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1.
Environ Res ; 252(Pt 1): 118780, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38555089

RESUMO

In this experiment, the prepared tea biochar-cellulose@LDH material (TB-CL@LDH) was combined with mycelium pellets to form the composite mycelial pellets (CMP), then assembled and immobilized with strains Pseudomonas sp. Y1 and Cupriavidus sp. ZY7 to construct a bioreactor. At the best operating parameters, the initial concentrations of phosphate (PO43--P), ammonia nitrogen (NH4+-N), chemical oxygen demand (COD), zinc (Zn2+), and phenol were 22.3, 25.0, 763.8, 1.0, and 1.0 mg L-1, the corresponding removal efficiencies were 80.4, 87.0, 83.4, 91.8, and 96.6%, respectively. Various characterization analyses demonstrated that the strain Y1 used the additional carbon source produced by the strain ZY7 degradation of cellulose to enhance the removal of composite pollutants and clarified the principle of Zn2+ and PO43--P removal by adsorption, co-precipitation and biomineralization. Pseudomonas and Cupriavidus were the dominant genera according to the high-throughput sequencing. As shown by KEGG results, nitrification and denitrification genes were affected by phenol. The study offers prospects for the simultaneous removal of complex pollutants consisting of NH4+-N, PO43--P, Zn2+, and phenol.


Assuntos
Amônia , Reatores Biológicos , Celulose , Micélio , Fenol , Fosfatos , Zinco , Reatores Biológicos/microbiologia , Celulose/química , Celulose/metabolismo , Micélio/metabolismo , Fosfatos/metabolismo , Amônia/metabolismo , Nitrogênio/metabolismo , Biodegradação Ambiental , Pseudomonas/metabolismo , Cupriavidus/metabolismo , Cupriavidus/genética , Poluentes Químicos da Água/análise , Carvão Vegetal
2.
Environ Res ; 222: 115253, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36702191

RESUMO

Epoxy resins are important thermosetting polymers. They are widely used in many applications i.e., adhesives, plastics, coatings and sealers. Epoxy molding compounds have attained dominance among common materials due to their excellent mechanical properties. The sol-gel simple method was applied to distinguish the impact on the colloidal time. The properties were obtained with silica-based fillers to enable their mechanical and thermal improvement. The work which we have done here on epoxy-based nanocomposites was successfully modified. The purpose of this research was to look into the effects of cellulose nanocrystals (CNCs) on various properties and applications. CNCs have recently attracted a lot of interest in a variety of industries due to their high aspect ratio, and low density which makes them perfect candidates. Adding different amounts of silica-based nanocomposites to the epoxy system. Analyzed with different techniques such as Fourier-transformed infrared spectroscope (FTIR), thermogravimetric analysis (TGA) and scanning electronic microscopic (SEM) to investigate the morphological properties of modified composites. The various %-age of silica composite was prepared in the epoxy system. The 20% of silica was shown greater enhancement and improvement. They show a better result than D-400 epoxy. Increasing the silica, the transparency of the films decreased, because clustering appears. This shows that the broad use of CNCs in environmental engineering applications is possible, particularly for surface modification, which was evaluated for qualities such as absorption and chemical resistant behavior.


Assuntos
Celulose , Nanopartículas , Celulose/química , Celulose/ultraestrutura , Porosidade , Água/química , Dióxido de Silício/química , Nanopartículas/química
3.
Bioresour Technol ; 399: 130567, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38467263

RESUMO

The removal of complex pollutants from oligotrophic water is an important challenge for researchers. In this study, the HCl-modified loofah sponge crosslinked polyethyleneimine loaded with biochar (LS/PEI@biochar) biofilm reactor was adapted to achieve efficient removal of complex pollutants in oligotrophic water. On the 35 d, the average removal efficiency of chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), calcium (Ca2+), and phosphate (PO43--P) in water was 51, 95, 81, and 77 %, respectively. Additionally, it effectively used a low molecular weight carbon source. Scanning electron microscopy (SEM) results showed that the LS/PEI@biochar biocarrier had superior biofilm suspension performance. Meanwhile, analysis of the biocrystals confirmed Ca2+ and PO43- removal through the generation of CaCO3 (calcite and vaterite) and Ca5(PO4)3OH. This study demonstrated that the system has great efficiency and application prospect in treating oligotrophic water on the laboratory scale, and will be further validated for practical application on large-scale oligotrophic water.


