RESUMEN
The pervasive occurrence of emerging contaminants (ECs) in sewage sludge (SWS) poses significant safety challenges concerning the processing, disposal, and secure application, ultimately jeopardizing both human health and the ecological environment. To comprehensively comprehend the evolutionary trajectories, present state, and research advancements in the field of ECs in SWS, a systematic was conducted, scrutinizing the annual publication quantity, disciplinary distribution, core authors, involved nations/regions, pertinent keywords, and citation status of 2082 research publications related to ECs in SWS from 1990 to 2023. The results indicate a substantial upward trajectory in the research literature pertaining to ECs in SWS. The study of ECs in SWS encompasses 78 disciplines, including Environmental Sciences, Environmental Engineering, and Water Resources. China, Spain, and the USA ranked among the top three countries in terms of both total publications and citation frequency. The majority of publications were published in reputable high-impact journals such as Science of the Total Environment, Chemosphere, and Bioresource Technology. Based on high-frequency keywords, co-occurrence networks of keywords, and keywords burst analysis, it is found that the occurrence and environment behavior of ECs in SWS (ARGs, microplastics, PPCPs, and POPs), the detection and analytical methods, the impact on SWS treatment and disposal processes, and the accumulation and ecological risks in plants and soil during SWS land utilization, are the main research directions and hot topics in this field. In the future, the study of the impact of SWS treatment technologies on ECs removal is expected to receive increased research attention.
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Bibliometría , Aguas del Alcantarillado , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Investigación , Eliminación de Residuos Líquidos/métodosRESUMEN
The emergence and persistence of antibiotic resistance genes (ARGs) in wastewater treatment plants (WWTPs) has aroused growing public concern for its risk to human health and ecological safety. Moreover, heavy metals concentrated in sewage and sludge could potentially favour co-selection of ARGs and heavy metal resistance genes (HMRGs). In this study, the profile and abundance of antibiotic and metal resistance genes in influent, sludge and effluent were characterized based on the Structured ARG Datebase (SARG) and Antibacterial Biocide and Metal Resistance Gene Datebase (BacMet) by metagenomic analysis. Sequences were aligning against the INTEGRALL, ISFinder, ICEberg and NCBI RefSeq databases to obtain the diversity and abundance of mobile genetic elements (MGEs, e.g.plasmid and transposon). Among them, 20 types of ARGs and 16 types of HMRG were detected in all samples, the influent metagenomes contained many more resistance genes (both ARGs and HMRGs) than the sludge and the influent sample, large reductions in the relatively abundance and diversity of ARG were achieved by biological treatment. ARGs and HMRGs cannot be completely eliminated during the oxidation ditch. A total of 32 species of the potential pathogens were detected, relative abundances of pathogens had no obvious changes. It is suggested that more specific treatments are required to limit their proliferation in the environment. This study can be helpful for further understanding the removal of antibiotic resistance genes in the sewage treatment process via metagenomic sequencing.
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Metales Pesados , Purificación del Agua , Humanos , Antibacterianos/farmacología , Aguas del Alcantarillado/microbiología , Aguas Residuales , Genes Bacterianos , Bacterias/genética , MetagenomaRESUMEN
OBJECTIVE: The objective of the study was to systemically evaluate the clinical efficacy of minimally invasive stereotactic puncture for intracranial hematoma evacuation in patients with cerebral hemorrhage. MATERIALS AND METHODS: Relevant studies in PubMed, Web of Science, MEDLINE, China National Knowledge Infrastructure, Wanfang, and VIP databases were searched. A meta-analysis was performed following the inclusion and exclusion criteria screening, data extraction, and literature quality evaluation. RESULTS: Fifteen studies involving 1312 patients were included with 673 participants in the experimental group and 639 in the control group. The results of the meta-analysis showed that, compared with traditional craniotomy or treatment, minimally invasive stereotactic puncture intracranial hematoma removal had a higher clinical total effective rate in patients with cerebral hemorrhage, an outcome that could significantly shorten the hospitalization time of patients with cerebral hemorrhage. The level of post-operative activities of daily living was significantly higher, the incidence of postoperative complications was lower, and the mortality rate was lower. However, there was no significant difference in the degree of post-operative neurological deficit. CONCLUSION: Compared with traditional craniotomy or conservative treatment, minimally invasive stereotactic puncture intracranial hematoma removal has a higher clinical efficacy in the treatment of patients with cerebral hemorrhage, which can improve the post-operative daily life and abilities of patients.
