The present study evaluated the level of heavy metal (HM) pollution in Vistula river sediments in a highly urbanized Warsaw agglomeration (Poland). Magnetometry was used to assess the pollution level by measuring the fine fractions (0.071 mm and < 0.071 mm) of sediments collected from the surface layer of the riverbank. The magnetic methods (e.g., mass magnetic susceptibility χ, temperature-dependence magnetic susceptibility, and hysteresis loop parameters) were supplemented by microscopy observations and chemical element analyses. The results showed the local impact of Warsaw’s activity on the level of HM pollution, indicated by the maximum concentrations of magnetic particles and HM in the city center. The sediment fraction < 0.071 mm was dominated by magnetite and by a large amount of spherical-shaped anthropogenic magnetic particles. The pollution from the center of Warsaw was transported down-river over a relatively short distance of approximately 11 km. There was a gradual decrease in the concentrations of magnetic particles and HM in areas located to the north of the city center (down-river); furthermore, χ and concentrations of HM did not decrease to the values observed for the area to the south of Warsaw (up-river). The study showed two possible sources of sediment pollution: traffic-related and heat and power plant emissions. The influence of an additional source of pollution cannot be excluded as the amount of spherules in the sediments at the center was extremely high. The present study demonstrates that magnetometry has a practical application in detecting and mapping HM pollution in river systems.

There exists a high demand for fast, simple, and reliable methodologies for determining the presence of organochlorine pesticides (OCPs) on environmental samples. Moreover, the toxicity and accumulation of potential OCPs in several environments have led to the development of technologies that achieve their removal from contaminated waters. In this study, a novel method combining a dispersive liquid–liquid microextraction procedure based on the solidification of floating organic drop is developed and validated for the extraction, preconcentration, and determination of 10 OCPs: α-BHC, p,p′-DDE, δ-BHC, dieldrin, p,p′-DDT, endosulfan I, endosulfan sulfate, heptachlor, heptachlor epoxide (isomer B), and methoxychlor in water samples. The results show that the calibration curves were linear for all the studied compounds, and the coefficients of correlation higher than 0.99. The variation coefficient for precision and accuracy was lower than 10%, and the accuracy ranged from 93 to 105%. Low limit of detection and limit of quantification values ranging from 0.06–3.00 ng mL⁻¹ and 0.20–10 ng mL⁻¹ were obtained, respectively. The capability of the proposed method was confirmed using an analysis of the water samples before and after the degradation process; this was achieved by employing nanomaterials, while performing an analysis of 160 real samples that were sourced from a Brazilian river. A cobalt-doped magnetite was applied for the environmental remediation of the studied compounds, and it was verified that the novel material has the potential to be used in environmental remediation with a degradation efficiency exceeding 80% for the majority of the studied compounds.

Secondhand tobacco smoke (SHS) is a significant public health problem for all ages worldwide. Children are more vulnerable to the health effects of SHS because of the inhalation of more air per body volume compared to adults. The study aimed to assess neurobehavioral performance among SHS exposed Egyptian basic school children (10–12 years) and its relationship with urinary cotinine levels. Multistage cluster sampling was carried out, where 181 children (80 exposed and 101 non-exposed children) were recruited. A questionnaire on SHS exposure was sent to students’ parents/caregivers. Urine samples were taken for assessment of cotinine levels by enzyme immunoassay. A Neurobehavioral test battery was measured. The exposed children had significantly lower performance in tests of attention (PASAT) [5.22 ± 5.10 vs. 6.98 ± 5.87, p = 0.035], visuomotor speed (Digit Symbol and Trail making A) [41.40 ± 18.01 vs. 46.53 ± 15.89 and 107.92 ± 44.34 vs. 92.44 ± 37.09; respectively] than non-exposed subjects. The neurobehavioral effects were correlated with urinary cotinine levels among children exposed to SHS compared to unexposed children. The study revealed poor performance in neurobehavioral domains of attention and visuomotor skills among children exposed to SHS. This necessitates the implementation of antismoking media awareness programs on the harmful effects of SHS and how to protect children from it.

