Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Autoimmunity ; 57(1): 2281242, 2024 12.
Artículo en Inglés | MEDLINE | ID: mdl-38093504

RESUMEN

The objective of this retrospective cohort study was to assess the relationship between Corona Disease 2019 (COVID-19) and Secukinumab treatment in patients with Spondylarthritis (SpA) in China during the omicron surge. Researchers retrieved 1018 medical records of Secukinumab-treated patients between January 2020 and January 2023 from the West China Hospital of Sichuan University. Out of these, 190 SpA patients from the rheumatology clinic were selected for the study. Guided phone questionnaires were administered by research staff to collect baseline characteristics, SpA disease status, and COVID-19 clinical outcomes. Cohabitants served as the control group and provided COVID-19 related data. Of the 190 potential SpA patients, 122 (66%) completed the questionnaire via phone, along with 259 cohabitants. 84.4% of SpA patients were diagnosed with Ankylosing Spondylitis (AS), and 15.6% were diagnosed with Psoriatic Arthritis (PsA). The rate of SARS-CoV-2 infection was 83.6% in the Secukinumab group and 88.8% in the cohabitants control group, with no significant difference (OR = 0.684, CI 0.366-1.275). One instance of severe COVID-19 was observed in the Secukinumab group, while two were identified in the cohabitants control group. Patients in the Secukinumab group had less time with fever caused by COVID-19 (p = 0.004). Discontinuing Secukinumab after SARS-CoV-2 infection did not significantly affect the course of COVID-19 or worsen SpA status according to our data. Our study suggests that administering Secukinumab to SpA patients does not increase their susceptibility to contracting SARS-CoV-2, and may have a positive effect on the course of SARS-CoV-2 infection.


Asunto(s)
Artritis Psoriásica , COVID-19 , Espondiloartritis , Humanos , Artritis Psoriásica/diagnóstico , Artritis Psoriásica/tratamiento farmacológico , Estudios Retrospectivos , SARS-CoV-2 , Espondiloartritis/diagnóstico , Espondiloartritis/tratamiento farmacológico
2.
Immunol Res ; 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-38133855

RESUMEN

BACKGROUND: Routine use of immunosuppressive agents in systemic lupus erythematosus (SLE) patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) potentially increases the risk of adverse outcomes. belimumab, a monoclonal antibody for the treatment of SLE, remains untested for its specific impact on coronavirus disease 2019 (COVID-19) symptoms in these patients. Here, this research investigated the effect of belimumab on COVID-19 symptoms in SLE patients infected with SARS-CoV-2. METHODS: This study enrolled SLE patients who underwent treatment with belimumab. After thorough screening based on the inclusion and exclusion criteria, data pertaining to COVID-19 for both the participants and their cohabitants were obtained through telephone follow-up. The potential impact of belimumab on COVID-19 was evaluated by comparing COVID-19 symptoms and medication use across various groups to investigate the association between belimumab treatment and COVID-19 in SLE. RESULTS: This study involved 123 SLE patients, of whom 89.4% tested positive for SARS-CoV-2. Among cohabitants of SLE patients, the SARS-CoV-2 positive rate was 87.2% (p = 0.543). Patients treated with belimumab exhibited a lower incidence of multiple COVID-19 symptoms than their cohabitating counterparts (p < 0.001). This protective effect was found to be partially related to the time of last belimumab administration. Among those with COVID-19, 30 patients opted to discontinue their anti-SLE drugs, and among them, 53% chose to discontinue belimumab. Discontinuing drugs did not increase the risk of hospitalization due to SARS-CoV-2 infection. CONCLUSION: This study concluded that treatment with belimumab did not increase susceptibility to COVID-19 and beneficially alleviated the symptoms of COVID-19.

3.
World J Microbiol Biotechnol ; 40(1): 19, 2023 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-37993701

RESUMEN

The microorganisms and functional predictions of leaf biofilms on submerged plants (Vallisneria natans (Val)) and in water samples (surface water (S) and bottom water (B)) in different seasons were evaluated in this study. S and B groups had 3249 identical operational taxonomic units (OTUs) (50.03%), while the Val group only had 1201 (18.49%) unique OTUs. There was significant overlap between microbial communities of S and B groups in the same season, while Val group showed the greater diversity. The dominant microbial clades were Proteobacteria (18.2-47.3%), Cyanobacteria (3.74-39.3%), Actinobacteria (1.64-29.3%), Bacteroidetes (1.31-21.7%), and Firmicutes (1.10-15.72%). Furthermore, there was a significant relationship between total organic carbon and the distribution of microbial taxa (p = 0.047), and TN may have altered the status of Cyanobacteria by affecting its biological nitrogen fixation capacity and reproductive capacity. The correlation network analysis results showed that the whole system consisted of 249 positive correlations and 111 negative correlations, indicating strong interactions between microbial communities. Functional predictions indicated that microbial functions were related to seasonal variation. These findings would guide the use of submerged plants to improve the diversity and stability of wetland microbial communities.


