Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 120(18): e2221097120, 2023 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-37094155

RESUMEN

Western dietary patterns have been unfavorably linked with mental health. However, the long-term effects of habitual fried food consumption on anxiety and depression and underlying mechanisms remain unclear. Our population-based study with 140,728 people revealed that frequent fried food consumption, especially fried potato consumption, is strongly associated with 12% and 7% higher risk of anxiety and depression, respectively. The associations were more pronounced among male and younger consumers. Consistently, long-term exposure to acrylamide, a representative food processing contaminant in fried products, exacerbates scototaxis and thigmotaxis, and further impairs exploration ability and sociality of adult zebrafish, showing anxiety- and depressive-like behaviors. Moreover, treatment with acrylamide significantly down-regulates the gene expression of tjp2a related to the permeability of blood-brain barrier. Multiomics analysis showed that chronic exposure to acrylamide induces cerebral lipid metabolism disturbance and neuroinflammation. PPAR signaling pathway mediates acrylamide-induced lipid metabolism disorder in the brain of zebrafish. Especially, chronic exposure to acrylamide dysregulates sphingolipid and phospholipid metabolism, which plays important roles in the development of anxiety and depression symptoms. In addition, acrylamide promotes lipid peroxidation and oxidation stress, which participate in cerebral neuroinflammation. Acrylamide dramatically increases the markers of lipid peroxidation, including (±)5-HETE, 11(S)-HETE, 5-oxoETE, and up-regulates the expression of proinflammatory lipid mediators such as (±)12-HETE and 14(S)-HDHA, indicating elevated cerebral inflammatory status after chronic exposure to acrylamide. Together, these results both epidemiologically and mechanistically provide strong evidence to unravel the mechanism of acrylamide-triggered anxiety and depression, and highlight the significance of reducing fried food consumption for mental health.


Asunto(s)
Metabolismo de los Lípidos , Pez Cebra , Masculino , Animales , Depresión , Enfermedades Neuroinflamatorias , Acrilamida , Ansiedad , Contaminación de Alimentos/análisis
2.
Water Sci Technol ; 84(6): 1487-1497, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34559082

RESUMEN

To assess the spatial distribution characteristics and health risk of heavy metals (Cu, Zn, Ni, Cd, Pb, and Cr) in surface sediment of the Hai River and its tributaries in Tianjin, China, 32 surface sediment samples were collected. All the heavy metals mainly occurred in residue, except Cd. Cd primarily existed in the exchangeable fraction and posed a high risk to the aquatic environment. The mean values of pollution index followed a decreasing trend of Cu > Cd > Ni > Pb > Cr > Zn. The results of health risk assessment showed that the heavy metals were not a threat to local residents and Cr and Pb were the main contributors to the health risk. The carcinogenic risk posed by Cr was two orders of magnitude higher than that posed by Cd. A self-organizing map divided the 32 sites into three clusters and more attention should be paid to cluster 3. The results will be conducive to understanding the heavy metal pollution patterns and implementing effective and accurate management programs.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Sedimentos Geológicos , Metales Pesados/análisis , Medición de Riesgo , Ríos , Contaminantes Químicos del Agua/análisis
3.
Langmuir ; 36(22): 6292-6303, 2020 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-32423217

RESUMEN

Studies that explore the transport and retention behavior of colloidal-sized microplastic (MP) with focusing on the governing mechanisms for their attachment and detachment process using colloidal-atomic force microscopy (C-AFM) were still limited. In the present study, multiscale investigations ranging from pore-scale column test to microscale visualization and eventually to nanoscale interfacial and adhesive force measurement were conducted. Pore- and microscale tests were conducted at various flow velocity and over a broad range of IS values and found that IS and flow velocity could synergically impact the deposition of MPs during filtration, in particular under unfavorable condition at small flow velocity. The net difference between the highest and lowest deposition conditions became smaller while flow velocity was decreasing in porous media. However, the net difference between the high and low IS conditions in parallel plate chamber were not sensitive to the change of flow velocity. The measurement from C-AFM suggested that not only the interfacial force but also the adhesive forces changed while MP was approaching/retracting to the collector surface. Information related to the magnitude, location, and occurrence of interfacial/adhesive forces were analyzed. Comparisons of the interaction energy determined from the measured force and ones derived from surface energy components using DLVO theory were conducted to explain the synergies of IS and flow velocity on pathogenic size MPs transport and deposition during filtration.

