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1.
J Hazard Mater ; 477: 135331, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39067288

RESUMEN

Microplastic (MP) accumulation has recently become a pressing global environmental challenge. As a major producer and consumer of plastic products, China's MP pollution has garnered significant attention from researchers. However, accurate and comprehensive investigations of national-level MP pollution are still lacking. In this study, we systematically collated a national MP pollution dataset consisting of 7766 water, soil, and sediment sampling sites from 544 publicly published studies, revealing the spatiotemporal distribution and potential risks of MP pollution in China. The results indicate that MP distribution is influenced by various regional factors, including economic development level, population distribution, and geographical environment, exhibiting considerable range and complexity. MP concentrations are generally higher in economically prosperous areas, but the degree of pollution varies significantly across different environmental media. Given the uncertainty and lack of standardized data in traditional microplastic risk assessment methods, this article highlights the urgency of developing a comprehensive big data and artificial intelligence (AI)-based regulatory framework. This work provides a substantial amount of accurate MP pollution data and offers a fresh perspective on leveraging AI for microplastic pollution regulation.

2.
Water Res ; 251: 121113, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38215539

RESUMEN

A novel treatment technique by coupling granular activated carbon (GAC) adsorption and ozone regeneration was constructed for long-lasting water decontamination. The GAC adsorption showed high performance for atrazine (ATZ) removal (99.9 %), and the ozone regeneration ensured the recyclability of GAC for water purification. The regeneration process was evaluated via several paths to assist the efficient adsorption process. Employing ozone micro-nano bubbles (O3-MNBs) for regenerating GAC showed superior performance compared to traditional ozone. Meantime, inhibiting the formation of bromate (BrO3-). ATZ adsorption process suffered from the pore-filling, hydrogen bonding effect and π-π EDA interaction. The surface phenolic hydroxyl group, carboxyl group and pyridine nitrogen benefitted the triggering of ozone to generate reactive oxygen species, and regenerate the GAC surface. The superior performance of the adsorption and regeneration process was verified via a long-term running by a pilot study. It significantly improved the removal of organic micropollutants, UV254 and permanganate index. Additionally, the intermittent O3-MNBs regeneration process resulted in efficient decontamination within the pores structure of GAC, which also effectively preserved the pore structure from destruction. For actual application, the cost of water production can be saved around 0.63 kWh m-3. This work proposed new ideas and theoretical support for economic water production.


Asunto(s)
Atrazina , Bencenosulfonatos , Ozono , Contaminantes Químicos del Agua , Purificación del Agua , Carbón Orgánico/química , Proyectos Piloto , Ozono/química , Purificación del Agua/métodos , Contaminantes Químicos del Agua/análisis , Agua , Adsorción
3.
Molecules ; 27(21)2022 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-36364281

RESUMEN

Natural organic matter (NOM) has always been considered the main precursor of disinfection by-products (DBPs) during the chlorine disinfection of drinking water. This research focuses on investigating the correlation between the functional group (carboxyl and carbonyl groups) content of NOM and the formation of trichloromethane (TCM) and chloral hydrate (CH). The quantitative determination of carboxyl groups, carbonyl groups, TCM, and CH were conducted during the drinking water treatment processes with different coagulant dosages and with/without pre-oxidation by KMnO4 or NaClO. The most appropriate coagulant for the removal of conventional components was polyaluminum chloride (PAC), and the dosage was 110 mg/L. Up to 43.7% and 14.5% of the carboxyl and carbonyl groups, respectively, were removed through the coagulation and sedimentation processes, which can be enhanced by increasing PAC dosage. The filtration process further increased the removal rates of these two functional groups to 59.8% and 33.5%, respectively. The formation potential of the TCM and CH decreased as the PAC dosage increased. Pre-oxidation by KMnO4 (0.8-1.0 mg/L) effectively controlled the formation of DBPs while increasing the carboxyl and carbonyl group content. Pre-oxidation by NaClO decreased the formation of TCM rather than CH, and a suitable amount (0.5-1.0 mg/L) decreased the carboxyl and carbonyl groups. It was found that there was a good linear correlation between carboxyl groups and TCM and CH. The linear fit R2 values of the carboxyl groups to TCM and CH were 0.6644 and 0.7957, respectively. The linear fit R2 values of the carbonyl groups to TCM and CH were 0.5373 and 0.7595, respectively.


