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1.
J Environ Manage ; 354: 120401, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38382437

RESUMO

Aluminum (Al)-based drinking water treatment residue (DWTR) has often been attempted to be recycled as dominant ingredient to produce sintered ceramsite for water treatment. This study aimed to determine the long-term performance of DWTR-based ceramsite in treating domestic wastewater based on a 385-d biofilter test and by using physicochemical, metagenomic, and metatranscriptomic analyses. The results showed that the ceramsite-packed biofilter exhibited high and stable capability in removing phosphorus (P) and chemical oxygen demand (COD), with removal efficiencies of 92.6 ± 3.97% and 81.1 ± 14.0% for total P and COD, respectively; moreover, 88-100% of ammonium-nitrogen (N) was normally converted, and the total N removal efficiency reached 80-86% under proper aeration. Further analysis suggested that the forms of the removed P in the ceramsite were mainly NH4F- and NaOH-extractable. Microbial communities in the ceramsite biofilter exhibited relatively high activity. Typically, various organic matter degradation-related genes (e.g., hemicellulose and starch degradations) were enriched, and a complete N-cycling pathway was established, which is beneficial for enriching microbes involved in ammonium-N conversion, especially Candidatus Brocadia, Candidatus Jettenia, Nitrosomonas, and Nitrospira. In addition, the structures of the ceramsite had high stability (e.g., compressive strength and major compositions). The ceramsites showed limited metal and metalloid pollution risks and even accumulated copper from the wastewater. These results demonstrate the high feasibility of applying ceramsite prepared from Al-based DWTR for water treatment.


Assuntos
Compostos de Amônio , Misturas Complexas , Água Potável , Purificação da Água , Águas Residuárias , Purificação da Água/métodos , Nitrogênio , Alumínio
2.
J Environ Manage ; 328: 117000, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36502704

RESUMO

The use of ceramsite to construct filtration systems (e.g., biofilters) is a common method for water treatment. To promote such applications, the development of low-cost, high-performance, and environmentally friendly ceramsites has received increasing attention from scientists, and a critical step in the development is the preparation of raw materials. As an inevitable and non-hazardous by-product during potable water production, drinking water treatment residue (DWTR) is typically recycled to make water treatment ceramsite to promote recycling in filtration systems. This study aims to bridge the knowledge gap regarding DWTR in making ceramsites for water treatment. The results suggest that the fabrication methods for DWTR-based ceramsite can be generally classified into sintering and non-sintering procedures. For the sintering method, owing to the heterogeneous properties (especially aluminum, iron, and calcium), DWTR has been applied as various sub-ingredients for raw materials preparations. In contrast, for the non-sintering method, DWTR is commonly applied as the main ingredient, and natural curing, physical crosslinking, and thermal treatment methods have been typically adopted to make ceramsite. However, DWTR-based ceramsites tend to have a high adsorption capability and favorable microbial effects to control different kinds of pollution (e.g., phosphorus, nitrogen, and organic matter). Future work is typically recommended to thoroughly evaluate the performance of DWTR-based ceramsite-constructed filtration systems to control water pollution concerning the making procedures, the potential to control pollution, the stability, and the safety of raw DWTR-based ceramsite, providing systematic information to design more proper planning for beneficial recycling.


Assuntos
Água Potável , Purificação da Água , Ferro , Alumínio , Purificação da Água/métodos
3.
J Environ Manage ; 308: 114611, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35114517