OBJETIVO: Evaluación sistemática de la eficacia clínica de la punción estereotáctica mínimamente invasiva para la evacuación de hematomas intracraneales en pacientes con hemorragia cerebral. MATERIAL Y MÉTODOS: Se realizaron búsquedas en estudios relevantes en PubMed, Web of Science, MEDLINE, Infraestructura Nacional de Conocimiento de China, base de datos Wanfang y base de datos VIP. El metanálisis se realizó después de la selección de criterios de inclusión y exclusión, la extracción de datos y la evaluación de la calidad de la literatura. RESULTADOS: Se incluyeron 15 estudios en los que participaron 1.312 sujetos, 673 en el grupo experimental y 639 en el grupo control. En comparación con la Craneotomía tradicional o el tratamiento, el aclaramiento estereotáctico mínimamente invasivo de hematomas intracraneales tiene una alta eficiencia clínica total en pacientes con hemorragia intracerebral y puede acortar significativamente el tiempo de hospitalización de los pacientes con hemorragia intracerebral. El nivel de actividad de la vida diaria postoperatoria (ADL) aumentó significativamente, la incidencia de complicaciones postoperatorias disminuyó y la mortalidad disminuyó. Sin embargo, no hubo diferencia significativa en el grado de déficit neurológico postoperatorio. CONCLUSIÓN: En comparación con la Craneotomía tradicional o el tratamiento conservador, la Craneotomía estereotáctica mínimamente invasiva tiene un mayor efecto clínico en el tratamiento de la hemorragia cerebral y puede mejorar la capacidad de la vida diaria de los pacientes después de la operación.
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Actividades Cotidianas , Hemorragia Cerebral , Humanos , Hemorragia Cerebral/etiología , Hemorragia Cerebral/cirugía , Punciones , Craneotomía/métodos , Resultado del Tratamiento , Hematoma/etiología , Hematoma/cirugíaRESUMEN
Erythromycin (ERY), as a common macrolides antibiotic, is widely used for sterilisation and disinfection of humans or livestock whose migration and transformation in the surface water environment are significantly related to dissolved organic matter (DOM). The characteristics of DOM can be greatly influenced by the complexation between ERY with itself in soil infiltration system. Using spectroscopic techniques (excitation-emission matrices, parallel factor analysis, Fourier infrared spectroscopy, and synchronous fluorescence spectroscopies) to explore the complexation properties of each DOM component with ERY in the system. The binding order of ERY with DOM functional groups was determined by two-dimensional correlation spectroscopy combined with FTIR. The amide I band v(C = O) exhibited stronger binding affinity. After the treatment, the DOM fluorescence intensity sharply decreased and the ERY concentration declined by 88.36%. Thus, synchronous degradation may occur between them. The result of synchronous fluorescence spectroscopy integrated with two-dimensional correlation spectroscopy indicated that the complexation sequencing and ability of DOM with ERY can be changed by a soil infiltration system. There are more binding sites exhibited in DOM with ERY in effluent than influent. A protein-like component of DOM showed priority binding order and more stable binding with ERY and had the highest Log KM value of 3.61. These results demonstrated that the binding of DOM with ERY in a soil infiltration system could take out most fluorescent DOM, and reduce the concentration and risk of ERY in the surface water body.
