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1.
J Environ Manage ; 359: 120967, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38723494

RESUMO

In recent years, the Chinese government has actively pursued the implementation of its 'dual-carbon' strategy, concurrently establishing a national carbon emissions trading market. Accurate carbon price forecasts have become essential for policymakers and investors involved in related initiatives. Nevertheless, influenced by the interaction of various information sources, carbon trading prices exhibit non-linear and non-stationary characteristics, posing challenges for accurate prediction. Current research, centered around deep learning models, predominantly emphasizes intricate network structures, optimisation algorithms, and data decomposition. However, these models face a developmental bottleneck in extracting carbon price features and efficiently leveraging multi-source information. Consequently, novel ideas and methodologies are imperative. This study focuses on the Hubei and Guangdong regional carbon markets as research subjects. It develops a prediction framework based on a generative adversarial network model to capture the time-series change characteristics of carbon trading prices and the condition matrix. First, a generator prediction model is used to obtain the input matrix features and extract the time series features through a complex network to predict the carbon price data at the next moment using a fully connected layer. Second, a discriminator is utilised to distinguish between the actual values and the predicted values. The generator and the discriminator undergo continuous iterative training and alternate optimisation. This process aims to bring the generated prediction distributions closer to the actual sample data, resulting in more accurate final predictions. The empirical results convincingly show that the proposed model achieves unparalleled forecasting precision in both markets. The proposed model demonstrates the lowest MAE (0.804 and 0.839), lowest MAPE (0.023 and 0.018), lowest RMSE (1.174 and 1.383), and highest R2 (0.971 and 0.989) across both markets, indicating superior predictive accuracy. Additionally, the proposed model consistently outshines traditional forecasting approaches across one-step, five-step, and ten-step forecasts, affirming its robustness and universal applicability in modelling carbon trading price series. The findings suggest that this study can aid policymakers in optimizing the carbon pricing system. Furthermore, it offers a reference for policymakers to comprehensively leverage external factors, such as regulating traditional energy prices, leveraging international carbon market experiences, and monitoring economic dynamics. This comprehensive strategy can streamline the exploration and management of carbon price fluctuations, ultimately strengthening the carbon market's risk control system.


Assuntos
Carbono , Previsões , China , Comércio , Algoritmos
2.
J Hazard Mater ; 471: 134390, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38678712

RESUMO

The extensive use of per- and polyfluoroalkyl substances (PFAS) in many industrial and consumer contexts, along with their persistent nature and possible health hazards, has led to their recognition as a prevalent environmental issue. While various PFAS removal methods exist, adsorption remains a promising, cost-effective approach. This study evaluated the PFAS adsorption performance of a surfactant-modified clay by comparing it with commercial clay-based adsorbents. Furthermore, the impact of environmental factors, including pH, ionic strength, and natural organic matter, on PFAS adsorption by the modified clay (MC) was evaluated. After proving that the MC was regenerable and reusable, magnetic modified clay (MMC) was synthesized, characterized, and tested for removing a wide range of PFAS in pure water and snowmelt. The MMC was found to have similar adsorption performance as the MC and was able to remove > 90% of the PFAS spiked to the snowmelt. The superior and much better performance of the MMC than powdered activated carbon points to its potential use in removing PFAS from real water matrices at an industrial scale.

3.
Env Sci Adv ; 3(2): 304-313, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38322792

RESUMO

Per- and polyfluoroalkyl substances (PFAS) are a class of recalcitrant, highly toxic contaminants, with limited remediation options. Phytoremediation - removal of contaminants using plants - is an inexpensive, community-friendly strategy for reducing PFAS concentrations and exposures. This project is a collaboration between the Mi'kmaq Nation, Upland Grassroots, and researchers at several institutions who conducted phytoremediation field trials using hemp to remove PFAS from soil at the former Loring Air Force base, which has now been returned to the Mi'kmaq Nation. PFAS were analyzed in paired hemp and soil samples using targeted and non-targeted analytical approaches. Additionally, we used hydrothermal liquefaction (HTL) to degrade PFAS in the harvested hemp tissue. We identified 28 PFAS in soil and found hemp uptake of 10 of these PFAS. Consistent with previous studies, hemp exhibited greater bioconcentration for carboxylic acids compared to sulfonic acids, and for shorter-chain compounds compared to longer-chain. In total, approximately 1.4 mg of PFAS was removed from the soil via uptake into hemp stems and leaves, with an approximate maximum of 2% PFAS removed from soil in the most successful area. Degradation of PFAS by HTL was nearly 100% for carboxylic acids, but a portion of sulfonic acids remained. HTL also decreased precursor PFAS and extractable organic fluorine. In conclusion, while hemp phytoremediation does not currently offer a comprehensive solution for PFAS-contaminated soil, this project has effectively reduced PFAS levels at the Loring site and underscores the importance of involving community members in research aimed at remediating their lands.