Assuntos
Carvão Vegetal , Luffa , Poluentes Químicos da Água , Polietilenoimina , Água , Biofilmes , Carbonato de Cálcio , Nitrogênio/química , Poluentes Químicos da Água/análise
4.
Bioresour Technol ; 369: 128433, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36473584

RESUMO

Optimization of nitrate removal rate under low carbon-to-nitrogen ratio has always been one of the research hotspots. Biofilm reactor based on functional carrier and using interspecific synergic effect of strains provides an insight. In this study, iron-loaded corn cob was used as a functional carrier that can contribute to the cellulose degradation, iron cycling, and collaborative denitrification process of microorganisms. During biofilm reactor operation, the maximum nitrate removal efficiency was 99.30% and could reach 81.73% at no carbon source. Dissolved organic carbon and carrier characterization showed that strain ZY7 promoted the release of carbon source. The crystallinity of cellulose I and II in carrier of experimental group increased by 31.26% and decreased by 21.83%, respectively, in comparison to the control group. Microbial community showed the synergistic effect among different strains. The vitality and metabolic activity of the target microorganisms in bioreactor were increased through interspecific bacterial cooperation.


Assuntos
Microbiota , Nitratos , Nitratos/metabolismo , Zea mays/metabolismo , Desnitrificação , Celulose , Ferro , Biofilmes , Reatores Biológicos/microbiologia , Nitrogênio/metabolismo
5.
Bioresour Technol ; 360: 127600, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35820558

RESUMO

This study emphasizes on the cellulase production characteristics of strain ZY7 and its collaboration with nitrate-dependent ferrous oxidizing (NFO) strain XL4 to achieve efficient denitrification at low carbon-to-nitrogen (C/N) ratio. Results indicated that the denitrification efficiency increased from 65.47 to 97.99% at 24 h after co-culture at C/N of 1.0. Three-dimensional fluorescence excitation-emission matrix (3D-EEM) showed significant changes in the intensity of soluble microbial products (SMP), fulvic-like materials, and aromatic proteins after co-culture. Bio-precipitates were characterized by Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), and X-ray diffraction (XRD), which showed that cellulose structure was disrupted and the metabolites were potential carbon source for denitrification. In addition, cellulase activity suggested that the hydrolysis of ß-1,4-glycosidic bonds and oligosaccharides may be the rate-limiting steps in cellulose degradation. This work promoted the understanding of denitrification characteristics of co-culture and expanded the application of cellulose degrading bacteria in sewage treatment.


Assuntos
Celulase , Cupriavidus , Reatores Biológicos/microbiologia , Carbono/química , Celulase/metabolismo , Celulose , Cupriavidus/metabolismo , Desnitrificação , Nitratos/metabolismo , Nitrogênio/química
6.
Bioresour Technol ; 348: 126818, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35139430

RESUMO

Water pollutants, such as nitrate, heavy metals, and organics have attracted attention due to their harms to environmental and biological health. A novel polyvinyl alcohol/sodium alginate with biochar (PVA/SA@biochar) gel beads immobilized bioreactor was established to remove nitrate, manganese, and phenol. The optimum conditions for preparing gel beads were studied by response surface methodology (RSM). Notably, the removal efficiencies of nitrate, Mn(II), and phenol were 94.64, 72.74, and 93.97% at C/N of 2.0; the concentrations of Mn(II) and phenol were 20 and 1 mg L-1, respectively. Moreover, addition of different concentrations of phenol significantly affected the components of dissolved organic matter, bacterial activity, and bioreactor performance. The biological manganese oxide (BMO) with three-dimensional petal-type structure produced during Mn(II) oxidation showed excellent adsorption capacity. The removal of phenol relied on a combination of biological action and adsorption processes. High-throughput analysis showed that Zoogloea sp. was the predominant bacterial group.


