To protect forest cultures against browsing, chemical repellents can be used. With their applications, however, a problem arises with disruption of biological and chemical equilibria in the environment (e.g., soil-plant system). The aim of this study were to assess possible interactions of repellents, denatonium benzoate (DB), and capsaicin (Cps), with the soil matrix, especially the impact of their addition on the mobility of individual micronutrients and macronutrients, such as calcium, copper, iron, magnesium, manganese, phosphorus, sulfur, and zinc, and to verify the hypothesis that the presence of repellent compounds does not affect the plant-available nutrient concentrations in soil. Batch laboratory soil sorption experiment and the “diffusive gradient in thin films” (DGT) technique were applied to evaluate the elements’ mobility in the soils. Sorption experiment using Chernozem and Fluvisol showed decreased mobile forms of Cu and S with the additions of both repellents and conversely increased mobile forms of Ca and Mn for DB, in both soil types. With increasing Cps rates, the mobile forms of Fe in Chernozem decreased and Mn in Fluvisol increased. The DGT experiment confirmed increased mobile/available Mn in both soils for both repellents and Fe in Fluvisol in the case of capsaicin. Soil application of both, DB and Cps, suggested to be able to influence the elements’ mobility, particularly, Mn mobility in soil significantly increased after repellent application. Their possible behavior in rhizosphere soil/soil solution should be investigated in further research.

Amaranthus hybridus L. has great potential for use in phytoremediation of soils contaminated with cadmium (Cd). In this study, we found higher absorption of Cd by the roots of A. hybridus than by its other organs. To understand the mechanism of Cd accumulation in A. hybridus roots, a comparative proteomic approach was used to differentiate the two-dimensional electrophoretic profiles of root proteins in Cd-free and Cd-treated plants. Twenty-eight differentially expressed proteins were successfully identified using matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry. Of these, 10 were specifically expressed under Cd stress, and another 11 were upregulated and 7 downregulated by >2.5-fold under Cd stress. We observed increased expression of proteins involved in energy metabolism, protein metabolism, stress and defense, and signal transduction. These changes likely enhanced Cd tolerance and enrichment in A. hybridus. The downregulated proteins were mainly involved in the synthesis of microRNAs, cell walls, and other structural components. These observations were further confirmed by quantitative fluorescence PCR. The resulting differences in protein expression patterns suggest that redirection of root cell metabolism might be an important survival mechanism for A. hybridus under Cd stress.

Ninety-seven seasonal, passive indoor and outdoor air samples were collected in Shanghai to study polybrominated diphenyl ethers (ΣPBDEs, 16 congeners including BDE-209), their concentrations, composition profiles, seasonal variations, influencing factors, emission sources, and human inhalation exposure. In summer, median indoor concentrations of Σ ₁₅ PBDEs (excluding BDE-209) were 82 pg m⁻³ in offices and 30 pg m⁻³ in homes, ∼3 times the winter concentrations. The average summer concentration of 130 pg m⁻³ BDE-209 in homes was higher than that in offices (which was 90 pg m⁻³); in winter, home and office concentrations were similar (46 and 47 pg m⁻³, respectively). For outdoor air, the median concentration of Σ ₁₅ PBDEs in summer (12 pg m⁻³) was twice the winter concentration (6 pg m⁻³), while the summer median concentration of BDE-209 (398 pg m⁻³) was half the winter concentration (794 pg m⁻³). Higher concentrations of Σ ₁₅ PBDEs indoors compared with outdoors showed that the lower brominated BDEs found were mainly from indoor sources. Meanwhile, the much lower indoor concentration of BDE-209 compared with the outdoors showed that BDE-209 came mainly from outdoor sources. The data set also indicated that electric/electronic appliances were the main sources of indoor ΣPBDEs, and old appliances emitted more lower brominated BDEs, while industrial emissions should be the main source of the outdoor BDE-209. Median daily human exposures to Σ ₁₅ PBDEs and BDE-209 through inhalation were estimated to be 0.23 and 1.73 ng day⁻¹ in winter and 0.65 and 2.28 ng day⁻¹ in summer for adults. The human inhalation exposure to ΣPBDEs (3.44 ng day⁻¹ for adults and 1.33 ng day⁻¹ for toddlers) was comparable to that from eating contaminated fish for both toddlers and adults in Shanghai.

