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1.
J Hazard Mater ; 383: 121243, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31563764

RESUMO

Bioretention systems, as one of the most practical management operations for low impact development of water recovery, utilize different soil amendments to remove contaminants from stormwater. For the sake of urban sustainability, the utilization of amendments derived from waste materials has a potential to reduce waste disposal at landfill while improving the quality of stormwater discharge. This study investigated the efficiency of food waste compost and wood waste biochar for metal removal from synthetic stormwater runoff under intermittent flow and co-presence of colloids. Throughout intermittent infiltration of 84 pore volumes of stormwater, columns amended with compost and biochar removed more than 50-70% of influent metals, whereas iron-oxide coated sand was much less effective. Only a small portion of metals adsorbed on the compost (< 0.74%) was reactivated during the drainage of urban pipelines that do not flow frequently, owing to abundant oxygen-containing functional groups in compost. In comparison, co-existing kaolinite enhanced metal removal by biochar owing to the abundance of active sites, whereas co-existing humic acid facilitated mobilization via metal-humate complexation. The results suggest that both waste-derived compost and biochar show promising potential for stormwater harvesting, while biochar is expected to be more recalcitrant and desirable in field-scale bioretention systems.

2.
J Hazard Mater ; 383: 121240, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31563767

RESUMO

High-efficiency and cost-effective catalysts are critical to completely mineralization of organic contaminants for in-situ groundwater remediation via advanced oxidation processes (AOPs). The engineered biochar is a promising method for waste biomass utilization and sustainable remediation. This study engineers maize stalk (S)- and maize cob (C)-derived biochars (i.e., SB300, SB600, CB300, and CB600, respectively) with oxygen-containing functional groups as a carbon-based support for nanoscale zero-valent iron (nZVI). Morphological and physiochemical characterization showed that nZVI could be impregnated within the framework of the synthesized Fe-CB600 composite, which exhibited the largest surface area, pore volume, iron loading capacity, and Fe0 proportion. Superior degradation efficiency (100% removal in 20 min) of trichloroethylene (TCE, 0.1 mM) and fast pseudo-first-order kinetics (kobs =22.0 h-1) were achieved via peroxymonosulfate (PMS, 5 mM) activation by the Fe-CB600 (1 g L-1) under groundwater condition (bicarbonate buffer solution at pH = 8.2). Superoxide radical and singlet oxygen mediated by Fe0 and oxygen-containing group (i.e., CO) were demonstrated as the major reactive oxygen species (ROSs) responsible for TCE dechlorination. The effectiveness and mechanism of the Fe/C composites for rectifying organic-contaminated groundwater were depicted in this study.

3.
Neurosci Res ; 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31790723

RESUMO

Early life stress usually causes the abnormal brain development and results in the onset of cognitive and emotional disorders in later childhood. Neonatal hypoxic ischemia (HI) causes dramatic brain damage in early life and resulted in serious impairment to brain development. Hippocampal neurogenesis, as one of the key structural plasticity to mediate animal behaviors, can be impact by neonatal HI until child stage. In our study, we identified the natural product resveratrol (RES) as the potential alternative therapy to improve brain functions of childhood mice after underwent neonatal HI. Treatment of RES improved the spatial learning and memory in morris water maze and increased the recognize ability in objective recognition task. Moreover, RES also attenuate the depressive and anxiety like mood in child mice after experiencing neonatal HI. Brain morphological study showed RES promote the proliferation of neural stem cells and increase the neuronal differentiation in hippocampal dentate gyrus (DG) region. Our in vitro study in C17.2 neural stem cell line demonstrated RES could prevent the mitochondrial fragmentation induced by hypoxia. Moreover, same effect was also observed in primary cultural neurons. To summarize, RES could prevent the cognitive deficit and depressive/anxiety mood in childhood with experience of neonatal HI via promoting hippocampal neurogenesis. Improving mitochondrial dynamics could be one of the key biological mechanisms underlying such effects of RES.