Asunto(s)
Desinfectantes , Agua Potable , Contaminantes Químicos del Agua , Purificación del Agua , Trihalometanos/análisis , Hidrato de Cloral/análisis , Agua Potable/análisis , Cloro/análisis , Desinfección , Cloroformo , Contaminantes Químicos del Agua/análisis , Halogenación , Desinfectantes/análisis
4.
Chemosphere ; 308(Pt 1): 136264, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36064014

RESUMEN

Peroxymonosulfate (PMS)-based advanced oxidation process is considered a potential technology for water treatment. Here, palygorskite (PAL)-mediated cobalt-copper-ferrite nanoparticles (16%-CoCu0.4Fe1·6O4@PAL, donated as 16%-CCFO@PAL) were employed for PMS activation to remove bisphenol S (BPS). BPS degradation was greater than 99% under the optimal conditions within 25 min, on which the effects of various influencing factors were explored. The adsorption dissociation energy of PMS over 16%-CCFO@PAL was -6.27 eV, which was lower than that of the Cu-free catalyst (-6.15 eV), demonstrating the excellent catalytic ability of 16%-CCFO@PAL. The efficient catalytic ability of 16%-CCFO@PAL was also verified in real water samples. The oxidation intermediates were identified and their generations were systematically analyzed by DFT calculations. The possible degradation pathways of BPS were proposed and the toxicity of products was predicted. BPS affected the normal development of zebrafish embryos and the levels of sex hormone in adult male zebrafish, and was harmful to the tissues, such as testis, liver, and intestine of zebrafish. The 16%-CCFO@PAL/PMS process can effectively reduce the toxicity of BPS-polluted water. This study paves the way for the real application of 16%-CCFO@PAL/PMS oxidation process and provides a new perspective for the evaluation of water toxicity.


Asunto(s)
Nanopartículas , Contaminantes Químicos del Agua , Animales , Cobalto/toxicidad , Cobre/toxicidad , Compuestos Férricos , Compuestos de Magnesio , Masculino , Peróxidos , Fenoles , Compuestos de Silicona , Sulfonas , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad , Pez Cebra
5.
Chemosphere ; 301: 134769, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35500634

RESUMEN

The severe cold in winter with harsh natural conditions in Northeastern China seriously affect the water quality of the reservoir, showing the increased content and more complex types of organic matter, which brings severe challenges to the control of disinfection by-products (DBPs) in drinking water treatment with reservoir water as the water source. In this study, the fractions of dissolved organic matter (DOM) in source water at before ice formation period (P1), ice-age period (P2), and ice begin to melt period (P3) were separated by membrane separation technology. Subsequently, the contributions of DOM fractions with different molecular weights (MW) to DOC, UV254, and SUVA254, and their disinfection by-product formation potential (DBPFP) were evaluated. Although DOM with high MW (5-10 kDa) contributed the most to dissolved organic carbon (DOC) and UV254, but the contribution of DOM with low MW (0-1 kDa) to DBPs formation could not be ignored, especially during ice-age period. There was no significant difference in the total numbers of DOM formula belonged to low MW fraction at these three periods, mainly including lignin, followed by N-containing saturated compounds and tannins. Additionally, redundancy analysis revealed that DOC and UV254 as the predictors had good correlation with DBPFP, while SUVA254 could not be used as a single indicator to predict the generation potential of DBPs, and could be used as the prediction factors together with AImodwa parameter closely related to DBPFP. The study provided key information for controlling the DBPs formation of DOM in water, especially in the ice-age period, and provided the theoretical basis for water plant production.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Desinfección , Materia Orgánica Disuelta , Halogenación , Hielo , Contaminantes Químicos del Agua/análisis
6.
J Hazard Mater ; 435: 128968, 2022 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35487000