RESUMEN
Sulfadiazine (SD) is a common antibiotic administered to treat bacterial infections in livestock, and its fate and migration are greatly affected by dissolved organic matter (DOM). The soil infiltration system [a typical low-impact development (LID) facility] can significantly alter DOM properties during runoff pollution, thus affecting the complexation of SD with DOM. Here, the binding characteristics of different DOM components and SD in the soil infiltration system were explored using spectroscopic techniques (excitation-emission matrices, parallel factor analysis, and synchronous fluorescence spectroscopy). Combined with the weakening of DOM fluorescence intensity and 78.63% reduction in mean SD concentration following treatment, synchronous degradation may have occurred. The binding sequence of SD and DOM fluorophores was further explored using two-dimensional correlation spectroscopy. Effluent DOM showed greater sensitivity to SD and more binding sites than influent DOM. Moreover, hydrophobic protein-like substances exhibited higher log KM values than other fluorescent components, indicating that protein-like components play significant roles in SD complexation. The soil percolation system improved the complexation stability and binding sequence of fulvic-like substances. Thus, SD-DOM can be intercepted and degraded using LID facilities to reduce the risk of SD in aquatic environments.
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Materia Orgánica Disuelta , Sustancias Húmicas , Sustancias Húmicas/análisis , Sulfadiazina , Suelo/química , Espectrometría de Fluorescencia/métodos , Análisis FactorialRESUMEN
A storm-drain inlet is an important link in the transport of microplastic pollutants in urban rainwater runoff. In three functional districts (agricultural, commercial, and residential) from Beijing South 2nd Ring Road to South 6th Ring Road, microplastics in storm-drain inlet sediments were analyzed for abundance and characteristics. The abundance of microplastics in the collected samples ranged from 1121 ± 247 items kg-1 to 7393 ± 491 items kg-1. Among the sample areas, the commercial area had the greatest abundance (11094 items kg-1), while the agricultural area had the lowest (833 items kg-1). The microplastics in the samples were mainly fragments, accounting for 50.4%. Microplastics of less than 1 mm accounted for 74.8%. The color of microplastics was diverse, with colored MPs accounting for 26% and transparent ones for 47.8%. Most of the polymers detected were PET, PS, and PP, which are the most commonly used polymers. Overall, the results provide baseline data on microplastic pollution and its associated risks, in addition to guidelines for controlling runoff pollution.
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Microplásticos , Contaminantes Químicos del Agua , Plásticos , Beijing , Bahías , Sedimentos Geológicos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , DemografíaRESUMEN
Cr(VI) has drawn growing concern because of its acute toxicity and strong carcinogenic properties to most organisms. Metal-organic frameworks (MOFs) have attracted broad interest in removing Cr(VI) as a novel porous adsorbent. In this work, a novel modified Cu@MIL-53(Fe) material and its derivatives have been successfully synthesized via solvothermal and calcination methods and applied for Cr(VI) removal. Experimental parameters, such as the amount of the added Cu, the calcination temperature, the pollutant concentrations, the pH value of solution, etc. were optimized. The Cu@MIL-53(Fe) optimized synthesis parameters were determined as a 0.5 M ratio of Cu/Fe and 800 °C of calcination temperature. The Cr(VI) removal capacities were 20.65 mg/g at 180 min and 13.35 mg/g in 15 min, and 45.55% of total chromium and 99.05% of Cr(VI) were removed at a dose of 0.5 g/L, pH = 3, 25 °C. Batch experiments revealed that the reaction process applied for Langmuir adsorption isotherm and pseudo-second-order models most suitable with qm = 724.6 mg/g. Additionally, Cr (VI) could be reduced to less toxic Cr(III) by Fe0 and Cu0 during redox reactions. According to further mechanism analysis, the process was primarily monolayer chemical adsorption, followed by electrostatic interaction, redox reaction co-precipitation and coordination effect, etc. A novel promising method of Cr(VI) removal from acidic water by MOFs adsorption is presented in this study.