4.
J Hazard Mater ; 384: 121321, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31655386

RESUMO

The degradation of di-(2-ethylhexyl) phthalate (DEHP) was examined as an example to capitalize on the potential interactions of peroxydisulfate (PS) and ferrous iron (Fe2+) in the model Day-1/Day-90 and on-site hydraulic fracturing wastewater (FWW). The primary oxidative radicals in the Fe2+/PS system (i.e., SO4- and OH) were less effective for the degradation of DEHP (6.45%) in ultrapure water. Both chloride (Cl-) and bromide (Br-) at equivalent molar ratio with PS enhanced DEHP degradation (15.6% and 45.5%, respectively) via the generation of Cl and Br radicals, whereas the degradation rate was inhibited by the excessive amount of Cl- or Br- in the Day-1/Day-90 FWW. However, the co-presence of ethylene glycol (C2H4(OH)2, 0.043% v/v in the FWW) and halide ions (Cl- or Br-, 0.05 mM) resulted in the highest removal efficiency of 82.6 - 88.5% within 10 min by Fe2+/PS. Further investigation revealed that the formation of reductive alcohol radicals (C2H3(OH)2) slowed down or replenished the Fe2+ exhaustion. This study demonstrated that the Fe2+/PS-based advanced oxidation may show a synergistic interplay with Cl-/Br- and C2H4(OH)2 in the FWW, which depends on their relative concentrations. Thus, the inherent constituents in the fracturing wastewater can be utilized for the catalytic degradation of co-existing organic contaminants.

5.
Phytomedicine ; 65: 153102, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31654989

RESUMO

BACKGROUND: Euphorbia factor L1 (EFL1) is a lathyrane-type diterpenoid from the medicinal herb Euphorbia lathyris L., and has been reported with intestinal toxicity, but the potential mechanisms remain unknown. PURPOSE: The objective of this study was to investigate the intestinal toxicity of EFL1 and the underlying mechanisms using nematode Caenorhabditis elegans. METHODS: C. elegans were exposed to 0-200 µM EFL1 for 72 h, then the survival rate, body length and body width, locomotion and chemoreception behavior, intestinal ROS and lipofuscin accumulation, intestinal permeability, and defecation rhythm were detected. The γ-aminobutyric acid(GABA) energic neurons AVL and DVB were shown via green fluorescent protein under a laser scanning confocal microscope. The structure of GABA transporter UNC-47 were predicted by homology modeling, and the interaction between EFL1 and UNC-47 was simulated by molecular docking. The mRNA expression of genes related to oxidative stress, intestinal permeability and defecation after EFL1 exposure were detected by RT-qPCR. RESULTS: EFL1 did not induce lethality of nematodes. The general toxicity was characterized by abnormal growth, locomotion and chemoreception. The intestinal barrier was leaky, due to down-regulated cell junction and active cation transport. The mean defecation cycle length in nematodes was decreased, relating to disorder vesicular and ion transport, enhanced rhythm behavior and muscle contraction. The dysfunctional defecation also attributed to injured UNC-47 protein, as well as GABAergic neurons AVL and DVB. Excessive ROS and lipofuscin accumulation were observed in intestine, along with activation of antioxidant enzymes of SOD, COQ7 and CAT. CONCLUSION: This study elucidated the EFL1-induced intestinal toxicity in nematodes, characterized as leaky intestinal barrier and accelerated defecation behavior. The underlying mechanisms were involved in oxidative stress, cell junctions, transportation, rhythm behavior, muscle contraction, and GABAergic neurons.