RESUMEN

Extensive studies revealed that Cl- could inhibit the removal of targeted pollutants under low Cl- conditions in the peroxymonosulfate (PMS) system. However, the enhanced effect of Cl- has always been overlooked under high Cl- conditions. Here, we find that high concentration of Cl- played a critical role in bisphenol S (BPS) degradation by activating PMS using 16%-CoFe2O4@PAL (16%-CFO@PAL). The removal of BPS was sharply enhanced after introducing 0.5 and 1.0 M Cl-, and the corresponding kobs increased to 0.922 min-1 and 1.103 min-1, which was 6-fold and 7-fold higher than the control (0.144 min-1), respectively. HOCl was demonstrated as the dominant species for removing BPS in 16%-CFO@PAL/PMS system under high Cl- circumstances. The typical chlorinated BPS intermediates were identified, which showed higher eco-toxicity than BPS. The chlorinated byproducts along with their toxicity could be effectively eliminated after 30 min. The possible formation mechanism of chlorinated products was further revealed by theoretical calculations. Toxicity assessment experiments showed that BPS significantly affected hormone levels of zebrafish and showed toxicity on the testis and liver of zebrafish, which could be reduced using 16%-CFO@PAL/PMS system. This study attracts attention to the overlooked HOCl in PMS-based processes under high salinity conditions.


Asunto(s)
Salinidad , Contaminantes Químicos del Agua , Animales , Peróxidos , Fenoles , Sulfonas , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad , Pez Cebra
7.
J Hazard Mater ; 432: 128757, 2022 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-35344892

RESUMEN

Novel nitrogen (N)-doped cellulose biochar (NC1000-10) with large adsorption capacity (103.59 mg g-1) for atrazine (ATZ) was synthesized through the one-pot method. It has the best adsorption efficiency than N-doped biochars prepared from hemicellulose and lignin. The adsorption behaviors of ATZ by N-doped biochars with different N doping ratios (NC1000-5, NC1000-10, NC1000-20 and NC1000-30) were significantly different, which was attributed to the difference of sp2 conjugate C (ID/IG = 0.99-1.18) and doped heteroatom N (pyridinic N, pyrrolic N and graphitic N). Adsorption performance of ATZ on NC1000-10 conformed to the pseudo-second-order kinetic and Langmuir adsorption isotherm model. Thermodynamic calculations showed that adsorption performance was favorable. Besides, wide pH adaptability (pH = 2-10), good resistance to ionic strength and excellent recycling efficiency make it have extensive practical application potential. Further material characterizations and the density functional theory (DFT) calculations indicated that good adsorption performance of NC1000-10 for ATZ mainly depended on chemisorption, and π-π electron donor-acceptor (EDA) interaction contributed the most due to high graphitization degree. Specifically, pyridinic N and graphitic N further promoted adsorption performance by hydrophobic effect and π-π EDA interaction between ATZ and NC1000-10, respectively. Pyrrolic N and other surface functional groups (-COOH, -OH) facilitated the hydrogen bond effect.


Asunto(s)
Atrazina , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico/química , Electrones , Cinética , Oxidantes , Contaminantes Químicos del Agua/análisis
8.
Sci Total Environ ; 825: 153706, 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35143787

RESUMEN

In this study, the dissolved organic matter (DOM) profiles of water samples from a water source in northeastern China were analyzed by high-resolution mass spectrometry (HRMS), and its changes after chlorination were investigated. The results showed that lignin substances accounted for a significant proportion in DOM and chlorinated products and were the main precursors of disinfection by-products (DBPs). During disinfection, macromolecular DOM was transformed into small molecules, and lignin substances have the most obvious and complex changes in reaction. Two lignin monomers 4-propylphenol (4PP) and 4-propylguaiacol (4PG) were used as model compounds to study their reaction kinetics and degradation pathways during disinfection. The degradation of both lignin monomers conformed to pseudo-first-order reaction kinetics, and the reaction rate constant of 4PG was higher than that of 4PP. The effects of chlorine dosage, pH and temperature on the degradation reaction kinetics of two lignin monomers were investigated. The degradation rates of 4PP and 4PG increased with increasing chlorine dosage, pH and temperature. The two monomers showed similar properties in the chlorination degradation process, and generated multiple intermediates, which were mainly transformed into small molecules by chlorine electrophilic substitution and nucleophilic substitution, and further generated DBPs.