4.
Prev Med Rep ; 39: 102639, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38357224

RESUMO

Objectives: The Albumin-Bilirubin (ALBI) score has been widely used to assess the prognosis in patients with cirrhosis and hepatocellular carcinoma. This study aimed to analyze the relationship between ALBI score and all-cause mortality in patients with hepatitis B virus (HBV) infection in general. Methods: Patients aged ≥ 18 years with previous or current HBV infection from the National Health and Nutrition Examination Survey (NHANES) in the United States between 1999 and 2018 were enrolled in this retrospective cohort study. Weight univariate and multivariate Cox regression models were used to assess the relationship between ALBI score and all-cause mortality. The area under the receiver operating characteristic curve (AUC) was utilized to assess the predictive effect of ALBI score for all-cause mortality. Results: A total of 3,666 patients were included, of whom 925 (23.53 %) patients died. Compared with ALBI score ≤ -2.6, HBV-infected patients with ALBI score > -2.6 [hazard ratio (HR) = 1.75; 95 % confidence interval (CI): 1.43-2.14] were corrected with a higher all-cause mortality risk after adjusting for confounders. Stratified analyses showed that higher ALBI score was related to a higher risk of all-cause mortality in different patients with HBV infection (All P < 0.05). Furthermore, the ALBI score had good predictive ability for 1-year (AUC = 0.816, 95 %CI: 0.754-0.878), 3-year (AUC = 0.808, 95 %CI: 0.775-0.841), 5-year (AUC = 0.809, 95 %CI: 0.783-0.835), and 10-year (AUC = 0.806, 95 %CI: 0.784-0.827) all-cause mortality. Conclusion: Higher ALBI score was related to a higher risk of all-cause mortality in patients with HBV infection, and the ALBI score showed a good predictive effect for short- and long-term all-cause mortality.

6.
Plant Physiol Biochem ; 205: 108149, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37939545

RESUMO

Radish (Raphanus sativus L.) is one of the most vital root vegetable crops worldwide. Cadmium (Cd), a non-essential and toxic heavy metal, can dramatically restrict radish taproot quality and safety. Although the Peiotrpic Drug Resistance (PDR) genes play crucial roles in heavy metal accumulation and transport in plants, the systematic identification and functional characterization of RsPDRs remain largely unexplored in radish. Herein, a total of 19 RsPDR genes were identified from the radish genome. A few RsPDRs, including RsPDR1, RsPDR8 and RsPDR12, showed significant differential expression under Cd and lead (Pb) stress in the 'NAU-YH' genotype. Interestingly, the plasma membrane-localized RsPDR8 exhibited significantly up-regulated expression and enhanced promoter activity under Cd exposure. Ectopic expression of RsPDR8 conferred Cd tolerance via reducing Cd accumulation in yeast cells. Moreover, the transient transformation of RsPDR8 revealed that it positively regulated Cd tolerance by promoting ROS scavenging and enhancing membrane permeability in radish. In addition, overexpression of RsPDR8 increased root elongation but deceased Cd accumulation compared with the WT plants in Arabidopsis, demonstrating that it could play a positive role in mediating Cd efflux and tolerance in plants. Together, these results would facilitate deciphering the molecular mechanism underlying RsPDR8-mediated Cd tolerance and detoxification in radish.