RESUMO

As an inevitable by-product of potable water production, drinking water treatment residue (DWTR) recycling to make ceramsite can provide both environmental and economic benefits in constructing filtration treatment system for water environment remediation. Given the varied properties of DWTR from different waterworks, this study aims to identify the key factors affecting ceramsite production from DWTR as main ingredient based on five different DWTR with using clay as the auxiliary material. The results showed that of sintering temperature (500-1000 °C), DWTR:clay ratio (5:5 to 9:1), sintering time (5-60 min), and granule diameter (5-15 mm), the sintering temperature was the key parameter. Increasing temperatures from 500 to 1000 °C gradually promoted DWTR sintering by enhancing Si and Al crystallization, which typically increased the formation of SiO2 and CaAl2Si2O8 crystals in ceramsite. Ceramsites made from different DWTR tended to have different properties, mainly resulting from varied contents of Si (20.2%-48.6%), K (0.0894%-2.39%), Fe (4.56%-14.3%), and loss on ignition (11.7%-39.5%). During ingredients preparation to produce up-to-standard ceramsite, supplying additional Si and diluting loss on ignition were necessary for all DWTR, while supplying K and diluting Fe may be required for specific DWTR, due to the potential varied DWTR compositions caused by different water production processes applied (e.g., type of flocculants). Further toxicity characteristic leaching procedure analysis indicated the increased leaching of Cu. However, DWTR based ceramsite was identified as non-hazardous material; even, sintering treatment reduced the leachability of Ba, Be, Cd, and Cr. DWTR based ceramsite also had relatively high specific surface area (22.1-50.5 m2/g) and could adsorb Cd, Cu, and Pb from solution. Overall, based on appropriate management, DWTR can be recycled as the main ingredient in the production of ceramsite for water environment remediation.


Assuntos
Dióxido de Silício , Purificação da Água , Adsorção , Misturas Complexas , Reciclagem , Purificação da Água/métodos
4.
J Environ Manage ; 280: 111640, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33187785

RESUMO

Eutrophication of natural water commonly involves the pollution of both P and N. Here, we developed a new application of drinking water treatment residuals (DWTRs) for suspensions that permits the simultaneous removal of excess P and N from natural water and demonstrates that DWTRs recycling can provide a means for eutrophication control. Based on 364-day continuous flow tests, the suspension application of DWTRs effectively adsorbed P from overlying water under various conditions, decreasing total P concentrations from 0.0739 ± 0.0462 to 0.0111 ± 0.0079-0.0149 ± 0.0106 mg L-1, which achieved a class Ⅱ level of the China surface water quality standards during the tests. The total N concentrations were also reduced from 1.46 ± 0.63-1.52 ± 0.63 to 0.435 ± 0.185-0.495 ± 0.198 mg L-1, which achieved a class Ⅲ level during the stable stage of the tests. N removal was closely related to doses of DWTRs and aeration intensities. Effective N removal was mediated by the enriched microbial communities in the suspended DWTRs with simple, stable, and resilient networks, including many taxa associated with the N cycle (e.g., Rhodoplanes, Brevibacillus, and Pseudomonas). Further analysis indicated that both effective P adsorption and functional microbial community construction were closely related to Fe and Al in DWTRs. Suspension application prevented the burial effect of solids sinking from overlying water, which aided the ability of DWTRs to control pollution, and is potentially applicable to other materials for natural water remediation.


Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , China , Água Potável/análise , Estudos de Viabilidade , Fósforo/análise
5.
J Environ Manage ; 266: 110579, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32310120

RESUMO

This study used a relatively long-term (350 d) continuous flow test to determine the bioturbation effect of a benthic macroinvertebrate (the snail Bellamya aeruginosa) on sediment internal phosphorus (P) pollution control by in-situ immobilisation using drinking water treatment residue (DWTR) as the inactivating agent. The results showed that DWTR substantially reduced P concentration in overlying water, had a limited effect on other overlying water properties, and tended to reduce nitrogen release from the sediment. Variations in overlying water properties induced by DWTR were generally not associated with snail activity or population density. However, the snails were found to promote DWTR burial and induce DWTR mixing within the sediment, indicating that bioturbation could change the distribution of P inactivating agents in sediment. The mobility of P was closely related to oxalate extractable aluminium, iron, and P (Alox, Feox, and Pox, respectively) in sediments at different depths. Typically, mobile P was stable at a relatively low level when the total content of Alox and Feox was >0.750 mmol g-1 or when the ratio of Pox to (Alox + Feox) was <0.05. Given these results, recommended practices include repeated dosing of the immobilising agents at intervals determined by the relationships among mobile P, Pox, Alox, and Feox in the sediment, especially for Al- and Fe-based agents such as DWTR. Overall, the effect of bioturbation on the stability of in-situ P immobilisation in sediment should be fully considered during long-term pollution control.


Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , Animais , Eutrofização , Sedimentos Geológicos , Lagos , Fósforo , Pseudomonas aeruginosa , Caramujos
6.
J Environ Manage ; 182: 21-28, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27454093

RESUMO

Drinking water treatment residue (DWTR) seems to be very promising for controlling lake sediment pollution. Logically, acquisition of the potential toxicity of DWTR will be beneficial for its applications. In this study, the toxicity of DWTR and sediments amended with DWTR to Aliivibrio fischeri was evaluated based on the Microtox(®) solid and leachate phase assays, in combination with flow cytometry analyses and the kinetic luminescent bacteria test. The results showed that both solid particles and aqueous/organic extracts of DWTR exhibited no toxicity to the bacterial luminescence and growth. The solid particles of DWTR even promoted bacterial luminescence, possibly because DWTR particles could act as a microbial carrier and provide nutrients for bacteria growth. Bacterial toxicity (either luminescence or growth) was observed from the solid phase and aqueous/organic extracts of sediments with or without DWTR addition. Further analysis showed that the solid phase toxicity was determined to be related mainly to the fixation of bacteria to fine particles and/or organic matter, and all of the observed inhibition resulting from aqueous/organic extracts was identified as non-significant. Moreover, DWTR addition not only had no adverse effect on the aqueous/organic extract toxicity of the sediment but also reduced the solid phase toxicity of the sediment. Overall, in practical application, the solid particles, the water-soluble substances transferred to surface water or the organic substances in DWTR had no toxicity or any delayed effect on bacteria in lakes, and DWTR can therefore be considered as a non-hazardous material.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Bioensaio/métodos , Água Potável/química , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos , Aliivibrio fischeri/crescimento & desenvolvimento , Água Potável/análise , Lagos/química
7.
J Environ Sci (China) ; 46: 5-15, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27521931

RESUMO

Drinking water treatment residuals (WTRs) have a potential to realize eutrophication control objectives by reducing the internal phosphorus (P) load of lake sediments. Information regarding the ecological risk of dewatered WTR reuse in aquatic environments is generally lacking, however. In this study, we analyzed the eco-toxicity of leachates from sediments with or without dewatered WTRs toward algae Chlorella vulgaris via algal growth inhibition testing with algal cell density, chlorophyll content, malondialdehyde content, antioxidant enzyme superoxide dismutase activity, and subcellular structure indices. The results suggested that leachates from sediments unanimously inhibited algal growth, with or without the addition of different WTR doses (10% or 50% of the sediment in dry weight) at different pH values (8-9), as well as from sediments treated for different durations (10 or 180days). The inhibition was primarily the result of P deficiency in the leachates owing to WTR P adsorption, however, our results suggest that the dewatered WTRs were considered as a favorable potential material for internal P loading control in lake restoration projects, as it shows acceptably low risk toward aquatic plants.


Assuntos
Desinfetantes/toxicidade , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos , Desinfetantes/análise , Monitoramento Ambiental , Eutrofização , Sedimentos Geológicos , Lagos , Fósforo/toxicidade , Poluentes Químicos da Água/análise
8.
J Environ Manage ; 159: 178-185, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26071931