Asunto(s)
Desinfectantes , Contaminantes Químicos del Agua , Purificación del Agua , Cloro/química , Desinfectantes/análisis , Desinfección/métodos , Halogenación , Lignina , Agua , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos
9.
J Hazard Mater ; 428: 128191, 2022 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-35033910

RESUMEN

This study found that peroxymonosulfate (PMS) oxidation without activation has the potential to generate a suspected human carcinogen, N-nitrosodimethylamine (NDMA), in water containing N,N-dimethylhydrazine compounds. Considerable amounts of NDMA formed from three compounds by PMS oxidation were observed. 1,1,1',1'-Tetramethyl-4,4'-(methylene-di-p-phenylene) disemicarbazide (TMDS), which is an industrial antiyellowing agent and light stabilizer, was used as a representative to elucidate the kinetics, transformation products, mechanism and NDMA formation pathways of PMS oxidation. TMDS degradation and NDMA formation involved direct PMS oxidation and singlet oxygen (1O2) oxidation. The oxidation by PMS/1O2 was pH-dependent, which was related to the pH-dependent characteristics of the reactive oxygen species and intermediates. The degradation mechanism of TMDS mainly included the side chain cleavage, dealkylation, and O-addition. NDMA was generated from TMDS mainly via O-addition and 1,1-dimethylhydrazine (UDMH) generation. The cleavage of amide nitrogen in O-addition products and primary amine nitrogen in UDMH are likely the key steps in NDMA generation. The results emphasized that the formation of harmful by-products should be taken into account when assessing the feasibility of PMS oxidation.


Asunto(s)
Dimetilnitrosamina , Contaminantes Químicos del Agua , Dimetilhidrazinas , Humanos , Cinética , Oxidación-Reducción , Peróxidos , Contaminantes Químicos del Agua/análisis
10.
J Hazard Mater ; 428: 128264, 2022 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-35051770

RESUMEN

The regrowth of chlorine-resistant bacteria in drinking water can deteriorate water quality. The study evaluated the relationship between organic carbon and the regrowth potential of chlorine-resistant bacteria remaining in chloraminated water samples. The results showed that the community structure of bacteria changed with the increase of chloramine dosage. The order in which organic carbon utilized by bacteria was affected by the composition of bacterial community. The biodegradable dissolved organic carbon (BDOC), assimilable organic carbon (AOC), bacterial regrowth potential (BRP) and total cell concentration (TCC) in cultivated water sample after disinfection with 1.8 mg/L chloramine increased form 0.22 mg/L, 33.68 µg/L, 2.70 × 105 cells/mL and 3.48 × 104 cells/mL before cultivation to 1.20 mg/L, 193.90 µg/L, 4.74 × 105 cells/mL and 1.46 × 105 cells/mL, respectively. The increase of TCC did not result in the decrease of BDOC, AOC and BRP in the cultivated water samples. The results showed that other biodegradable organic carbon in chloraminated water samples assimilated by residual chlorine-resistant bacteria besides AOC, BDOC, and organic carbon assimilated by indigenous bacteria. AOC, BDOC, and BRP indicators used to characterize the biostability of drinking water were not enough to accurately assess the regrowth potential of chlorine-resistant bacteria remaining in drinking water. It is suggested to supplement the index of TCC in cultivated water samples, which might be able to more accurately evaluate the regrowth potential of chlorine-resistant bacteria remaining in drinking water.


Asunto(s)
Agua Potable , Purificación del Agua , Bacterias , Carbono/análisis , Cloro/análisis , Microbiología del Agua , Abastecimiento de Agua
11.
Chemosphere ; 289: 133198, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34890616

RESUMEN

Iohexol as an iodinated X-ray contrast agent is widely used, and it is the potential precursor for toxic iodinated disinfection by-products in the disinfection process. In this study, a series of CuFe2O4 catalysts were prepared by sol-gel method with different molar ratios of total metal cations to citric acid ([Men+]T/CA) and employed as heterogeneous catalysts to activate peroxymonosulfate (PMS) for the removal of iohexol. The catalysts were characterized by various technologies, and the effect of [Men+]T/CA molar ratio on the catalysts' properties was explored. The CuFe2O4 synthesized with [Men+]T/CA molar ratio of 1:1 showed the best catalytic activity to PMS, and 95.0% of 1.0 mg/L iohexol was removed within 15 min by using 50 mg/L CuFe2O4 and 20 mg/L PMS. The quenching experiment and electron spin resonance (ESR) spectra indicated the generation of SO4- and OH in the CuFe2O4/PMS system, and the quantity experiments revealed that the generation concentration of SO4- was ten times higher than that of OH. The generation mechanism of SO4- and ·OH were investigated by ATR-FTIR and X-ray photoelectron spectroscopy (XPS) spectra. The effects of catalyst dosage, PMS and iohexol concentration on the removal of iohexol were studied, and various water matrix factors including solution pH, natural organic matter (NOM) concentration and inorganic ions were also considered. Based on the twelve intermediate products of iohexol detected by UPLC-QTOF/MS, the degradation pathway was proposed. The high catalytic activity and reusability of CuFe2O4 indicated that CuFe2O4 activating PMS is an effective and sustainable way for the treatment of iohexol.