Assuntos
Nitratos , Álcool de Polivinil , Alginatos , Reatores Biológicos , Carvão Vegetal , Desnitrificação , Manganês , Fenol , Fenóis
7.
Bioresour Technol ; 362: 127875, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36049713

RESUMO

This study aims to develop a functional biocarrier with hydrophilic spongy biochar crosslinked with starch and polyvinyl alcohol (WSB/starch-PVA) for simultaneous removal of NO3--N, total phosphorus (TP) and Cd2+ in low carbon wastewater. Results showed that the WSB/starch-PVA bioreactor achieved the maximum NO3--N removal efficiency in subphase 1.2 with 98.07 % (3.64 mg L-1h-1) versus control (75.30 %, 2.81 mg L-1h-1), and removed 54.84 % and 73.97 % of TP and Cd2+. Material characterization suggested that functional groups (related to C, N and O) on biocarrier and biofilm, and biogenic co-precipitation facilitated TP and Cd2+ removal. The WSB made the biocarrier pores larger and regular, and decreased fluorescent soluble microbial products. The predicted metagenome further suggested that central citrate cycle, oxidative phosphorylation of bio-community, and NO3--N removal were enhanced. Functions for microbial induced co-precipitation, Cd2+ transport/efflux, antioxidants, and enhanced biofilm formation favored the NO3--N/TP removal and Cd2+ detoxification.


Assuntos
Fósforo , Águas Residuárias , Reatores Biológicos , Cádmio , Carbono , Carvão Vegetal , Desnitrificação , Nitratos , Nitrogênio , Óxidos de Nitrogênio , Álcool de Polivinil , Amido
8.
Environ Pollut ; 299: 118896, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35085648

RESUMO

The coexistence of nitrate and endocrine substances (EDCs) in groundwater is of global concern. Herein, an efficient and stable polypyrrole@corn cob (PPy@Corn cob) bioreactor immobilized with Zoogloea sp. was designed for the simultaneous removal of 17ß-estradiol (E2), nitrate and Mn(II). After 225 days of continuous operation, the optimal operating parameters and enhanced removal mechanism were explored, also the long-term toxicity and microbial communities response mechanisms under E2 stress were comprehensively evaluated. The results showed that the removal efficiencies of E2, nitrate, and Mn(II) were 84.21, 82.96, and 47.91%, respectively, at the optimal operating conditions with hydraulic retention time (HRT) of 8 h, pH of 6.5 and Mn(II) concentration of 20 mg L-1. Further increased of initial E2 (2 and 3 mg L-1) resulted in the inhibiting effect of denitrification and manganese oxidation, but excellent E2 removal efficiencies maintained, which were associated with the formation and continuous accumulation of biomanganese oxides (BMO). Characterization analysis of biological precipitation demonstrated that adsorption and redox conversion on the BMO surface played key roles in the removal of E2. In addition, different levels of E2 exposure are decisive factors in community evolution, and bioaugmented bacterial communities with Zoogloea as the core group can dynamically adapt to E2 stress. This study offers the possibility to better utilize microbial metabolism and to advance opportunities that depend on microbial physiology and material characterization applications.


Assuntos
Microbiota , Nitratos , Reatores Biológicos , Desnitrificação , Estradiol , Polímeros , Pirróis , Zea mays
9.
Bioresour Technol ; 323: 124630, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33418348

RESUMO

A novel layered double hydroxide (LDH)-orange peel (OP) biochar/sodium alginate (SA) (LBSA) synthetic material was prepared as an immobilized carrier for Acinetobacter sp. FYF8 to improve the removal of nitrogen and phosphorus in the bioreactor. Results demonstrated that under optimum conditions, the nitrate and phosphate removal efficiency reached 95.32 and 86.11%, respectively. The response surface methodology was used to illustrate the adsorption properties of the material and obtained optimal conditions for the removal of nitrate. The adsorption kinetics and isotherm were well fitted with the pseudo-second-order and Langmuir isotherm model, respectively, indicating that the adsorption process was mainly controlled by chemical adsorption and was favorable. Moreover, the morphology and composition of LBSA immobilized bacteria were analyzed and the mechanism of removing nitrate and phosphate was the synergistic effect of biological metabolism and adsorption. Community structure analysis and microbial distribution showed that FYF8 might was the dominant strain in bioreactors.