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Estructuras Metalorgánicas , Contaminantes Químicos del Agua , Adsorción , Carbono/química , Cromo/análisis , Concentración de Iones de Hidrógeno , Cinética , Agua/química , Contaminantes Químicos del Agua/análisisRESUMEN
Citrate (Ct) was chosen as a typical chelator used in the Fe2+-peroxydisulfate (PDS) process to improve sludge dewaterability. The PDS-Fe2+-Ct process exhibited better performance in sludge dewatering than PDS-Fe2+. Specifically, with a PDS dosage of 1.2 mmol/g VS, the molar ratio of PDS/Fe2+ and Ct/Fe2+ were 4:5 and 1:4, respectively, the capillary suction time decreased from 155.8 to 24.8sec, and the sludge cake water content decreased from 82.62% to 64.11% (-0.06MPa). The oxidation led to a reduced negative charge and a decrease in particle size. The enhanced sludge dewaterability and changes of sludge properties were attributed to the decomposition of extracellular polymeric substances, and it was explored by protein, polysaccharide, 3D-EEMs, and FT-IR. Additionally, the quenching experiments of radical species demonstrated that SO4-⢠played a more important role than â¢OH, and its productivity was improved with the addition of Ct. Moreover, the reasons for the improved productivity of radicals with the addition of Ct were discussed. The results of this study could serve as a basis for improving sludge dewatering using the PDS-Fe2+-Ct process and suggest that the addition of Ct may improve the productivity of SO4-⢠in the activation of PDS via Fe2+.
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Ácido Cítrico , Aguas del Alcantarillado , Espectroscopía Infrarroja por Transformada de Fourier , Hierro , Matriz Extracelular de Sustancias Poliméricas , Oxidación-Reducción , Agua , Eliminación de Residuos Líquidos/métodosRESUMEN
Stormwater wetlands play a crucial role in the urban environment, providing many ecosystem services. In this work, a stormwater wetland was developed to study the effects on the removal of pollutants and the characteristics of dissolved organic matter (DOM) under different operating conditions, such as hydraulic retention time (HRT) and water depth. The results showed that the stormwater wetland exhibited excellent pollutant-removal performance, such as NH4+_N, TN, TP, COD, and suspended solids (SS). The removal rates for these substances reached 79.1%, 73.2%, 89.0%, 84.3%, 80.4%, and 73.77, respectively, with 24 h of HRT and 15 cm of water depth. An increase in HRT can improve the removal rates of TN, TP, COD, and TOC. The removal rates for these parameters decreased with increasing water depth, though, except for TP; the UV-VIS spectral parameters indicated that an obvious decrease occurred in the degrees of humification and aromaticity of DOM with increasing HRT and water depth after the stormwater wetland treatment. Parallel factor (PARAFAC) analysis identified six fluorescent components (one combination of freshly produced biologically labile matter and a tryptophan-like component, one fulvic-like, one humic-like, and three tryptophan-like), whose fluorescence intensity was weakened after the stormwater wetland treatment. The lowest intensity appeared with 24 h of HRT and 15 cm of water depth. This study could be beneficial for understanding and managing stormwater wetlands, thus alleviating the impacts of pollutants on urban environments.
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Contaminantes Ambientales , Materia Orgánica Disuelta , Humedales , Ecosistema , Triptófano , Espectrometría de Fluorescencia , Sustancias Húmicas/análisisRESUMEN
In this present study, an advection ecological permeable dam (AEPD) based on a biofilm reactor was established to investigate pollution control performance and dissolved organic matter (DOM) bio-degradation. The AEPD achieved optimal efficiency-chemical oxygen demand, 6-53â mg/L; total nitrogen concentration, 1.47-6.89â mg/L; total phosphorus concentration, 0.53-3.93â mg/L, and increases in values for ultraviolet-visible parameters-SUVA254, from 0.392 to 0.673-1.438; E4/E6, from 1.09 to 1.11-1.26; A240-400, from 12.06 to 13.09-19.95; and A253-203, from 0.03 to 0.04-0.23. This showed that DOM degradation promoted its humification, aromatisation, and unsaturation as well as increased the number of polar functional groups in the organic aromatic rings of DOM. Synchronous fluorescence and parallel factor analyses indicated that AEPD could effectively degrade tyrosine-like and tryptophan-like compounds, which showed the most significant decrease in fluorescence intensity. Additionally, AEPD displayed some stable dominant bacterial genera (e.g. Proteobacteria_unclassified, Bacteroidetes_unclassified, Gemmobacter, Pseudofulvimonas, Flavobacterium, Pseudomonas, and Nitrospira), although their relative abundance differed under variable hydraulic loading rates. This research provided further technical support for the application of AEPD in the treatment of water environment pollution.