Asunto(s)
Yohexol , Agua , Catálisis , Peróxidos
12.
Nanomaterials (Basel) ; 11(10)2021 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-34685091

RESUMEN

α-Fe2O3 fusiform nanorods were prepared by a simple hydrothermal method employing the mixture of FeCl3·6H2O and urea as raw materials. The samples were examined by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and UV-vis diffuse reflectance spectra (UV-DRS). Its visible-light photocatalytic performances were evaluated by photocatalytic decolorization methylene blue (MB) in visible light irradiation. It was found that pure phase α-Fe2O3 nanorods with a length of about 125 nm and a diameter of 50 nm were successfully synthesized. The photocatalytic decolorization of MB results indicated that α-Fe2O3 nanorods showed higher photocatalytic activity than that of commercial Fe2O3 nanoparticles-these are attributed to its unique three-dimensional structure and lower electron-hole recombination rate.

13.
Front Cell Dev Biol ; 9: 687788, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34336838

RESUMEN

To improve the survival rate and cure rate of patients, it is necessary to find a new treatment scheme according to the molecular composition of (ESCC) in esophageal squamous cell carcinoma. Long non-coding RNAs (lncRNAs) regulate the progression of ESCC by various pathophysiological pathways. We explored the possible function of the lncRNA LINC00261 (LINC00261) on cisplatin (DDP) resistance of ESCC and its relative molecular mechanisms. In the study, we found that LINC00261 was downregulated in ESCC tissues, cell lines, and DDP-resistant ESCC patients. Besides, overexpression of LINC00261 not only inhibited cell proliferation, and DDP resistance but also promotes cell apoptosis. Further mechanistic research showed that LINC00261 sponged miR-545-3p which was negatively correlated with the expression of LINC00261. In addition, functional experiments revealed that upregulation of miR-766-5p promoted proliferation and enhanced DDP resistance. Subsequently, MT1M was testified to be the downstream target gene of miR-545-3p. Rescue experiments revealed that overexpression of MT1M largely restores miR-545-3p mimics-mediated function on ESCC progression. Our results demonstrate that the LINC00261 suppressed the DDP resistance of ESCC through miR-545-3p/MT1M axis.

14.
Accid Anal Prev ; 160: 106328, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34385086

RESUMEN

The prediction of traffic crashes is an essential topic in traffic safety research. Most of the previous studies conducted experiments on real-time crash prediction of expressways or freeways, based on traffic flow data. However, the influence of risky driving behavior on traffic crash risk prediction has rarely been considered. Thus, a traffic crash risk prediction model based on risky driving behavior and traffic flow has been developed. The data employed in this research were captured using the in-vehicle AutoNavigator software. A random forest to select variables with strong impacts on crashes and the synthetic minority oversampling technique (SMOTE) to adjust the imbalanced dataset were included in the research. A logistic regression model was developed to predict the risk of traffic crash and to interpret its relationship with traffic flow and risky driving behavior characteristics. This model accurately predicted 84.48% of the crashes, while its false alarm rate remained as low as 9.75%, which indicated that this traffic crash risk prediction model had high accuracy. By analyzing the relationship between traffic flow, risky driving behavior, and crashes through partial dependency plots (PDPs), the impact of traffic flow and risky driving behavior variables on certain traffic crashes in the prediction model were determined. Through this study, the data of traffic flow and risky driving behavior could be used to assess the traffic crash risk on freeways and lay a foundation for traffic safety management.