Asunto(s)
Cianobacterias , Hydrocharitaceae , Estaciones del Año , Hydrocharitaceae/microbiología , Biopelículas , Hojas de la Planta , Agua
4.
Front Cell Infect Microbiol ; 13: 1243512, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37692165

RESUMEN

Aim: The gut microbiota plays an important role in human health. In this study, we aimed to investigate whether and how gut microbiota communities are altered in patients with immune-mediated necrotizing myopathy (IMNM) and provide new ideas to further explore the pathogenesis of IMNM or screen for its clinical therapeutic targets in the future. Methods: The gut microbiota collected from 19 IMNM patients and 23 healthy controls (HCs) were examined by using 16S rRNA gene sequencing. Alpha and beta-diversity analyses were applied to examine the bacterial diversity and community structure. Welch's t test was performed to identify the significantly abundant taxa of bacteria between the two groups. Spearman correlation analysis was performed to analyze the correlation between gut microbiota and clinical indicators. A receiver operator characteristic (ROC) curve was used to reflect the sensitivity and specificity of microbial biomarker prediction of IMNM disease. P < 0.05 was considered statistically significant. Results: Nineteen IMNM patients and 23 HCs were included in the analysis. Among IMNM patients, 94.74% (18/19) of them used glucocorticoids, while 57.89% (11/19) of them used disease-modifying antirheumatic drugs (DMARDs), and the disease was accessed by MITAX (18.26 ± 8.62) and MYOACT (20.68 ± 8.65) scores. Participants in the groups were matched for gender and age. The diversity of the gut microbiota of IMNM patients differed and decreased compared to that of HCs (Chao1, Shannon, and Simpson indexes: p < 0.05). In IMNM patients, the relative abundances of Bacteroides, Roseburia, and Coprococcus were decreased, while that of Lactobacillus and Streptococcus were relatively increased. Furthermore, in IMNM patients, Lactobacillus was positively correlated with the levels of anti-signal recognition particle (SRP) antibodies, anti-Ro52 antibodies, and erythrocyte sedimentation rate (ESR), while Streptococcus was positively correlated with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies and C-reactive protein (CRP). Roseburia was negatively correlated with myoglobin (MYO), cardiac troponin T (cTnT), ESR, CRP, and the occurrence of interstitial lung disease (ILD). Bacteroides was negatively correlated with ESR and CRP, and Coprococcus was negatively correlated with ESR. Finally, the prediction model was built using the top five differential genera, which was verified using a ROC curve (area under the curve (AUC): 87%, 95% confidence interval: 73%-100%). Conclusion: We observed a characteristic compositional change in the gut microbiota with an abnormal elevation of Lactobacillus in IMNM patients, which was accompanied by changes in clinical indicators. This suggests that gut microbiota dysbiosis occurs in IMNM patients and is correlated with systemic autoimmune features.


Asunto(s)
Enfermedades Autoinmunes , Disbiosis , Microbioma Gastrointestinal , Lactobacillus , Miositis , Disbiosis/complicaciones , Disbiosis/microbiología , Lactobacillus/clasificación , Lactobacillus/aislamiento & purificación , Humanos , Miositis/complicaciones , Enfermedades Autoinmunes/complicaciones , Necrosis , Masculino , Femenino , Persona de Mediana Edad
6.
J Environ Manage ; 343: 118246, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37245312