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Bacterias , Materia Orgánica Disuelta , Bacterias/metabolismo , Biodegradación Ambiental , Contaminación del Agua/análisis , Espectrometría de Fluorescencia , Sustancias Húmicas/análisisRESUMEN
Mixtures of N, N-bis(carboxymethyl)-L-glutamic acid tetrasodium salt (GLDA) with citric acid (CA), glutamic acid (GLU), and aspartic acid (ASP) at the optimal proportion of 1:1, 1:2, and 2:1, respectively. They were employed for heavy metal removal from the sludge. The removal rate of common heavy metals (Cu, Pb, Zn, Ni, Cr, and Cd) and the retention degree of nutrients (total nitrogen, total phosphorus, available-N, Olsen-P, and organic matter) in the treated sludge were analyzed. Fuzzy comprehensive evaluation of the sludge was performed using MATLAB to determine the agricultural grade of the sludge. The sludge after GLDA-acid treatment was mixed with soil at different proportions, and Chinese cabbage, cucumber, and wheat were cultured. SPSS was used for survival analysis to analyze the feasibility of the sludge agriculture. The results showed that the optimal ratio of GLDA-CA and GLDA-GLU was 1:2 and that of GLDA-ASP was 1:1. After GLDA-acid treatment, the sludge was classified as Grade A agricultural sludge based on MATLAB fuzzy comprehensive evaluation and analysis. When the amount of sludge added was 20%, the growth of Chinese cabbage, cucumber, and wheat was promoted. Survival analysis further proved that the amount of sludge only affected the median germination time. Without considering the economic benefits, GLDA-acid can be preferred for sludge treatment, which can not only effectively remove heavy metals in sludge, but also have a small impact on agricultural use.
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Metales Pesados , Contaminantes del Suelo , Quelantes , Ácido Cítrico , Germinación , Metales Pesados/análisis , Semillas/química , Aguas del Alcantarillado , Suelo , Contaminantes del Suelo/análisisRESUMEN
In order to investigate the photocatalytic degradation of dissolved organic matter (DOM) in landfill leachate, TiO2/ZnO heterostructural composite powders were fabricated combining with hydrothermal synthesis and solid-state reaction method. The prepared TiO2/ZnO composite powders consist of anatase TiO2 nanoparticles distributing on the surface of wurtzite ZnO particles. The optical band gap of TiO2/ZnO powder is less than that of pure ZnO or TiO2 powder. TiO2/ZnO catalyzers show high ultraviolet-degradation efficiency for methylene blue and dissolved organic matter. The degradation rate of TiO2/ZnO powder for fulvic acid-like substances in landfill leachate is 2.99 times that of pure ZnO powder, and is 1.30 times that of pure TiO2 powder. The degradation of fulvic acid-like substances by TiO2/ZnO photocatalyst reduced some molecular weight of benzene ring structure substances in leachate. The effective separation of electron and hole in heterostructural TiO2/ZnO photocatalyst is the main reason for its high photocatalytic degradation efficiency of DOM in landfill leachate.
RESUMEN
Effluent organic matter (EfOM) contains a large number of substances that are harmful to both the environment and human health. To avoid the negative effects of organic matter in EfOM, advanced treatment of organic matter is an urgent task. Four typical oxidants (H2O2, PS, PMS, NaClO) and UV-combined treatments were used to treat micro-contaminants in the presence or absence of EfOM, because the active radical species produced in these UV-AOPs are highly reactive with organic contaminants. However, the removal efficiency of trace contaminants was greatly affected by the presence of EfOM. The degradation kinetics of two representative micro-contaminants (benzoic acid (BA) and para chlorobenzoic acid (pCBA)) was significantly reduced in the presence of EfOM, compared to the degradation kinetics in its absence. Using the method of competitive kinetics, with BA, pCBA, and 1,4-dimethoxybenzene (DMOB) as probes, the radicals (HO·, SO4-·, ClO·) proved to be the key to reaction species in advanced oxidation processes. UV irradiation on EfOM was not primarily responsible for the degradation of micro-contaminants. The second-order rate constants of the EfOM with radicals were determined to be (5.027 ± 0.643) × 102 (SO4-·), (3.192 ± 0.153) × 104 (HO·), and 1.35 × 106 (ClO·) (mg C/L)-1 s-1. In addition, this study evaluated the production of three radicals based on the concept of Rct, which can better analyze its reaction mechanism.
