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1.
Bioresour Technol ; 414: 131568, 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39366511

RESUMO

The precise structure and assembly process of pyrite-based biofilms remain poorly understood. The polysaccharides (PN), proteins (PS), and extracellular DNA were enriched in the soluble extracellular polymeric substance (EPS), loosely bound EPS, and tightly bound EPS, respectively, indicating a significant stratified structure of biofilms. The tryptophan facilitated mixotrophic metabolic processes. Both dominant (>1%) and rare species (<0.01 %) harbored core bacteria, including sulfur autotrophic bacteria, sulfate-reducing bacteria, and heterotrophic bacteria. Furthermore, partial least-squares path modeling quantified the contributions of total phosphorus (TP) (λ = 0.32), dissolved organic matter (DOC) (λ = 0.29), and NH4+-N (λ = 0.26) to variations in the microbial community. Nonmetric multidimensional scaling analysis revealed three distinct stages in biofilm development: colonization (0-36 d), succession (36-149 d), and maturation/old (149-215 d). Furthermore, neutral community model indicated that stochastic processes drove the colonization and maturation/old stages, while deterministic processes dominated the succession stage. This study offered valuable insights into the regulation of pyrite-based engineered ecosystems.

2.
Environ Sci Technol ; 58(23): 10149-10161, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38808456

RESUMO

Further reducing total nitrogen (TN) and total phosphorus (TP) in the secondary effluent needs to be realized effectively and in an eco-friendly manner. Herein, four pyrite/sawdust composite-based biofilters were established to treat simulated secondary effluent for 304 days. The results demonstrated that effluent TN and TP concentrations from biofilters under the optimal hydraulic retention time (HRT) of 3.5 h were stable at <2.0 and 0.1 mg/L, respectively, and no significant differences were observed between inoculated sludge sources. The pyrite/sawdust composite-based biofilters had low N2O, CH4, and CO2 emissions, and the effluent's DOM was mainly composed of five fluorescence components. Moreover, mixotrophic denitrifiers (Thiothrix) and sulfate-reducing bacteria (Desulfosporosinus) contributing to microbial nitrogen and sulfur cycles were enriched in the biofilm. Co-occurrence network analysis deciphered that Chlorobaculum and Desulfobacterales were key genera, which formed an obvious sulfur cycle process that strengthened the denitrification capacity. The higher abundances of genes encoding extracellular electron transport (EET) chains/mediators revealed that pyrite not only functioned as an electron conduit to stimulate direct interspecies electron transfer by flagella but also facilitated EET-associated enzymes for denitrification. This study comprehensively evaluates the water-gas-biofilm phases of pyrite/sawdust composite-based biofilters during a long-term study, providing an in-depth understanding of boosted electron transfer in pyrite-based mixotrophic denitrification systems.


Assuntos
Biofilmes , Desnitrificação , Nitratos , Fósforo , Fósforo/metabolismo , Nitratos/metabolismo , Nitrogênio/metabolismo , Transporte de Elétrons , Ferro , Sulfetos
3.
J Chromatogr Sci ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38812294

RESUMO

Food-derived agricultural chemical residues (FACRs) accumulate gradually in organisms and can damage their nervous system, endocrine system and reproductive system, posing significant harm. Currently, there is little literature on the detection of FACRs in waste wool fibers. In this paper, an ultrasound-assisted extraction-QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) cleanup-UPLC-Ms/Ms method was applied for the qualitative analysis and quantitative determination of trace FACRs in waste wool fibers with 0.2% formic acid-methanol as extraction solvent and multi-selective ion scanning. Using the external standard method, it was shown that the 13 target FACRs showed good linearity in the mass concentration range of 0.1-50 µg/kg. The limits of detection were 1.0- 10.0 µg/kg and the limits of quantification were 4.0-40.0 µg/kg. The recoveries of the 13 target FACRs ranged from 78 to 112.6% at the 5-, 10- and 20-fold detection limit spiked levels, and the intra- or inter-day relative standard deviations were 2.05-6.98% or 1.98-6.99%, respectively. This method satisfied the detection requirements and can be used in applications.