7.
Phytomedicine ; 64: 152929, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31454650

RESUMO

BACKGROUND: Euphorbia factor L1 (EFL1), a lathyrane-type diterpenoid from the medicinal herb Euphorbia lathyris L. (Euphorbiaceae), has been reported for many decades to induce gastric irritation, but the underlying mechanisms remain unclear. PURPOSE: The objective of this study was to investigate EFL1-induced cytotoxicity and the potential mechanisms of action on the human normal gastric epithelial cell GES-1. METHODS: GES-1 cells were treated with EFL1 (12.5-200 µM) for different time intervals, and cell survival, LDH release, intracellular reactive oxygen species (ROS), malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity were detected. Mitochondrial membrane potential (MMP) assay, DAPI staining, DNA fragment assay, and annexin V-FITC/PI staining were performed. The interaction between EFL1 and Bcl-2, cytochrome c, caspase-9, caspase-3, PI3K, AKT, and mTOR proteins was simulated by molecular docking. The mRNA and protein expression of apoptosis and autophagy factors were detected by RT-qPCR and Western blotting. RESULTS: EFL1 decreased survival, increased LDH leakage, and induced abnormal production of ROS, MDA and SOD in GES-1 cells. Mitochondria-mediated apoptosis was characterized by decreased MMP, condensed nuclei, fragmented DNA, and increased apoptosis rate. EFL1 interacted with proteins via hydrogen bonding. The mRNA, total or phosphorylated protein expression of Bcl-2, mitochondrial cytochrome c, PI3K, AKT, mTOR and p62 were downregulated; in contrast, those of cytoplasmic cytochrome c, cleaved caspase-9, cleaved caspase-3, LC3-ll and Beclin-1 were upregulated. CONCLUSION: These findings indicated that EFL1 decreased the survival of GES-1 cells through EFL1-induced oxidative stress, activation of the mitochondria-mediated apoptosis as well as autophagy via inhibition of the PI3K/AKT/mTOR pathway.

8.
Food Chem ; 301: 125307, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31387043

RESUMO

Predominant contributors to thermally-induced off-notes in muskmelon juice were investigated by combination of sensory evaluation, GC-olfactometry (GC-O), multidimensional GC, odor activity value (OAV) calculation and addition experiments. "Fermented" and "sulfurous" were revealed as the dominant heat-induced offensive off-notes, and fundamental heat-led changes in odorant compositions were observed. Comparative aroma extract dilution analysis revealed that the off-flavors were mainly caused by newly heat-formed compounds with extremely low odor threshold and unpleasant smells. These included volatile sulfur compounds with "rotten" odors, Strecker aldehydes having "fermented" notes, and heterocyclics exhibiting "roasted" smells. Specifically, dimethyl sulfide, methional, methanethiol, dimethyl trisulfide, dimethyl disulfide, and acetaldehyde were identified as the predominant off-note contributors, among which DMS was the most important one, showing the highest OAV. Multiple extraction techniques, GC-O coupling to GC × GC-QTOF-MS and OAV calculation are powerful tools for accurate location and reliable identification of trace and key off-odorants in natural complex matrices.


Assuntos
Cucumis melo/química , Sucos de Frutas e Vegetais/análise , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Temperatura Alta , Humanos , Olfatometria/métodos , Olfato , Paladar
9.
PLoS One ; 14(8): e0221641, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31454376

RESUMO

DNA methylation has frequently been implicated in sex determination and differentiation in teleost species. In order to detect the DNA methylation patterns established during sexual differentiation in tiger pufferfish T. rubripes, we performed comprehensive whole genome methylation sequencing and analyses of the gonads of male, female, and pseudo male. We obtained a total of 33.12, 32.44, and 31.60 Gb clean data for male, female, and pseudo male, with a sequencing depth of 66.44×, 60.47× and 54.86×, respectively. The methylation level of cytosine (C) residues in the genomic DNA from gonads was 11.016%, 10.428%, and 11.083% in male, female, and pseudo male, respectively. More than 65% of C methylation was at CpG sites, and less than 1% was at CHG and CHH sites. In each regulatory element, there were low methylation levels on both sides of the transcription start site, and higher methylation levels in exons, introns, and downstream of genes. The highest mCpG was on chromosome 8 and the lowest mCpG was on chromosome 5. Comparisons of whole-genome DNA methylation between pairs of samples revealed that there were 3,173 differentially methylated regions (DMRs) between female and male, and 3,037 DMRs between male and pseudo male, corresponding to 0.232% and 0.223% of the length of the genome, respectively. There were only 1,635 DMRs between female and pseudo male, representing 0.127% of the length of the genome. A number of differentially methylated genes (DMGs) related to sex determination and differentiation were selected, such as amhr2 and pfcyp19a. After Bisulfite Sequencing PCR (BSP) verification, amhr2 was exhibited low methylation level in normal males and pseudo male, and high methylation level in normal females but pfcyp19a showed low methylation level in normal females and high methylation level in normal males and pseudo males. These results provide information about the molecular epigenetic mechanisms of DNA methylation during low-temperature induced masculinization of tiger pufferfish, and increase our understanding of the mechanisms of sex determination and differentiation in this important aquaculture fish species.