RESUMO

Aluminum and Fe-based drinking water treatment residuals (DWTRs) have shown a high potential for use by geoengineers in internal P loading control in lakes. In this study, aging of Al/Fe-based DWTRs in lake water under different pH and redox conditions associated with their P immobilization capability was investigated based on a 180-day incubation test. The results showed that the DWTRs before and after incubation under different conditions have similar structures, but their specific surface area and pore volume, especially mesopores with radius at 2.1-5.0 nm drastically decreased. The oxalate extractable Al contents changed little although a small amount of Al transformed from oxidizable to residual forms. The oxalate extractable Fe contents also decreased by a small amount, but the transformation from oxidizable to residual forms were remarkable, approximately by 14.6%. However, the DWTRs before and after incubation had similar P immobilization capabilities in solutions and lake sediments. Even the maximum P adsorption capacity estimated by the Langmuir model increased after incubation. Therefore, it was not necessary to give special attention to the impact of Al and Fe aging on the effectiveness of DWTRs for geoengineering in lakes.


Assuntos
Alumínio/química , Ferro/química , Lagos/química , Fósforo/química , Purificação da Água/métodos , Adsorção , Água Potável/química , Sedimentos Geológicos/química , Concentração de Íons de Hidrogênio , Oxalatos/química
9.
J Environ Sci (China) ; 33: 60-8, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-26141878

RESUMO

Knowledge of the effective radiation spectrum irradiating substrates from microwave powered electrodeless discharge lamps (MEDLs), and the active species that directly oxidize substrates in the photolytic process, is fragmentary and unclear. In this work, we conducted a comparative study using MEDLs made with quartz envelopes (MEDL-quartz) and with borosilicate Pyrex envelopes (MEDL-Pyrex) targeting the degradation of Rhodamine B (RhB) via radical-extinguishing tests. We found that UVC/UVB radiation is essential to generate •OH and H2O2 in the MEDL-quartz system. The degradation of RhB mostly originates from •OH species, which account for a contribution of 53.8%, while the remaining contribution is attributed to oxidation by H2O2 and direct photolysis. This degradation is influenced by several parameters. Acidic and neutral pHs, but not extreme alkaline pH, benefit the degradation. To ensure a high intensity of UVC/UVB, the optimum ratio of the MEDL volume to the aqueous solution volume (VL/VS) is 0.4. Concentrations of 0.15-0.20 mmol/L of RhB are suitable to obtain an effective quantum absorbance in the MEDL-quartz system, showing a high decomposition rate of 5.6×10(-3) (mmol/L) min(-1). Moreover, two other substrates, Reactive Brilliant Red X-3B and Safranine T, were tested and found to be efficiently degraded in the MEDL-quartz system.


Assuntos
Micro-Ondas , Fotólise , Poluentes Químicos da Água/química , Catálise , Eletrodos
10.
J Environ Qual ; 43(1): 389-97, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25602573

RESUMO

Drinking water treatment residuals (WTRs), by-products generated during treatment of drinking water, can be reused as environmental amendments to remediate contamination. However, this beneficial reuse may be hampered by the potential release of toxic contaminants (e.g., metals) in the WTRs. In present study, batch tests and then fractionation, in vitro digestion, and the toxicity characteristic leaching procedure were used to investigate the release and extractability of metals in the Fe/Al hydroxides comprised WTRs under differing pH. The results demonstrated that significant release from WTRs for Ba, Be, Ca, Cd, Co, Cr, Fe, Mg, Mn, Pb, Sr, and Zn occurred under low pH (acid condition); for As, Mo, and V under high pH (alkaline condition); and for Al, Cu, and Ni under both conditions. In comparison, most metals in the WTRs were more easily released under low pH, but the release was stable at a relatively low level between pH 6 and 9, especially under alkaline conditions. Further analysis indicated that the chemical extractability and bioaccessibility of many metals was found to increase in the WTRs after being leached, even though the leached WTRs could still be considered nonhazardous. These results demonstrated that pH had a substantial effect on the lability of metals in WTRs. Overall, caution should be used when considering pH conditions during WTRs reuse to avoid potential metal pollution.