4.
Europace ; 25(9)2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37433113

RESUMO

AIMS: Opioids are associated with increased risk of sudden cardiac death. This may be due to their effects on the cardiac sodium channel (Nav1.5) current. In the present study, we aim to establish whether tramadol, fentanyl, or codeine affects Nav1.5 current. METHODS AND RESULTS: Using whole-cell patch-clamp methodology, we studied the effects of tramadol, fentanyl, and codeine on currents of human Nav1.5 channels stably expressed in HEK293 cells and on action potential (AP) properties of freshly isolated rabbit ventricular cardiomyocytes. In fully available Nav1.5 channels (holding potential -120 mV), tramadol exhibited inhibitory effects on Nav1.5 current in a concentration-dependent manner with an IC50 of 378.5 ± 33.2 µm. In addition, tramadol caused a hyperpolarizing shift of voltage-gated (in)activation and a delay in recovery from inactivation. These blocking effects occurred at lower concentrations in partially inactivated Nav1.5 channels: during partial fast inactivation (close-to-physiological holding potential -90 mV), IC50 of Nav1.5 block was 4.5 ± 1.1 µm, while it was 16 ± 4.8 µm during partial slow inactivation. The tramadol-induced changes on Nav1.5 properties were reflected by a reduction in AP upstroke velocity in a frequency-dependent manner. Fentanyl and codeine had no effect on Nav1.5 current, even when tested at lethal concentrations. CONCLUSION: Tramadol reduces Nav1.5 currents, in particular, at close-to-physiological membrane potentials. Fentanyl and codeine have no effects on Nav1.5 current.


Assuntos
Analgésicos Opioides , Tramadol , Animais , Humanos , Coelhos , Analgésicos Opioides/farmacologia , Tramadol/farmacologia , Células HEK293 , Bloqueadores dos Canais de Sódio/farmacologia , Fentanila/farmacologia , Miócitos Cardíacos , Codeína
5.
Chemosphere ; 336: 139219, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37327824

RESUMO

Manganese oxides (MnOx) are recognized as a strongest oxidant and adsorbent, of which composites have been proved to be effective in the removal of contaminants from wastewater. This review provides a comprehensive analysis of Mn biochemistry in water environment including Mn oxidation and Mn reduction. The recent research on the application of MnOx in the wastewater treatment was summarized, including the involvement of organic micropollutant degradation, the transformation of nitrogen and phosphorus, the fate of sulfur and the methane mitigation. In addition to the adsorption capacity, the Mn cycling mediated by Mn(II) oxidizing bacteria and Mn(IV) reducing bacteria is the driving force for the MnOx utilization. The common category, characteristics and functions of Mn microorganisms in recent studies were also reviewed. Finally, the discussion on the influence factors, microbial response, reaction mechanism and potential risk of MnOx application in pollutants' transformation were proposed, which might be the promising opportunities for the future investigation of MnOx application in wastewater treatment.


Assuntos
Manganês , Águas Residuárias , Manganês/química , Óxidos/química , Compostos de Manganês/química , Oxirredução , Bactérias
6.
Biomedicines ; 11(2)2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36831014

RESUMO

Anti-epileptic drugs (AEDs) are associated with increased risk of sudden cardiac death. To establish whether gabapentin, lamotrigine, levetiracetam, pregabalin, and valproic acid reduce the Nav1.5 current, we conducted whole-cell patch-clamp studies to study the effects of the five AEDs on currents of human cardiac Nav1.5 channels stably expressed in HEK293 cells, and on action potential (AP) properties of freshly isolated rabbit ventricular cardiomyocytes. Lamotrigine and valproic acid exhibited inhibitory effects on the Nav1.5 current in a concentration-dependent manner with an IC50 of 142 ± 36 and 2022 ± 25 µM for lamotrigine and valproic acid, respectively. In addition, these drugs caused a hyperpolarizing shift of steady-state inactivation and a delay in recovery from inactivation. The changes on the Nav1.5 properties were reflected by a reduction in AP upstroke velocity (43.0 ± 6.8% (lamotrigine) and 23.7 ± 10.6% (valproic acid) at 1 Hz) and AP amplitude; in contrast, AP duration was not changed. Gabapentin, levetiracetam, and pregabalin had no effect on the Nav1.5 current. Lamotrigine and valproic acid reduce the Nav1.5 current density and affect its gating properties, resulting in a decrease of the AP upstroke velocity. Gabapentin, levetiracetam, and pregabalin have no effects on the Nav1.5 current.

