Glyphosate and glufosinate ammonium are the active ingredients of commonly used herbicides. Active agricultural lands extend over a large part of the Veneto region (Eastern Po Valley, Italy) and glyphosate and glufosinate ammonium are widely used. Consequently, surface waters can be potentially contaminated. This study investigates the occurrence of glyphosate and glufosinate ammonium as well as aminomethylphosphonic acid (AMPA, the degradation product of glyphosate) in river water of Veneto. Eighty-six samples were collected in 2015 at multiple sampling points across the region. Samples were analyzed for the two target herbicides, AMPA as well as for other variables, including water temperature, pH, dissolved oxygen, conductivity, hardness, BOD, COD, inorganic ions, total nitrogen, total phosphorus, total suspended solids, arsenic, and lead. The average concentrations (all samples) were 0.17, 0.18, and 0.10 μg L⁻¹ for glyphosate, AMPA, and glufosinate ammonium, respectively. The European upper tolerable level for pesticides (annual average 0.1 μg L⁻¹) was often exceeded. Chemometric analysis was therefore applied to (i) investigate the relationships among water pollutants, (ii) detect the potential sources of water contamination, (iii) assess the effective water pollution of rivers by identifying river basins with anomalous pollution levels, and (iv) assess the spatial variability of detected sources. Factor analysis identified four factors interpreted as potential sources and processes (use of herbicides, leaching of fertilizers, urban/industrial discharges, and the biological activity on polluted or stagnant waters). A discriminant analysis revealed that the pollution from anthropogenic discharges is homogeneously present in surface water of Veneto, while biological activity and fertilizers present heterogeneous distributions. This study gives insights into the concentrations of herbicides in rivers flowing through a wide region that has heavy use of these chemicals in agriculture. The study also points out some hot-spots and suggests the future implementation of the current monitoring protocols and network.

Penguins can bioaccumulate metals, a portion of which can be deposited in the environment through organic remains such as excrement, carcasses, and eggshells. In order to determine Cu and Pb concentrations and their relationship to soil, organic matter and grain size were determined in 27 samples collected in zones without penguins, penguin transit zones, and Adelie (Pygoscelis adeliae), Chinstrap (P. antarctica), and Gentoo penguin (P. papua) colonies on the Ardley Peninsula, Maritime Antarctica. An atomic absorption spectrophotometry analysis was carried out, organic matter was determined by loss on ignition, and grain size was measured with a laser diffraction particle size analyzer. The principal component analysis shows a relationship between the variables Cu, Pb, and grain size and areas with penguin presence. Cu concentrations in soils varied among areas (χ², 15.707; p = 0.0004), with higher concentrations in transit zones and penguin colonies (142.63 and 140.79 mg/kg, respectively) than in zones without penguins (83.33 mg/kg). Pb concentrations in soils also varied among areas (χ², 6.5029; p = 0.0387), and were higher in transit zones (5.92 mg/kg) than in the penguin colonies (4.45 mg/kg). Grain size differed significantly among areas (χ², 13.506; p = 0.0012), with higher values in transit zones (avg. 37.38 μm) than in penguin colonies (avg. 26.93 μm) and zones without penguins (avg. 20.72 μm). Organic matter did not differ significantly among the studied zones (χ², 2.0882; p = 0.3520). There is a positive correlation between Cu-Pb (Rho, 0.5532; p = 0.0028), Cu-grain size (Rho, 0.4756; p = 0.0130) and Pb-grain size (Rho, 0.4879; p = 0.0098). The presence of penguins increases Cu concentrations in Antarctic soils due to its bioaccumulation and elimination through excrement; however, the presence of penguins has a minor influence on Pb concentration in soil, probably because this metal is stored efficiently in bones, feathers, and eggshells.