RESUMEN

Algal-bacterial symbiotic system is a biological purification system that combines sewage treatment with resource utilization and has the dual effects of carbon sequestration and pollution reduction. In this study, an immobilized algal-bacterial biofilm system was constructed for the treatment of natural sewage. Effects of exposure to microplastics (MPs) with different particle diameters (0.065 µm, 0.5 µm and 5 µm) were determined in terms of algal biomass recovery efficiency, the composition of extracellular polymeric substances (EPS) and morphologic characteristics. The impacts of MPs on the bacterial diversity and community structure of biofilms were also examined. The metagenomic analysis of key microorganisms and related metabolism pathways involved in system was further investigated. Results showed that following exposure to 5 µm MP, a maximum algal recovery efficiency of 80% was achieved, with a minimum PSII primary light energy conversion efficiency (Fv/Fm ratio) of 0.513. Furthermore, 5 µm MP caused the highest level of damage to the algal-bacterial biofilm, enhancing the secretion of protein-rich EPS. The biofilm morphology became rough and loose following exposure to 0.5 µm and 5 µm MP. Community diversity and richness were significantly high in biofilms exposed to 5 µm MP. Proteobacteria (15.3-24.1%), Firmicutes (5.0-7.8%) and Actinobacteria (4.2-4.9%) were dominant in all groups, with exposure to 5 µm MP resulting in the highest relative abundance for these species. The addition of MPs promoted the related metabolic functions while inhibited the degradation of harmful substances by algal-bacterial biofilms. The findings have environmental significance for the practical application of algal-bacterial biofilms for sewage treatment, providing novel insights into the potential effects of MPs on immobilized algal-bacterial biofilm systems.


Asunto(s)
Microbiota , Microplásticos , Bacterias/metabolismo , Biopelículas , Microplásticos/metabolismo , Microplásticos/farmacología , Plásticos , Aguas del Alcantarillado
7.
Int J Mol Sci ; 25(1)2023 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-38203565

RESUMEN

Osteoarthritis (OA) is a chronic, degenerative joint disease presenting a significant global health threat. While current therapeutic approaches primarily target symptom relief, their efficacy in repairing joint damage remains limited. Recent research has highlighted mesenchymal stem cells (MSCs) as potential contributors to cartilage repair, anti-inflammatory modulation, and immune regulation in OA patients. Notably, MSCs from different sources and their derivatives exhibit variations in their effectiveness in treating OA. Moreover, pretreatment and gene editing techniques of MSCs can enhance their therapeutic outcomes in OA. Additionally, the combination of novel biomaterials with MSCs has shown promise in facilitating the repair of damaged cartilage. This review summarizes recent studies on the role of MSCs in the treatment of OA, delving into their advantages and exploring potential directions for development, with the aim of providing fresh insights for future research in this critical field.


Asunto(s)
Células Madre Mesenquimatosas , Osteoartritis , Humanos , Materiales Biocompatibles , Edición Génica , Osteoartritis/terapia , Trasplante de Células Madre
8.
J Environ Manage ; 322: 116124, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36063697

RESUMEN

Ecological floating beds could enable roots to become suspended and this allowed submerged roots to harbour various types of microbes. But, there was a lack of systematic research on microbial community structure changes and the influencing mechanisms. In this study, the ecological floating beds were constructed using selected plants [Cyperus involucratus Rottboll (Cyp), Thalia dealbata Fraser (Tha) and Iris tectorum Maxim (Iri)] that was compared with a control group [static water (S)]. The results showed that the highest abundance and diversity of root microbial communities were found in autumn, with the dominant taxa being Proteobacteria, Actinobacteriota, Cyanobacteria, Chloroflexi, Firmicutes, Bacteroidota, and Acidobacteriota. The microbial communities of Tha and Cyp groups greatly overlapped, while the Iri and control groups exhibited distinctly diverse communities. The root microbial populations of the same plant also reflected a large change in different seasons. Conversely, photosynthetic autotrophs and specialized anaerobes were more inclined to thrive at higher temperatures and lower DO concentrations and then they gradually became the dominant species. Microbial co-occurrences of the Tha and control groups were complex and showed both cooperation and competition. In addition, TOC was an important environmental factor that shaped the microbial community structures and DO changed the microbial community by affecting the abundance of aerobic and anaerobic bacteria. Microorganisms showed potential for degradation and metabolism of non-food substances with low/no corresponding metabolic pathways.