11.
Med Phys ; 50(10): 6137-6150, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36775901

RESUMO

BACKGROUND: Diffusion tensor imaging (DTI) is a promising technique for non-invasively investigating the myocardial fiber structures of human heart. However, low signal-to-noise ratio (SNR) has been a major limit of cardiac DTI to prevent us from detecting myocardium structure accurately. Therefore, it is important to remove the effect of noise on diffusion weighted (DW) images. PURPOSE: Although the conventional and deep learning-based denoising methods have shown the potential to deal with effectively the noise in DW images, most of them are redundant information dependent or require the noise-free images as golden standard. In addition, the existed DW image denoising methods often suffer from problems of over-smoothing. To address these issues, we propose a self-supervised learning model, structural similarity based convolutional neural network with edge-weighted loss (SSECNN), to remove the noise effectively in cardiac DTI. METHODS: Considering that the DW images acquired along different diffusion directions have structural similarity, and the noise in these DW images is independent and identically distributed, the structural similarity-based matching algorithm is proposed to search for the most similar DW images. Such similar noisy DW image pairs are then used as the input and target of the denoising network SSECNN, which consists of several convolutional and residual blocks. Through the self-supervised training with these image pairs, the network can restore the clean DW images and retain the correlations between the denoised DW images along different directions. To avoid the over-smoothing problem, we design a novel edge-weighted loss which enables the network to adaptively adjust the loss weights with iterations and therefore to improve the detail preserve ability of the model. To verify the superiority of the proposed method, comparisons with state-of-the-art (SOTA) denoising methods are performed on both synthetic and real acquired DTI datasets. RESULTS: Experimental results show that SSECNN can effectively reduce the noise in the DW images while preserving detailed texture and edge information and therefore achieve better performance in DTI reconstruction. For synthetic dataset, compared to the SOTA method, the root mean square error (RMSE), peak signal-to-noise ratio (PSNR), and structure similarity index measure (SSIM) between the denoised DW images obtained with SSECNN and noise-free DW images are improved by 6.94%, 1.98%, and 0.76% respectively when the noise level is 10%. As for the acquired cardiac DTI dataset, the SSECNN method could significantly improve SNR and contrast to noise ratio (CNR) of cardiac DW images and achieve more regular helix angle (HA) and transverse angle (TA) maps. The ablation experimental results validate that using the structure similarity-based method to search the similar DW image pairs yield the smallest loss, and with the help of the edge-weighted loss, the denoised DW images and diffusion metric maps can preserve more details. CONCLUSIONS: The proposed SSECNN method can fully explore the similarity between the DW images along different diffusion directions. Using such similarity and an edge-weighted loss enable us to denoise cardiac DTI effectively in a self-supervised manner. Our method can overcome the redundancy information dependence and over-smoothing problem of the SOTA methods.


Assuntos
Imagem de Tensor de Difusão , Redes Neurais de Computação , Humanos , Algoritmos , Razão Sinal-Ruído , Coração/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos
12.
Mol Ecol ; 21(20): 5073-87, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22989375

RESUMO

Previous studies have indicated that China is one of the domestication centres of Asian cultivated rice (Oryza sativa), and common wild rice (O. rufipogon) is the progenitor of O. sativa. However, the number of domestication times and the geographic origin of Asian cultivated rice in China are still under debate. In this study, 100 accessions of Asian cultivated rice and 111 accessions of common wild rice in China were selected to examine the relationship between O. sativa and O. rufipogon and thereby infer the domestication and evolution of O. sativa in China through sequence analyses of six gene regions, trnC-ycf6 in chloroplast genomes, cox3 in mitochondrial genomes and ITS, Ehd1, Waxy, Hd1 in nuclear genomes. The results indicated that the two subspecies of O. sativa (indica and japonica) were domesticated independently from different populations of O. rufipogon with gene flow occurring later from japonica to indica; Southern China was the genetic diversity centre of O. rufipogon, and the Pearl River basin near the Tropic of Cancer was the domestication centre of O. sativa in China.