Assuntos
Arabidopsis , Raphanus , Raphanus/genética , Raphanus/metabolismo , Cádmio/toxicidade , Cádmio/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo
7.
Environ Sci Pollut Res Int ; 30(50): 108393-108410, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37775629

RESUMO

The C-F bonds, due to their many unique features, have been incorporated into numerous compounds in countless products and applications. These fluorinated compounds eventually are disposed of and released into the environment through different pathways. In this review, we analyzed the occurrence of these fluorinated compounds in seven types of products (i.e., refrigerants/propellants, aqueous film-forming foam, cosmetics, food packaging, agrochemicals, pharmaceuticals, coating materials) and discussed their fate in the environment. This is followed by describing the quantity of fluorinated compounds from each source based on available data. Total on- and off-site disposal or other releases of 536 fluorinated compounds in 2021 were analyzed using the data sourced from the U.S. EPA Toxics Release Inventory (TRI). Among the chemicals examined, chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) were the primary contributors in terms of total mass. Upon examining the seven sources of fluorinated compounds, it became evident that additional contributors are also responsible for the presence of organofluorine compounds in the environment. Although various toxic degradation products of fluorinated compounds could form in the environment, trifluoroacetic acid (TFA) was specifically highlighted in this review given the fact that it is a common dead-end degradation product of > 1 million chemicals. This paper ended with a discussion of several questions raised from this study. The path forward was elaborated as well for the purpose of protecting the environment and human health.


Assuntos
Clorofluorcarbonetos , Clorofluorcarbonetos/química
8.
Chemosphere ; 341: 140081, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37678594

RESUMO

The application of biosolids or treated sewage sludge containing per- and polyfluoroalkyl substances (PFAS) in agricultural lands and the disposal of sludge in landfills pose high risks to humans and the environment. Although PFAS precursors have not been regulated yet, their potential transformation to highly regulated perfluoroalkyl acids (PFAAs) may enable them to serve as a long-term source and make remediation of PFAAs a continuing task. Therefore, treating precursors in sewage sludge is even more, certainly not less, critical than treating or removing PFAAs. In this study, a green surfactant-modified clay sorbent was evaluated for its efficacy in stabilizing two representative PFAA precursors in sludge, e.g., N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA) and 6:2 fluorotelomer sulfonic acid (6:2 FTSA), in comparison with unmodified clay and powdered activated carbon (PAC). Results showed N-EtFOSAA and 6:2 FTSA exhibited distinct adsorption behaviors in the sludge without sorbents due to their different physicochemical properties, such as hydrophobicity and functional groups. Among the three sorbents, the modified clay reduced the water leachability of N-EtFOSAA and 6:2 FTSA by 91.5% and 95.4%, respectively, compared to controls without amendments at the end of the experiment (47 days). Within the same duration, PAC decreased the water leachability of N-EtFOSAA and 6:2 FTSA by 60.6% and 37.3%, respectively. At the same time, the unmodified clay demonstrated a poor stabilization effect and even promoted the leaching of precursors. These findings suggested that the modified clay had the potential for stabilization of precursors, while negatively charged and/or hydrophilic sorbents, such as the unmodified clay, should be avoided in the stabilization process. These results could provide valuable information for developing effective amendments for stabilizing PFAS in sludge or biosolids. Future research should evaluate the long-term effect of the stabilization approach using actual sludge from wastewater treatment facilities.


Assuntos
Fluorocarbonos , Surfactantes Pulmonares , Humanos , Tensoativos , Esgotos , Argila , Biossólidos , Lipoproteínas , Carvão Vegetal , Pós
9.
BJS Open ; 7(4)2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37584435

RESUMO

BACKGROUND: Previous meta-analyses reporting significant associations between perioperative allogeneic blood transfusions and poor prognosis in gastric cancer or colorectal cancer had a high risk of confounding bias. This meta-analysis explored this issue using observational studies that applied propensity score analysis. METHODS: PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched for manuscripts published between 2013 and 2022. Studies applying propensity score analysis were included to investigate the association between perioperative allogeneic blood transfusions and prognosis in gastric cancer or colorectal cancer after radical surgery. Pooled HRs for overall survival and disease-free survival were calculated using a fixed-effect model or random-effect model according to heterogeneity. RESULTS: Twelve retrospective cohort studies with 17 607 patients reported were included. Ten studies applied propensity score matching and two applied inverse probability of treatment weighting using propensity score. A total of 5962 patients were analysed after propensity score adjustment. After propensity score adjustment, perioperative allogeneic blood transfusions did not correlate with disease-free survival in gastric cancer (HR 1.16; 95 per cent c.i. 0.96-1.39; heterogeneity was assessed by the chi-squared test and inconsistency index (I2) = 57 per cent) or colorectal cancer (HR 1.12; 95 per cent c.i. 0.84-1.49; I2 = 54 per cent). However, after propensity score adjustment, perioperative allogeneic blood transfusions were significantly associated with worse overall survival in gastric cancer (HR 1.20; 95 per cent c.i. 1.08-1.32; I2 = 25 per cent) and colorectal cancer (HR 1.40; 95 per cent c.i. 1.06-1.85; I2 = 52 per cent). Subgroup analyses showed that perioperative allogeneic blood transfusions did not correlate with overall survival in colorectal cancer when major postoperative complications were balanced after propensity score. CONCLUSION: Perioperative allogeneic blood transfusion is not correlated with recurrence of gastric cancer and colorectal cancer. Perioperative allogeneic blood transfusions are significantly associated with worse overall survival in gastric cancer and colorectal cancer, which may be attributable to unbalanced major postoperative complications after propensity score adjustment.