Asunto(s)
Cianobacterias , Microbiota , Raíces de Plantas/microbiología , Plantas , Rizosfera , Estaciones del Año , Microbiología del Suelo , Agua
9.
Chemosphere ; 307(Pt 2): 135826, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35948104

RESUMEN

Surface water contains a large amount of dissolved organic matter (DOM). Interactions between DOM and micropollutants have a significant impact on micropollutant degradation. In this study, algal extracellular polymeric substances (EPS) and natural organic matter (NOM) were selected as two DOM sources and oxytetracycline (OTC) as a representative micropollutant. EPS was mainly composed of tryptophan and protein-like organics, while NOM was mainly composed of fulvic acid-like, humic acid-like, and hydrophobic acid components. In addition, OTC degradation significantly decreased when bound with EPS and the C=O and C-H bonds of CH2 or CH3 groups may be involved in binding EPS and OTC, respectively, while -COOH may be involved in the binding of NOM and OTC. Furthermore, triplet intermediates were found to play a major role in OTC photodegradation in both EPS and NOM, with the contribution calculated as 49.96% and 44.61%, respectively. Steady-state concentrations of 3EPS* in EPS and 3NOM* in NOM were 3.59 × 10-14 mol L-1 and 5.54 × 10-15 mol L-1, respectively. These results provide new insights into the degradation of antibiotic-containing wastewater in the natural environment or engineering applications.


Asunto(s)
Oxitetraciclina , Oxitócicos , Contaminantes Químicos del Agua , Antibacterianos , Matriz Extracelular de Sustancias Poliméricas/química , Sustancias Húmicas/análisis , Oxitetraciclina/química , Triptófano , Aguas Residuales , Agua , Contaminantes Químicos del Agua/análisis
10.
Sci Total Environ ; 820: 153266, 2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35074383

RESUMEN

The effects of different sized MPs on the formation process of algal-fungal co-pellets were studied. The results show that a maximum biomass recovery of 70.96% and a minimum Fv/Fm ratio of 0.463 reached with 5.000 µm-microplastics. Chlorella vulgaris cells and microplastics adhered evenly to the mycelia of Ganoderma lucidum. The contact angle decreased 24.02% and 34.68% with addition of 0.065 µm and 0.500 µm microplastics, respectively, compared to the control group, while the lowest crystallinity index (7.05%) was obtained with 0.065 µm-microplastics addition. Moreover, 5.000 µm microplastics promoted the extracellular polymeric substances (EPS) secretion, with the soluble polysaccharide content increasing by 40.50% and the soluble protein content increasing by 23.25% compared with the single algal-fungal system, while bound polysaccharides increased by 113.26% and bound proteins increased by 29.48%. The 5.000 µm microplastics also significantly promoted enzyme activity in the co-pellets. These results provide a theoretical basis for algal recovery in microplastic-containing water.


Asunto(s)
Chlorella vulgaris , Reishi , Contaminantes Químicos del Agua , Microplásticos , Plásticos , Contaminantes Químicos del Agua/análisis
11.
Chemosphere ; 286(Pt 3): 131917, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34426270

RESUMEN

Oxytetracycline (OTC) and enrofloxacin (EFX) pollution in surface water are very common. Using the algal-bacterial consortia system to remove antibiotics remains to be further studied. In this study, the algal growth and sewage purification performance were studied in an algal-bacterial consortia system with different concentrations of antibiotics. The enzyme activity, malondialdehyde content, chlorophyll-a content, extracellular polysaccharide, and protein content of algae were also tested. It was found that the algal growth was promoted by low-dose antibiotics, 21.83% and 22.11% promotion at 0.1 mg L-1 OTC and EFX, respectively. The nutrients and antibiotics removals of the low-dose groups (OTC <5 mg L-1, EFX <1 mg L-1) were not affected significantly. More than 70% of total organic carbon and total phosphorus, and 97.84-99.76% OTC, 42.68-42.90% EFX were removed in the low-dose groups. However, the algal growth was inhibited, and the nutrients removals performance also declined in the high-concentration groups (10 mg L-1 OTC, 5 mg L-1 EFX). The superoxide dismutase and catalase activity, and malondialdehyde content increased significantly (P < 0.05), indicating the increased activity of reactive oxygen species. In addition, the decreased chlorophyll-a content, thylakoid membrane deformation, starch granules accumulation, and plasmolysis showed that the algal physiological functions were affected. These results showed that the algal-bacterial consortia system was more suitable to treat low-concentration antibiotics and provided basic parameters for the consortia application.


