalized by the theoretical stoichiometric value); moreover, a non-toxic effluent was generated. Under these conditions, the intermediates and final oxidation compounds identified and quantified were a few carboxylic acids, namely, maleic, pyruvic, and oxalic. As a strategy to improve the TOC removal, a gradual dosage of the optimal H₂O₂ concentration was implemented, being obtained ~ 55% of mineralization (with complete HQ degradation). Finally, the matrix effect was evaluated, for which a real wastewater was spiked with 100 mg/L of HQ; no reduction in terms of HQ degradation and mineralization was observed compared to the solution in distilled water.

In this work, a novel magnetic carbon nanotube@zeolitic imidazolate framework-67 (MCNT@ZIF-67) composite was prepared facilely by a one-pot method using Fe₃O₄@SiO₂ as the magnetic element, CNTs as the carbon matrix, and 2-methylimidazole (2-MIM) and cobaltous nitrate (Co(NO₃)₂·6H₂O) as the organic and inorganic elements, respectively. The obtained MCNT@ZIF-67 composite was characterized by transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). Static adsorption experiments demonstrated that the maximum adsorption capacity of MCNTs@ZIF-67 for tetrabromobisphenol A (TBBPA) is 83.23 mg g⁻¹, and the sorption isotherm was fitted well by the Freundlich adsorption model. Dynamic adsorption experiments illustrated that the adsorption of TBBPA on MCNTs@ZIF-67 can reach equilibrium in 20 min, and the adsorption kinetics of TBBPA were fitted well by a pseudo-second-order kinetic model. The adsorption of TBBPA on MCNTs@ZIF-67 showed favorable selectivity. The pH and the NaCl and NH₄Cl common salts did not affect the TBBPA adsorption. Then, the proposed magnetic composite was applied as the adsorbent for the rapid removal of TBBPA in water samples, and the removal ratio of MCNTs@ZIF-67 for TBBPA in different spiked water samples with different volumes was above 95% with RSD < 5%. Furthermore, as a new removal sorbent, the removal reproducibility of MCNTs@ZIF-67 for TBBPA was favorable and stable, with only a 6.0% decrease after 6 cycles.

Effects of functionalization and grafting of TiO₂, CeO₂, and SiO₂ nanoparticles (NPs) were investigated, and toxicity of pristine, functionalized, and grafted NP towards Daphnia magna was measured. Surface functionalization of NP with amine groups decreased hydrophobicity of NP. When NPs were hydrophilic, they were less toxic than hydrophobic NP towards D. magna. Grafting agents influenced toxicity: no toxicity of NP was observed when bio-based and hydrogenated synthetic polymers were used, whereas perfluorinated polymers induced a higher toxicity.

Cycloxaprid (CYC) is a novel neonicotinoid insecticide with high activity against resistant pests but is safe for mammals. The toxic effects of CYC on earthworms (Eisenia fetida) were studied in this paper. The 14-day exposure results showed that CYC is potentially toxic to earthworms, with a 14d-LC₅₀ of 10.21 mg/kg dᵣy ₛₒᵢₗ, and that it induced tissue damage to the epidermis, gut, and neurochord at sublethal doses. During a 21-day exposure, CYC induced oxidative stress in earthworms, and both enzyme activities of catalase (CAT) and superoxide dismutase (SOD) were impacted. In addition, expression of the genes Cat and Sod were down- and upregulated, respectively. The activity of the enzyme acetylcholinesterase (AChE) was increased at day 7 but decreased at day 21 after CYC exposure, while expression of the signal transduction-related genes was significantly regulated. Our study shows for the first time that negative impacts could be induced by CYC on earthworms under both acute and chronic exposure through oxidative stress and gene regulation. The present study provides a database for assessing the environmental risk to non-target organisms resulting from the use of CYC.

Natural deep eutectic solvents (NADES) are a new generation of green solvents. They are mixtures of two or three compounds such as choline chloride as a cationic salt and alcohols, acids, amides, amines or sugars as hydrogen-bond donors. Although the majority of NADES’ components are of natural origin and therefore NADES are often presumed to be non-toxic, the evaluation of their toxicity and biodegradability must accompany the research on their synthesis and application. Therefore, the aim of this work was to investigate the effect of ten synthesised NADES towards bacteria (i.e., Escherichia coli, Proteus mirabilis, Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus), yeast (i.e., Candida albicans) and human cell lines (i.e., HeLa, MCF-7 and HEK293T). In addition, oxygen radical absorbance capacity (ORAC) method was used to determine the antioxidative activity of the tested NADES. Differences in toxicity response between microorganisms and cell lines were observed, and only NADES that contained organic acid showed toxicity towards the test systems. Furthermore, the NADES containing compounds that possess antioxidative activity also showed antioxidative activity. However, research whose primary purpose is the synthesis and application of NADES must be followed by an evaluation of their biological properties (e.g., antimicrobial activity, toxicity towards animal cells and antioxidative or other biological activity) to find the solvent with the best profile for wider industrial applications.