Assuntos
Produtos Agrícolas/genética , Evolução Molecular , Variação Genética , Oryza/genética , Núcleo Celular/genética , China , DNA de Cloroplastos/genética , DNA Mitocondrial/genética , DNA de Plantas/genética , Fluxo Gênico , Genética Populacional , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Filogenia
13.
Curr Drug Metab ; 23(1): 30-37, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35081887

RESUMO

BACKGROUND: Scutebarbatine A is a new neo-Clerodane Diterpenoid Alkaloids from Scutellaria barbata, which has many pharmacological effects, such as anti-tumor, antibacterial, and anti-inflammatory. However, there are no studies on the metabolism of Scutebarbatine A. OBJECTIVE: The objective of this study is to explore the metabolism of Scutebarbatine A in the body, the bile, plasma, urine, and feces samples of rats after administration were investigated. METHODS: The biological samples were investigated using ultra-high-performance liquid chromatography coupled with Q Exactive hybrid quadrupole-orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap-HRMS). RESULTS: A total of 20 metabolites were identified: 16 phase I metabolites and 4 phase II metabolites. The main metabolic pathways were hydrolysis, oxidation, hydrogenation, dehydration, and combination with sulfate. CONCLUSION: This study further elucidates the metabolism of Scutebarbatine A in rats and provides a reference for the study of its pharmacodynamic material basis and pharmacological mechanism.


Assuntos
Bile , Espectrometria de Massas em Tandem , Animais , Cromatografia Líquida de Alta Pressão/métodos , Fezes/química , Humanos , Naftóis , Niacina , Ratos , Espectrometria de Massas em Tandem/métodos
14.
Brain Res Bull ; 188: 187-196, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35961529

RESUMO

OBJECTIVE: Diabetic encephalopathy (DE), a chronic complication of diabetes, is characterized by decline of cognitive function. The molecular mechanism of DE remains unclear. The purpose of this study is to evaluate the roles of advanced glycation end products (AGEs) in the pathogenesis of DE and investigate its underlying mechanisms in this process. METHODS: DE rats were developed by incorporating a high-fat diet and streptozotocin injection followed by the Morris Water Maze test. HT-22 cells were used to mimic the in vitro neuronal injuries of DE. Expression levels of long non-coding RNA H19, miR-15b and ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) mRNA in the hippocampus of DE rats or HT-22 cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The levels of BACE1 proteins were analyzed by western blotting or immunohistochemical staining. The contents of Aß1-42 in supernatant of the cell culture were analyzed by enzyme-linked immu-nosorbent assay (ELISA). The relationship between H19 or BACE1 and miR-15b was verified with dual-luciferase reporter assay. RESULTS: We found that the accumulation of Aß1-42 and the phosphorylation of Tau (Ser404) were increased in the hippocampus CA3 regionof DE rats. MiR-15b was downregulated while H19 and BACE1 were upregulated in the hippocampus CA3 regionof DE rats and AGEs-treated HT-22 cells. The expression of BACE1 protein was negatively regulated by miR-15b at the post-transcriptional level in HT-22 cells. In vivo, administration of miR-15b mimics by the intranasal delivery markedly decreased the BACE1 protein in hippocampal CA3 region and improved the cognitive decline in DE rats. Besides, the luciferase activity assay confirmed the binding site of miR-15b to both the 3'-untranslated region (3'-UTR) of BACE1 mRNA and H19. Then, miR-15b inhibitor reversed H19 knockdown-mediated decrease of Aß1-42 level in AGEs-treated HT-22 cells. CONCLUSION: These results suggested that AGEs induced Aß1-42 deposition andcognitive decline through H19/miR-15b/ BACE1 axis in DE.