Asunto(s)
Oxitetraciclina , Aguas del Alcantarillado , Bacterias , Enrofloxacina , Fósforo
12.
Sci Total Environ ; 818: 151750, 2022 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-34808184

RESUMEN

Microplastics pose a serious threat to ecological processes and environmental health. To evaluate the toxic effects of the exposure of microplastics on submerged plants and biofilms, eel grass (Vallisneria natans) was exposed to different concentrations of microplastics (10-50 mg L-1). The changes in microbial community on leaf biofilms were also tested. The results showed that the ratio of variable fluorescence to maximum fluorescence was largely unchanged, but the contents of chlorophyll a and b increased by 56.5% and 23.0% respectively. Different concentrations of exposure to microplastics effectively induced antioxidant responses, such as increasing the activities of superoxide dismutase, peroxidase and catalase, as well as increasing the activity of glutathione S-transferase and the contents of glutathione and malondialdehyde. In addition, the leaf flesh cells of Vallisneria natans showed some degree of organelle damage when examined by transmission electron microscopy. Moreover, a high-throughput sequencing analysis showed that the abundances and structure of the microbial community on the leaf biofilms were altered by exposure to microplastics. These results demonstrated that environmentally relevant concentrations of microplastics could disrupt homeostasis, induce effective defense mechanisms of Vallisneria natans and alter the biofilms in aquatic ecosystems.


Asunto(s)
Microbiota , Microplásticos , Biopelículas , Clorofila A , Hojas de la Planta , Plásticos/toxicidad , Agua
13.
Environ Sci Pollut Res Int ; 28(35): 49032-49041, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33929666

RESUMEN

The mechanism of morphological and physiological regulation of submerged aquatic plants (Hydrilla verticillata) is influenced by spatial and environmental changes related to water depth gradients. In the present study, changes in the aquatic microcosm were explored at the depth gradients of 0.3 m, 0.6 m, 0.9 m, 1.2 m, and 1.5 m, and the depth was recognized as a critical factor for improving water quality, especially for the removal of total phosphorus (TP) and recalcitrant protein-like molecules. At 0.9 m, the removal rates of TP and protein-like substances reached 78% and 18.67%, respectively, 1.76 times and 1.28 times the rates at 0.3 m. The maximum shoot/root growth and chlorophyll (a + b) suggest photosynthesis inhibition is minimal at 1.2 m. Fluctuations in enzyme activities imply an antioxidant response to lipid peroxidation damage under different oxidative stress. The adjusted activities of glutamine synthetase (GS) and alkaline phosphatase (APA) were an adaptive nutrient utilization strategy to different water depths. Microbiological diversity analysis of biofilms indicates that community structure changes in response to water depth. Considering the growth status and nutrient removal effects, the results indicate that the optimal planting depth for H. verticillata is 0.9-1.2 m. These findings contribute to understanding water purification mechanisms in depth gradients, and support the effective rebuilding and management of submerged macrophyte communities in natural shallow lakes.


Asunto(s)
Hydrocharitaceae , Biopelículas , Nutrientes , Fósforo , Hojas de la Planta
14.
Environ Sci Pollut Res Int ; 28(13): 15954-15965, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33244700

RESUMEN

Chlorella vulgaris and Bacillus licheniformis consortium was added to synthetic wastewater with exogenous vitamin B12. In the presence of 100 ng/L vitamin B12, removal efficiencies of TN, NH3-N, PO43-P, and COD were 80.1%, 76.8%, 87.9%, and 76.7%, respectively. The functional groups on the cell surface of the consortium, including -NH, -CH3, C=O, C=C, and P-O-C, increased with 100 ng/L vitamin B12. These functional groups improved the biological adsorption of the consortium; however, higher concentrations of vitamin B12 resulted in an occlusion of the functional groups. Furthermore, there were 5 significantly enriched protein pathways, namely carbon fixation in photosynthetic organisms; amino acid metabolic pathways; the pathway of one carbon pool by folate; nitrogen metabolism; and photosynthesis. Most proteins in these pathways were upregulated, which enhanced carbon fixation and photosynthesis in the algal cells. Simultaneously, B12 promoted significant upregulation of proteins associated with the quorum-sensing pathway, which promoted the interaction between algae and bacteria.


