Plants play a fundamental role by intercepting air particulate matter (PM) and improving air quality. The link between the accumulation of pollutants and the leaf exposure time to air pollution remains unclear as it depends on different factors. The aim of this study is to test if the metal and PM accumulation in holm oak leaf is linked to exposure time to air pollution. For this study, 1- (1y) and 2-year (2y) old holm oak leaves were sampled in an urban area near Naples. Those leaves were analyzed to measure the amount of particulate matter (PM₂.₅–₁₀ and PM>₁₀) and the Cr, Cu, Mn, and Ni metal concentrations. The results displayed that leaf Cr, Cu, and Mn accumulation are linked to exposure time, whereas leaf PM deposit was not directly linked to the exposure time. PM deposit on leaves could be influenced by rainfall events or by the saturation of leaves’ surface.

The fine fraction of the Tagaran natural clay (TC) from the Kurdistan region of Iraq-Sulaimani was characterized and used to remove Cd ions from industrial swage. Using XRF, XRD, SEM, and FTIR, the dominant clay mineral of the Tagaran clay mineral was identified as saponite, with minor amounts of chlorite. The clay was examined for its efficiency to adsorb and remove (Cd²⁺) in the presence of other heavy metal contaminants from Sulaimani industrial zone sewage by a batch method. The effect of initial pH, equilibrium time, temperature, clay dosage, and Cd²⁺ concentration was studied. Results were evaluated using Langmuir, Freundlich, Temkin, and Redlich-Peterson isotherms. The kinetics could be best fitted to pseudo-second-order reaction kinetic model. In addition, the activation energy and the amount of calculated and experimentally determined heavy metal loads were consistent. The thermodynamic studies showed spontaneous endothermic adsorption. The trioctahedral smectite (saponite) showed a good efficiency for the adsorption of Cd²⁺ from the real sample (up to 100%) which at least partly can be explained by cation exchange. Tagaran clay is a candidate material for the production of an adsorber material for removing Cd²⁺ from aqueous solutions.

Mercury-based electrode was the choice of electrode material for many years, and it has been extensively used in voltammetry studies. Nonetheless, alternative electrode materials are highly preferred in voltammetry studies due to the toxicity of mercury. This work introduces a novel green sensor, nylon 6,6-modified graphite HB pencil electrode (Nyl-MHBPE) as electrochemical method for chlorothalonil determination by differential pulse cathodic stripping voltammetry (DPCSV). The Nyl-MHBPE was significantly improved electroactivity towards the reduction of chlorothalonil, under the optimal conditions (at pH 8.0). It was clearly observed that nylon 6,6 revealed as an efficient modifier for enhancing stripping signal for voltammetric analysis. Moreover, the developed sensor showed great feature such as a remarkably low detection limit in nanomolar level (0.94 × 10⁻⁸ M) with a linear range from 1 to 26 × 10⁻⁷ M. It presented excellent repeatability with high sensitivity and selectivity. Besides, analysis of chlorothalonil in real water samples was successfully carried out with good recovery values (92.5–103%) and relative standard deviation (RSD) values < 2.2%. The performance of Nyl-MHBPE was also compared to bare pencil electrode (HBPE). Another significant feature of this work is that the conductivity properties of the Nyl-MHBPE were superior as compared to hanging mercury drop electrode (HMDE). The present study provides admirable merits that make the Nyl-MHBPE selected as a promising electrochemical sensor to perform routine analysis of chlorothalonil.

Plant species diversity could enhance plant productivity and pollutant removal efficiency in constructed wetlands (CWs). However, the potential importance of plant density for ecosystem functioning has largely been neglected. In this study, we conducted a factorial experiment in which three common plant species were planted in a gradient of species richness (one, two, and three) and seven species compositions at two densities (six and twelve individuals per microcosm). Plant total biomass and total organic carbon (TOC) and total inorganic nitrogen (TIN) removal efficiency were measured to explore the effect of plant species diversity and density on the ecosystem functioning of CWs. Results showed that (1) plant species richness had no significant effect on plant total biomass and TOC and TIN removal efficiency under high and low plant density. (2) There were significant differences in TIN removal efficiency among seven species compositions under low plant density; especially, the presence of Canna indica reduced the TIN removal efficiency. In contrast, species composition and species identity had no significant effect on ecosystem functioning under high plant density. (3) High plant density increased plant total biomass of C. indica monocultures, and also enhanced TIN removal efficiency in mixtures of two species. These results indicated C. indica alone may not be an ideal species for enhancing pollutant removal in constructed wetlands but planting at high density could mitigate its negative effect on ecosystem functioning.