Assuntos
Neoplasias Colorretais , Transplante de Células-Tronco Hematopoéticas , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirurgia , Estudos Retrospectivos , Transfusão de Sangue , Neoplasias Colorretais/cirurgia , Complicações Pós-Operatórias , Estudos Observacionais como Assunto
10.
Environ Pollut ; 331(Pt 1): 121865, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37225078

RESUMO

Green, renewable, and sustainable materials are needed for removing per- and polyfluoroalkyl substances (PFASs) in water. Herein, we synthesized and tested alginate (ALG) and chitosan (CTN) based and polyethyleneimine (PEI) functionalized fibers/aerogels for the adsorption of mixtures of 12 PFASs (9 short- and long-chain PFAAs, GenX, and 2 precursors) from water at an initial concentration of 10 µg/L each. Out of 11 biosorbents, ALGPEI-3 and GTH CTNPEI aerogels had the best sorption performance. Through detailed characterization of the sorbents before and after PFASs sorption, it was revealed that hydrophobic interaction was the dominant mechanism controlling PFASs sorption while electrostatic interactions played a minor role. As a result, both aerogels had fast and superior sorption of relatively hydrophobic PFASs from pH 2 to 10. Even at extreme pH conditions, the aerogels retained their shape perfectly. Based upon the isotherms, the maximum adsorption capacity of ALGPEI-3 and GTH-CTNPEI aerogels towards total PFASs removal was 3045 and 12,133 mg/g, respectively. Although the sorption performance of the GTH-CTNPEI aerogel toward short chain PFAS was less than satisfactory and varied between 70 and 90% in 24 h, it may find its use in removing relatively hydrophobic PFAS at high concentrations in complex and extreme environments.


Assuntos
Fluorocarbonos , Poluentes Químicos da Água , Água , Poluentes Químicos da Água/análise , Fluorocarbonos/análise , Adsorção
11.
Plant Biotechnol J ; 21(5): 990-1004, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36648398

RESUMO

High-quality radish (Raphanus sativus) genome represents a valuable resource for agronomical trait improvements and understanding genome evolution among Brassicaceae species. However, existing radish genome assembly remains fragmentary, which greatly hampered functional genomics research and genome-assisted breeding. Here, using a NAU-LB radish inbred line, we generated a reference genome of 476.32 Mb with a scaffold N50 of 56.88 Mb by incorporating Illumina, PacBio and BioNano optical mapping techniques. Utilizing Hi-C data, 448.12 Mb (94.08%) of the assembled sequences were anchored to nine radish chromosomes with 40 306 protein-coding genes annotated. In total, 249.14 Mb (52.31%) comprised the repetitive sequences, among which long terminal repeats (LTRs, 30.31%) were the most abundant class. Beyond confirming the whole-genome triplication (WGT) event in R. sativus lineage, we found several tandem arrayed genes were involved in stress response process, which may account for the distinctive phenotype of high disease resistance in R. sativus. By comparing against the existing Xin-li-mei radish genome, a total of 2 108 573 SNPs, 7740 large insertions, 7757 deletions and 84 inversions were identified. Interestingly, a 647-bp insertion in the promoter of RsVRN1 gene can be directly bound by the DOF transcription repressor RsCDF3, resulting into its low promoter activity and late-bolting phenotype of NAU-LB cultivar. Importantly, introgression of this 647-bp insertion allele, RsVRN1In-536 , into early-bolting genotype could contribute to delayed bolting time, indicating that it is a potential genetic resource for radish late-bolting breeding. Together, this genome resource provides valuable information to facilitate comparative genomic analysis and accelerate genome-guided breeding and improvement in radish.