Asunto(s)
Chlorella vulgaris , Bacterias , Nitrógeno/análisis , Nutrientes , Vitamina B 12/farmacología , Vitaminas , Aguas Residuales
15.
Environ Sci Pollut Res Int ; 26(30): 31414-31421, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31478174

RESUMEN

Phosphorus (P) characteristics in eutrophic lakes change during algal growth. Furthermore, algae have a significant relationship with the microbial communities of lake sediments. This study addressed the influence of algal growth and soluble reactive phosphorus (SRP) concentrations on P characteristics within the sediment-water-algal (SWA) system. Results indicated that the SWA system simulating a high algal bloom level (SWA-HAB) had a correspondingly high SRP concentration (258.9 µg L-1), and that algal growth promoted a high SRP concentration in the overlying water. The high SRP concentration in overlying water could support algal growth, resulting in a high chlorophyll a (Chl-a) concentration (285.23 mg L-1). During algal growth, the P release flux was high in sediments from the high-SRP SWA system, with the highest P release flux measured at 0.982 mg m-2 day-1. Furthermore, microbial community abundance had a significant relationship with Chl-a concentrations in overlying water (p < 0.05) and increases with algae growth.


Asunto(s)
Eutrofización , Sedimentos Geológicos/microbiología , Microbiota , Fósforo/análisis , Contaminantes Químicos del Agua/análisis , China , Clorofila/análogos & derivados , Clorofila A , Lagos , Agua
16.
Water Environ Res ; 91(6): 491-499, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30791185

RESUMEN

A pilot-scale quartz sand deep bed denitrification filter (DBDF) using sodium acetate as the additional carbon source was implemented to treat secondary effluent, with a high nitrate nitrogen (NO3 -N) concentration and low C/N ratio, from an urban municipal water resource recovery facility. By the 18th day, results showed that the removal efficiency of NO3 -N and the chemical oxygen demand (COD) were stable at above 85% and 70%, respectively. When the filter layer depth was set to 1,600 mm and the concentration of additional sodium acetate was maintained at 51 mg/L, the total nitrogen and COD concentrations of the DBDF effluent were stabilized below 5 and 30 mg/L, respectively. The quartz sand DBDF had a good effect on the removal of dissolved organic matter, especially for aromatic protein-like and tryptophan protein-like substances. Bacteria with denitrification function, such as Cloacibacterium and Zoogloea, became increasingly dominant with increasing filling layer depth. PRACTITIONER POINTS: The denitrification filter had a good effect on the removal of aromatic protein-like and tryptophan protein-like substances. Cloacibacterium and Zoogloea became increasingly dominant with increasing filling layer depth.


Asunto(s)
Carbono/metabolismo , Desnitrificación , Filtración/métodos , Acetato de Sodio/metabolismo , Purificación del Agua/métodos , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos/microbiología , Ciudades , Proyectos Piloto , Recursos Hídricos
17.
Environ Sci Pollut Res Int ; 26(2): 1723-1732, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30448953

RESUMEN

Phosphorus is one of the main limiting and strong influencing factors of eutrophication, and phosphorus controlling in lake is of great significance for eutrophication. To do this, sediment materials were taken from Dianchi Lake, a typically eutrophic lake, and modified by hexadecyltrimethylammonium bromide (CTAB) and ZnSO4 to remove phosphorus and inhibit alkaline phosphatase activity (APA). Results indicated that phosphorus removal efficiencies of sediments modified by CTAB (S-CTAB), ZnSO4 (S-Zn), and oxidized sediments (OS) were higher than that of the raw sediment (RS). Ability to absorb phosphorus varied, following the order S-Zn>S-CTAB>OS>RS. Sorption was influenced by ionic strength, with the former decreasing with the increase of the latter. Freundlich model well described the sorption isotherm, with an R2 ranging from 0.9168 to 0.9958. Furthermore, compared with the raw sediments, the maximum phosphorus sorption capacities of S-Zn and S-CTAB increased by 12.2% and 124.5%, respectively. Results of desorption studies suggest that the desorption rate of S-Zn was from 3.88 to 13.76%, lower than that of other sediment materials. APA was inhibited by S-CTAB and S-Zn at the same time, with inhibition rates from 29.6% and 61.0% when the concentrations of S-CTAB and S-Zn were 10 nmol L-1 and 0.2 nmol L-1, respectively. This study provides new insights into phosphorus removal and phosphatase activity inhibition in water treatment.