10.
Sci Rep ; 9(1): 12250, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31439882

RESUMO

The genus Allium is one of the largest monocotyledonous genera, containing over 850 species, and most of these species are found in temperate climates of the Northern Hemisphere. Furthermore, as a large number of new Allium species continue to be identified, phylogenetic classification based on morphological characteristics and a few genetic markers will gradually exhibit extremely low discriminatory power. In this study, we present the use of complete chloroplast genome sequences in genome-scale phylogenetic studies of Allium. We sequenced and assembled four Allium chloroplast genomes and retrieved five published chloroplast genomes from GenBank. All nine chloroplast genomes were used for genomic comparison and phylogenetic inference. The chloroplast genomes, ranging from 152,387 bp to 154,482 bp in length, exhibited conservation of genomic structure, and gene organization and order. Subsequently, we observed the expansion of IRs from the basal monocot Acorus americanus to Allium, identified 814 simple sequence repeats, 131 tandem repeats, 154 dispersed repeats and 109 palindromic repeats, and found six highly variable regions. The phylogenetic relationships of the Allium species inferred from the chloroplast genomes obtained high support, indicating that chloroplast genome data will be useful for further resolution of the phylogeny of the genus Allium.

11.
Psychol Med ; : 1-9, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31239006

RESUMO

BACKGROUND: Genome-wide association studies (GWAS) have consistently revealed that a variant of microRNA 137 (MIR137) shows a quite significant association with schizophrenia. Identifying the network of genes regulated by MIR137 could provide insights into the biological processes underlying schizophrenia. In addition, DLPFC functional connectivity, a robust correlate of MIR137, may provide plausible endophenotypes. However, the regulatory role of the MIR137 gene network in the disrupted functional connectivity remains unclear. Here, we tested the effects of the MIR137 regulated genes on the risk for schizophrenia and DLPFC functional connectivity. METHODS: To evaluate the additive effects of the MIR137 regulated genes (N = 1274), we calculated a MIR137 polygenic risk score (PRS) for schizophrenia and tested its association with the risk for schizophrenia in the genomic data of a Han Chinese population that included schizophrenia patients (N = 589) and normal controls (N = 575). We then investigated the association between MIR137 PRS and DLPFC functional connectivity in two independent young healthy cohorts (N = 356 and N = 314). RESULTS: We found that the MIR137 PRS successfully captured the differences in genetic structure between the patients and controls, but the single gene MIR137 did not. We then consistently found that a higher MIR137 PRS was correlated with lower functional connectivities between the DLPFC and both the superior parietal cortex and the inferior temporal cortex in two independent cohorts. CONCLUSION: The findings suggested that these two functional connectivities of the DLPFC could be important endophenotypes linking the MIR137-regulated genetic structure to schizophrenia.

12.
Br J Psychiatry ; : 1-8, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31169117

RESUMO

BACKGROUND: Schizophrenia is a complex mental disorder with high heritability and polygenic inheritance. Multimodal neuroimaging studies have also indicated that abnormalities of brain structure and function are a plausible neurobiological characterisation of schizophrenia. However, the polygenic effects of schizophrenia on these imaging endophenotypes have not yet been fully elucidated.AimsTo investigate the effects of polygenic risk for schizophrenia on the brain grey matter volume and functional connectivity, which are disrupted in schizophrenia. METHOD: Genomic and neuroimaging data from a large sample of Han Chinese patients with schizophrenia (N = 509) and healthy controls (N = 502) were included in this study. We examined grey matter volume and functional connectivity via structural and functional magnetic resonance imaging, respectively. Using the data from a recent meta-analysis of a genome-wide association study that comprised a large number of Chinese people, we calculated a polygenic risk score (PGRS) for each participant. RESULTS: The imaging genetic analysis revealed that the individual PGRS showed a significantly negative correlation with the hippocampal grey matter volume and hippocampus-medial prefrontal cortex functional connectivity, both of which were lower in the people with schizophrenia than in the controls. We also found that the observed neuroimaging measures showed weak but similar changes in unaffected first-degree relatives of patients with schizophrenia. CONCLUSIONS: These findings suggested that genetically influenced brain grey matter volume and functional connectivity may provide important clues for understanding the pathological mechanisms of schizophrenia and for the early diagnosis of schizophrenia.Declaration of interestNone.