The effects of atmospheric precipitation on heavy metal accumulation and deactivation amendment in wheat surrounding a lead smelter were studied. The total precipitation amounts of Cd, Pb, and As in an in situ test were noticeably more than their amounts in an off-site test over the entire growing period of wheat. In the same soil-wheat system, the heavy metal concentrations of wheat leaves in the off-site test were significantly lower than those in the in situ test near the lead smelter. Specifically, Cd, Pb, and As were 53.1%, 89.2%, and 85.7% less, without the amendment of the heavy metal deactivator (HMD). Meanwhile, the deactivation effect improved in the off-site test, resulting in the respective Cd, Pb, and As decreases of 6.0%, 46.3%, and 22.1% more, compared with it in the in situ test. The changes in heavy metal concentrations of wheat grains were consistent with those of wheat leaves. The concentrations of Cd and Pb in the off-site test were 10.7% and 91.0% lower than the in situ values, without the amendment of the HMD, and deactivation effect also had enhanced, with Cd and Pb decreasing by 1.3% and 9.6% more. The heavy metal concentrations of wheat leaves in the indoor pot test were significantly lower than those in the in situ test, with Cd, Pb, and As 74.4%–87.3%, 95.6%–97.0%, and 86.2%–87.4% less, respectively. After repeated leaf-washing treatment, the effect of HMD amendment was further enhanced, with Cd, Pb, and As decreasing by 30.8%, 33.6%, and 34.7%, respectively. All tests conducted indicate atmospheric precipitation is the controlling pollution source. Deactivation amendment can reduce the heavy metal concentrations of wheat leaves and grains, even in the presence of precipitation contamination, although the presence of precipitation reduces the effect of HMD amendment. Repeated leaf-washing can enhance the effect of HMD amendment and decrease the accumulation of heavy metals from atmospheric precipitation in wheat.

Pesticides are widely used chemicals in the agricultural sector to control pests, diseases, and other plant pathogens. This study aimed to assess the storage conditions of pesticides, the community perception, and health risk of pesticide exposure. The study was conducted in three different zonal cities in Ethiopia, East Africa, namely Mekelle, Aksum, and Alamata. Community perception was studied in a community living near a pesticide stockpile with a cross-sectional study of 384 randomly selected households. In addition, questionnaires were administered, a field investigation was conducted, and focused group discussions with responsible bodies were held to assess storage condition. Accidental ingestion and inhalation were considered to determine average daily exposure (ADE) and incremental lifetime cancer risk (ILCR). This study reveals that all obsolete and banned hazardous pesticides were stored in one area. The storage sites were only secured with simple locks and exposed to rain, sunlight, and temperature variation. The majority of the residents perceived that pesticides pose risk to human health (46.6%), to the environment (28.4%), and to animals (25%). The association between residence proximity of respondents to the store and side effect of obsolete pesticides is statistically significant (p = 0.008). Children aged 2 years and below have higher ADE when exposed to the same concentration of contaminant via inhalation. The probability of a person developing cancer was very low with a risk value of 2.54E−08 and 1.65E−07 as a result of exposure to air containing heptachlor and dichlorodiphenyltrichloroethane (DDT), respectively.

Mushrooms are rich sources of organic nutrients (especially proteins). However, they can excessively accumulate metals in their fruiting bodies that pose a risk to human health. The aim of this study was the determination of Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn contents, daily intake, and health risk index values of some mushroom species collected from the eastern Black Sea region of Turkey (Arsin, Trabzon). The samples were collected from hazelnut gardens that are free from industrial pollution and have a low population density. As a result of elemental analysis, it was determined that the concentration ranges of Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn in the mushrooms were as follows: 0.29–9.11, 0.04–3.70, 0.01–8.29, 0.18–20.82, 3.1–79.8, 5.2–673.0, 14.9–752.0, 63.0–7769.0 mg/kg dry weight. Daily intakes of all the elements were found to be below the reference dose in Fistulina hepatica, Hydnum repandum, Macrolepiota procera, and Tapinella atrotomentosa. Amanita caesarea, Agrocybe praecox, Amanita vaginata, Cantharellus cibarius, Craterellus cornucopioides, Daedalea quercina, Gymnopus dryophilus, Ganoderma lucidum, and Infundibulicybe gibba were found to have high risk index values especially with respect to Cd, Co, and Pb. According to Pearson correlation analysis, the correlations between Fe–Mn (0.840, p < 0.01) and Pb–Ni (0.7540, p < 0.01) couples are significant.