4.
Water Sci Technol ; 77(9-10): 2190-2203, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29757171

RESUMEN

High color concentrations in inflows at reclaimed water treatment plants are typically considered as emergency situations, which must be solved using an appropriate decolorizing process. Using the decoloration mechanism of a modified dicyandiamide-formaldehyde polymer (DFP), a urea-formaldehyde polymer and a melamine-formaldehyde polymer (MFP) were prepared with ammonium chloride and ammonium sulfate as the modifiers. An orthogonal experiment indicated that a modified urea-formaldehyde polymer had no effect on decolorization; however, the MFP modified by ammonium chloride in number 16 (MMFP-C16), the DFP modified by ammonium chloride in number 9 (MDFP-C9) and modified by ammonium sulfate in number 6 (MDFP-S6) were successful. The removal rates were above 50% in acidic and reactive dye reclaimed water. Fourier transform infrared spectroscopy was used to microscopically analyze the differences in decolorization effect among the polymers. The effect of pH on decolorization was analyzed. Compared to the MDFP-C9 and MDFP-S6, the MMFP-C16 was not sensitive to changes in conditions. The pilot plant test proved that the three optimal decolorizers also had a good decolorizing effect, and MMFP-C16 was better both at decolorizing and floc sedimentation. Thus, the latter can be considered as an efficient modified decolorizer for rapid treatment of high color reclaimed water.


Asunto(s)
Colorantes/química , Formaldehído/química , Purificación del Agua/métodos , Agua/química , Polímeros/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química
5.
Water Sci Technol ; 75(12): 2829-2840, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28659523

RESUMEN

Given that the common medium in existing green roofs is a single layer composed of organic and inorganic substrates, seven pilot-scale dual-substrate-layer extensive green roofs (G1-G7), which include nutrition and adsorption substrate layers, were constructed in this study. The effectiveness of porous inert substrates (activated charcoal, zeolite, pumice, lava, vermiculite and expanded perlite) used as the adsorption substrate for stormwater retention was investigated. A single-substrate-layer green roof (G8) was built for comparison with G1-G7. Despite the larger total rainfall depth (mm) of six types of simulated rains (43.2, 54.6, 76.2, 87.0, 85.2 and 86.4, respectively), the total percent retention of G1-G7 varied between 14% and 82% with an average of 43%, exhibiting better runoff-retaining capacity than G8 based on the maximum potential rainfall storage depth per unit height of adsorption substrate. Regression analysis showed that there was a logarithmic relationship between cumulative rainfall depth with non-zero runoff and stormwater retention for G1-G4 and a linear relationship for G5-G8. To enhance the water retention capacity and extend the service life of dual-substrate-layer extensive green roofs, the mixture of activated charcoal and/or pumice with expanded perlite and/or vermiculite is more suitable as the adsorption substrate than the mixture containing lava and/or zeolite.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Movimientos del Agua , Arquitectura y Construcción de Instituciones de Salud , Hidrología , Porosidad , Lluvia , Eliminación de Residuos Líquidos
6.
Water Sci Technol ; 74(5): 1155-62, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27642835

RESUMEN

A design approach for determining the optimal flow pattern in a landscape lake is proposed based on FLUENT simulation, multiple objective optimization, and parallel computing. This paper formulates the design into a multi-objective optimization problem, with lake circulation effects and operation cost as two objectives, and solves the optimization problem with non-dominated sorting genetic algorithm II. The lake flow pattern is modelled in FLUENT. The parallelization aims at multiple FLUENT instance runs, which is different from the FLUENT internal parallel solver. This approach: (1) proposes lake flow pattern metrics, i.e. weighted average water flow velocity, water volume percentage of low flow velocity, and variance of flow velocity, (2) defines user defined functions for boundary setting, objective and constraints calculation, and (3) parallels the execution of multiple FLUENT instances runs to significantly reduce the optimization wall-clock time. The proposed approach is demonstrated through a case study for Meijiang Lake in Tianjin, China.