Assuntos
Raphanus , Raphanus/genética , Genoma de Planta/genética , Melhoramento Vegetal , Genótipo , Cromossomos
12.
Environ Sci Pollut Res Int ; 30(15): 43833-43842, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36680712

RESUMO

Even though the potential toxicity and treatment methods for per- and polyfluoroalkyl substances (PFAS) have attracted extensive attention, the plant uptake and accumulation of PFAS in edible plant tissues as a potential pathway for human exposure received little attention. Our study in a hydroponic system demonstrated that perfluorooctanoic acid (PFOA) and its replacing compound, 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy) propanoic acid (GenX) displayed markedly different patterns of plant uptake and accumulation. For example, the root concentration factor (RCF) of PFOA in lettuce is almost five times of that of GenX while the translocation factor (TF) of GenX is about 66.7% higher than that for PFOA. The co-presence of zinc amendments affected the phyto-effect of these two compounds and their accumulation in plant tissues, and the net effect on their plant accumulation depended on both the properties of Zn amendments and PFAS. Zinc oxide nanoparticles (ZnONPs) at 100 mg/L did not affect the uptake of PFOA in either lettuce roots or shoots; however, Zn2+ at the same concentration significantly increased PFOA accumulation in both tissues. In contrast, both Zn amendments significantly lowered the accumulation of GenX in lettuce roots, but only ZnONPs significantly hindered the GenX accumulation in lettuce shoots. The co-exposure to ZnONPs and PFOA/GenX resulted in lower oxidative stress than the plants exposed to PFOA or GenX alone. However, both zinc agrochemicals with or without PFAS led to lower root dry biomass. The results shed light on the property-dependent plant uptake of PFAS and the potential impact of co-existing nanoagrochemicals and their dissolved ions on plant uptake of PFOA and GenX.


Assuntos
Alcaloides , Fluorocarbonos , Óxido de Zinco , Humanos , Lactuca/metabolismo , Zinco , Agroquímicos , Fluorocarbonos/toxicidade
13.
Bioresour Technol ; 368: 128340, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36400272

RESUMO

In this study, the potential effect of surfactant assisted ultrasonic pretreatment on mixed food waste was investigated. Surfactants, such as Rhamnolipid, Sodium dodecyl sulfate; Glucopon and Triton X 100 were evaluated in this work. Among them, the maximum solubilization of chemical oxygen demand of 45.5 % and the highest release of soluble COD of 31 g/L were observed for ultrasonication assisted by Triton X 100 at a dose of 0.01 g/g TS in 30 min. The presence of a surfactant also reduced 27.5 % of energy demand when compared to ultrasonic pretreatment alone. Compared to the non-pretreated samples after anaerobic digestion, ultrasonication assisted by Triton X 100 led to 95 % increase of volatile fatty acid titers and 83 % increase of carbon conversion efficiency. Thus, sonication with the addition of Triton X 100 was proven to be highly effective toward increasing digestibility of and yield of volatile fatty acid from mixed food waste.


Assuntos
Eliminação de Resíduos , Tensoativos , Octoxinol , Alimentos , Ultrassom , Ácidos Graxos Voláteis
14.
Environ Pollut ; 318: 120941, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36566675

RESUMO

The broad application of perfluoroalkyl acid (PFAA) precursors has led to their occurrence in soil, resulting in potential uptake and bioaccumulation in plants. In this study, we investigated the effect of powdered activated carbon (PAC) and montmorillonite on the distribution and transformation of a perfluorooctanesulfonic acid (PFOS) precursor, N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA), in soil-plant systems. The results showed that N-EtFOSAA at 300 µg/kg was taken up by soybean roots and shoots together with its transformation products (i.e., perfluorooctane sulfonamide (PFOSA), PFOS), while decreasing the biomass of shoots and roots by 47.63% and 61.16%, respectively. PAC amendment significantly reduced the water leachable and methanol extractable N-EtFOSAA and its transformation products in soil. In the presence of soybean and after 60 days, 73.5% of the initially spiked N-EtFOSAA became non-extractable bound residues. Compared to the spiked controls, the PAC addition also decreased the total plant uptake of N-EtFOSAA by 94.96%. In contrast, montmorillonite showed limited stabilization performance for N-EtFOSAA and its transformation products and was ineffective to lower their bioavailability. Overall, the combination of PAC and soybean was found to be effective in immobilizing N-EtFOSAA in soil.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Solo/química , Glycine max/metabolismo , Bentonita , Fluorocarbonos/química , Ácidos Alcanossulfônicos/metabolismo , Plantas/metabolismo
15.
Environ Pollut ; 308: 119724, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35809706

