1,720,967 research outputs found
Nitrate removal from polluted water by using a vegetated floating system
No full textNitrate (NO3−) water pollution is one of the most prevailing and relevant ecological issues. For instance, the wide
presence of this pollutant in the environment is dramatically altering the quality of superficial and underground
waters. Therefore,we set up a floating bed vegetatedwith a terrestrial herbaceous species (Italian ryegrass) with
the aim to remediate hydroponic solutions polluted with NO3−.
The floating bed allowed the plants to growand achieve an adequate development. Ryegrasswas not affected by
the treatments. On the contrary, plant biomass production and total nitrogen content (N-K) increased proportionally
to the amount of NO3− applied. Regarding to the water cleaning experiments, the vegetated floating
beds permitted to remove almost completely all the NO3− added from the hydroponic solutions with an initial
concentration of 50, 100 and 150 mg L−1. Furthermore, the calculation of the bioconcentration factor (BCF) indicated
this species as successfully applicable for the remediation of solutions polluted by NO3−. In conclusion, the
results highlight that the combination of ryegrass and the floating bed system resulted to be effective in the remediation
of aqueous solutions polluted by NO3−
Use of Biostimulants as a New Approach for the Improvement of Phytoremediation Performance—A Review
No full textEnvironmental pollution is one of the most pressing global issues, and it requires priority attention. Environmental remediation techniques have been developed over the years and can be applied to polluted sites, but they can have limited effectiveness and high energy consumption and costs. Bioremediation techniques, on the other hand, represent a promising alternative. Among them, phytoremediation is attracting particular attention, a green methodology that relies on the use of plant species to remediate contaminated sites or prevent the dispersion of xenobiotics into the environment. In this review, after a brief introduction focused on pollution and phytoremediation, the use of plant biostimulants (PBs) in the improvement of the remediation effectiveness is proposed. PBs are substances widely used in agriculture to raise crop production and resistance to various types of stress. Recent studies have also documented their ability to counteract the deleterious effects of pollutants on plants, thus increasing the phytoremediation efficiency of some species. The works published to date, reviewed and discussed in the present work, reveal promising prospects in the remediation of polluted environments, especially for heavy metals, when PBs derived from humic substances, protein and amino acid hydrolysate, inorganic salts, microbes, seaweed, plant extracts, and fungi are employed
Effect of three safeners on sulfur assimilation and iron deficiency response in barley (Hordeum vulgare) plants
No full textBACKGROUND: Safeners are agrochemicals used in agriculture to protect crops from herbicide injuries. They act by stimulating herbicide metabolism. As graminaceous plants, to cope with iron (Fe) deficiency, activate sulfur (S) metabolism and release huge amounts of Fe-chelating compounds, or phytosiderophores (PSs), we investigated, in barley plants (Hordeum vulgare, L.) grown in Fe deficiency, the effects of three safeners on two enzymes of S assimilation, cysteine (Cys) and glutathione (GSH), and PS release. Finally, we monitored the root Fe content in plants treated with the most effective safener. RESULTS: Generally, all the safeners activated S metabolism and increased Cys and GSH contents. In addition, the safened plants excreted higher levels of PSs. Given that mefenpyr-diethyl (Mef) was the most effective in causing these effects, we assessed the Fe concentration inMef-treated barley and found higher Fe levels than those in untreated plants.