In this study, the effect of flue gas CO₂ on growth, lipid production, and fatty acid composition of a green microalga Acutodesmus obliquus KGE 30 was investigated. The highest growth rate (0.46 g L⁻¹ and μₘₐₓ = 1.09 day⁻¹), total inorganic carbon removal (95.9 mg L⁻¹), and lipid productivity (20.1 mg L⁻¹ day L⁻¹) was obtained at 14.1 % CO₂ after 4 days of cultivation. In a semicontinuous batch reactor, the highest biomass production (1.19 g L⁻¹) was achieved after 12 days with continuous injection of flue gas CO₂. Compared with synthetic CO₂, fatty acid methyl ester analysis showed that the amount of unsaturated fatty acid increased by 19.2 % with 14.1 % flue gas CO₂. The application of flue gas CO₂ improved biomass production and lipid productivity in A. obliquus. The current investigation demonstrated that the use of flue gas CO₂ could reduce the cost of microalgae biomass production for better biofuel generation.

The Orcia River basin lies north of the Mt. Amiata mining district and may receive potentially harmful/toxic elements such as mercury (Hg) and arsenic (As) therefrom. The Orcia River eventually flows to the Ombrone River, which in turn flows to the Tyrrhenian Sea. The analysis of stream sediments collected in the Orcia River and its main tributaries, as well as in the Ombrone River, indicates moderate concentrations of both Hg and As (median values, Hg 118 μg/kg and As 5.25 mg/kg), rarely exceeding Italian environmental quality standards. Exceptionally high values for both elements are observed only in close proximity to the former Pietrineri Hg mine (Hg 195 mg/kg and As 35 mg/kg). Travertine and unconsolidated deposits associated with thermal springs in the area generally exhibit low Hg concentrations (4–320 μg/kg), with a significant exception of 23 mg/kg at Bagni San Filippo. Arsenic concentration in the same deposits is more variable with a peak level of 358 mg/kg. Surface waters collected at the same sites as stream sediments show Hg and As concentrations below the Italian mandatory limits for drinking waters (1 μg/L for Hg and 10 μg/L for As). Likewise, in thermal springs, Hg concentrations are low, whereas As concentrations are relatively high (up to 23.4 μg/L), which is in agreement with previous studies. At present, the input of toxic elements from the mining district into the Orcia and Ombrone watersheds is lower than inputs documented in the Paglia and Tiber catchments south of Mt. Amiata and does not pose an immediate environmental threat. However, the possible remobilization of Hg-contaminated sediments during flash flood events cannot be dismissed.

The Mediterranean area is highly vulnerable to climate changes that combined with potential land use changes could influence its aquatic systems significantly. The Evros River is one of the most important surface water bodies in the Balkans with an ecologically significant delta that is protected by international legislation. The aim of this study is to analyze the impacts of climate and land use changes on Evros River water quality, for different climatic and socioeconomic scenarios. For this purpose, a hydrodynamic and advection-dispersion model was set up and calibrated, three IPCC climatic scenarios were applied, and the pollution loads of the catchment area were estimated. These scenarios involved river discharge decrease due to regional climate changes and socioeconomic and technological development that would lead to population growth and to the decrease of agricultural activities. The results indicated that in the case of discharge reduction only, the total nitrate and phosphate concentrations will be increased, while in case of combined land use and discharge changes, the concentration of nutrients will be decreased. Thus, a transboundary long-term management plan of the entire River is needed that would eliminate the pollution pressures and restore its good ecological status.