7.
J Environ Manage ; 326(Pt B): 116709, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36395533

RESUMO

In this study, an integrated treatment system was proposed and applied in situ, including detention tank, multistage constructed wetlands (CWs) and wastewater treatment plants (WWTPs), preventing nutrients flowing into Dianchi Lake, in which the treatment performance of multistage CWs were evaluated principally. Results skillfully realized the bypass purification of upstream river at dry reasons, as well as the effective management and treatment of the collected diffuse pollution at rainy reasons. The purified water flowing into water bodies could satisfy the Grade III of environmental quality standards for surface water in China with the average effluent concentrations of COD, NH4+-N, TN and TP decreased to 10 (51.2-72.7%), 0.5 (67.2-83.0%), 1.0 (71.2-79.6%) and 0.15 (72.3-89.4%) mg L-1, respectively. High-throughput sequencing results indicated that the application of poly-3-hydroxybutyrate-cohyroxyvelate-sawdust (PS) blends could enrich norank_f_Anaerolineaceae (7.95%) and Bradyrhizobium (10.2%), which were distinct from the dominant genera of Pleurocapsa (13.0%) in gravel-based CWs. Functional genes and metabolism analysis uncovered that the heterotrophic denitrification was the main pathway of nitrogen removal with the abundance of genes encoding TCA cycle, glycolysis and denitrification process up-regulated. In addition, molecular ecological network (MEN) analysis suggested the denitrification genes were positively correlated with the predominant microbes in PS-based CWs, favorable for denitrifiers to transfer and utilize electron donors during denitrification process. This study proved that the developed PS blends as carbon supplies in CWs and the proposed integrated treatment system are effective methods for watershed management, providing valuable reference to low-pollution wastewater treatment in practical engineering projects.


Assuntos
Carbono , Áreas Alagadas , Humanos , Desnitrificação , Nitrogênio/análise , Nutrientes , Interações Microbianas , Água/análise , Águas Residuárias/análise , Eliminação de Resíduos Líquidos
8.
Plant Dis ; 107(3): 926-928, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36265148

RESUMO

The basidiomycetous fungus Rhizoctonia solani Kühn (teleomorph Thanatephorus cucumeris [Frank] Donk) is a fungal pathogen that causes various diseases on economically important crops, such as foxtail millet, maize, and rice. Using the PacBio Sequel platform, we assembled a draft genome of an R. solani strain AG4-JY that was isolated from foxtail millet with sheath blight at the stem. The genome was approximately 43.43 Mb on 53 scaffolds, with a scaffold N50 length of 2.10 Mb. In all, 10,545 genes and 179 noncoding RNAs were predicted, and 10,488 genes had at least one database annotation. In addition, the proteins encoded by 709 genes were predicted as secretory proteins. The AG4-JY genome sequence provides a valuable resource for understanding the interactions between R. solani and foxtail millet and controls sheath blight in the world.


Assuntos
Setaria (Planta) , Setaria (Planta)/genética , Rhizoctonia/genética
10.
Polymers (Basel) ; 14(17)2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36080612

RESUMO

Because of the advantageous characteristics of strong integrity, lightweight, high performance, and various designs, woven spacer fabric (WSF) and its composite are extensively used in construction, traffic, and aerospace, among other fields. This paper first describes the WSF structure, including core yarns and cross-linking, and then discusses the influence of the processing parameters, among angle of the wall decisive the failure mode on the plate properties. Moreover, we summarize the molding and filling technology of WSF composite sandwich panels and discuss the process order, resulting in a significant effect on the stiffness of the sandwich composite plate; the current processing is mostly hand lay-up technology. In addition, we introduce the core and matrix material of the sandwich composite plate, which are mainly polyurethane (PU) foam and epoxy resin (70% of matrix material), respectively. Finally, the mechanical properties of WSF composite sandwich panels are summarized, including bending, compression, impact, shear, and peel properties. Factors influencing the mechanical properties are analyzed to provide a theoretical basis for future plate design and preparation.