Asunto(s)
Fosfatasa Alcalina/metabolismo , Sedimentos Geológicos/química , Fósforo/aislamiento & purificación , Fosfatasa Alcalina/química , Cetrimonio/química , China , Restauración y Remediación Ambiental/métodos , Eutrofización , Lagos , Modelos Teóricos , Monoéster Fosfórico Hidrolasas , Fósforo/química , Sulfato de Zinc/química
18.
Bioprocess Biosyst Eng ; 42(2): 199-212, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30353223

RESUMEN

A pilot-scale deep bed denitrification filter using quartz sand as the filter media was operated under filtration velocity of 5.23 m/h. Nitrate, nitrite, ammonia, and total nitrogen removal rates were relatively high at influent C/N ratios of 4:1 and 5:1. A model was developed using software to simulate the processes operating in the filter and improve the related parameters in the actual operations. The normalized sensitivity coefficient and the mean square sensitivity measure were used for the sensitivity analysis. Results showed that the stoichiometric parameters were the most sensitive, which were related to methylotrophs and biofilm. Measured data were consistent with the simulations. Moreover, the order of significance of factors affecting nitrate nitrogen removal was as follows: influent chemical oxygen demand, influent nitrate nitrogen, and hydraulic retention time. Last, the denitrification dynamic model was obtained at influent C/N ratio of 5:1.


Asunto(s)
Nitratos/química , Nitrógeno/química , Eliminación de Residuos Líquidos/métodos , Biopelículas , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos , Calibración , Simulación por Computador , Desnitrificación , Filtración/métodos , Metanol/química , Nitritos/química , Programas Informáticos , Aguas Residuales , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos
19.
Water Sci Technol ; 77(11-12): 2723-2732, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29944137

RESUMEN

With the improvement of wastewater discharge standards, wastewater treatment plants (WWTPs) are continually undergoing technological improvements to meet the evolving standards. In this study, a quartz sand deep bed denitrification filter (DBDF) was used to purify WWTP secondary effluent, utilizing high nitrate nitrogen concentrations and a low C/N ratio. Results show that more than 90% of nitrate nitrogen (NO3-N) and 75% of chemical oxygen demand (COD) could be removed by the 20th day of filtration. When the filter layer depth was set to 1,600 mm and the additional carbon source CH3OH was maintained at 30 mg L-1 COD (20 mg L-1 methanol), the total nitrogen (TN) and COD concentrations of DBDF effluent were stabilized below 5 and 30 mg L-1, respectively. Analysis of fluorescence revealed that DBDF had a stronger effect on the removal of dissolved organic matter (DOM), especially of aromatic protein-like substances. High throughput sequencing and qPCR results indicate a distinctly stratified microbial distribution for the main functional species in DBDF, with quartz sand providing a good environment for microbes. The phyla Proteobacteria, Bacteroidetes, and Chloroflexi were found to be the dominant species in DBDF.


Asunto(s)
Nitrógeno/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos/microbiología , Carbono/química , Desnitrificación , Filtración/instrumentación , Filtración/métodos , Metanol/química , Consorcios Microbianos/genética , Consorcios Microbianos/fisiología , Nitratos/química , Nitrógeno/química , Eliminación de Residuos Líquidos/instrumentación , Aguas Residuales/química
20.
Artículo en Inglés | MEDLINE | ID: mdl-27314419

RESUMEN

This study was undertaken to develop an extraction method for seven acidic pharmaceuticals and five steroidal estrogens from wastewater, treated wastewater and sludge samples. The temperature and time of sample derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide was optimized. Our results show that pretreatment combined with solid phase extraction (SPE) for wastewater samples (using an ENVI-C18 cartridge) and liquid-solid extraction combined with SPE (using an HLB cartridge) for sludge samples increased the analytical efficiency for acidic pharmaceuticals and estrogenic hormones using gas chromatography-mass spectrometry (GC-MS). The derivatization conditions were optimized at 40°C for 2 h. In addition, the derivatized samples were stable at ambient temperature. The new method was validated and applied to the analysis of real wastewater and discharged sludge samples from a local wastewater treatment plant. Except for 17α-ethinylestradiol, all acidic pharmaceuticals and estrogens were detected in the influent, effluent and discharged sludge samples. The concentrations of these compounds were particularly high in the discharged sludge samples.


Asunto(s)
Ácidos/análisis , Estrógenos/análisis , Preparaciones Farmacéuticas/análisis , Aguas del Alcantarillado/química , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Acetamidas/química , Cromatografía de Gases y Espectrometría de Masas , Reproducibilidad de los Resultados , Extracción en Fase Sólida , Compuestos de Trimetilsililo/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...