To examine how two dominant species coexist within a tidal wetland in the Yellow River Delta, we studied the spatial distribution patterns and ecological relationships of Tamarix chinensis and Suaeda salsa. We also analyzed the relationship between these two plant species and soil chemical properties. Nine quadrats were established, and aerial photography was carried out in July 2018 in the study area to investigate plants and soil. Results showed that T. chinensis showed an aggregation distribution at scales of 0–10 m, 0–30 m, and 0–50 m from the sea to inland. Unlike T. chinensis, S. salsa showed an aggregation distribution at approximately 0–50 m in the study area, which meant the aggregation distributions of T. chinensis and S. salsa were found at different scales and S. salsa tended to aggregate distribution compared with T. chinensis. Meanwhile, T. chinensis and S. salsa had negative correlations far from the sea at a scale of 0–20 m and at the offshore area at a scale of 0–30 m. However, in the intermediate area, S. salsa and T. chinensis showed a positive correlation at a scale of 0–30 m. In general, the relationship between the two groups tends to be negatively correlated in a small range. Given that the tidal action decreased from the sea to inland, the driving factors of population aggregation gradually changed from tidal flooding to an interspecific relationship. The different characteristics of the different species may also have had an effect. And the aggregation of adult plant species had a beneficial impact on the establishment and growth of seedlings and plants. Furthermore, soil properties comprised complex actions including environmental conditions and ecological processes. The soil chemical properties such as soil salinity and nutrients were also influenced by the species’ canopy.

Pervious concrete (PC) provides multiple benefits, including reducing stormwater runoff, purifying water, recharging groundwater, and reducing the heat island effect. This study aims to determine an effective way to reuse municipal solid waste incinerator (MSWI) fly ash (FA), MSWI bottom ash (BA), and rice husk ash (RHA) as single or binary partial replacements for ordinary Portland cement (OPC) in PC. The ashes and PC specimens were characterized via X-ray fluorescence spectroscopy, X-ray powder diffraction, field emission-scanning electron microscopy, and Fourier transform infrared spectroscopy. The compressive strength, water permeability, and toxicity characteristic leaching procedure (TCLP)-released metals were investigated to evaluate the PC quality. The main components of the ashes were similar to those of OPC, suggesting that the ashes could be reused as cement materials; however, the cementitious activity of the ashes, especially MSWI FA, was relatively low. All ashes except 1100 °C MSWI FA met the standard requirements and can be applied as pozzolanic materials. The three PC specimens with binary replacements containing RHA (550, 700, and 900 °C) and MSWI BA (1100 °C) showed a synergistic effect and exhibited a higher 90-day compressive strength than the other specimens with single and binary ash replacements containing RHA (550 and 900 °C). The water permeability ranged between 0.106 and 0.391 cm/s, and the TCLP-released metal concentrations from all specimens met the regulatory standards of Taiwan. The results indicated that replacement with MSWI BA and RHA in cement materials provides an acceptable compressive strength and water permeability.

Graphene oxide has great potential for use as an adsorbent due to the high specific surface area, high negative charges, and abundant oxygen-containing functional groups. However, the difficulty of graphene oxide to separate from water renders it impractical for real water treatment. In the present study, a novel graphene oxide/hexadecyltrimethylammonium composite sponge (GO/HDTMA) was prepared and investigated for use as a filtration material for the removal of Cu(II) from water. The formed porous GO/HDTMA sponge was highly stable in water. The adsorption was spontaneous and exothermic, increasing with decreasing temperatures. The material showed good ability to remove Cu(II) with competing cations (K⁺, Na⁺, Ca²⁺, and Mg²⁺) present. Five cycles of adsorption-desorption-regeneration studies showed that, after adsorption, the material could be successfully regenerated for repeated use by using a 1-M HCl solution as the desorption reagent. At a sufficiently high dose, GO/HDTMA showed an excellent performance for Cu(II) removal from river water containing different coexisting solutes. Finally, our 30-day column study revealed that the GO/HDTMA sponge is a good filtering material for the removal of Cu(II) from river water. In conclusion, the GO/HDTMA sponge is an excellent adsorbent material for use in flow-through water treatment applications for Cu(II) removal.