Asunto(s)
Simulación por Computador , Lagos , China , Agua
7.
J Hazard Mater ; 474: 134745, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-38820751

RESUMEN

Pipe scales in drinking water distribution systems (DWDS) potentially adsorb chromium (Cr). Meanwhile, the fate of Cr in pipe scales and water could be influenced by the disinfectants used in DWDS since they might influence the valence state of Cr. Therefore, the adsorption of Cr (Cr(VI) and Cr(III)) on pipe scales, the transformation between different valence states, and the effects of disinfectants present in DWDS are important research topics for improving tap water quality but have not yet been sufficiently investigated. This study investigated the properties of layered pipe scales and conducted adsorption kinetic experiments in single and binary Cr(VI) and Cr(III) systems, as well as experiments related to the oxidation and adsorption of Cr(III) under the influence of decaying disinfectants. According to the results, pipe scales exhibited distinct layered structures with varying mechanisms for the adsorption of Cr(VI) and Cr(III). Cr(VI) was adsorbed through surface complexation on the surface and porous core layers, while redox reactions predominantly occurred on the shell-like layer. Furthermore, Cr(III) was adsorbed via surface precipitation on the three-layer pipe scales. Importantly, disinfectants promoted the transformation of Cr(III) to the less readily released Cr(VI) in pipe scales, reducing the Cr exposure risk from the pipe scale phase. Pipe scales also decreased the Cr(VI) concentration in water (almost 0 mg/L), enhancing the safety of DWDS. This study provides theoretical guidance on the safe operation of DWDS.

8.
J Hazard Mater ; 476: 134997, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-38908188

RESUMEN

Microplastics (MPs) co-exist with plastic additives and other emerging pollutants in the drinking water distribution systems (DWDSs). Due to their strong adsorption capacity, MPs may influence the occurrence of additives in DWDSs. The article investigated the occurrence of typical additives bisphenol A (BPA) and dibutyl phthalate (DBP) in DWDSs under the influence of polyamide 6 (PA6) MPs and further discussed the partitioning of BPA/DBP on PA6s, filling a research gap regarding the impact of adsorption between contaminants on their occurrence within DWDSs. In this study, adsorption experiments of BPA/DBP with PA6s and pipe scales were conducted and their interaction mechanisms were investigated. Competitive adsorption experiments of BPA/DBP were also carried out with site energy distribution theory (SEDT) calculations. The results demonstrated that PA6s might contribute to the accumulation of BPA/DBP on pipe scales. The adsorption efficiencies of BPA/DBP with both PA6s and pipe scales were 26.47 and 2.61 times higher than those with only pipe scales. It was noteworthy that BPA had a synergistic effect on the adsorption of DBP on PA6s, resulting in a 26.47 % increase in DBP adsorption. The article provides valuable insights for the compounding effect of different types of additives in water quality monitoring and evaluation.

9.
Water Res ; 256: 121613, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38663210

RESUMEN

Microplastics (MPs) and Cu have been detected in drinking water distribution systems (DWDSs). Investigating MP effects on Cu adsorption by pipe scales and concomitant variations of pipe scales was critical for improving the water quality, which remained unclear to date. Therefore, polystyrene microplastics (PSMPs) were adopted for the model MPs to determine their effects on Cu fate and pipe scale stabilization, containing batch adsorption, metal speciation extraction, and Cu release experiments. Findings demonstrated that complexation and electrostatic interactions were involved in Cu adsorption on pipe scales. PSMPs contributed to Cu adsorption via increasing negative charges of pipe scales and providing additional adsorption sites for Cu, which included the carrying and component effects of free and adsorbed PSMPs, respectively. The decreased iron and manganese oxides fraction (45.57 % to 29.91 %) and increased organic fraction (48.51 % to 63.58 %) of Cu in pipe scales when PSMPs were coexisting illustrated that PSMPs had a greater affinity for Cu than pipe scales and thus influenced its mobility. Additionally, the release of Cu could be facilitated by the coexisted PSMPs, with the destabilization of pipe scales. This study was the first to exhibit that Cu fate and pipe scale stabilization were impacted by MPs, providing new insight into MP hazards in DWDSs.