Assuntos
Encefalopatias , Disfunção Cognitiva , Diabetes Mellitus , MicroRNAs , RNA Longo não Codificante , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides , Animais , Ácido Aspártico Endopeptidases/metabolismo , Produtos Finais de Glicação Avançada , MicroRNAs/genética , MicroRNAs/metabolismo , Fragmentos de Peptídeos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , Ratos
15.
Chemosphere ; 262: 127930, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182151

RESUMO

The beneficial recycling of drinking water treatment residue (DWTR) for environmental remediation has received increasingly interests; whereas, the reported potential effect of microbial communities in different DWTR was ambiguous, which was unfavorable for the beneficial recycling. This study hypothesized that the varied treatment to DWTR in different waterworks induced the ambiguous effect; accordingly, responses of microbial communities in DWTR to the sequential dewatering and drying treatment were determined based on samples from three waterworks, in combination with 180-d incubation tests. The results showed that the microbial communities varied remarkably in different DWTR before being dewatered (DWTS). However, after dewatering, the increased microbial diversities were observed, and the microbial communities exhibited higher similarities among the dewatered DWTR from different waterworks; furthermore, the dewatered DWTR with subsequent drying treatment enriched more bacteria genus with potential environmental functions after incubation tests. The variations of microbial communities were closely related to DWTR properties, such as pH, organic matter, metals, P, and water extractable nutrients. Further analysis indicated that with maintaining high adsorption capability of DWTR, the dewatering treatment tended to retain specific microbial communities that may be induced by the applied similar techniques in different waterworks; the accumulated nutriments due to drying treatment and the stable DWTR pH enhanced the potential functional bacteria enrichment. Overall, the dewatering and drying treatment led to microbial communities with generality in different DWTR and increased the potential favorable microbial effect, promoting DWTR recycling in environmental remediation.


Assuntos
Água Potável/química , Purificação da Água/métodos , Adsorção , Dessecação , Água Potável/análise , Recuperação e Remediação Ambiental , Metais , Microbiota , Reciclagem
16.
Artigo em Inglês | MEDLINE | ID: mdl-32823506

RESUMO

There have been widespread attempts to recycle drinking water treatment residue (DWTR) after dewatering for environmental remediation, which is beneficial for both the environment and the economy. The directly discharged DWTR without dewatering to natural water bodies, however, was reported to show signs of chronic toxicity to Daphnia magna (D. magna), a typical zooplankton in the aquatic environment. This study comprehensively assessed the effect of dewatered DWTR on the physiological and biochemical characteristics of D. magna based on acute and chronic toxicity tests. The results showed that the survival, growth, reproduction, body morphology of offspring, and the antioxidant enzymes of D. magna were not affected by the dewatered DWTR. These physiological and biochemical indexes also had no undesirable changes for the DWTR-amended sediments (with ratios of 0-50%) incubated for 10 and 180 d; the growth and reproduction were even promoted when D. magna was exposed to 5000 mg-sediment L-1, which may be due to the extra nutrients supplied by the amended sediments for the animals. The results demonstrated that by contrast with the directly discharged DWTR without dewatering, the dewatered DWTR could be safe to D. magna. Further analysis suggested that heavy metals (Pb, Ni, Cu, Cr, and Zn) with relatively low concentrations and high stability could be the main reasons leading to the high safety of the dewatered DWTR. Overall, dewatered DWTR can be considered a non-hazardous material for zooplankton.


Assuntos
Recuperação e Remediação Ambiental , Metais Pesados , Poluentes Químicos da Água , Purificação da Água , Animais , Daphnia , Metais Pesados/análise , Reciclagem , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
18.
Front Chem ; 8: 72, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32266201