The toxic effects of four powder detergents: two laundry detergents (A and B), one household detergent (C), one dishwashing detergent (D), and the surfactant alkylbenzene sulfonate (LAS) were analyzed in this study on organisms from different trophic levels (microalgae, cladocerans, ostracods, amphipods, macrophytes, and fish). LC₅₀ and EC₅₀ values obtained in the toxicity bioassays varied between 0.019 and 116.9 mg L⁻¹. The sensitivity of the organisms to the detergents was (from most sensitive to least sensitive) Ostracods > microalgae > amphipods > cladocerans > fishes > macrophytes. The toxicity of the commercial products (from most toxic to least toxic) was LAS > D (dishwashing detergent) > A (laundry detergent) > B (laundry detergent) > C (household detergent). When comparing the sensitivity of organisms that inhabit temperate zones (T = 18 °C) to those that are found in tropical zones (T > 25 °C), it was clear that the species that inhabit the tropics are more sensitive to detergents.

SO₂, NOₓ, and metals (including Cd, Cu, Pb, Zn, Mn, Mg, Fe) present in airborne particulate matter are a major threat to preserving good air quality. The complicated pathways and transformation processes that can change their physical/chemical state in the atmosphere renders identifying their origin extremely difficult. With the objective of alleviating this difficulty, we identified and characterized potential local and regional sources of atmospheric pollutants using bioindicators (Hypogymnia physodes) from the Świętokrzyski National Park (SE Poland): 20 lichen samples were collected during winter (February; heating period) and summer (June; vegetative period) seasons and analyzed for metal contents and free radicals concentrations. Our results indicate that the highest gaseous pollutant levels were observed during the heating season, along roads (NO₂) and at the highest elevation (SO₂). The semiquinone/phenoxyl radical concentrations correlated during the heating season with the atmospheric SO₂: ln (free radicals concentrations) = 0.025 SO₂ₐₜₘₒₛₚₕₑᵣₑ + 39.11. For Mn/Fe ≥ 2, the electron paramagnetic resonance (EPR) spectra presented a hyperfine splitting. Results showed that since 1994 metal concentrations increased for Cd, Mn, and Mg, Fe remained somewhat constant for Zn and Cu but slightly decreased for Pb, in agreement with the phasing out of lead in gasoline. Finally, a principal component analysis (PCA) identified two main factors controlling variability within the analyzed parameters: air pollutants transport over long distances and local fuel combustion by both transport and home heating.

Antifouling chemicals have a long history of causing toxicity to aquatic organisms. We measured growth and developmental timing in wood frog tadpoles exposed to the antifouling chemical medetomidine (10 nM–10 μM) starting at two different developmental stages in static renewal experiments. For tadpoles hatched from egg masses and exposed for 3 weeks to 100 nM and 1 μM, head width/total body length ratio was significantly shorter compared to control. For field-collected tadpoles at Gosner stage 24–25 and exposed for 2 weeks, 1 and 10 μM medetomidine significantly slowed development as measured by Gosner stage. Medetomidine (1 and 10 μM) significantly increased the time to metamorphosis by over 16 days on average, and at 100 nM and 1 μM, it significantly decreased mass at metamorphosis. We discuss the possible effects of antifouling chemicals containing medetomidine on globally threatened groups such as amphibians.

Seepage faces, the outer rim of subterranean estuaries, are an important reaction node for SGD-borne nitrate (NO₃⁻) on a global scale. Labile dissolved organic matter (DOM) has been suggested to be a key factor constraining the NO₃⁻ removal rate in aquifer systems. To determine whether and to what extent the availability of labile DOM affects benthic NO₃⁻ reduction in seepage faces, a series of flow-through reactor (FTR) experiments with sandy sediment collected from a seepage face was conducted under oxic conditions. Experimental results revealed that the addition of labile DOM (glucose) to porewater did not trigger a significant enhancement in NO₃⁻ reduction rate. In contrast, the aerobic respiration was boosted from ca. 50 to 90 μmol dm⁻³ sediment h⁻¹ by glucose amendments, accounting for approximately 70% consumption of the labile DOM pool. This rapid consumption may increase the NO₃⁻ reducing capability within the sediment, but only indirectly. Together with fluorescent DOM (FDOM) analyses, it can be inferred that NO₃⁻ reducers tend to choose sediment organic matter the prime electron donor under the experimental conditions. As a result, enrichment of DOM in seepage faces, depending on composition, might only stimulate aerobic respiration and nitrification, thus promoting the increase of ensuing NO₃⁻ fluxes to adjacent coastal waters.