Asunto(s)
Cobre , Agua Potable , Microplásticos , Poliestirenos , Contaminantes Químicos del Agua , Poliestirenos/química , Agua Potable/química , Cobre/química , Contaminantes Químicos del Agua/química , Adsorción , Abastecimiento de Agua , Coloides/química
10.
Environ Technol ; : 1-15, 2023 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-36730831

RESUMEN

Multilayered graphene oxide (GO) membranes are promising to be widely applied to purify water effectively. However, the performance of most membranes prepared at present is not ideal, which may be related to the pore diameter of the substrate (determining the real loading amount of GO) and the size of the GO nanosheets (determining the number of channels on the unit area), which has not been fully studied. In this study, a rotating dip-coating reactor were firstly developed to ensure the uniform deposition of reactants on the surface of the substrate. Then, the preparation method for the membrane was improved. Microfiltration membranes were used as the supporting substrate, polydopamine was deposited as the adhesive layer, ethylenediamine was used to restrict the layer spacing to strengthen the size exclusion effect, and positively charged polyethyleneimine (PEI) was used to strengthen the Donnan effect. Finally, the effects of the pore size of the substrate and the size of the GO nanosheets on the membrane performance were investigated. Compared with the substrates with a pore size of 0.22 µm in most literatures, substrates of 0.1 µm can retain more small GO (SGO) nanosheets, thereby improving the performance. The performance of the SGO membrane was much better than that of the large-sized GO membrane. With a water permeability of no less than 7.9 L/(m2·h·bar), rejection rates for Pb2+ and Cd2+ of the SGO membrane could reach more than 97%. These findings are constructive to separate heavy metals from water effectively.

11.
Chemosphere ; 330: 138762, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37088206

RESUMEN

The stability of metalloid arsenic (As(Ⅲ)) and As(V) in corrosion scales of drinking water distribution systems (DWDS) is closely related to drinking water safety. The effects of colloidal microplastics entering the DWDS on the stability of As(Ⅲ) and As(V) have not been understood. This study investigated the migration and transformation behaviors of As (Ⅲ) and As(V) in the galvanized steel pipe scales employing speciation simulation and sequential extraction methods. The stability of As(Ⅲ) and As(V) in the pipe scales coexisting with colloidal polystyrene microplastics (CPMPs) under drinking water conditions was studied for the first time from the release behaviors and form distributions. Finally, the optimum water quality conditions for As(Ⅲ) and As(V) fixation were summarized. The existing forms of As(Ⅲ) and As(V) under different pH conditions, the competitive action of anions, and the hydrolysis of cations all would significantly affect the stability of As(Ⅲ) and As(V). Sequential extraction method results revealed that the content of As fractions increased in different forms after the pipe scales adsorbed As(Ⅲ) and As(V). The contents of As and iron (Fe) in the form of residual fractions increased in the presence of CPMPs. The effect of three cations on the stability of As(Ⅲ) and As(V) was Fe3+ > Zn2+ > Ca2+. Neutral to weak alkalescence, proper Cl- and cation concentrations were conducive to the fixation of As in DWDS. Notably, the presence of CPMPs could increase the stability of As(Ⅲ) and As(V) in corrosion scales, thus reducing the risk of metalloid As release in DWDS.


Asunto(s)
Arsénico , Agua Potable , Contaminantes Químicos del Agua , Abastecimiento de Agua , Microplásticos , Plásticos , Poliestirenos , Acero , Corrosión
12.
J Hazard Mater ; 459: 131892, 2023 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-37487336

RESUMEN

The emerging global problems of microplastics pollution and their co-occurrence with other pollutants have presented major new challenges for environmental health and protection. This study used column experiments to investigate the co-transport behavior and Trojan-horse effect of colloidal microplastics (non-functional polystyrene microspheres (MS), carboxyl-modified polystyrene microspheres (CMS) and sulfonate-modified polystyrene microspheres (SMS)) and lead (Pb) in porous media. Results showed that a Trojan-horse effect occurred during the co-transport of colloidal microplastics and Pb. In the process of co-transport, colloidal microplastics and Pb mutually inhibited each other's transport at an ionic strength of 1 mM, which may be due to Pb absorption by microplastics, resulting in the destabilization of agglomerates and a reduction in the electronegativity of microplastics. At an ionic strength of 100 mM, colloidal microplastics and Pb promoted each other's transport, potentially due to their competition for adsorption in porous media. The functional groups present on colloidal microplastics inhibited the transport of Pb at low ionic strengths, while at high ionic strengths Pb transport was promoted. Furthermore, deposition experiments verified that quartz crystal microbalance with dissipation (QCM-D) monitoring could effectively account for and predict the transport and deposition behavior of microplastics in the presence or absence of Pb.