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Contaminantes Químicos del Agua , Purificación del Agua , Humanos , Peróxido de Hidrógeno , Cinética , Compuestos Orgánicos , Oxidación-Reducción , Rayos Ultravioleta , Purificación del Agua/métodosRESUMEN
Resource recovery from wastewater is a promising and challenging topic. Herein, a well-designed ion exchange membrane optimized light-driven photoelectrochemical unit (MPECS) was constructed to reduce the effect of inorganic salt on the photoelectrochemical performance of the photoanode. TiO2/carbon dots/WO3 (TCDW) photoanode with the indirect Z-scheme heterojunction structure was successfully fabricated, achieving a strong light harvest performance (10.82%) and a high photocurrent density (5.39 mA/cm2). For the simulated solution (0.01 M phenol and 0.01 M CuSO4), the phenol degradation and Cu recovery efficiencies reached 99.67% and 62.20% in 60 min, respectively, and the corresponding photoelectric conversion efficiency (PECE) reached 4.64% in the TCDW/Pt-based MPECS. For the actual Cu-laden mine wastewater, over 98% of inorganic salt was removed. Compared to the traditional photoelectrochemical system (PECS), the COD removal and Cu recovery efficiencies were further improved by 23.77% and 49.41% in MPECS, respectively. The results exhibited a promising light-driven mine wastewater treatment technology.
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Titanio , Aguas Residuales , Carbono , Intercambio Iónico , MetalesRESUMEN
Biochar-derived water-extractable organic matter (WEOM) was obtained under low-temperature pyrolysis (300⯰C) using corncob as raw material. WEOM may affect the mobility and bioavailability of soil heavy metals (HMs) through complexation when biochar was used for soil HM remediation. Herein, the characteristics of complexation between HMs (Cr(III) and Cu(II)) and biochar-derived WEOM were investigated by using spectroscopic techniques in conjunction with parallel factor (PARAFAC) analysis and two-dimensional correlation spectroscopy (2D-COS). Six components were identified by PARAFAC modeling, in which protein-, fulvic- and humic-like components accounted for 48.86%, 25.63% and 25.51%, respectively. A nonlinear model was employed to determine the conditional stability constant (KM) and total ligand concentration (CL) of WEOM-HM complexes. The log KM values were in the range of 4.02-5.04 for WEOM-Cr(III) and 4.04-6.58 for WEOM-Cu(II). The 2D-COS in conjunction with log-transformed synchronous fluorescence spectroscopy (SFS) suggested that WEOM components were preferentially complexed with HMs in the following order: 433/270, 433/335, 496/270, 496/335, 370/335, 433/402, 496/402, 335/290, 402/290 for Cr(III), and 290/280, 390/280, 433/280, 496/280, 433/335, 496/335, 390/335, 433/420, 496/402, 335/290, 316/290 for Cu(II). The results of 2D-FTIR-COS suggested a preferential bonding of Cr(III) to the C-N group of alkyl, and Cu(II) to the CO group of alcohols, ethers and esters. Meanwhile, the CO group of ethers and the CN group of alkyl indicated preferential susceptibilities for the addition of Cr(III) and Cu(II) at different concentrations. In addition, protein-like components had remarkably higher total ligand concentration (CL) than fulvic- or humic-like components.