13.
PLoS One ; 14(5): e0217604, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31120998

RESUMO

C/EBPα plays a key role in specifying myeloid lineage development. HoxA9 is expressed in myeloid progenitors, with its level diminishing during myeloid maturation, and HOXA9 is over-expressed in a majority of acute myeloid leukemia cases, including those expressing NUP98-HOXD13. The objective of this study was to determine whether HoxA9 directly represses Cebpa gene expression. We find 4-fold increased HoxA9 and 5-fold reduced Cebpa in marrow common myeloid and LSK progenitors from Vav-NUP98-HOXD13 transgenic mice. Conversely, HoxA9 decreases 5-fold while Cebpa increases during granulocytic differentiation of 32Dcl3 myeloid cells. Activation of exogenous HoxA9-ER in 32Dcl3 cells reduces Cebpa mRNA even in the presence of cycloheximide, suggesting direct repression. Cebpa transcription in murine myeloid cells is regulated by a hematopoietic-specific +37 kb enhancer and by a more widely active +8 kb enhancer. ChIP-Seq analysis of primary myeloid progenitor cells expressing exogenous HoxA9 or HoxA9-ER demonstrates that HoxA9 localizes to both the +8 kb and +37 kb Cebpa enhancers. Gel shift analysis demonstrates HoxA9 binding to three consensus sites in the +8 kb enhancer, but no affinity for the single near-consensus site present in the +37 kb enhancer. Activity of a Cebpa +8 kb enhancer/promoter-luciferase reporter in 32Dcl3 or MOLM14 myeloid cells is increased ~2-fold by mutation of its three HOXA9-binding sites, suggesting that endogenous HoxA9 represses +8 kb Cebpa enhancer activity. In contrast, mutation of five C/EBPα-binding sites in the +8 kb enhancer reduces activity 3-fold. Finally, expression of a +37 kb enhancer/promoter-hCD4 transgene reporter is reduced ~2-fold in marrow common myeloid progenitors when the Vav-NUP98-HOXD13 transgene is introduced. Overall, these data support the conclusion that HoxA9 represses Cebpa expression, at least in part via inhibition of its +8 kb enhancer, potentially allowing normal myeloid progenitors to maintain immaturity and contributing to the pathogenesis of acute myeloid leukemia associated with increased HOXA9.

14.
Opt Express ; 27(8): 11112-11121, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31052960

RESUMO

By introducing additional spin angular momentum (SAM) induced spiral phase, the spin-dependent transverse displacement of surface plasmon polaritons (SPPs) focus is effectively enlarged. The separation between the SPPs focuses generated by left circularly polarized (LCP) light and right circularly polarized (RCP) light reaches 1500 nm, which is six times larger than the previously reported values with semicircular plasmonic lens. The relationship between the displacement of the SPPs focus and the total spiral phase that consisted of the intrinsic and the additional spiral phase is theoretically established. Furthermore, the flexibility and versatility of the proposed mechanism is demonstrated by reversing or continuously controlling the SPPs focus. These findings hold great promise for spin-based plasmonic devices and the related applications, such as on-chip communication.

15.
J Hazard Mater ; 374: 412-419, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31029746

RESUMO

This study fabricated a new and multifunctional mixed metal-biochar composites (MMBC) using the mixture of two abundant industrial wastes, red mud (RM) and lignin, via pyrolysis under N2 atmosphere, and its ability to treat wastewater containing various contaminants was comprehensively evaluated. A porous structure (BET surface area = 100.8 m2 g-1) was created and metallic Fe was formed in the MMBC owing to reduction of Fe oxides present in RM by lignin decomposition products during pyrolysis at 700 °C, which was closely associated with the transformation of liquid to gaseous pyrogenic products. The potential application of the MMBC was investigated for the removal of heavy metals (Pb(II) and Ni(II)), oxyanions (As(V) and Cr(VI)), dye (methylene blue), and pharmaceutical/personal care products (para-nitrophenol and pCBA). The aluminosilicate mineral, metallic Fe, and porous carbon matrix derived from the incorporation of RM and lignin contributed to the multifunctionality (i.e., adsorption, chemical reduction, and catalytic reaction) of the MMBC. Thus, engineered biochar composites synthesized from selected industrial wastes can be a potential candidate for environmental applications.