13.
Huan Jing Ke Xue ; 44(10): 5861-5869, 2023 Oct 08.
Artículo en Zh | MEDLINE | ID: mdl-37827801

RESUMEN

Currently, micro- and nanoplastics are the most concerning pollutants, which have been confirmed to exist in every stage of drinking water treatment process. Micro- and nanoplastics in drinking water have large specific surface areas, which could adsorb inorganic matter, organic matter, and microorganisms, thereby increasing their risk to human health. The adsorption and agglomeration behavior of micro- and nanoplastics on typical pollutants is called the "colloid pump effect." Focused on the micro- and nanoplastics in drinking water, the occurrence, colloid pump effect, and toxic effect on the human body and the effect of colloid pumps on the removal of micro- and nanoplastics were summarized and described. The results revealed that micro- and nanoplastics existed widely in source water, treated water, pipe network water, and tap water. The colloid pump effect of micro- and nanoplastics promoted their agglomeration with inorganic matter, organic matter, and microorganisms, which not only intensified the toxic effect of micro- and nanoplastics but also affected the removal effect. There were different viewpoints on the effect of coagulation and sedimentation on the removal of micro- and nanoplastics, and the removal effect of sand filters was limited. The advanced treatment was an efficient process to remove micro- and nanoplastics with a particle size smaller than 5 µm. The removal rate of micro- and nanoplastics could be effectively improved by exploring the mechanism of the colloid pump effect and its initiation conditions. Finally, from the perspective of the drinking water treatment process and colloid pump effect, the control of micro- and nanoplastics in drinking water was prospected in order to provide reference for reducing the occurrence and toxicity of micro- and nanoplastics in drinking water, ensuring drinking water quality safety and human health.


Asunto(s)
Agua Potable , Contaminantes Ambientales , Contaminantes Químicos del Agua , Purificación del Agua , Humanos , Microplásticos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Plásticos
14.
Environ Sci Pollut Res Int ; 30(6): 15217-15229, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36166128

RESUMEN

Metal contaminants in corrosion products of drinking water distribution systems (DWDS) can be released into potable water under specific conditions, thereby polluting drinking water and posing a health risk. Under stagnation conditions, the release characteristics, occurring forms, and environmental risks of ten metals were determined in loose and tubercle scale solids of an unlined cast iron pipe with a long service history, before and after immersion. Most Al, As, Cr, Fe, and V in corrosion scales existed in the residual fraction, with the released concentration and pollution risk being low. Since more than 59% of Ca in pipe scales existed in the exchangeable fraction, Ca release was high. Although the Pb and Cd content of corrosion solids was low, a high proportion of Pb and Cd was present in non-residual fractions with high mobility. Sudden severe Pb or Cd pollution events in DWDS could result in high pollution and environmental risk levels. The total content and released amount of Mn and Zn in corrosion scales were both high. Therefore, while special attention should be paid to Mn and Zn, Pb and Cd also present a high risk in pipe scales, despite their low concentrations. During stagnation immersion, metal release from powdered pipe scales occurred via the processes of mass release, re-adsorption into scales, and slow release until equilibrium was reached. The levels of metal re-adsorption into scales were much higher than the concentrations dissolved into bulk water. However, the amount of metal re-adsorption into tubercle scale blocks was less. Importantly, these findings highlight that during DWDS operation, the sudden release of metal pollutants caused by pipe scale breakage should be avoided.


Asunto(s)
Agua Potable , Metales Pesados , Contaminantes Químicos del Agua , Abastecimiento de Agua , Corrosión , Cadmio , Plomo , Contaminantes Químicos del Agua/análisis
15.
Environ Sci Pollut Res Int ; 30(28): 72675-72689, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37178295

RESUMEN

Extensive application of reclaimed water alleviated water scarcity obviously. Bacterial proliferation in reclaimed water distribution systems (RWDSs) poses a threat to water safety. Disinfection is the most common method to control microbial growth. The present study investigated the efficiency and mechanisms of two widely used disinfectants: sodium hypochlorite (NaClO) and chlorine dioxide (ClO2) on the bacterial community and cell integrity in effluents of RWDSs through high-throughput sequencing (Hiseq) and flow cytometry, respectively. Results showed that a low disinfectant dose (1 mg/L) did not change the bacterial community basically, while an intermediate disinfectant dose (2 mg/L) reduced the biodiversity significantly. However, some tolerant species survived and multiplied in high disinfectant environments (4 mg/L). Additionally, the effect of disinfection on bacterial properties varied between effluents and biofilm, with changes in the abundance, bacterial community, and biodiversity. Results of flow cytometry showed that NaClO disturbed live bacterial cells rapidly, while ClO2 caused greater damage, stripping the bacterial membrane and exposing the cytoplasm. This research will provide valuable information for assessing the disinfection efficiency, biological stability control, and microbial risk management of reclaimed water supply systems.