CONCLUSION: The three safeners, in different ways but specifically, activated S reductive metabolism and regulated Cys and GSH contents, PS release rate and Fe content (Mef-treated barley). The results of this research provide new indications of the biochemical and physiological mechanisms involved in the safening action
Use of two grasses for the phytoremediation of aqueous solutions polluted with terbuthylazine
No full textThe capacity of two grasses, tall fescue (Festuca arundinacea) and orchardgrass (Dactylis glomerata), to remove terbuthylazine (TBA) from polluted solutions has been assessed in hydroponic cultures. Different TBA concentrations (0.06, 0.31, 0.62, and 1.24mg/L) were chosen to test the capacity of the two grasses to resist the chemical. Aerial biomass, effective concentrations (to cause reductions of 10, 50, and 90% of plant aerial biomass) and chlorophylls contents of orchardgrass were found to be more affected. Tall fescue was found to be more capable of removing the TBA from the growth media. Furthermore, enzymes involved both in the herbicide detoxification and in the response to herbicide-induced oxidative stress were investigated. Glutathione S-transferase (GST, EC. 2.5.1.18) and ascorbate peroxidase (APX, EC. 1.11.1.11) of tall fescue were found to be unaffected by the chemical. GST and APX levels of orchardgrass were decreased by the treatment. These negative modulations exerted by the TBA on the enzyme of orchardgrass explained its lower capacity to cope with the negative effects of the TBA
Lignin for metal ion remediation in aqueous systems
No full textThis chapter deals with the pollution of aquatic environments due to heavy metals and the use of lignin to remediate water-contaminated environments. Firstly, aspects of their toxicity, content in the environment, and remediation technologies are presented and discussed. Particular emphasis has been made on the use of lignin and its derivatives to remediate polluted water with a double benefit: to prompt effective solutions to restore polluted water and use a natural material that otherwise could impact on the environment, being lignin biomass produced in high amounts, often burned regardless of the value of this precious material. We demonstrated that lignin that does not have specific selectivity for complex polluted water can be chemically modified, promoting at the same time adsorption capability, stability, selectivity, and recyclability. Lignin chemical modification that gives desired physical, chemical, and mechanical properties is crucial to achieving hydrophilicity, hydrophobicity, and broadening pollutant kinds for efficient removal. Analysis of the published literature also confirmed that the development of nanoscaled lignin-based adsorbents is under investigation and could represent the advanced solution in the coming decades
) Wheatgrass
No full textThis work aimed to study the effect of some light spectra on the growth, oxidative state, and stress of einkorn
wheatgrass (Triticum monococcum L. ssp. monococcum). To this end, six light treatments, having the same total incident photon flux
density (PFD) of 200 μmol m−2 s−1, were applied to einkorn and compared: only blue light; only red; three blue:red combinations,
at different proportions of total PFD (75:25%, 50:50%, and 25:75%, respectively); and a wide spectrum, taken as a control
treatment, composed of blue (18% of PFD), red (18%), and intermediate wavelengths (64%). Light treatments affected the contents
of pigments (chlorophylls and carotenes), hydrogen peroxide (H2O2), and malondialdehyde (MDA). These results revealed the changes in the oxidative status of wheatgrass, in response to the different light treatments. However, the dichromatic light with blue ≥50% of the total PFD appeared to be the best combination, guarantying good wheatgrass yield, increasing pigment content, and reducing H2O2 and MDA when compared to the other light treatments. Our findings also contribute to explaining the available literature on the effect of these kinds of light on the increase in phenolic compounds and antioxidant activity in einkorn wheatgrass
Phytodepuration of Nitrate Contaminated Water Using Four Different Tree Species
No full textWater pollution by excessive amounts of nitrate (NO3−) has become a global issue. Technologies to clean up nitrate-contaminated water bodies include phytoremediation. In this context, this research aimed to evaluate four tree species (Salix alba L., Populus alba L., Corylus avellana L. and Sambucus nigra L.) to remediate nitrate-contaminated waters (100 and 300 mg L−1). Some physiological parameters showed that S. alba L. and P. alba L. increased particularly photosynthetic activity, chlorophyll content, dry weight, and transpired water, following the treatments with the above NO3− concentrations. Furthermore, these species were more efficient than the others studied in the phytodepuration of water contaminated by the two NO3− levels. In particular, within 15 days of treatment, S. alba L. and P. alba L. removed nitrate quantities ranging from 39 to 78%. Differently, C. avellana L. and S. nigra L. did not show particular responses regarding the physiological traits studied. Nonetheless, these species removed up to 30% of nitrate from water. In conclusion, these data provide exciting indications on the chance of using S. alba L. and P. alba L. to populate buffer strips to avoid NO3− environmental dispersion in agricultural areas