16.
Food Chem Toxicol ; 128: 163-170, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30954639

RESUMO

The broad use of traditional Chinese medicines (TCMs) and the accompanied incidences of kidney injury have attracted considerable interest in investigating the responsible toxic ingredients. It is challenging to evaluate toxicity of TCMs since they contain complex mixtures of phytochemicals. Quantitative structure-activity relationship (QSAR) is an efficient tool to predict toxicity and QSAR study on TCMs-induced nephrotoxicity remains lacked. We developed QSAR models using three datasets of 609 compounds: natural products, drugs, and mixed (contained both kinds of data) datasets. Each dataset was used for modelling by utilizing artificial neural networks (ANN) and support vector machines (SVM) algorithms separately. Both internal and external validations were performed on each model. Six QSAR models were developed and yielded reliable performance in the internal validation. For external validation, 30 ingredients in the TCMs were predicted well by the natural product models (accuracy: ANN 96.7%, SVM 93.3%). The mixed models (accuracy: ANN 76.7%, SVM 66.7%) showed a better performance than the drug models (accuracy: ANN 50%, SVM 53.3%). Particularly, natural product models produced the most reliable results. It has the application not only on screening the nephrotoxic ingredients in TCMs, but it is also helpful at prioritizing the subsequent toxicity testing of natural products.


Assuntos
Rim/efeitos dos fármacos , Medicina Tradicional Chinesa/efeitos adversos , Relação Quantitativa Estrutura-Atividade , Algoritmos , Animais , Conjuntos de Dados como Assunto , Humanos , Modelos Teóricos , Redes Neurais (Computação) , Reprodutibilidade dos Testes , Máquina de Vetores de Suporte
17.
Environ Int ; 126: 771-790, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30884277

RESUMO

Thallium (Tl) is a typical toxic metal, which poses a great threat to human health through drinking water and the food chain (biomagnification). China has rich Tl-bearing mineral resources, which have been extensively explored and utilized, leading to release of large amounts of Tl into the environment. However, research on Tl pollution and removal techniques is relatively limited, because Tl has not been listed within the scope of environmental monitoring in China for several decades. This paper reviewed Tl pollution in wastewater arising from various industries in China, as well as the latest available methods for treating Tl-containing industrial wastewater, in order to give an outlook on effective technologies for controlling Tl pollution. Conventional physical and chemical treatment technologies are efficient at removing trace amounts of Tl, but it proved to be difficult to achieve the stringent environmental standard (≤0.1-5 µg/L) cost-effectively. Adsorption by using newly developed nanomaterials, and metal oxide modified polymer materials and microbial fuel cells are highly promising and expected to become next-generation technologies for remediation of Tl pollution. With the potential for greater Tl contamination in the environment under accelerated growth of industrialization, researches based on lab-scale implementation of such promising treatment technologies should be further expanded to pilot and industrial scale, ensuring environmental protection and the safety of drinking water for sustainable development. Comprehensive insights into experiences of Tl pollution in China and in-depth perspectives on new frontier technologies of Tl removal from wastewaters will also benefit other nations/regions worldwide, which are susceptible to high exposure to Tl likewise.


Assuntos
Monitoramento Ambiental , Recuperação e Remediação Ambiental/métodos , Tálio/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/prevenção & controle , China , Águas Residuárias/análise , Poluição Química da Água/análise
18.
Bioresour Technol ; 281: 457-468, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30827730

RESUMO

Due to abundant biomass and eco-friendliness, biochar is exemplified as one of the most promising candidates to mediate the degradation of environmental contaminants. Recently, environmentally persistent free radicals (EPFRs) have been detected in biochars, which can activate S2O82- or H2O2 to generate reactive oxygen species for effective degradation of organic and inorganic contaminants. Comprehending the formation mechanisms of EPFRs in biochars and their interactions with contaminants is indispensable to further develop their environmental applications, e.g., direct and indirect EPFR-mediated removal of organics/inorganics by biochars. With reference to the information of EPFRs in environmental matrices, this article critically reviews the formation mechanisms, characteristics, interactions, and environmental applications of EPFRs in biochars. Synthesis conditions and loading of metals/organics are considered as key parameters controlling their concentrations, types, and activities. This review provides new and important insights into the fate and emerging applications of surface-bound EPFRs in biochars.