RESUMO

PLA-1-Al2O3@LNCM synthesized using an efficient and facile plasma-enhanced method exhibits markedly improved capacity retention of 98.6% after 100 cycles, which is much larger than that of LNCM at 80% after 100 cycles. What is more, it also exhibits significantly enhanced cyclicity compared to that of 1-Al2O3@LNCM cathodes prepared using the normal solid state method, which further illustrates the efficiency and superiority of this plasma-enhanced method. More importantly, the rate performance of PLA-1-Al2O3@LNCM is improved because of the better electrolyte storage of the assembled hierarchical architecture of the Al2O3 coating layer according to unimpeded Li+ diffusion from electrode to electrolyte. When cycling at 55°C, the PLA-1-Al2O3@LNCM shows 93.6% capacity retention after 100 cycles, which is greatly enhanced due to the uniform Al2O3 layer. Further, growth of polarization impedance during cycling can be effectively suppressed by the Al2O3 layer, which can further confirm the effect the Al2O3 layer coated on the surface of the LNCM. The enhanced cycling performance and thermal stability illustrates that this facile surface modification, using the plasma-enhanced method, can form an effective structured coating layer, which indicates its prospects as an application in the modification of other electrode materials.

19.
Chemosphere ; 247: 125919, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31978660

RESUMO

This study proposes the use of an aluminum-based drinking water treatment residue (DWTR) to adsorb ferrocyanide. The batch tests and chemical characterization results showed that ferrocyanide adsorption increased as the pH, ion strength, and the solid and solution ratio decreased, and as the initial ferrocyanide concentration increased. The pseudo-first (R2 = 0.906) and pseudo-second-order (R2 = 0.966) kinetic models well described the adsorption kinetics, and the adsorption isotherm was also well fittted by Langmuir (R2 = 0.989) and Freundlich (R2 = 0.989) models. The calculated initial ferrocyanide adsorption rate by the pseudo-second-order kinetic model was 0.0190 mg-CN g-1 h-1, and the estimated maximum adsorption capacity determined by the Langmuir model was 20.9 mg-CN g-1. The main structure and elemental distributions showed nearly no change in DWTR after adsorption. Adsorption involved electrostatic interactions and ligand exchanges with Al in DWTR, as evidenced by the 1.40 eV increase in the Al binding energy after adsorption. Furthermore, ferrocyanide adsorption had a dual effect on the DWTR porosity (including both increase and decrease effect), resulting in a slight increase in the specific surface area and total pore volume of DWTR after adsorption. This dual effect was likely related to Fe present in ferrocyanide, which introduced new vacant sites on DWTR. Overall, recycled DWTR is a promising potential adsorbent for ferrocyanide.


Assuntos
Alumínio/química , Ferrocianetos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Reciclagem
20.
Aging (Albany NY) ; 13(3): 4590-4604, 2020 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-33406505

RESUMO

Diabetic encephalopathy (DE) is a global concern and Gordian knot worldwide. miRNA-132 (miR-132) is a class of negative gene regulators that promote diabetic pathologic mechanisms and its complications. However, the molecular mechanisms of miR-132 in DE are elusive, thus an alternative therapeutic strategy is urgently in demand. The present study explored the protective effect and the underlying mechanism of miR-132 on DE via the GSK-ß/Tau signaling pathway. Experimentally, a type 2 DM rat model was developed by incorporating a high-fat diet and streptozotocin injection. Further, the DE model was screened via the Morris Water Maze test. Primary hippocampal neurons and HT-22 cells were used for in vitro analysis. We found that hyperglycemia exacerbates cognitive impairment in T2DM rats. When we isolated the primary hippocampus neurons, the expression of miR-132 RNA was low in both the DE hippocampus and primary neurons. GSK-3ß and Tau 404 were highly expressed in injured HT-22 cells and diabetic hippocampal tissues. miR-132 downregulated the expression of GSK-3ß. Besides, a binding and colocalized relationship between GSK3ß and Tau was also reported. These findings suggest that miR-132 exerts protective effects from DE injury by repressing GSK-3ß expression and alleviating Tau hyperphosphorylation in HT-22 cells and hippocampus tissues.


Assuntos
Encefalopatias/metabolismo , Complicações do Diabetes/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , MicroRNAs , Proteínas tau/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Regulação para Baixo , Hipocampo/citologia , Hiperglicemia/metabolismo , Aprendizagem em Labirinto/fisiologia , MicroRNAs/genética , MicroRNAs/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Ratos , Transdução de Sinais/genética
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