A magnetic glycine-grafted chitosan sorbent (Gly) was functionalized to produce a hydrazide derivative (HGly). The two sorbents were tested in batch mode for the sorption of a series of 10 metal ions present in the groundwater collected in three wells in the Wadi (valley) Nasib mining area (SW Sinai, Egypt). HGly is much more efficient for metal recovery than Gly. Under selected experimental conditions (sorbent dosage 1.5 g L⁻¹), the sorption efficiency is not sufficient for achieving the standard levels for drinking water: the most problematic metal ions in terms of drinkability remain aluminum (too high metal concentration in the groundwater), cadmium, and chromium for the three wells (and nickel in the case of only one well). Increasing the sorbent dosage improves the treatment efficiency. The sorbent (HGly) was tested in fixed-bed columns. The breakthrough curves were compared for the different metals for the groundwater collected in the most contaminated of the three wells. The levels of metal concentration in the treated groundwater are too high for direct use in irrigation. However, they are consistent with the standards for livestock drinking water (based on FAO recommendations, Food and Agriculture Organization of the United Nations). The metals can be readily desorbed using 0.5 M HCl solutions with a relatively high concentrating effect (i.e., 50 times). The re-use of the sorbent for three successive cycles of sorption/desorption cycles shows a progressive but weak decrease in sorption and desorption performances.

Inorganic anion monitoring is essential for bioreactor operation and is related for pollution control or energy and products recovery. However, there is a lack of studies validating methods for inorganic anions analyses in conditions compatible to those in bioreactor operations treating different types of wastewater. This paper provides a systematic statistical study and matrix-effect assessment for sugarcane vinasse, leachate, sewage and synthetic sewage. Sample preparation consisted of only a filtration and sample dilution. Cl⁻, NO₂⁻, NO₃⁻, PO₄³⁻ and SO₄²⁻ were determined in a Dionex ICS 5000® equipped with a chemical conductivity suppressor. Calibration curves were linear and well-adjusted between 2.5 and 50 mg L⁻¹ for all the anions in all the tested matrices, except PO₄³⁻ and SO₄²⁻ in vinasse. A calibration range for PO₄³⁻ in all tested matrices was 5.0 to 100 mg L⁻¹, whereas a range from 5.0 mg L⁻¹ to 50 mg L⁻¹ was obtained for SO₄²⁻ in vinasse. All the anions yielded recoveries in the range of 85–115% for all the tested matrices. Relative standard deviations lower than 10 and 2% were achieved for peak areas and retention times, respectively. A signal enhancement was observed for all the tested matrices and all the anions. The matrix effect level varied from −1.7 (NO₂⁻ in vinasse) to −33.9% (Cl⁻ in leachate). Sewage was the less affected matrix, while leachate gave higher matrix effects. Validation results and the matrix effect assessment showed that a simple sample preparation is suitable for multi-elemental analyses of inorganic anions for complex environmental samples.

Lack of scientific literature exists regarding the effects of gibberellic acid (GA₃) application timings on various phenological and physiological aspects of seed crop of locally available onion cultivars. Therefore, current study was planned in Vegetable Research Area, University of Agriculture, Faisalabad to optimize the growth stage for GA₃ application on seed production in two local onion cultivars (Phulkara and Dark Red) during 2013 and 2014. Application timings of gibberellins at 100 mg/L of H₂O were as (G₁) control (no spray), (G₂) foliar application at 2–3 leaf stage, (G₃) foliar application at 6–7 leaf stage, and (G₄) foliar application at the time of flowering. Data on average of both years showed that tallest plants (66.15 cm) and maximum number of leaves per plant (84.56) were noted in cv. Phulkara when GA₃ was applied at 2–3 leaf stage. Minimum number of days to initiate flowering (47.92) and maximum number of umbels per plant (15.45) were noted with GA₃ application at 6–7 leaf stage in Phulkara and Dark Red, respectively. The highest seed yield per umbel (2.94 g) was recorded in cv. Dark Red when GA₃ sprayed at 6–7 leaf stage, while GA₃ application at the time of flowering in the cv. Phulkara produced seeds with highest seedling vigor index (586.79). Overall, it appears that seed yield and quality characters were promoted by the application of GA₃ at different growth stages and could be valuable for seed production of onion.