Assuntos
Carvão Vegetal/química , Radicais Livres/química , Peróxido de Hidrogênio/química
19.
Environ Int ; 125: 452-469, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30763832

RESUMO

Shale gas extraction via horizontal drilling and hydraulic fracturing (HF) has enhanced gas production worldwide, which has altered global energy markets and reduced the prices of natural gas and oil. Water management has become the most challenging issue of HF, as it demands vast amounts of freshwater and generates high volumes of complex liquid wastes contaminated by diverse potentially toxic elements at variable rates. This critical review focuses on characterizing HF wastewater and establishing strategies to mitigate environmental impacts. High prioritization was given to the constituents with mean concentrations over 10 times greater than the maximum contamination level (MCL) guidelines for drinking water. A number of potentially harmful organic compounds in HF wastewaters were identified via the risk quotient approach to predict the associated toxicity for freshwater organisms in recipient surface waters. Currently, two options for HF wastewater treatment are preferred, i.e., disposal by deep well injection or on-site re-use as a fracturing fluid. Supplementary treatment will be enforced by increasingly rigorous regulations. Partial treatment and reuse remain the preferred method for managing HF wastewater where feasible. Otherwise, advanced technologies such as membrane separation/distillation, forward osmosis, mechanical vapor compression, electrocoagulation, advanced oxidation, and adsorption-biological treatment will be required to satisfy the sustainable requirements for reuse or surface discharge.


Assuntos
Recuperação e Remediação Ambiental , Substâncias Perigosas , Fraturamento Hidráulico , Águas Residuárias/análise , Poluentes Químicos da Água , Poluição Química da Água , Substâncias Perigosas/efeitos adversos , Substâncias Perigosas/análise , Poluentes Químicos da Água/efeitos adversos , Poluentes Químicos da Água/análise , Poluição Química da Água/efeitos adversos , Poluição Química da Água/análise
20.
Sci Total Environ ; 664: 312-321, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30743124

RESUMO

In this work, the degradation of cefalexin, norfloxacin, and ofloxacin was examined via various advanced oxidation processes (AOPs). Direct photolysis by ultraviolet (UV) and vacuum ultra violet (VUV) was less effective for the degradation of fluoroquinolone antibiotics such as norfloxacin and ofloxacin than that of cefalexin. Both hydrogen peroxide (H2O2) and potassium persulfate (K2S2O8) assisted UV/VUV process remarkably enhanced fluoroquinolone degradation. The addition of K2S2O8 was superior to H2O2 under VUV irradiation, with the best removal efficiency of norfloxacin and ofloxacin being almost 100% within 3 min in the presence of VUV/K2S2O8. The ofloxacin degradation rate was accelerated as concentrations of H2O2 and K2S2O8 was increased to 3 mM, but the degradation rate was slightly decreased with excess H2O2 (>3 mM). The performance of modified VUV processes (i.e., VUV/H2O2 and VUV/K2S2O8) was inhibited at highly alkaline condition (pH 11). The co-existence of halides (Cl- and Br-) enhanced antibiotics degradation via the modified VUV processes, but the reaction was almost unaffected in the presence of single halides. This study demonstrated that modified VUV processes (especially VUV/K2S2O8) are efficient for eliminating fluoroquinolone antibiotics from water, which can be considered as a clean and green method for the treatment of antibiotics-containing industrial wastewater.


Assuntos
Antibacterianos/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Antibacterianos/química , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/química , Norfloxacino , Fotólise , Compostos de Potássio/química , Sulfatos/química , Raios Ultravioleta , Vácuo , Águas Residuárias , Poluentes Químicos da Água/química
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