RESUMO

Biosolids containing per- and polyfluoroalkyl substances (PFAS) could contaminate the receiving environments once they are land applied. In this study, we evaluated the feasibility of controlling the bioavailability of PFAS in biosolids to timothy-grass through stabilization or mobilization approaches. Stabilization was accomplished by adding a sorbent (i.e. granular activated carbon (GAC), RemBind, biochar) to biosolids, while mobilization was achieved by adding a surfactant, sodium dodecyl sulphate (SDS), to biosolids. The results showed that the ΣPFAS concentration in grass shoots grown in biosolids amended soil treated by GAC or RemBind at 2% was only 2.77% and 3.35% of the ΣPFAS concentration detected in shoots grown in biosolids amended soil without a sorbent, respectively, indicating the effectiveness of GAC and RemBind for stabilizing PFAS and reduce their bioavailability. On the other hand, mobilization by adding SDS to biosolids at a dose range of 10-100 mg/kg significantly increased the plant uptake of ΣPFAS by 15.48%-108.57%. Thus, mobilization by adding SDS could be a valuable approach for enhancing the PFAS removal if phytoremediation is applied. Moreover, higher rate of PFAS uptake took place after grass cutting was observed in this study. Thus, proper mowing and regrowth of timothy-grass could lead to efficient and cost-effective removal of PFAS from biosolids amended soil through phytoremediation and leave the site clean to be used for other purposes.


Assuntos
Fluorocarbonos , Poluentes do Solo , Disponibilidade Biológica , Biossólidos , Fluorocarbonos/análise , Plantas/metabolismo , Solo , Poluentes do Solo/análise
16.
Sci Total Environ ; 838(Pt 4): 156640, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35697220

RESUMO

In this study, we set up a soil-microbe-soybean system spiked with PFOA, PFOS, or a PFAS mixture of eight PFAS and investigated the distribution of PFAS in the system and impacts on the abundance and expression level of genes involved in the nitrogen (N) cycle. When soybean was exposed to the PFAS mixtures, synergistic uptake by shoots was detected. PFAS exhibited remarkable impacts on abundance of nitrification and denitrification genes in both bulk soil and rhizosphere as well as expression of N fixation gene in soybean nodules. The abundance of nitrification genes AOA and AOB amoA and denitrification gene nirK was significantly reduced (p < 0.05) in almost all treatments in bulk soil, except PFOA at 10 µg/kg. The abundance of other functional genes, such as nirS and norZ was affected differently depending on PFAS concentrations and sample location, either bulk soil or the rhizosphere. Interestingly, the N fixation gene nifH in soybean nodules was overexpressed by a PFAS mixture at 100 µg/kg. Hence, this work provided in-depth knowledge regarding the distribution of PFAS and their impacts on the N cycle for the studied system. Results from this study provide insights on assessing risks posed by individual or mixed PFAS to soybean.


Assuntos
Fluorocarbonos , Nitrificação , Desnitrificação , Fluorocarbonos/toxicidade , Nitrogênio/análise , Fixação de Nitrogênio , Solo , Microbiologia do Solo , Glycine max/genética , Glycine max/metabolismo
17.
Chemosphere ; 286(Pt 2): 131748, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34352549

RESUMO

Concerns have been raised about per- and polyfluoroalkyl substances (PFAS) in sewage sludge given the urgent need of finding suitable disposal methods for sludge. In this study, we evaluated the effect of ultrasonication on PFAS changes in sewage sludge. It was revealed that although ultrasonication at 20 kHz increased the soluble chemical oxygen demand (SCOD) of treated sewage sludge, this technique was ineffective for degrading perfluoroalkyl acids (PFAAs) and their precursors. Ultrasonic treatment for longer time (>15 min) led to concentration increase of perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), and perfluorohexanoic acid (PFHxA) in the liquid phase, possibly due to their release from disrupted sludge flocs during cavitation. Adding permanganate (10 mM) to the ultrasonic system could also enhance the disruption of sludge particles, resulting in higher concentrations of PFOA and PFHxA in the solid phase and PFOA, PFHpA, PFHxA, and perfluorobutanesulfonic acid (PFBS) in the liquid phase. Overall, ultrasonic pretreatment at 20 kHz and 0.7 W/mL is unlikely to remove PFAS from sewage sludge. Instead, it could increase the risk of PFAS pollution upon final sludge disposal. Effective treatment technologies are thus demanded if PFAS in sludge are regulated.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Poluentes Químicos da Água , Fluorocarbonos/análise , Esgotos , Poluentes Químicos da Água/análise
18.
Bioresour Technol ; 346: 126342, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34785330