11.
Front Cell Dev Biol ; 10: 891996, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35721495

RESUMO

Aim: To assess the risk of sudden cardiac arrest (SCA) associated with the use of carbamazepine (CBZ) and establish the possible underlying cellular electrophysiological mechanisms. Methods: The SCA risk association with CBZ was studied in general population cohorts using a case-control design (n = 5,473 SCA cases, 21,866 non-SCA controls). Effects of 1-100 µM CBZ on action potentials (APs) and individual membrane currents were determined in isolated rabbit and human cardiomyocytes using the patch clamp technique. Results: CBZ use was associated with increased risk of SCA compared with no use (adjusted odds ratio 1.90 [95% confidence interval: 1.12-3.24]). CBZ reduced the AP upstroke velocity of rabbit and human cardiomyocytes, without prominent changes in other AP parameters. The reduction occurred at ≥30 µM and was frequency-dependent with a more pronounced reduction at high stimulus frequencies. The cardiac sodium current (INa) was reduced at ≥30 µM; this was accompanied by a hyperpolarizing shift in the voltage-dependency of inactivation. The recovery from inactivation was slower, which is consistent with the more pronounced AP upstroke velocity reduction at high stimulus frequencies. The main cardiac K+ and Ca2+ currents were unaffected, except reduction of L-type Ca2+ current by 100 µM CBZ. Conclusion: CBZ use is associated with an increased risk of SCA in the general population. At concentrations of 30 µM and above, CBZ reduces AP upstroke velocity and INa in cardiomyocytes. Since the concentration of 30 µM is well within the therapeutic range (20-40 µM), we conclude that CBZ increases the risk of SCA by a reduction of the cardiac INa.

12.
Front Public Health ; 10: 896974, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35757619

RESUMO

Background: Serious games (SGs) as one kind of intervention that can improve the level of knowledge and change behavior to affect health outcomes has been increasingly applied in health care. Objective: Analyze hotspots and trends of the application of SGs in health care and provide reference and direction for further research in the future. Methods: The Web of Science (WoS) Core Collection database was used for extracting the literature on SGs in health care for the period from the database established to 11 October, 2021. Scoping review and bibliometric analysis were used to deeply analyze and visualize countries, categories of studies, annual study output, cited authors, cited journals, cited articles, and keywords of healthcare field. Results: A total of 1,322 articles were retrieved, then every articles' title and abstract were read one by one, and 795 articles were included after screening with an exponential increase in publication volume. The United States of America made the greatest contribution to global publications regarding SGs in health care. From the total, 20.8% of articles fall under the category of health care sciences services. The target groups were mainly concentrated in children (18.0%), youth (13.8%), the elderly (10.9%), adolescents (9.1%), and adults (3.4%). Baranowski T (n = 103 citations) is the most influential author, followed by Kato PM (n = 73 citations) and Desmet A (n = 58 citations). The top three cited journals were "Plos One" (n = 268 citations), "Games for Health Journal" (n = 209 citations), and "Journal of Medical Internet Research" (n = 197 citations), and the top three cited articles were "A meta-analysis of serious digital games for healthy lifestyle promotion," "A Systematic Review of Serious Games in Training Health Care Professionals," and "Video game training enhances cognitive control in older adults." More and more studies focus on specific age groups, such as children, adolescents, and the elderly. The research hotspots and trends included "rehabilitation," "medical education," and "design." Conclusions: The application of SGs in health care remains important areas for future research. "Rehabilitation," "medical education," and "design" reflected the latest research hotpots and future trends.


Assuntos
Bibliometria , Pesquisa Biomédica , Adolescente , Idoso , Criança , Bases de Dados Factuais , Atenção à Saúde , Humanos , Estados Unidos
13.
ACS Omega ; 7(18): 15267-15274, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35571832

RESUMO

The fluorescent probe has become an important method for accurate detection of H2O2, with advantages of simple operation, high sensitivity, good selectivity, and real-time dynamic monitoring. This paper reviews the research progress in organic small-molecule fluorescent probe H2O2 detection methods that are based on different recognition reactions. In addition, the application prospect of fluorescent probes in the detection of trace H2O2 is anticipated.

14.
Chemosphere ; 296: 134054, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35202664

RESUMO

With the advancement of water ecological protection and water control standard, it is the general trend to upgrade the wastewater treatment plants (WWTPs). The simultaneous removal of nitrogen and phosphorus is the key to improve the water quality of secondary effluent of WWTPs to prevent the eutrophication. Therefore, it is urgent to develop the applicable technologies for simultaneous biological removal of nitrogen and phosphorus from secondary effluent. In this review, the composition of secondary effluent from municipal WWTPs were briefly introduced firstly, then the three main treatment processes for simultaneous nitrogen and phosphorus removal, i.e., the enhanced denitrifying phosphorus removal filter, the pyrite-based autotrophic denitrification and the microalgae biological treatment system were summarized, their performances and mechanisms were analyzed. The influencing factors and microbial community structure were discussed. The advanced removal of nitrogen and phosphorus by different technologies were also compared and summarized in terms of performance, operational characteristics, disadvantage and cost. Finally, the challenges and future prospects of simultaneous removal of nitrogen and phosphorus technologies for secondary effluent were proposed. This review will deepen to understand the principles and applications of the advanced removal of nitrogen and phosphorus and provide some valuable information for upgrading the treatment process of WWTPs.