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Carbón Orgánico/química , Cromo/química , Cobre/química , Benzopiranos/química , Sustancias Húmicas , Proteínas/química , Pirólisis , Temperatura , Agua/química , Zea maysRESUMEN
Hydrophyte decomposition caused large amounts of dissolved organic matter (DOM) to enter aquatic environment that influence the migration and transformation of heavy metals (HMs). Six hydrophytes with five dry weight gradients (DWG) were used for the decomposition experiments. The results showed that protein-like materials occupy relatively high content in the hydrophyte-derived DOM. The binding properties of DOM-Cu(II) have been explored by using two-dimensional correlation spectroscopy (2D-COS) in conjunction with synchronous fluorescence spectroscopy (SFS) and log-transformed SFS. The weak signals of binding site can be amplified by the log-transformed 2D-COS analysis. Herein, more binding sites can be identified by the log-transformed 2D-COS analysis. The results reveal that tryptophan-like materials show a preferential sequence of binding Cu(II) in the hydrophyte-derived DOM with a relatively low DWG and sediment DOM, and fulvic-like substances indicate a preferential sequence of binding Cu(II) in the hydrophyte-derived DOM with a relatively high DWG. Meanwhile, the results of binding parameters indicate that the log K is the range of 3.61-4.25, 4.33-4.74, 4.59-4.97, 3.91-4.41, and 4.14-4.78 for D1-D5, respectively, suggesting that hydrophyte decomposition can change the binding affinity between DOM components and Cu(II). The complexes of fluorescent components with Cu(II) showed a high log K value at long wavelength (e.g. humic-like substances), and a relatively low ï¬uorescent ligand proportion (f%) at shorter wavelength in the hydrophyte-derived DOM. However, the log K is the range of 3.08-4.31, 4.09-4.45, 3.93-4.35, 4.39-4.75, and 3.95-4.36 for C1-C5, separately. Protein-like substances with Cu(II) showed a relatively high log K value with the exception of C4. The log-transformed 2D-COS can be an analytical tool to understand the binding heterogeneity of DOM with HMs. The study can provide a guide for managing and controlling the effects of hydrophyte decomposition.
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Cobre/metabolismo , Contaminantes Químicos del Agua/metabolismo , Colorantes , Cobre/química , Sustancias Húmicas/análisis , Metales Pesados/química , Espectrometría de Fluorescencia/métodosRESUMEN
In this study, an efficient adsorption and reusable magnetic ligand material (Fe3O4@Chitosan-EDTA) was synthesized by binding EDTA dianhydride onto magnetic chitosan, and it was employed in removal of Co(II) from aqueous solution. The maximum adsorption capacity of Co(II) onto Fe3O4@CS-EDTA was 48.78â mg/g at pH = 5 (303â K), which is much higher than that of Fe3O4@Chitosan as well as chitosan. The kinetics of Co(II) on the Fe3O4@CS-EDTA was consistent with the pseudo-second-order model. The equilibrium data were better fit with the Langmuir isothermal model than with the Freundlich isothermal model, suggesting that the adsorption mechanism was chemical monolayer homogeneous adsorption. The thermodynamic data showed that the sorption of Co(II) was spontaneous. Furthermore, after four cycles, the adsorption capacity of Co(II) onto the Fe3O4@CS-EDTA still retained 84.5% of the capacity of the fresh adsorbent, indicating that Fe3O4@CS-EDTA can be considered a promising recyclable adsorbent to remove heavy-metal ions from wastewater.
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Quitosano , Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Ácido Edético , Concentración de Iones de Hidrógeno , Cinética , Fenómenos MagnéticosRESUMEN
Magnetic phosphorylated chitosan composite (P-MCS), an excellent adsorbent for Co(II), was synthesized in this experiment via a facile fabrication. Its removal efficiency was improved by optimizing pH, contact time, and initial concentration. The adsorption isotherms and kinetic models of Co(II) by P-MCS followed the Langmuir model and the pseudo-second-order model, respectively. However, the rate of adsorption was also affected by intragranular diffusion. The maximum adsorption capacity was 46.1 mg g-1 for Co(II). The results of spectroscopic analysis also indicated that good adsorption performance of Co(II) mainly depends on surface chelation between functional groups and metal ions. The saturation magnetic susceptibilities of P-MCS and P-MCS-Co were 22.29 emu g-1 and 18.18 emu g-1, respectively. The excellent magnetic properties of P-MCS enabled the easy achievement of solid-liquid separation via the use of an external magnetic field. In complex aqueous solutions, K+, Na+, Ca2+, and Mg2+ have less influence on P-MCS adsorption Co(II), but the adsorption capacity on Co(II) is still good. This study shows the feasibility of using P-MCS to treat wastewater containing Co(II).