This study evaluates bioaccumulation and translocation potentials of trace elements (TEs) by Saponaria officinalis L. (soapwort) and Achillea millefolium L. (yarrow) in order to select and optimize phytoremediation methods for the polluted environment of the city of Bor, Serbia. According to the enrichment factor for soil (i.e., 57.9–128.8 for Cd and As), pollution index (i.e., 6.6–84.7 for Cu), pollution load index (2.9–98.8), individual potential risk factors (11.5–5163), and potential ecological risk index values (260–6379), urban and rural soils from the city of Bor were classified as very contaminated with the investigated TEs. The results from all the indices and statistical analysis showed significant ecological risks of Cu, As, and Cd at the investigated sites and urge the need for remediation. The enrichment factor of the plants for As (566.3) and Cd (306.2) indicated a high enrichment level of the herb organs at all the sites. Since there are small differences in metal accumulation index values between the herbs and their parts (root, shoot), soapwort and yarrow can be considered as potential bioindicators. Based on the biological concentration and translocation factors, soapwort can be recommended as a suitable herb for phytoextraction purposes of Pb, As, and Cd polluted areas. Yarrow shows good characteristics for phytoextraction of Cu, Pb, and As from the contaminated soil. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) results indicate their similar origin from atmospheric deposition. Therefore, these herbs can be utilized as a bioindicator and phytoremediator in polluted areas influenced by metallurgical activities to detect possible levels of TEs.

Pharmaceutically active compounds are gradually increasing in different environments such as surface waters, groundwater, and soil. Paracetamol is a pharmaceutical used as a pain reliever and antipyretic. In this study, paracetamol removal was investigated using manganese oxide octahedral molecular sieves (OMS-2) and persulfate. In the first stage of the study, OMS-2 was produced in a laboratory, and then paracetamol removal was investigated in OMS-2 only, persulfate only, and a combination of OMS-2/PS. When using 5 mM persulfate and 0.1 g/L OMS-2, the paracetamol removal efficiency increased to 99.5%. The use of OMS-2 with persulfate resulted in faster and more effective removal of paracetamol compared with OMS-2 only and persulfate only. In another stage of the study, the effects of reaction temperature and pH were investigated. For this purpose, the pH was changed in the range of 2–8, while the temperature was examined at 20, 30, and 40 °C. A high rate of paracetamol removal occurred at all pH and temperature values tested. Paracetamol removal was investigated at different OMS-2 and persulfate concentrations, optimum OMS-2 amount was determined as 0.1 g/L, and optimum persulfate dosage was 20 mM. The reusability of the OMS-2 catalyst was investigated, showing a decrease in removal efficiency with each cycle. In the later stages of the study, free radical quenching studies, the effect of humic acid and inorganic anions and the characterization of the synthesized OMS-2 were performed.

Chlorinated ethene contaminations are a widespread environmental hazard and a threat to drinking water supplies. Electrochemical methods for in situ degradation of the chlorinated ethenes in the plume are under development. In laboratory, complete electrochemical removal of chlorinated ethenes in undivided flow-through reactors is reported when using palladized iron (Fe) cathodes (C) and cast Fe anodes (A). The cost of the electrodes depends on the Fe purity. In this study, 99.95%, 99.8% and 98+% palladized Fe cathodes, and 99.8% Fe and cast Fe anodes were investigated. The surfaces of the palladized Fe electrodes were examined by scanning electron microscopy. Deposition of palladium by electroless plating onto the Fe surfaces was uneven and disconnected. The less pure the Fe material, the higher the degree of oxide coverage of the cathode’s surface during electroless plating. Electrochemical application via Fe electrodes installed in a flow-through reactor of field-extracted groundwater and sandy sediment was studied for three-electrode configurations of A–A–C and C–C–A. The anodes of 99.8% Fe and cast Fe demonstrated different corrosion patterns; uniform corrosion and graphitization, respectively. Corrosion products clogged the sandy matrix. The corrosion product compositions differed between the A–A–C and C–C–A electrode configurations. The groundwater pH of 7.35 ± 0.05 changed downgradient to the electrochemical zone to 9.5 and 6.2 for the A–A–C and C–C–A reactors, respectively. The response of the hydrogeochemical settings to the established redox zones showed that the C–C–A electrode configuration was less intrusive to the surrounding environment. Graphical Abstract .