Assuntos
Fósforo , Purificação da Água , Reatores Biológicos , Desnitrificação , Nitrogênio , Esgotos , Eliminação de Resíduos Líquidos , Águas Residuárias/química
15.
Bioresour Technol ; 347: 126724, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35065223

RESUMO

In this study, a biofilter was developed with a ZVI/PHBV/sawdust (ZPS) composite for treating simulative secondary effluent from wastewater treatment plants. Results showed that effluent concentrations of NO3--N and TP in the ZPS biofilter were stable below 2.0 mg/L and 0.1 mg/L, corresponding to 95% NO3--N removal and 99% TP removal, respectively. Microbial community analysis revealed that the transformation of dominant taxa from Dechloromonas to Clostridium sensu stricto_7 from 30 d to 120 d suggested that the ZVI-induced succession of dominant fermentation bacteria ensured the stable carbon supply for denitrification. Co-occurrence network analysis showed that the ZVI directly enhanced the interaction of microbial community. Fe-related bacteria occupied a key position in the rare species, which might maintain the function of iron-mediated organic matter decomposition and denitrification. These findings provide an alternative for advanced removal of nitrogen and phosphorus in biofilters packed with ZPS composites.


Assuntos
Nitrogênio , Fósforo , Bactérias , Reatores Biológicos , Desnitrificação , Poliésteres , Águas Residuárias
16.
J Colloid Interface Sci ; 607(Pt 1): 769-781, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34536934

RESUMO

In this study, non-noble metal Cd decorated cubic phase CdS (CdS/Cd) thin layer on a millimeter-scale chitosan-Mg(OH)2 xerogel beads (CMB) were elaborately designed and successfully synthesized via facile hydrated electrons (eaq•-) assistant strategy. The in-situ formation of metallic Cd was driven by eaq•- generated from UV/Na2SO3 process. Owing to metallic Cd, CMB@CdS/Cd exhibited better visible-light absorption ability and more efficient separation capability for photo-induced carriers, its hydrogen production efficiency was about threefold improved compared to CMB@CdS. Both characterization methods and density functional theory calculations determined a built-in electric field from metallic Cd to CdS and Ohmic-contact between Cd and CdS, which largely promoted the carriers transfer efficiency. Moreover, the introduction of metallic Cd on the CdS could reduce the ΔGH*, thus greatly boosting the photocatalytic hydrogen production efficiency. This work provides a simple and green approach to construct metallic Cd coupled semiconductor to achieve efficient photocatalytic applications.

17.
Sci Total Environ ; 793: 148469, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34328995

RESUMO

In this study, batch experiments were conducted to investigate the immobilization of HMs (Cr and Pb) by DOM derived from biochar in the presence and absence of zero-valent iron (Fe) in nitrate and HMs co-contaminated groundwater. Both Cr and Pb were removed effectively in biochar-Fe aqueous systems, while only Pb could be mitigated in biochar systems. Excitation-emission spectrophotometry combined with parallel factor analysis (EEM-PARAFAC) revealed that DOM released from biochar mainly contained human-like and tryptophan-like substances. Moreover, the fluorescence of hemic-like components could be quenched differently by the complexation of HMs, which proved the different removal efficiencies of Cr and Pb in biochar aqueous phase. In biochar-Fe aqueous systems, Fe-C micro-electrolysis was formed in prior to the complexation of DOM-Fe hydroxides. Thus, the chemical reduction was the primary way to removal HMs in batch-Fe systems, which was corresponding with the less variation of DOM components when adding Cr and Pb into aqueous systems. Besides, the observed DOM components with higher aromaticity and humification after adding Cr and Pb, further indicated the complexation of DOM-HMs through the analysis of adsorption and fluorescence indices. These results will provide new insights into the HMs retention on biochar, particularly for the role of Fe on the complexation process.