Asunto(s)
Compuestos de Cloro , Desinfectantes , Purificación del Agua , Agua , Purificación del Agua/métodos , Óxidos , Desinfección/métodos , Hipoclorito de Sodio , Bacterias , Cloro
16.
Huan Jing Ke Xue ; 44(3): 1244-1257, 2023 Mar 08.
Artículo en Zh | MEDLINE | ID: mdl-36922186

RESUMEN

As an emerging pollutant of global concern, microplastics (plastics with size<5 mm) and heavy metals are widely found in freshwater environments. Microplastics migrate easily, are difficult to degrade, and have large specific surface areas. They can enrich a variety of pollutants such as heavy metals and greatly increase their potential harm to the environment and ecology. Firstly, the special environmental behavior of microplastics carrying heavy metals and migrating together in freshwater environments was defined as the "Trojan-horse effect." Then, the Trojan-horse effect and its mechanism of microplastics and heavy metals in the freshwater environment were summarized and expounded from four aspects:the source and distribution of microplastics in the freshwater environment, the enrichment effect of microplastics on heavy metals, the impact of microplastics and the heavy metal Trojan-horse effect on its migration behavior, and the biological impact of microplastics and the heavy metal Trojan-horse effect. The results showed that, as a wide range of non-point source pollutants, microplastics widely existed in freshwater environments. In freshwater environments, the adsorption degree of single metals was different in different environments. It was mainly affected by microplastics, metals, and environmental factors. There was competitive adsorption in the presence of multiple metal ions. The Trojan-horse effect of microplastics and heavy metals could also affect their co-transport behavior. The Trojan-horse effect of microplastics and heavy metals in the freshwater environment frequently exacerbated their toxicity to aquatic organisms. This study provides references for comprehensively understanding the Trojan-horse effect and its mechanism in microplastics and heavy metals in the freshwater environment, which could effectively reduce the ecological risk and impact on human health of microplastics and heavy metals in the freshwater environment.


Asunto(s)
Contaminantes Ambientales , Metales Pesados , Contaminantes Químicos del Agua , Humanos , Microplásticos , Plásticos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Agua Dulce
17.
Sci Total Environ ; 803: 150004, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34500280

RESUMEN

Microplastic (MP) pollution has received widespread attention; however, its occurrence and distribution in water supply systems, particularly in pipe scales, remains unclear. In this study, MPs were observed in water and pipe scale samples from the drinking water treatment plant (DWTP) and distribution system (DWDS), respectively. The MP concentrations ranged from 13.23 to 134.79 n/L and 569.99 to 751.73 n/kg in the water and pipe scale samples, respectively. The predominant particles in the pipe scales (50-100 µm) were smaller than those in the water samples (> 200 µm). Overall, MP fragments were the most abundant. Of all the identified MPs, nylon and polyvinyl chloride were predominant in the water and pipe scale samples, respectively. Furthermore, the DWTP and DWDS both prevented MPs from entering the tap water, thereby reducing their risk. The results of this study provide direct evidence for the strong adsorption of MPs onto pipe scales, indicating that pipe scale stability may play a role in improving water quality and security. However, the abundance of MPs in pipe scales cannot be ignored. Additionally, the results provide valuable background information on MP pollution in water supply systems.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Plásticos , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Abastecimiento de Agua
18.
Sci Total Environ ; 838(Pt 3): 156465, 2022 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-35660623