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Quitosano , Cobalto/química , Contaminantes Químicos del Agua , Purificación del Agua/métodos , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Fenómenos Magnéticos , AguaRESUMEN
In this study, the performance of LaCoO3 (LCO) catalytic ozonation was evaluated comprehensively, including the degradation efficiency of benzotriazole (BZA) as a typical emerging pollutant, toxic bromate reduction and the disinfection by-products (DBPs) precursors removal ability in effluent organic matter (EfOM), as well as EfOM reactive activity in catalytic ozonation. Additionally, the reduction of toxic halogenated by-products in (catalytic) ozonation was reported, which was not focused on previous researches before. Results showed that LCO catalytic ozonation improved the removal efficiency of BZA, UV254 and SUVA via enhanced HO· formation. Interestingly, LCO catalytic ozonation showed the ability on the reduction of aldehydes and toxic halogenated organic by-products. Moreover, the formed [trichloromethane (TCM)], [bromochloroacetonitrile (BCAN)] and [dichloroacetamide (DCAcAm)] decreased significantly in catalytic ozonation. Catalytic ozonation was also able to remove DBPs precursors to decline the formation of DBPs, such as TCM, bromodichloromethane (BDCM), trichloroacetonitrile (TCAN) and trichloronitromethane (TCNM). This process was involved in the transformation of EfOM in catalytic ozonation, which was confirmed by multi-spectrum methods, two-dimensional correlation spectroscopy (2D-COS) and hetero-spectral 2D-COS. In summary, LCO was shown to be an effective catalyst to improve the performance of the sole ozonation on the removal of emerging contaminants and DBPs precursors, as well as toxic by-products reduction. Additionally, the strategy of toxic by-products reduction in catalytic ozonation was proposed. Results indicated this technology was an important contribution on removal of refractory organics and formation of toxic by-products in water supply and wastewater treatment industry.
Asunto(s)
Contaminantes Ambientales , Ozono , Contaminantes Químicos del Agua , Purificación del Agua , Aguas ResidualesRESUMEN
BACKGROUND: Netrin-1 exhibits anti-inflammatory properties. Netrin-1 could alleviate brain injury of subarachnoid hemorrhage (SAH) rat. This study was designed to discern the utility of serum netrin-1 as a biomarker for assessing the severity and prognosis of patients with aneurysmal SAH. METHODS: Netrin-1 concentrations were gauged in serum from 104 patients and 104 controls. Hemorrhagic clinical and radiological severity was assessed utilizing World Federation of Neurological Surgeons (WFNS) score, modified Fisher score, and Hunt Hess score. Glasgow Outcome Scale (GOS) score was recorded at 6â¯months after SAH. GOS score of 1-3 was considered as a poor outcome. RESULTS: Patients showed substantially lower serum netrin-1 concentrations than controls (median, 237.9â¯pg/ml; interquartile range, 189.6-271.2â¯pg/ml vs. median, 815.4â¯pg/ml; interquartile range, 581.8-990.4â¯pg/ml). Netrin-1 concentrations were independently correlated with WNFS score, modified Fisher score, Hunt Hess score and serum C-reactive protein concentrations (tâ¯=â¯-4.667, -3.792, -4.304 andâ¯-â¯3.549 respectively). Area under ROC curve was 0.837 (95% CI, 0.752-0.902) for predicting 6-month poor prognosis. Serum netrin-1 concentrations <229.3â¯pg/ml emerged as an independent prognostic predictor (odds ratio, 14.316; 95% confidence interval, 5.032-40.726). CONCLUSIONS: Serum netrin-1 might represent a potential biomarker for reflecting severity, inflammation and prognosis of human aneurysmal SAH.