Assuntos
Nitratos , Poluentes Químicos da Água , Adsorção , Alginatos , Materiais Biocompatíveis , Reatores Biológicos , Carvão Vegetal , Hidróxidos , Cinética
10.
Bioresour Technol ; 331: 125065, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33819908

RESUMO

The co-existence of nitrate, manganese (Mn), and antibiotics are of a wide concern. In this study, a denitrifying and manganese-oxidizing Zoogloea Q7 bacterium was immobilized using polyvinyl alcohol/sodium alginate with sponge cube (PVA/SA@sponge cube) in the reactor. The optimal operation parameters of the bioreactor were explored. Maximum nitrate, Mn(II), and tetracycline (TC) removal efficiencies of 93.00, 72.34, and 57.32% were achieved with HRT of 10 h, pH of 6.5, Mn(II) concentration of 20 mg L-1, and TC of 1 mg L-1, respectively. Fluorescence excitation-emission matrix (EEM) proved that the microorganism in the bioreactor was greatly active. Scanning electron microscope (SEM) images demonstrated that Zoogloea Q7 was commendably immobilized on the novel material. X-ray diffraction (XRD) analysis suggested that the bioprecipitate was mainly composed of MnO2 and MnCO3. Through high-throughput analysis, Zoogloea sp. Q7 was considered to be the dominant bacteria present in the bioreactor.


Assuntos
Nitratos , Álcool de Polivinil , Alginatos , Antibacterianos , Reatores Biológicos , Desnitrificação , Manganês , Compostos de Manganês , Óxidos
11.
Bioresour Technol ; 321: 124447, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33302007

RESUMO

In the current research, a novel bioreactor composed of porous polymer carriers and iron-carbon (PPC@FeC) was established through bacterial immobilized technology. The influence of key factors was studied on the nitrate removal performance of the PPC@FeC bioreactor. The experimental results showed that the highest removal rate of nitrate (7.33 mg L-1 h-1) can be obtained with short hydraulic retention times (HRT = 2.0 h) and low carbon-to-nitrogen ratio (C/N = 2.0). The results of high-throughput sequencing revealed that Zoogloea sp. L2 was the dominant strain in bioreactor responsible for nitrate removal. Moreover, the SEM and XRD analyses elucidated that Fe2O3 was the final product produced by the interaction of FeC and strain L2. These findings showed that the PPC@FeC bioreactor successfully combined micro-electrolysis and biological denitrification, which exhibited great potential in removing nitrate effectively from wastewater under low C/N ratio and short HRT conditions.


Assuntos
Nitratos , Águas Residuárias , Reatores Biológicos , Carbono , Desnitrificação , Eletrólise , Ferro , Nitrogênio , Polímeros , Porosidade
12.
Int J Biol Macromol ; 129: 944-951, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30742921

RESUMO

Edible starch film reinforced by laver was developed and characterized. The relationship between processing technologies, microstructures and performances was established. When the laver was added into cold starch suspension, the laver flack (fiber) simply act as reinforcing agent to improve the mechanical properties of the starch matrix, which results in increasing modulus and tensile strength. When the laver was added into hot starch suspension and mixed under shear stress, the protein containing in laver will release out and mix with starch, which results in a starch-protein-laver fiber hybrid composites. In the hybrids system, fiber improves the mechanical properties of the starch-based film about 25%, while the protein reduces the moisture sensitivity and gas permeability about 45%. Scanning electron microscopic observation indicated good compatibility between starch matrix and laver. The cellulose containing in laver kept its semi-crystalline structure after processing, which was used to explain the reinforcing mechanism. Some chemical bounds between starch and protein containing in laver was detected by FTIR. Since all the components used in this work are from food sources, the prepared films are safe for food packaging and application as edible films.


Assuntos
Membranas Artificiais , Amido , Fenômenos Químicos , Fenômenos Mecânicos , Permeabilidade , Reologia , Análise Espectral , Amido/química , Viscosidade
13.
Infect Genet Evol ; 66: 66-71, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30201500

RESUMO

To determine the genotypic distribution of HCV, frequency of risk factors involved in its transmission, and correlation of genotype with viral load in Mardan population which is the second largest city of Khyber Pakhtunkhwa (KPK), Pakistan. Blood samples of 1140 were collected from different regions of Mardan and major proportion of recruited patients were internally displaced people (IDPs), refugees, and slum dwellers. Complete patient's history was analyzed to assess the possible risks involved in HCV transmission. Viral genotype was determined by PCR (polymerase chain reaction) whereas, HCV RNA was measured by qRT-PCR. Data was analyzed using SPSS statistical software. Our results indicate 3a as the most abundant subtype in Mardan population followed by 3b, 2a, 2b, 4a, untypeable, mixed, 1a, and 1b. In contrast to previous findings, genotype 1 was the least prevalent genotype and the overall prevalence of HCV in Mardan population was significantly higher in females (n = 687, 60.2%) than males (n = 453, 39.7%). Significant difference between-genotypes and gender was observed in genotype 1 (p < .034) and genotype 3 (p < .004). The mean age was 44 (SD ±â€¯9.51). The most frequently found mixed genotype was 3a + 1b and mixed genotype was more prevalent in males. The proportion of middle-aged people (41-49 years) was higher whereas, older and younger people were least infected with HCV. This is the first study that showed substantial correlation of genotype 3 with low and intermediate viral load in Mardan population. Moreover, high and extremely high viral load was associated with other genotypes. Our findings showed that most of the patients who experienced high and extremely high viremia in their blood were males and belonged to Takhat Bhai and Mardaan regions. There were significant difference in the prevalence of HCV genotype 3a (p = .001) and genotype 3b (p = .005) in different regions of Mardan. Pre-treatment viral load is significantly high (p 0.001) in tehsil Mardan patients infected with HCV genotype 3 as compared to other genotypes. Unsafe medical practices such as medical and dental surgeries, intravenous drug use, and blood transfusions were the main risk factors for HCV transmission in Mardan, KPK Pakistan. This study gives clear insights into the epidemiological status of HCV in Mardan population. Genotype 3 is correlated with low and intermediate viral load whereas high viral loads were revealed among patients infected with genotypes other than genotype 3. In the absence of better data and robust epidemiological information, this detailed analysis of HCV genotypes with special reference to risk factors, pretreatment viral load, gender, and age will provide the baseline data for development of optimal HCV eradication and preventive strategies.


Assuntos
Hepacivirus/genética , Hepatite C/epidemiologia , Hepatite C/virologia , Adolescente , Adulto , Idoso , Criança , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Paquistão/epidemiologia , Carga Viral , Adulto Jovem
14.
J Hum Genet ; 53(10): 894-898, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18688569

RESUMO

Isolated hypodontia, or congenital absence of one to six permanent teeth (OMIM 300606), is a common condition that affects about 20% of individuals worldwide. We identified two extended Pakistani pedigrees segregating X-linked hypodontia with variable expressivity. Affected males show no other associated anomalies, and obligate carrier females have normal dentition. We analyzed the families with polymorphic markers in the ectodysplasin A (EDA) gene region and obtained significant linkage to the phenotype in each pedigree (Z(max) 3.29 and 2.65, respectively, at theta = 0.00). Sequence analysis of the coding regions of EDA revealed a novel missense mutation c.1091T>C resulting in a methionine to threonine substitution (p.M364T) in the tumor necrosis factor (TNF) homology domain. Met364 is a highly conserved residue located on the outer surface of the EDA protein. From our findings, we suggest that the mutation disturbs but does not destroy the EDA structure, resulting in the partial and unusually mild ED phenotype restricted to hypodontia.


Assuntos
Anodontia/genética , Cromossomos Humanos X/genética , Ectodisplasinas/genética , Genes Recessivos , Mutação de Sentido Incorreto/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Ectodisplasinas/química , Feminino , Humanos , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Linhagem , Fenótipo , Dobramento de Proteína , Recombinação Genética , Homologia de Sequência de Aminoácidos
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