RESUMO

Food waste (FW) characterized by a low carbon/nitrogen (C/N) ratio ranging between 6 and 19 was used to investigate the feasibility and mechanism of maneuvering inoculum-to-substrate ratio (ISR) to alleviate the metabolic imbalance caused by imbalanced nutrients in the AD process, through biochemical methane potential tests and methanogenic pathway analysis. The maximum methane yield of 0.4 L/g of volatile solid (VS) was obtained at a C/N ratio of 11 and an ISR of 10:3. Increasing ISR from 1:2 to 10:3 promoted methane production by ∼20% via an enhancement in acetoclastic methanogenesis and the hydrolysis of carbohydrates and proteins. At lower ISR < 1, hydrogenotrophic methanogenic and syntrophic bacteria dominated, and methane production decreased by âˆ¼ 20% due to the energy disadvantages of syntrophic methanogenesis. Efficient digestion of FW with low C/N ratio FW could be achieved by using metabolic pathways to regulate it and increasing ISR from 1:1 to 10:3.


Assuntos
Alimentos , Eliminação de Resíduos , Anaerobiose , Reatores Biológicos , Carbono , Metano , Nitrogênio , Nutrientes
19.
Chemosphere ; 292: 133436, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34968513

RESUMO

Advanced reduction by strong reducing hydrated electrons is a promising approach to degrade per- and polyfluoroalkyl substances (PFAS). This research aimed to investigate the effectiveness of UV/Iodide system for 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA, F-53B) degradation in aqueous solutions. Results from this work demonstrated that UV irradiation with an addition of 0.3 mM KI resulted in 55.99% degradation of F-53B within 15 min and almost 100% within 2 h. The defluorination efficiency of F-53B in the UV/Iodide system was 2.6 times higher than that in the sole UV system after 2 h of irradiation. The degradation efficiency of F-53B was not significantly affected by air purging. The defluorination efficiency with air bubbling, however, was 14.57% lower than that with nitrogen purging. The photodegradation of F-53B in the UV/Iodide system could be well described by a pseudo-first-order kinetic model. Degradation rate constant of F-53B correlated positively with the initial concentration. At 20 µg/L, the pseudo-first-order rate constant was 5.641 × 10-2 min-1 and the half-life was 12.29 min. Higher initial concentration also required less energy input to achieve the same degradation efficiency. The detection and identification of degradation intermediates implied that destruction of F-53B started from dechlorination and followed by continuously "flaking off" CF2 units.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Poluentes Químicos da Água , Iodetos , Fotólise , Poluentes Químicos da Água/análise
20.
Am J Transl Res ; 13(6): 6717-6723, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34306417

RESUMO

OBJECTIVE: To study the correlation of serum uric acid (UA), cystatin C (Cys-C) and high-sensitivity C-reactive protein (hs-CRP) with cognitive impairment in lacunar cerebral infarction. METHODS: Total 198 patients with lacunar cerebral infarction were selected and divided into 4 groups according to their cognitive function, with 65 cases in the normal group, 72 cases in the mild cognitive impairment group, 38 cases in the moderate cognitive impairment group and 23 cases in the severe cognitive impairment group. The hs-CRP, serum UA, Cys-C and Montreal Cognitive Assessment (MoCA) were measured upon admission. RESULTS: There were statistical differences in hs-CRP, UA and Cys-C among the four groups (all P<0.001). MoCA was negatively correlated with hs-CRP, UA and Cys-C (all P<0.001). Multivariate logistic regression analysis showed that elevated levels of hs-CRP, UA and Cys-C were the influencing factors of cognitive impairment in patients with lacunar cerebral infarction (all P<0.05). CONCLUSION: The levels of hs-CRP, UA and Cys-C in patients with lacunar cerebral infarction increase with the aggravation of cognitive impairment, and high hs-CRP, UA and Cys-C are independent risk factors of cognitive impairment in patients with lacunar cerebral infarction.

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