Asunto(s)
Accidentes de Tránsito , Conducción de Automóvil , Humanos , Modelos Logísticos , Asunción de Riesgos , Administración de la Seguridad
15.
Membranes (Basel) ; 11(2)2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33672826

RESUMEN

A defect-free, loose, and strong layer consisting of zirconium (Zr) nanoparticles (NPs) has been successfully established on a polyacrylonitrile (PAN) ultrafiltration substrate by an in-situ formation process. The resulting organic-inorganic nanofiltration (NF) membrane, NF-PANZr, has been accurately characterized not only with regard to its properties but also its structure by the atomic force microscopy, field emission scanning electron microscopy, and energy dispersive spectroscopy. A sophisticated computing model consisting of the Runge-Kutta method followed by Richardson extrapolation was applied in this investigation to solve the extended Nernst-Planck equations, which govern the solute particles' transport across the active layer of NF-PANZr. A smart, adaptive step-size routine is chosen for this simple and robust method, also known as RK4 (fourth-order Runge-Kutta). The NF-PANZr membrane was less performant toward monovalent ions, and its rejection rate for multivalent ions reached 99.3%. The water flux of the NF-PANZr membrane was as high as 58 L · m-2 · h-1. Richardson's extrapolation was then used to get a better approximation of Cl- and Mg2+ rejection, the relative errors were, respectively, 0.09% and 0.01% for Cl- and Mg2+. While waiting for the rise and expansion of machine learning in the prediction of rejection performance, we strongly recommend the development of better NF models and further validation of existing ones.

16.
J Hazard Mater ; 401: 123837, 2021 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-33113746

RESUMEN

In this study, kinetics, influencing factors and potential mechanisms involved in the degradation of chloral hydrate (CH) by UV/peroxymonosulfate (PMS) process were demonstrated. The degradation rate of CH could reach 89.6% by UV254/PMS process, significantly exceeding UV300/PMS (0.7%), UV350/PMS (6.3%), UV254 direct photolysis (9.0%) and PMS alone (0.0%) processes. CH degradation in UV254/PMS system followed pseudo first-order degradation kinetics with an apparent rate constant of 0.186 min-1, which was suppressed by Cl- and HCO3-. The optimal pH for CH degradation was around 5.0. Direct mineralization accounted for the CH degradation in UV/PMS system. Interestingly, the addition of PMS at the neutral condition before UV irradiation transferred CH into trichloroacetic acid (TCAA). The transformation efficiency of CH into TCAA at 10 min was enhanced from 2.17%-40.38% with the elevation of initial pH from 7.0-8.0. The subsequent exposure of UV lamps ceased the transformation of CH into TCAA and facilitated the direct mineralization of CH, but it did not work in the refractory TCAA degradation. Finally, it was revealed that HO predominantly participated CH degradation in UV/PMS process, while O2- was responsible for the transformation of CH into TCAA by addition of PMS before UV irradiation.

17.
J Hazard Mater ; 404(Pt A): 124142, 2021 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-33059248

RESUMEN

The performance of Fe(III)/H2O2 was extremely enhanced by a novel N-doped ligand dipicolinamide (Dpa) for removing various organic pollutants. This dramatic enhancement of contaminants degradation in Fe(III)-Dpa/H2O2 system under pH≥ 7 was ascribed to the coordinating capacity of Dpa to form the dissolved Fe(III)-Dpa/Fe(II)-Dpa, and the reductive capacity of Dpa to maintain the concentration of Fe(II), which made Dpa improve the catalytic performance of Fe(III) nearly twice as much as Fe(II). Dpa has a strong complexing ability than Cit, NTA, and EDTA to maintain the catalytic activity of Fe(III) without light. The single crystal of Fe-Dpa was obtained to reveal its structure activity relationship. Fe-Dpa was composed of four bonds of Fe-N and two bonds of Fe-Cl. The Fe-Cl bonds were labile sites, which was easily experienced ligand exchange with H2O2, resulting Fe-H2O2 bonds to initiate degradation reaction. The remaining Fe-N bonds were effectively planar, which had a large delocalized π electrons flow domain, enhancing the production of multiple reactive species, including iron(IV/V)-oxo species, HO· and O2-·. An empirical kinetic model of Fe(III)-Dpa/H2O2 system was established. In addition, the evaluation results of the toxicity of Fe-Dpa to larval zebrafish and chinese cabbage displayed that Fe-Dpa possesses low toxicity.