Process related to power generation, i.e., extraction and burning of coal, strongly affects the soil, water resources, and air quality. Pollutants generated by the coal mining can lead to a number of environmental problems and has become matter of global concern. This study has focused on to evaluate the cytotoxicity and phytotoxicity of surface waters collected in the surroundings of the Thermoelectric Power Plant President Médici-UTPM (Candiota, Brazil), through Allium cepa bioassay and physicochemical analyzes. Three water samples collected at points P1, P2, and P3 were compared to the negative control (NC) for all variables analyzed. The P2 sample resulted in the lowest mitotic index (MI) values (23, 33.1, and 40.7%), followed by P1 (23, 33.1, and 40.7%). However, the P3 sample had the highest MI values (50.2, 40.1, and 36.3%) and was the most mutagenic sample compared to NC and other treatments. Samples P1, P2, and P3 were phytotoxic to A. cepa, resulting in abnormal seedlings. Through physicochemical analysis, all collected water samples showed high electrical conductivity and turbidity, indicating an increase in the deposition of metallic ions and organic compounds in these samples. Based on these findings, we can conclude that the analysis of surface water is an important step for screening mining areas potentially contaminated by coal compounds. Therefore, our study points out some consequences of mining process, in terms of A. cepa bioassay as well as their harmful effect on physicochemical constituents of surface waters, indicating the need for environmental monitoring of this region.

Ecological footprint has been widely accepted as an indicator of environmental performance in recent years since it considers carbon dioxide emissions, the collapse of fisheries, the change in land use, and deforestation. This paper investigates, if exists, the convergence in per capita ecological footprint among G20 countries by employing the annual data for the period 1961 to 2014. A bootstrap-based panel KPSS test with structural breaks and club convergence test are carried out. Eventually, this paper is expected to contribute to the literature of natural resources and ecology/environment by (1) monitoring the panel variable of ecological footprint, (2) launching stochastic and deterministic convergence analyses, and (3) estimating the club convergence parameters. In conclusion, the confirmative results in favor of environmental convergence are obtained by exhibiting the stochastic and deterministic convergences and deriving the output of merging clubs.

Most technologies used for decontamination presents good results for high concentrations, but limitations for lower ones. The desirable Hg concentration in the water is extremely low because of its toxicity. The aims of this study were to evaluate inorganic mercury (Hg²⁺) and methylmercury (CH₃Hg⁺) toxicity in Nostoc paludosum, to assess the potential of this cyanobacteria strain to remove these Hg species from aqueous medium and also to investigate Hg methylation by the cyanobacteria. CH₃Hg⁺ determination was performed by gas chromatography-pyrolysis-atomic fluorescence spectrometry in cultures exposed to a concentration of 20 μg L⁻¹ for 30 days. Both Hg species were removed from the supernatant, ranging from 73 to 96% of Hg²⁺ and from 73 to 95% of CH₃Hg⁺. Ultrastructural Hg²⁺ effects in the cyanobacteria cells investigated by transmission electron microscopy revealed higher production of glycogen, cyanophycin, and intrathylacoidal spaces than the control group. When Hg was added to the culture in the form of CH₃Hg⁺, a decrease corresponding to approximately 60% of the initial concentration due to Hg volatilization was observed. The production of CH₃Hg⁺ by the cyanobacteria was detected in concentrations near the limit of detection (0.0025%) of the bioaccumulated THg. This is an advantage for biotechnological decontamination applications, as CH₃Hg⁺ is a very toxic specie and can be bioaccumulated and biomagnified. The results demonstrated that cyanobacteria cells are an efficient alternative to retain and/or remove Hg at low concentrations and they constitute a potential tool for a “final cleaning” of contaminated waste water.

In this work, disks containing different amount of the TiO₂ precursor impregnated on the raw red clay were produced. The disks were obtained by pressing in metal template and subsequently calcined at 500 °C. The raw clay was used as rigid support to fix the TiO₂. The materials were characterized by X-ray diffraction, diffuse reflectance spectroscopy, N₂ adsorption-desorption (BET and BJH), scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. The ability of disks to produce superoxide and hydroxyl radicals after photoexcitation with UV irradiation was monitored by EPR. The catalytic efficiency was evaluated by the Reactive Red 141 dye discoloration under artificial UV light and sunlight. The reaction parameters such as concentration of RR-141 and irradiation source were evaluated. The results showed that the disks were able to decolorize 97.5% under sunlight at 60 min. The disks were also efficient in the discoloration until the tenth cycle, resulting in discoloration values near the initial cycles. Additionally, the dye fragments produced in cleavage of molecule during the reaction were evaluated by LC/MS-MS. Graphical Abstract