The rapid growth of human population and global industrialization has resulted in the generation of larger amounts of wastewater containing various pollutants, among which toxic heavy metals. Adsorption is efficient for this purpose, but its application is limited by the high cost of adsorbent materials. Chitosan (CS) and phosphorylated microcellulose (PMC) have a high potential as low-cost and effective adsorbents for water remediation. Nonwoven CS/PMC nanocomposite fiber mats were produced by electrospinning with up to 50% by weight of PMC. The thermal, chemical, and morphological properties of the mats were studied. Batch adsorption trials were carried out using Cd²⁺ ions. Kinetics and isotherm models were tested against experimental results and the thermodynamic properties were calculated. Results showed that the pseudo-second order model best fitted experimental data and suggested chemisorption as the mechanism for Cd²⁺ removal. Langmuir isotherm best described equilibrium data reaching the maximum adsorption capacity of 283 mg/g at 60 °C. This high value was attributed mainly to the large amount of phosphate groups, which require less energy to capture the metal cations. Thermodynamic evaluation suggested that the adsorption is a spontaneous endothermic reaction. These results confirm that CS/PMC mats are easy to produce, and provide high adsorption capacity in simulated wastewater containing Cd²⁺. These laboratory-based adsorption experiments will assist in selecting/ranking of potential candidate matrices, and scale-up development of technologies for complex wastewater applications.

In different parts of the world, it is verified that green areas provide an improvement in the quality and well-being of the population in the environmental and psychological aspects. In this study, the micronucleus test is performed in Tradescantia pallida (Rose) D.R. Hunt var. purpurea (TRAD-MCN) to detect the mutagenic potential of atmospheric gases in different situations of vehicular flow and urban green areas. Following the protocols for TRAD-MCN, the results obtained confirm the positive correlation between the intensity of vehicle traffic and the frequency of micronuclei. However, in regions with green areas, the results obtained with TRAD-MCN are inferior even with intense vehicular flow. The period of high temperatures and low relative humidity can potentiate the action of stressors on plant species used as a bioindicator. Because of the results found in this study, we can infer that green areas reduce the effects of polluting gases. We emphasize here the importance of preserving or creating parks and reserves in an urban environment to improve air quality and consequently the health of the population.

Layered double hydroxides (LDHs), known as a class of anionic clays, have attracted considerable attention recently due to their potential applications in different areas as catalyst materials, energy materials, and adsorbent materials for environmental remediation, especially for anionic pollutant removal. In this study, magnesium aluminum layered double hydroxide (MgAl-LDH) was synthesized by two methods: standard coprecipitation and urea hydrolysis. Their textural properties and morphologies were examined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG) and differential (DTG) analysis, and point of zero charge (pHₚzc). The specific surface area was calculated from BET adsorption equation. The results indicated that the crystallinity and the regularity of the samples prepared by urea hydrolysis were much preferable to those prepared by the coprecipitation method. Their sorption properties toward phosphate were investigated and the experimental evidence showed that, at the initial concentration of 100 mg L⁻¹ and at room temperature, the LDH synthesized by urea hydrolysis had a percentage removal of 94.3 ± 1.12% toward phosphate ions while 74.1 ± 1.34% were uptaked by LDH synthesized by coprecipitation method, suggesting that the crystallinity affects the sorption capability. The sorption mechanism indicates that phosphate ions could be sorbed onto LDHs via electrostatic attraction, ligand exchange, and ion exchange.

Desiccation of the Namak Lake (NL) can result in the release of fine-grained dust contaminated with heavy metals, while there is little information available on the propagation of metals in the bed sediments of this lake. In this study, contamination of metals in the surface sediments of the NL was analyzed and the pollution status of sediments was assessed using geo-accumulation index (Igₑₒ), enrichment factor (EF), the consensus-based sediment quality guidelines (CBSQGs), and mean probable effect concentration quotient (mPECQ). Results indicated that metal concentrations at the southern part were higher than at the middle and northern parts of the lake. Possible reasons are (i) pollution loads mainly entered the lake through the rivers at the west and northwest, but accumulated at the southern parts, (ii) hard layer of salt covering the bottom of the NL at the northern part suppresses adsorption of metals to the sediment, and (iii) the muddy nature of sediments at the southern part makes it easier for metals to be absorbed. EF results showed that sediments at the southern part of the lake were moderately enriched with lead (Pb). The low Igₑₒ values suggested no pollution with the metals, and CBSQG values showed that the sediments of the NL were not toxic, while the mPECQ index suggested a toxicity probability of less than 25%. Cluster analysis classified the metals into two clusters. In general, the results showed that metal pollution in the surface sediments of NL was generally low although the concentration of Pb at the southern part of the lake was worrisome.