Effect of Light Spectrum on Gas Exchange, Growth and Biochemical Characteristics of Einkorn Seedlings
No full textThe use of Light Emitting Diode (LED) lights in microscale vegetable production is more and more widespread. In this context, the effect of light spectrum on photosynthesis, growth, shoot yield, pigment content, and nutritional status of einkorn seedlings (Triticum monococcum L. ssp. monococcum), germinated and grown in a nutrient solution, was investigated. Plants were subjected to six different LED light treatments, all having a photon flux density (PFD) of 200 μmol m−2 s−1. Two light treatments were monochromatic (red or blue), three dichromatic (blue and red in the proportion), and one of a wider spectrum (selected as a control). All the light treatments affected the morphological, biochemical, and nutritional status of einkorn seedlings. Overall, the dichromatic treatments were the most effective in stimulating biomass production, CO2 assimilation, and evapotranspiration, as well as contents in chlorophyll a and b and carotenoids, and additionally nitrogen, phosphorous, manganese, iron, and zinc. These results are of relevance for the beneficial effects of dichromatic LED treatments in maximizing einkorn shoot yield and nutritional values, and in limiting energy consumption in indoor cultivation
Effect of agrochemicals on biomass production and quality parameters of tobacco plants
No full textModern agriculture involves the use of synthetic compounds (agrochemicals) in order to maximize crop yields. However, inappropriate fertilization and/or the use of pesticides can have adverse effects on crop productivity and quality. In this context, a study has been carried out to ascertain the effect of increasing dosages of a chemical fertilizer (Greenhouse Special) and some widely used pesticides on tobacco plants. To this purpose biomass, chlorophyll contents and the concentration of NO3- and NH4+ were determined. Results showed that NO3- and NH4+ significantly accumulated in tobacco plants following the application of the two the highest fertilizer dosages. Furthermore, some pesticides altered NO3- and NH4+ concentration
in leaves. Finally, in order to estimate the effect of these compounds on nitrogen acquisition and metabolism, Nitrogen Use Efficiency was evaluated. Data of NUE evidenced that the optimal dosage of fertilizer was 0.250 g/plant. Moreover, it was found that the active ingredients of pesticides affected NUE in the species studied
The treatment of duckweed with a plant biostimulant or a safener improves the plant capacity to clean water polluted by terbuthylazine
No full textWater pollution is becoming alarming since thousands contaminants are dispersed in the aquatic environments, and agricultural practices, for the massive use of pesticides, are contributing to exacerbating this problem. In this context, a research aimed at investigating the ability of duckweed (Lemna minor), a free-floating aquatic species widespread throughout the world, to remediate water polluted with five different concentrations of a herbicide - terbuthylazine (TBA) - was carried out. In addition, duckweed was treated with a plant biostimulant and a safener with the aim of increasing the plant's capacity to tolerate and remove the TBA from the water. The results evidenced that the herbicide affected the duckweed already at the lower concentrations, reducing its capacity to proliferate and the area of its fronds. On the contrary, when the TBA treatments were performed in combination with the biostimulant or the safener the average area of the fronds was affected of lesser extents, compared to the plants treated with the herbicide only. Antioxidant enzymes, namely ascorbate peroxidases (APX) and catalases (CAT), were investigated and it was found that the biostimulated and safened duckweed showed increased activities of these enzymes, compared to the plants treated with TBA only. At last, some phytofiltration experiments were planned. The biostimulated and safened duckweed removed more TBA from polluted water than the plants treated with the herbicide alone. In conclusion, this research showed that duckweed is suitable for cleaning water polluted with TBA and this potential can be successfully improved by treating the species with a biostimulant or a safener
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