Asunto(s)
Contaminantes Ambientales , Peróxido de Hidrógeno , Animales , Compuestos Férricos , Ligandos , Oxidación-Reducción , Relación Estructura-Actividad , Pez Cebra
18.
J Hazard Mater ; 407: 124759, 2021 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-33341571

RESUMEN

In the paper, molecularly imprinted TiO2 was prepared by surface molecularly imprinted technology and liquid phase deposition method for preferential removal of persistent toxic pollutants from complex environmental water. Diclofenac was selected as the template molecule and target for photodegradation study. The characterization results of SEM, TEM, FTIR and XRD showed that the TiO2 film with imprinted diclofenac was successfully synthesized on the surface of TiO2 particles. Meanwhile, the adsorption and photodegradation experiments also indicated that the molecularly imprinted TiO2 had larger adsorption capacity, better selectivity and higher photodegradation performance for diclofenac than non-imprinted TiO2. The primary active species and degradation pathways during photodegradation process were also elucidated according to radical capture experiments and UPLC-MS-TOF technology. The prepared molecularly imprinted TiO2 has the advantages of efficient removal ability, high stability and environmental protection, so it has a wide application value in water treatment and water environmental restoration, especially when involved persistent toxic pollutants.

19.
J Hazard Mater ; 402: 123574, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-32759003

RESUMEN

Iohexol, a widely used iodinated X-ray contrast media, is difficult to completely degrade with the traditional water treatment process. Catalytic ozonation with synthesized α-Fe0.9Mn0.1OOH as the catalyst can significantly promote the degradation of iohexol relative to that with ozonation alone. Hydroxyl radicals play a predominant role during the degradation of iohexol. The effect of various factors, including catalyst dose, ozone dose, iohexol concentration and water matrix factors, on the catalytic performance were investigated. The presence of α-Fe0.9Mn0.1OOH in the catalytic system can significantly promote the removal of iohexol and mineralization of the dissolved organic carbon in real water samples. The intermediate products were determined by high-resolution liquid chromatography, and the reaction site was predicted by frontier electron density (FED) calculations. The degradation mechanism of iohexol followed the processes of H-abstraction, amide hydrolysis, amide oxidation, and ·OH substitution. Higher exposure concentrations of iohexol had a negative effect on the survival and hatching rates in the development of zebrafish embryos. The autonomic movement process and heartbeat rate of the zebrafish larvae showed significant differences as the exposure concentration of iohexol increased. The catalytic ozonation process with α-Fe0.9Mn0.1OOH can decrease the toxicity of iohexol containing water.


Asunto(s)
Ozono , Contaminantes Químicos del Agua , Purificación del Agua , Animales , Catálisis , Yohexol , Agua , Contaminantes Químicos del Agua/toxicidad , Pez Cebra
20.
Biomed Res Int ; 2020: 8718097, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32851090

RESUMEN

BACKGROUND: The tumor volume of high-grade glioma (HGG) after surgery is usually determined by contrast-enhanced MRI (CE-MRI), but the clinical target volume remains controversial. Functional magnetic resonance imaging (multimodality MRI) techniques such as magnetic resonance perfusion-weighted imaging (PWI) and diffusion-tensor imaging (DTI) can make up for CE-MRI. This study explored the survival outcomes and failure patterns of patients with HGG by comparing the combination of multimodality MRI and CE-MRI imaging with CE-MRI alone. METHODS: 102 patients with postoperative HGG between 2012 and 2016 were included. 50 were delineated based on multimodality MRI (PWI, DTI) and CE-MRI (enhanced T1), and the other 52 were delineated based on CE-MRI as control. RESULTS: The median survival benefit was 6 months. The 2-year overall survival, progression-free survival, and local-regional control rates were 48% vs. 25%, 42% vs. 13.46%, and 40% vs. 13.46% for the multimodality MRI and CE-MRI cohorts, respectively. The two cohorts had similar rates of disease progression and recurrence but different proportions of failure patterns. The univariate analysis shows that characteristics of patients such as combined with epilepsy, the dose of radiotherapy, the selection of MRI were significant influence factors for 2-year overall survival. However, in multivariate analyses, only the selection of MRI was an independent significant predictor of overall survival. CONCLUSIONS: This study was the first to explore the clinical value of multimodality MRI in the delineation of radiotherapy target volume for HGG. The conclusions of the study have positive reference significance to the combination of multimodality MRI and CE-MRI in guiding the delineation of the radiotherapy target area for HGG patients.


Asunto(s)
Imagen de Difusión por Resonancia Magnética , Glioma/diagnóstico por imagen , Angiografía por Resonancia Magnética , Recurrencia Local de Neoplasia/diagnóstico por imagen , Adolescente , Adulto , Anciano , Niño , Femenino , Glioma/diagnóstico , Glioma/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Imagen Multimodal/métodos , Clasificación del Tumor , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/patología , Adulto Joven
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