Assuntos
Ferro , Metais Pesados , Carvão Vegetal , Humanos , Chumbo
18.
J Integr Plant Biol ; 63(8): 1555-1567, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34110093

RESUMO

Among the five members of AUX1/LAX genes coding for auxin carriers in rice, only OsAUX1 and OsAUX3 have been reported. To understand the function of the other AUX1/LAX genes, two independent alleles of osaux4 mutants, osaux4-1 and osaux4-2, were constructed using the CRISPR/Cas9 editing system. Homozygous osaux4-1 or osaux4-2 exhibited shorter primary root (PR) and longer root hair (RH) compared to the wild-type Dongjin (WT/DJ), and lost response to indoleacetic acid (IAA) treatment. OsAUX4 is intensively expressed in roots and localized on the plasma membrane, suggesting that OsAUX4 might function in the regulation of root development. The decreased meristem cell division activity and the downregulated expression of cell cycle genes in root apices of osaux4 mutants supported the hypothesis that OsAUX4 positively regulates PR elongation. OsAUX4 is expressed in RH, and osaux4 mutants showing longer RH compared to WT/DJ implies that OsAUX4 negatively regulates RH development. Furthermore, osaux4 mutants are insensitive to Pi starvation (-Pi) and OsAUX4 effects on the -Pi response is associated with altered expression levels of Pi starvation-regulated genes, and auxin distribution/contents. This study revealed that OsAUX4 not only regulates PR and RH development but also plays a regulatory role in crosstalk between auxin and -Pi signaling.


Assuntos
Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Fosfatos/deficiência , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacologia , Meristema/citologia , Mutação/genética , Oryza/genética , Raízes de Plantas/genética , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo
19.
Chemosphere ; 275: 130007, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33984901

RESUMO

A two-stage multi-soil-layering system with blended carbon sources (MSL-BCS) was constructed at pilot scale for treatment of rural non-point source wastewater. Results showed the MSL-BCS system had effective removal efficiencies with 64% of TN and 60% of TP, respectively. The addition of BCS could result in higher (1.6-3.1 fold) denitrification gene abundances (nirS and nosZ) for enhancing denitrification. High-throughput sequencing approach revealed that the higher abundance (>50%) of Epsilonbacteraeotra (Genus: Sulfuricurvum, Family: Thiovulaceae, Class: Campylobacteria, Phylum: Epsilonbacteraeota) enriched in the surface of BCS, which suggested that Epsilonbacteraeotra are the keystone species in achieving nitrogen removal through enhancing denitrification at oligotrophic level. KEGG analysis indicated that BCS might release some signaling molecules for enhancing the energy metabolism process, as well as stimulate the enzyme activities of histidine kinase, glycogen phosphorylase and ATPase, and thereby the denitrification processes were strengthened in MSL-BCS system. Consequently, this study could provide some valuable information on the removal performance and mechanism of engineering MSL systems packed with BCS to govern the rural wastewater treatment.


Assuntos
Poluentes Ambientais , Microbiota , Carbono , Desnitrificação , Nitrogênio/análise , Solo , Águas Residuárias/análise
20.
J Environ Manage ; 292: 112750, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33991828

RESUMO

Constructed wetlands (CWs) have been proved to be an alternative to the treatment of various wastewater. However, there are few studies focused on the removal performance and mechanisms of pollutants in pilot-scale CWs packed with novel solid carbon. In this study, we investigated the effect of poly-3-hydroxybutyrate-co-3-hydroxyvalerate/polyacetic acid (PHBV/PLA) blends as carbon source on pollutant's transformation, microbial communities and functional genes in pilot-scale aeration-anoxic two-stage CWs for polishing rural runoff in southern China. Results showed a striking improvement of TN removal in CWs with PHBV/PLA blends (64.5%) compared to that in CWs with ceramsite (52.9%). NH4+-N (61.3-64.6%), COD (40.4-53.8%) and TP (43.6-47.1%) were also removed effectively in both two CWs. In addition, the strains of Rhodocyclaceae and Bacteroidetes were the primary denitrifiers on the surface of PHBV/PLA blends. Further, the aerobic stage induced gathering of 16 S and amoA genes and the anoxic zone with PHBV/PLA blends increased the nirS genes, which fundamentally explained the better denitrification performance in CW based on PHBV/PLA blends. Consequently, this study will provide straightforward guidance for the operation of engineering CWs packed with polymers to govern the low-C/N rural wastewater.


Assuntos
Purificação da Água , Áreas Alagadas , Carbono , China , Desnitrificação , Nitrogênio , Eliminação de Resíduos Líquidos , Águas Residuárias
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