RESUMEN

The release of vanadium (V) from drinking water distribution systems (DWDS) can endanger water quality and human health. Therefore, in this study, the physicochemical characteristics of old steel pipe scales were analyzed, and dynamic pipeline devices were constructed. Subsequently, static release experiments were conducted to find an optimum scale-water ratio and investigate the release behaviors of V in lumpy pipe scales. Besides, the release behaviors of V from layered pipe scales to bulk, steady, and occluded water under the combined effect of multiple water quality conditions were studied for the first time. Computational fluid dynamics (CFD) was adopted to explain the release behaviors of V in the dynamic pipeline. Results revealed that the adsorption performance of the layered scales decreased in the order of surface layer > porous core layer > hard shell-like layer. The release behaviors of V in the lumpy pipe scales were mainly divided into rapid desorption and colloidal agglomeration stages. The Double constant and Weber-Morris models can suitably describe release stage I (R2 > 0.919) and release stage II (R2 > 0.948), respectively. Notably, the release of V was aggravated by low pH, high temperature, and high SO42- concentration, and the release amount of V in the pipeline was more significant than the layered pipe scales. Steady water in the gaps of scales contained more V than bulk water, and the malignant occluded water encased in scales contained relatively low V concentrations. In short, the main mechanism of V release was competitive adsorption in the early stage, and pH was the main influencing factor in the later stage. The above results are of great significance for revealing the release behaviors of V and reducing its release in DWDS.


Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Corrosión , Humanos , Hierro , Acero , Vanadio , Contaminantes Químicos del Agua/análisis , Abastecimiento de Agua
19.
Front Nutr ; 9: 837601, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35360694

RESUMEN

Perchlorate, commonly available in drinking water and food, acts on the iodine uptake by the thyroid affecting lipid metabolism. High-fat diets leading to various health problems continually raise public concern. In the present study, liver lipid metabolism profiles and metabolic pathways were investigated in C57BL/6J mice chronically exposed to perchlorate using targeted metabolomics. Mice were fed a high-fat diet and treated orally with perchlorate at 0.1 mg/kg bw (body weight), 1 mg/kg bw and 10 mg/kg bw daily for 12 weeks. Perchlorate induced disorders of lipid metabolism in vivo and hepatic lipid accumulation confirmed by serum biochemical parameters and histopathological examination. There were 34 kinds of lipid in liver detected by UHPLC-MS/MS and key metabolites were identified by multivariate statistical analysis evaluated with VIP > 1, p-value < 0.05, fold change > 1.2 or < 0.8. Perchlorate low, medium and high dose groups were identified with 11, 7 and 8 significantly altered lipid metabolites compared to the control group, respectively. The results of the metabolic pathway analysis revealed that the differential metabolites classified into different experimental groups contribute to the glycerophospholipid metabolic pathway. These findings provide insights into the effects of perchlorate on lipid metabolism during long-term exposure to high-fat diets and contribute to the evaluation of perchlorate liver toxic mechanisms and health effects.

20.
Chemosphere ; 309(Pt 1): 136593, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36167207

RESUMEN

As an emerging pollutant, the transport behavior of colloidal microplastic particles (CMPs) in saturated porous media may be affected by the simultaneous presence of other substances in the natural environment. In this study, colloidal polystyrene microplastic particles (PSMPs) were selected as the representative of CMPs to investigate the cotransport behaviors of CMPs in the presence of humic acid (HA) under varied environmental conditions (ionic strength: 1, 100 mM KCl; HA concentration: 0, 5, 10, 20 mg⋅L-1) in porous media. The presence of HA with different concentrations was found to increase the mobility of 1.0-µm and 0.2-µm CMPs in porous media in a non-linear and non-monotonic manner. Furthermore, the HA-facilitated transport of CMPs occurred under both electrostatically unfavorable and favorable attachment conditions (limited to the conditions examined in this study, corresponding to 1 and 100 mM KCl, respectively). The transport behavior of the smaller-sized CMPs (0.2-µm CMPs) was more sensitive to the change of ionic strength and the presence of HA than that of the larger-sized CMPs (1.0-µm CMPs). The cotransport process of CMPs and HA was affected by many factors. Modeling results showed that a small amount of competitive blocking occurred during the cotransport process. Moreover, both the presence of HA and change in ionic strength could affect the surface properties of CMPs. Thus, the cotransport behavior of CMPs with HA was different from the transport of individual CMPs in porous media. Experimental results revealed that HA induced complexity in the transport behavior of CMPs in the aqueous environment. Therefore, undeniably, a lot more systematic explorations are further demanded to better comprehend the CMPs cotransport mechanism in the presence of other substances.


Asunto(s)
Contaminantes Ambientales , Microplásticos , Porosidad , Sustancias Húmicas/análisis , Plásticos , Tamaño de la Partícula , Poliestirenos , Concentración Osmolar
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA