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1.
Sci Total Environ ; 806(Pt 2): 150520, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34600213

RESUMO

Parabens pose increasing threats to human health due to endocrine disruption activity. Adsorption and degradation of parabens by three types of graphene-family nanomaterials (GFNs) were therefore investigated. For a given paraben, the maximum adsorption capacities (Q0) followed the order of reduced graphene oxide (RGO) > multilayered graphene (MG) > graphene oxide (GO); for a given GFN, Q0 followed the order of butylparaben (BuP) > propylparaben (PrP) > ethylparaben (EtP) > methylparaben (MeP), dominated by hydrophobic interaction. MeP removal by all the three GFNs was highly enhanced (0.55-4.37 times) with the assistance of H2O2 due to additional catalytic degradation process, and MG showed the highest removal enhancement. ∙OH was confirmed as the dominant radicals responsible for parabens degradation. For MG and RGO, the metal impurities (Fe, Cu, Mn, and Co) initiated Fenton-like reaction with H2O2 to generate ∙OH. GO contained oxygen-centered free radicals, which were responsible for ∙OH formation via transferring electron to H2O2. Four degradation byproducts of MeP were identified, including oxalic, propanedioic, fumaric, and 2,5-dihydroxybenzoic acids. Combined with density function theory calculations, the degradation sites and pathways were identified and confirmed. These findings provide useful information on mechanistic understanding towards the adsorption and degradation of parabens by GFNs.

2.
Chemosphere ; 283: 131304, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34467944

RESUMO

Herbicides are commonly used globally. However, residual herbicides in soils for ages often result in phytotoxicity and serious yield loss to subsequent crops. In this paper, the multi-walled carbon nanotubes (MWCNTs) were utilized to amend the herbicide polluted soil, and the adsorption performance of herbicides to MWCNTs amended soil was studied. Results indicate efficient alleviation of herbicide-induced phytotoxicity to rice and tobacco due to MWCNTs amendment. When 0.4% MWCNTs were applied, the concentration of sulfentrazone that inhibited the same rice height by 50% (IC50) increased to more than 3 times that of pure soil. When the MWCNTs were used to alleviate the phytotoxicity of quinclorac to tobacco, the MWCNTs not only alleviated the phytotoxicity of quinclorac but also promoted the growth of tobacco. The MWCNTs amended soil significantly increased the adsorption of herbicide to soil than biochar. The soil microbial analysis shows that MWCNTs had no significant effect on soil microbial community diversity, but the long-term exposure to MWCNTs could change the structure of the soil microbial community. Above all, our results highlighted the potential implication of the MWCNTs to ensure crop production by promoting crop growth and reducing the residual bioavailability of herbicides.


Assuntos
Herbicidas , Nanotubos de Carbono , Poluentes do Solo , Adsorção , Herbicidas/análise , Herbicidas/toxicidade , Nanotubos de Carbono/toxicidade , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
3.
J Hazard Mater ; 416: 126126, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492920

RESUMO

Biomass-derived heteroatom-doped porous carbon-based materials are emerging as low-cost adsorbents for removing common pollutants, although the adsorption performance is still unsatisfactory and the main adsorption mechanisms are still controversial. Herein, we report a facile and general method for fabricating biomass-derived N/S dual-doped hierarchically porous carbon adsorbent (MZ-NSPC). The MZ-NSPC material exhibits excellent adsorption capacity (295.8 mg/g for bisphenol F (BPF), 308.7 mg/g for bisphenol S (BPS)), short equilibrium time (30 min), and good reusability (the decline efficiency < 6.15% after five times). The remarkable adsorption performance originates from a large BET surface area, hierarchically porous structure, and N/S heteroatoms dual-doping. Combined with comparative experiments and density functional theory (DFT) calculations, we revealed that the doped N, S heteroatoms played a synergistic effect which promoted the adsorption performance and adsorption sites are mainly the oxidized-S and pyridinic-N. Importantly, for BPF, the proportion contribution of different mechanisms followed the order of hydrophobic interaction > π-π interaction > hydrogen bonding interaction. However, adsorption mechanism of BPS was mainly controlled by π-π interaction. This work not only promotes the development of low-cost and sustainable heteroatom-doped carbon-based materials, but also systematically studies adsorption mechanism of heteroatom-doped carbon-based materials for bisphenols.


Assuntos
Carbono , Compostos Benzidrílicos , Biomassa , Fenóis , Porosidade , Sulfonas
4.
J Hazard Mater ; 416: 126230, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492984

RESUMO

The co-existence of engineered nanoparticles (ENPs) in the environment is an emerging issue remaining poorly investigated. The present study aimed at analyzing the fate of binary mixtures of CuO and ZnO ENPs in a soil-plant system. The ENPs were singly or jointly dosed into soil at 300 mg kg-1 and aged for 7 and 30 days. To evaluate nano-specific effects, individual and combined treatments of metal salts were also applied. Interactions between ENPs and soil-grown barley Hordeum vulgare were determined in terms of biomass, plant mineral composition as well as expression of genes regulating metal homeostasis (ZIP1,3,6,8,10,14, RAN1, PAA1,2, MTP1, COPT5) and detoxification (MT1-3). The bioavailability of Zn and Cu in bulk soil and in the rooting zone was determined using the 0.01 mol L-1 CaCl2 extraction. After combined treatment of ENPs, the extractable concentrations of Cu and Zn were lower than upon individual exposure in bulk soil. The opposite tendency was noted for metal salts. Genes related to metal uptake (ZIP) and cellular compartment (PAA2, RAN1) were mostly up-regulated by single rather than combined application of ENPs. The single and joint exposure to metals salts induced the down-regulation of these genes.


Assuntos
Hordeum , Nanopartículas Metálicas , Disponibilidade Biológica , Cobre , Homeostase , Hordeum/genética , Nanopartículas Metálicas/toxicidade , Solo
5.
Environ Sci Technol ; 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34570468

RESUMO

Rice is known to accumulate arsenic (As) in its grains, posing serious health concerns for billions of people globally. We studied the effect of nanoscale sulfur (NS) on rice seedlings and mature plants under As stress. NS application caused a 40% increase in seedling biomass and a 26% increase in seed yield of mature plants compared to untreated control plants. AsIII exposure caused severe toxicity to rice; however, coexposure of plants to AsIII and NS alleviated As toxicity, and growth was significantly improved. Rice seedlings treated with AsIII + NS produced 159 and 248% more shoot and root biomass, respectively, compared to plants exposed to AsIII alone. Further, AsIII + NS-treated seedlings accumulated 32 and 11% less As in root and shoot tissues, respectively, than the AsIII-alone treatment. Mature plants treated with AsIII + NS produced 76, 110, and 108% more dry shoot biomass, seed number, and seed yield, respectively, and accumulated 69, 38, 18, and 54% less total As in the root, shoot, flag leaves, and grains, respectively, compared to AsIII-alone-treated plants. A similar trend was observed in seedlings treated with AsV and NS. The ability of sulfur (S) to alleviate As toxicity and accumulation is clearly size dependent as NS could effectively reduce bioavailability and accumulation of As in rice via modulating the gene expression activity of As transport, S assimilatory, and glutathione synthesis pathways to facilitate AsIII detoxification. These results have significant environmental implications as NS application in agriculture has the potential to decrease As in the food chain and simultaneously enable crops to grow and produce higher yields on marginal and contaminated lands.

6.
Environ Pollut ; 289: 117912, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34365243

RESUMO

The innovative and sustainable technologies are highly needed to decrease serious environmental problems from current agriculture. Herein, the green and biosafe copper-based nano-agriculture was described for tomato production. Prepared Cu nanoclusters (NCs) showed small size (3.0 ± 0.5 nm) and high bioavailability. At low concentration (1 mg kg-1) in soil, Cu NCs improved the activities of antioxidant enzymes (superoxide dismutase, catalase and peroxidase) in the tomato plants, which could help to slow down leaf aging, increase photosynthesis and carbohydrates content by 19.4 % and 14.9 %, respectively. Cu NCs promoted the roots' growth, especially increasing the root tip' number, which might contribute to the increase in absorption of macronutrients (K, Mg and P) and micronutrients (B, Mn, Cu and Zn). The Cu NCs (1 mg kg-1) promoted tomato growth and increased the tomato fruit yields by 12.2 % compared to the control. Moreover, the tomato fruit qualities had been improved meanwhile the accumulation of Cu in fruits was not observed. These findings indicate that the Cu NCs have potential to be safely applied for tomato production.


Assuntos
Lycopersicon esculentum , Catalase/metabolismo , Cobre , Lycopersicon esculentum/metabolismo , Fotossíntese , Raízes de Plantas/metabolismo
7.
J Hazard Mater ; 422: 126831, 2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34391973

RESUMO

Microplastics (MPs), as an emerging pollutant, may cause deleterious changes to the nitrogen cycle in terrestrial ecosystems. However, single impact of MPs and synergistic effects of MPs with hydrochar on ammonia (NH3) volatilization and soil microbiome in paddy fields has been largely unexplored. In this study, polyethylene (PE), polyacrylonitrile (PAN) and straw-derived hydrochar (HBC) were selected for observations in an entire rice cycle growth period. Results showed that under the condition of 0.5% (w/w) MPs concentration, presence of MPs alone and co-existence of MPs and HBC (MPs + HBC) unexpectedly mitigated cumulative NH3 volatilization from paddy soil compared with the control with no MPs or HBC addition. MPs + HBC increased NH3 volatilization by 37.8-46.2% compared with MPs alone, indicating that co-existence of MPs and HBC weaken the mitigation effect of MPs on NH3 volatilization. Additionally, results of nitrogen cycle related microorganisms closely related to NH3 volatilization demonstrated that MPs + HBC altered the bacterial community structure and species diversity. These findings provide an important opportunity to advance our understanding of the impacts of MPs in agricultural environment and soils, and provide a sound theoretical basis for rationalizing the application of HBC in soil with MPs.

8.
Sci Total Environ ; 796: 148963, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34265616

RESUMO

The occurrence of environmental persistent free radicals (EPFRs) in the environment has attracted a great deal of research attention. Although the major sources of EPFRs in the environment is diesel engine exhaust, the study on the emission characteristics of EPFRs at different working conditions is still very limited. An integrated engine system was adopted to simulate different working conditions of various altitudes and engine speeds, and to examine the emission process of a diesel engine. The results suggested that low engine speed and high altitude are generally associated with high PM10 emission with more stable and ordered structures. Based on the analysis of PAHs on solid and gas phases, PM10 generated from diesel engine at altitude higher than 2000 m may contain substantial amounts of PAHs embedded inside particles, but not adsorbed on the surface. EPFRs signal up to 1.66 × 1020 spins/g were detected in PM10 of the diesel exhaust. Higher engine speed and lower altitude were associated with stronger EPR signals on PM10. However, the accumulated EPR signal intensities after consuming 1 L of diesel were higher at lower engine speed and higher altitude, suggesting higher overall risks. A positive correlation between R value (signal strength ratio of D and G peaks on the Raman spectra) and EPFRs intensity indicated that the EPR signals were associated with the defects of carbon structure. EPFRs intensity in particles showed no significant change in dark, and over 70% of the EPR signals survived under UV light in a one-month aging simulation. The strong persistence of these EPFRs suggested their potential long lasting and widespread risks, which should be investigated extensively.


Assuntos
Material Particulado , Emissões de Veículos , Altitude , Carbono , Radicais Livres , Gasolina/análise , Material Particulado/análise , Emissões de Veículos/análise
9.
Sci Total Environ ; 796: 148962, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34271377

RESUMO

Remediation of agricultural soils polluted with antibiotic resistance genes (ARGs) is important for protecting food safety and human health. However, the feasibility of co-application of biochar and pyroligneous acid, two multifunctional soil amendments, for mitigating dissemination of soil ARGs is unknown. Thus, a woody biochar (BC450) and its by-product, pyroligneous acid (PA450) simultaneously produced at 450 °C from blended wood wastes, were used to compare their individual and combined effects on soil ARG abundance using a 65-day pot experiment planted with leafy vegetable Brassica chinensis L. The individual and combined applications of PA450 and BC450 significantly reduced the absolute abundance of ARGs by 65.7-81.4% and 47.5-72.9% in the corresponding rhizosphere and bulk soil. However, the co-application showed little synergistic effect, probably due to the counteractive effect of BC450 on the PA450-mitigated soil ARG proliferation, resulted from the promoted soil bacterial growth and/or adsorption of antimicrobial components of PA450 by BC450. The decreased abundances of mobile genetic element intI1 and Tn916/1545 in the PA450 treatments demonstrated the potential of PA450 for weakening horizontal gene transfer (HGT). Furthermore, weakened HGT by individual PA450, lowered availability of heavy metals by individual BC450, and different bacterial community (e.g., reduced ARGs bacterial host) together with improved soil properties from co-application of PA450 and BC450 all contributed to the reduced ARG level. This study highlighted the feasibility of co-applications of biochar and pyroligneous acid amendment for mitigating soil ARG pollution. These findings provide important information for developing eco-friendly technologies using biochar and pyroligneous acid in remediating ARG-contaminated soils.


Assuntos
Antibacterianos , Solo , Antibacterianos/farmacologia , Carvão Vegetal , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Humanos , Esterco , Microbiologia do Solo , Terpenos
10.
Sci Total Environ ; 795: 148906, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34328922

RESUMO

Pyrolyzed carbon such as biochar and activated carbon could influence the methanogenesis in paddy soil, which is an important process controlling methane emission. Different electrochemical properties of pyrolyzed carbon may be involved in methanogenesis, such as conductivity and redox activity. However, their different roles have not been thoroughly illustrated before. In this study, we identified the roles of pyrolyzed carbon redox property and electron conductivity in methanogenesis with ethanol as a substrate, by comparing pyrolyzed carbon samples with sequential change of electrochemical properties. Right after the addition, pyrolyzed carbon with highest electron donating capacity (0.85 mmol/g) promoted the methane generation by 33.3%; while, other pyrolyzed carbon with higher electron accepting capacity and lower electron donating capacity than B4 inhibited the methane generation. The relative abundance of electroactive bacteria and certain methanogens increased with the pyrolysis temperature. The strict linear relationship between electroactive bacteria/certain methanogens and cyclic voltammetry peak currents of paddy soil implied that microbial structure was altered due to the improved the electron transfer situation by the electron shuttle ability of pyrolyzed carbon. This study could deepen our understanding about the effect of pyrolyzed carbon on methanogenesis process.


Assuntos
Oryza , Solo , Carvão Vegetal , Etanol , Metano , Oxirredução , Microbiologia do Solo
11.
Sci Total Environ ; 795: 148902, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34328941

RESUMO

Tire microplastics (TMPs) are identified as one of the most abundant types of microplastics, which originate from rubber with intended or unintended release. While increasing knowledge about TMPs concentrates on tire wear particles (TWPs), TMPs from other potential sources like recycled tire crumb (RTC) and tire repair-polished debris (TRD) are much less understood. Excessive levels of TMPs and their additives have been fragmentarily reported in the environment. The accumulating environmental TMPs from different sources may directly or indirectly cause adverse impacts on the environment and human health. The objectives of this review are to (1) summarize the properties, abundance, and sources of TMPs in the environment; (2) analyze the environmental fates and behaviors of TMPs, including their roles in carrying abiotic and biotic co-contaminants; (3) evaluate the potential impacts of TMPs on terrestrial and aquatic organisms, as well as human; and (4) discuss the potential solutions to mitigate the TMP pollution. By collecting and analyzing the up-to-date literature, this review enhances our better understanding of the environmental occurrence, fates, impacts, and potential solutions of TMPs, and further highlights critical knowledge gaps and future research directions that require cooperative efforts of scientists, policymakers, and public educators.


Assuntos
Microplásticos , Plásticos , Organismos Aquáticos , Monitoramento Ambiental , Poluição Ambiental , Humanos , Borracha
12.
Environ Sci Technol ; 55(18): 12317-12325, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34296850

RESUMO

Fluorescent carbon dots (CDs) have been reported as an artificial antenna to amplify the harvesting ability of light and enhance photosynthesis in plants. However, the main mechanism of this promotive effect and contributions of CDs' structure are unclear. Herein, CDs and nitrogen (N)-doped CDs (N-CDs) with blue fluorescence were synthesized, and they could promote photosynthesis and growth of corn at an application concentration of 50 mg·L-1 or lower, compared to the control. Foliar application of N-CDs (5 mg·L-1) on corn could increase the net photosynthesis rate (21.51%), carbohydrate content (66.43% in roots and 42.03% in shoots), fresh weight (24.03% in roots and 34.56% in shoots), and dry weight (72.30% in roots and 55.75% in shoots), which were much higher than those of CDs. Principal component analysis and density functional theory calculation demonstrated that, compared with undoped CDs, N doping enhanced the light conversion and electron supply via altering the structure of CDs, making N-CDs effective light conversion materials and electron donors to promote the photoelectron transfer rate. Furthermore, foliar application of N-CDs could increase the yield and 1000-grain weight by 24.50 and 15.03%, respectively. Therefore, the application of N-CDs could be a promising approach for increasing agricultural production.


Assuntos
Carbono , Pontos Quânticos , Elétrons , Nitrogênio , Zea mays
13.
Environ Sci Technol ; 55(17): 11624-11636, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34197711

RESUMO

Biochar-derived dissolved black carbon (DBC) varies in chemical composition and significantly affects the environmental fate of metal ions. However, the intrinsic molecular composition of DBC fractions and their molecular interaction mechanisms with metal ions remain unclear. We propose a novel, molecular-level covariant binding mechanism to comparatively interpret the heterogeneities, active sites, and sequential responses of copper binding with molecular compounds in DBC and natural dissolved organic matter (DOM). Relatively large proportions of lipid/aliphatic/peptide-like compounds with low mass distributions and lignin-like compounds with oxidized/unsaturated groups existed in acidic- and alkaline-extracted DBC, respectively. A larger percentage of tannin-like/condensed aromatic compounds and higher average conditional stability constants (logK̅Cu) of visible fluorescent components were found for DOM than for DBC. Overall, 200-320 Da and 320-480 Da molecular components contributed significantly to the logK̅Cu values of UVA and visible fluorescent components, respectively, in DBC/DOM. Nitrogenous groups likely exhibited stronger binding affinities than phenolic/carboxylic groups. The sequential copper-binding responses of molecular compounds in DBC/DOM generally followed the order lipid/aliphatic/peptide-like compounds → tannin-like compounds → condensed aromatic compounds. These insights will improve the prediction of the potential effects of DBC on various contaminants and the risks of biochar application to ecosystems.


Assuntos
Cobre , Ecossistema , Carvão Vegetal , Fuligem
14.
Environ Sci Technol ; 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34236843

RESUMO

The use of nanotechnology to suppress crop diseases has attracted increasing attention in agriculture. The present work investigated the antifungal efficacy of copper oxide nanoparticle (CuO NP)-embedded hydrogels, which were synthesized by loading CuO nanoparticles (NPs) in hydrogels formed from cross-linked interaction between chitosan and acrylic acid, against Fusarium wilt of lettuce (Lactuca sativa) caused by Fusarium oxysporum f. sp. lactucae. In comparison with CuO NPs, 7-day Cu dissolution from CuO NP-embedded hydrogels was 34.2-94.8% slower regardless of media type, including water, potato dextrose broth, or a soil extract. In a greenhouse study, upon exposure to CuO NP-embedded hydrogels, CuO NPs, or Kocide 3000 with equivalent amounts of Cu (31 mg/kg), the fresh shoot biomass was significantly increased by 40.5, 26.1 and 27.2%, respectively, as compared to that of the infected control. Notably, CuO NP-embedded hydrogels enhanced uptake of P, Mn, Zn, and Mg and increased the levels of organic acids as compared to the diseased control. Increased salicylic acid (SA) and decreased jasmonic acid (JA) and abscisic acid (ABA) levels with the addition of different forms of Cu may have enhanced disease resistance. Taken together, our findings provide useful information and approach for improving the delivery efficiency of agrichemicals via nanoenabled strategies and an advanced understanding of plant defense mechanisms triggered by Cu-based NPs.

15.
Environ Sci Technol ; 55(13): 9305-9316, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34138538

RESUMO

Interfacial interactions between antibiotic resistance genes (ARGs) and metallic nanomaterials (NMs) lead to adsorption and fragmentation of ARGs, which can provide new avenues for selecting NMs to control ARGs. This study compared the adsorptive interactions of ARGs (tetM-carrying plasmids) with two metallic NMs (ca. 20 nm), i.e., titanium dioxide (nTiO2) and zero-valent iron (nZVI). nZVI had a higher adsorption rate (0.06 min-1) and capacity (4.29 mg/g) for ARGs than nTiO2 (0.05 min-1 and 2.15 mg/g, respectively). No desorption of ARGs from either NMs was observed in the adsorptive background solution, isopropanol or urea solutions, but nZVI- and nTiO2-adsorbed ARGs were effectively desorbed in NaOH and NaH2PO4 solutions, respectively. Molecular dynamics simulation revealed that nTiO2 mainly bound with ARGs through electrostatic attraction, while nZVI bound with PO43- of the ARG phosphate backbones through Fe-O-P coordination. The ARGs desorbed from nTiO2 remained intact, while the desorbed ARGs from nZVI were splintered into small fragments irrelevant to DNA base composition or sequence location. The ARG removal by nZVI remained effective in the presence of PO43-, natural organic matter, or protein at environmentally relevant concentrations and in surface water samples. These findings indicate that nZVI can be a promising nanomaterial to treat ARG pollution.


Assuntos
Nanoestruturas , Poluentes Químicos da Água , Adsorção , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Ferro , Poluentes Químicos da Água/análise
16.
ACS Nano ; 2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-34148346

RESUMO

In agriculture, loss of crop yield to pathogen damage seriously threatens efforts to achieve global food security. In the present work, "organic" elemental sulfur nanoparticles (SNPs) were investigated for management of the fungal pathogen Fusarium oxysporum f. sp. lycopersici on tomatoes. Foliar application and seed treatment with SNPs (30-100 mg/L, 30 and 100 nm) suppressed pathogen infection in tomatoes, in a concentration- and size-dependent fashion in a greenhouse experiment. Foliar application with 1 mg/plant of 30 nm SNPs (30-SNPs) exhibited the best performance for disease suppression, significantly decreasing disease incidence by 47.6% and increasing tomato shoot biomass by 55.6% after 10 weeks application. Importantly, the disease control efficacy with 30-SNPs was 1.43-fold greater than the commercially available fungicide hymexazol. Mechanistically, 30-SNPs activated the salicylic acid-dependent systemic acquired resistance pathway in tomato shoots and roots, with subsequent upregulation of the expression of pathogenesis-related and antioxidase-related genes (upregulated by 11-352%) and enhancement of the activity and content of disease-related biomolecules (enhanced by 5-49%). In addition, transmission electron microscopy imaging shows that SNPs were distributed in the tomato stem and directly inactivated in vivo pathogens. The oxidative stress in tomato shoots and roots, the root plasma membrane damage, and the growth of the pathogen in stem were all significantly decreased by SNPs. The findings highlight the significant potential of SNPs as an eco-friendly and sustainable crop protection strategy.

17.
Environ Sci Technol ; 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078076

RESUMO

The present study investigated the mechanisms by which large- and small-sized nanoscale hydroxyapatite (nHA) suppressed Fusarium-induced wilt disease in tomato. Both nHA sizes at 9.3 mg/L (low) and 46.5 mg/L (high dose) phosphorus (P) were foliar-sprayed on Fusarium-infected tomato leaf surfaces three times. Diseased shoot mass was increased by 40% upon exposure to the low dose of large-sized nHA compared to disease controls. Exposure to both nHA sizes significantly elevated phenylalanine ammonialyase activity and total phenolic content in Fusarium-infected shoots by 30-80% and 40-68%, respectively. Shoot salicylic acid content was also increased by 10-45%, suggesting the potential relationship between antioxidant and phytohormone pathways in nHA-promoted defense against fungal infection. Exposure to the high dose of both nHA sizes increased the root P content by 27-46%. A constrained analysis of principal coordinates suggests that high dose of both nHA sizes significantly altered the fatty acid profile in diseased tomato. Particularly, the diseased root C18:3 content was increased by 28-31% in the large-sized nHA treatments, indicating that nHA remodeled the cell membrane as part of defense against Fusarium infection. Taken together, our findings demonstrate the important role of nHA in promoting disease suppression for the sustainable use of nHA in nanoenabled agriculture.

18.
Sci Total Environ ; 787: 147649, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34000547

RESUMO

Landfills can cause groundwater contamination, the pollution characteristics in groundwater near landfill sites have been extensively investigated, while the rapid identification of leachate leakage remained unclear. Comprehensively characterizing dissolved organic matter (DOM) is crucial for tracing the source, species, and migration of contaminants within groundwater and protecting groundwater sources. Here, we showed that DOM composition from newer landfills was mainly composed of newly-produced tryptophan and tyrosine, and protein-like and humic-like substances were more abundant in landfills that were relatively older. DOM in landfill groundwater was initially dominated by outputs from microbial activities, followed by terrigenous input. Leaked leachate contained an additional dye-derived fluorescent matter at the excitation/emission wavelength of 240-260/440-460 nm that was absent in uncontaminated groundwater. Leachate leakage increased the concentrations of humic-like substance, DOM molecular weight, and microbial activity in the downstream groundwater, resulting in the microorganisms rapidly multiply and secrete large amounts of microbial metabolism by-products, making them suitable indicators of groundwater pollution. Three criteria were proposed to establish an interpretable fluorescence method to identify leachate pollution. The obtained results provide a novel insight into not only the monitoring, early warning, and identification but also the transport, fate and removal or transformation of groundwater leachate in landfills.

19.
ChemSusChem ; 14(13): 2698-2703, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-33960137

RESUMO

It is a great challenge to refine precious metals from e-wastes under mild conditions without hazardous reagents. Herein, black phosphorus (BP) was covalently functionalized with poly(N-isopropylacrylamide) (PNIPAM) to obtain thermo/near-infrared (NIR)-responsive BP-P for precious metal recovery. Precious metals (Au, Ag, and Pd) with higher redox potentials than BP-P could be efficiently recovered by reduction-driven enrichment. Taking Au as an example, the recovery process presented fast kinetics (<15 min), excellent selectivity, and high efficiency (≈98 %). Remote operation with NIR light could generate heat by BP, which induced the hydrophilic-to-hydrophobic transition of PNIPAM, allowing the spontaneous gathering, facile collection, and practical recycle of BP-P following Au extraction. Thanks to the unique features of BP-P, not only could high-quality Au nanoparticles (20-30 nm) be economically extracted (cost: $0.731-1.222 g-1 Au nanoparticles; 5-6 orders of magnitude lower than the market price), but also the formed BP-P-Au nanocomposites have potential application in hydrogen evolution reaction.

20.
Anal Methods ; 13(23): 2567-2574, 2021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-34047309

RESUMO

Understanding the behavior and biological fate of silver nanoparticles (AgNPs) applied on plant surfaces is significant for their risk assessment. Our study's objective is to investigate the interactions between AgNPs and plant biomolecules as well as to monitor and quantify the penetration of AgNPs in spinach by an in situ and real-time surface enhanced Raman spectroscopic (SERS) mapping technique. AgNPs (2 µg per leaf) of different surface coatings (citrate, CIT, and polyvinylpyrrolidone, PVP) and sizes (40 and 100 nm) were foliarly applied onto spinach leaves with different exposure times (1-48 h). Cysteine is the major biomolecule that interacts with AgNPs in spinach based on the in situ and in vitro SERS pattern recognition. The interaction between CIT-AgNPs and cysteine happened in as early as 1 h after AgNP foliar deposition, which is faster than the interaction between PVP-AgNPs and cysteine. Also, the SERS depth mapping shows that particle size rather than surface coating determines the penetration capability of AgNPs in spinach, in which 40 nm AgNPs show a deeper penetration than the 100 nm ones. Last but not least, based on the results of SERS mapping, we detected significantly higher amounts of 40 nm CIT-/PVP-AgNPs than 100 nm CIT-AgNPs internalized in the leaf tissues after 1 h exposure. The estimated percentage of internalized AgNPs (0.2-0.8%) was significantly smaller than that of the total residual Ag (9-12%), indicating the potential transformation of the AgNPs into other Ag species inside the plant tissues. This study facilitates a better understanding of the behavior and biological fate of AgNPs in plant tissues.


Assuntos
Nanopartículas Metálicas , Prata , Folhas de Planta , Análise Espectral Raman , Spinacia oleracea
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