Accurately measuring air concentrations of agricultural fumigants is important for the regulation of air quality. Understanding the conditions under which sorbent tubes can effectively retain such fumigants during sampling is critical in mitigating chemical breakthrough from the tubes and facilitating accurate concentration measurements. Using laboratory experiments, we studied the effects of air flow rate (100–1000 mL min⁻¹) and sampling time (2–16 h) on the breakthrough of co-applied chloropicrin (CP) and 1,3-dichloropropene (1,3-D) from 600-mg XAD-4 sorbent tubes. Due to the reversible adsorption of the chemicals, it was not possible to determine a tube adsorption capacity that was true across all flow and sample time conditions. Flow rate exerted the stronger influence on breakthrough, particularly for CP, with flow rates in excess of 200 mL min⁻¹ resulting in significant system losses even at the shortest sampling time (2 h). A flow rate of 200 mL min⁻¹ should therefore not be exceeded, irrespective of flow rate. With the use of a single tube (no backup), sampling times up to 4 h showed no system losses (100 % retention). Using a primary and backup tube, sampling periods up to 16 h also resulted in retention of all the added chemical masses. The information will be useful in establishing effective air quality monitoring programs following fumigation events.

In this paper, Zn(0)-catalyzed ozonation degradation of acid orange 7 (AO7) and its impact factors including solution pH, Zn loading, and AO7 initial concentration were investigated through a series of bath experiments. The results demonstrated that Zn could markedly accelerate the degradation of AO7 by ozone (O₃) and the degradation efficiency of AO7 increased by 77 and 71 % within 30 min as compared with those in the systems of O₃ alone and Zn/air, respectively. The reuse of Zn resulted in a slight decline in AO7 degradation, suggesting that a coating of ZnO on the surface of Zn particles weakened Zn catalytic activity. The optimal removal of AO7 was achieved in a wide pH range of 4 to 10, and a lower or higher pH was not conducive to the degradation of AO7. In addition, the degradation efficiency of AO7 increased with Zn loading but decreased with AO7 initial concentration. The introduction of free radical scavengers into the system of AO7/Zn/O₃ confirmed that O₂ •⁻, rather than •OH, was the main free radicals responsible for the rapid removal of AO7. The degradation of AO7 by O₃ assisted with Zn could be well expressed with pseudo-first-order kinetic model.

The degradation of two pesticides, carbofuran (CBF) and ioprodine (IPR), was studied by the photolytic decomposition of hydrogen peroxide (UV/H₂O₂). The influence of two experimental parameters, H₂O₂ concentration and initial pH, as well as their interactions, was investigated. Optimization was carried out where experimental parameters were determined for the treatment of each pesticide. Both pesticides were totally eliminated by UV/H₂O₂ system under optimal conditions. However, significant differences were found: CBF degradation was influenced by both parameters and their interactions, while IPR degradation was not statistically affected by initial pH. Interestingly, analysis of degradation pathways showed a major influence of photolysis process and oxidation due to hydrogen peroxide for the CBF degradation, while the synergistic combination between both of them played the most relevant role during IPR degradation. A mixture of both pesticides was also submitted to UV/H₂O₂ action in which a lower rate was observed for IPR elimination while CBF was not affected. A 90 % of chemical oxygen demand (COD) was removed and 75 % of mineralization was achieved after the treatment of the mixture. Almost 92 % of the toxicity was eliminated making this technique a promising process to treat toxic mixtures of these pesticides.

The present study aimed to minimize the environmental impact from the disposal of electrocoagulated metal hydroxide sludge (EMHS) generated during an electrocoagulation process using aluminum electrode by reusing it as an effective adsorbent for simultaneous removal of fluoride ion (F⁻) and arsenic (As) from aqueous solutions. The adsorbent was characterized by using coupled plasma optical emission spectroscopy (ICP-OES), surface areas and porosity properties, point of zero charge, and X-Ray diffractometry techniques. The surface morphology of adsorbent was studied by scanning electron microscopy (SEM). The dissolution of the adsorbent in function of pH was analyzed in batch experiments. Batch adsorption tests were employed to evaluate the removal and adsorption capacity of adsorbent, under conditions of contact time and adsorbate concentration. In order to determine maximum adsorption capacity of adsorbent and to understand the nature of reaction on their surface, the Langmuir and Freundlich isotherm were calculated. Preferable fitting of the Langmuir isotherm over Freundlich isotherm suggests monolayer coverage of adsorbate at the surface of the adsorbent. Data obtained were also applied to pseudo-first-order and pseudo-second-order equations. The rates of adsorption were found to conform to pseudo-second-order kinetics. The findings of this study revealed that the reuse of EMHS is a promising and efficient adsorbent in order to diminish the fluoride and arsenic pollution from drinking water.