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5.
Acta Trop ; 249: 107051, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37875169

RESUMO

In the Yucatan Peninsula, tropical preserved forests harbor a high diversity of phlebotomine sand fly species, potential vectors of Leishmania. As a result, a significant risk of contracting localized cutaneous leishmaniasis (LCL) is associated with entry into these forest ecosystems. However, with the current trajectory of land use in the region, communities now live within modified landscapes which could increase their risk of contact with vectors. In this study, we characterized the sand fly fauna and its relationship with the characteristics of peridomestic habitats in two rural communities in Yucatan characterized by contrasting records of leishmaniasis. Five human dwellings in each community were randomly selected and the peridomestic landscape was characterized (i.e., type and percentage of land use). For the collection of sand flies, CDC traps were deployed in both the intra and peridomicile. Differences in alpha and beta diversity between communities and ecotopes were estimated considering three separate groups, all species together, zoophilic species, and anthropophilic species. In total, 1, 241 sand flies represented by eight species were collected from November 2021-March 2022. Both communities registered the presence of sand flies in the intra and peridomicile, and females were more abundant than males. However, the greatest diversity of species was recorded in the peridomicile of the community with the highest composition of land uses. Our study demonstrates that the transformation of the forest around the communities favors the abundance and richness of sand flies in the peridomestic environment. We discuss the limitations and implications of our findings regarding the potential risk of the emergence of peri­rural cycles of leishmaniasis in the region.


Assuntos
Leishmaniose Cutânea , Phlebotomus , Psychodidae , Humanos , Masculino , Animais , Feminino , Ecossistema , México/epidemiologia , População Rural , Insetos Vetores , Leishmaniose Cutânea/epidemiologia
6.
Med. infant ; 30(4): 336-339, Diciembre 2023. ilus, tab
Artigo em Espanhol | LILACS, UNISALUD, BINACIS | ID: biblio-1524212

RESUMO

La infección por Bartonella henselae (BH) adopta diversas formas de presentación clínica en pediatría. Según la bibliografía la forma de presentación más frecuente en pacientes inmunocompetentes es la linfadenopatía única asociada a fiebre. En el 85 % de los casos se compromete un solo ganglio siendo los axilares y los epitrocleares los más frecuentemente involucrados. Existen otras formas de presentación menos frecuentes que debemos tener en consideración, para poder realizar un diagnóstico precoz e indicar un tratamiento adecuado si así lo requiere. El diagnóstico requiere de la sospecha clínica del equipo de salud tratante, junto al antecedente epidemiológico, los hallazgos clínicos del examen físico y la realización de serologías que incluyan el dosaje de inmunoglobulina M y G. Los objetivos del presente trabajo fueron reconocer las manifestaciones clínicas típicas y atípicas de la EAG por Bartonella henselae, describir la epidemiología, características clínicas y evolución de esta enfermedad que se presentaron en nuestro hospital. Se estudiaron un total de 187 pacientes. La media de edad fue de 7.6 años (rango 1-14); siendo 53.5% de género masculino. Las formas de presentación más frecuentes en nuestro trabajo fueron la adenitis y la fiebre. La mayoría recibió diversos esquemas de tratamiento antibiótico, secundario al retraso en el diagnóstico. La tasa de hospitalización fue muy baja, remitió con tratamiento ambulatorio con antibióticos o sin ellos (AU)


Bartonella henselae infection has different clinical presentations in pediatrics. According to the literature, the most common form of presentation in immunocompetent patients is single lymphadenopathy associated with fever. In 85 % of the cases a single lymph node is involved, with the axillary and epitrochlear nodes being the most commonly involved. There are other, less frequent, forms of presentation that should be taken into consideration in order to make an early diagnosis and indicate appropriate treatment if required. Diagnosis relies on clinical suspicion by the treating healthcare team, together with the epidemiological history, clinical findings on physical examination, and serology including immunoglobulin M and G dosage. The objectives of this study were to identify both the typical and atypical clinical manifestations of Bartonella henselae cat scratch disease, to describe the epidemiology, clinical characteristics, and outcomes of cases presenting at our hospital. A total of 187 patients were studied. The mean age was 7.6 years (range 1-14); 53.5% were male. The most frequent forms of presentation in our study were adenitis and fever. Most of them received different antibiotic treatment regimens due to delayed diagnosis. The hospitalization rate was very low and the disease typically resolved with outpatient treatment, with or without antibiotics (AU)


Assuntos
Humanos , Lactente , Pré-Escolar , Criança , Adolescente , Gatos , Doença da Arranhadura de Gato/diagnóstico , Doença da Arranhadura de Gato/tratamento farmacológico , Doença da Arranhadura de Gato/epidemiologia , Bartonella henselae/isolamento & purificação , Febre , Linfadenopatia , Testes Sorológicos , Estudos Retrospectivos , Antibacterianos/uso terapêutico
7.
Acta Trop ; 248: 107014, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37696485

RESUMO

Could tropical forest conversion shape sand fly (Diptera: Phlebotominae) biting rhythms and Leishmania infection rates? Using a Shannon trap, we estimated the bite rate and infection prevalence among anthropophilic sand flies at sites with different land use in southern Mexico. We estimated the expected monthly infection rate of the Leishmania parasite along the gradient and generated information on the biting rhythm of sand flies in a poorly characterized cutaneous leishmaniasis endemic region. We used generalized mixed linear and mixed additives models to evaluate differences in the biting rate, nocturnal activity, and inoculation rate of female sand flies, as well as their relationship with the loss of forest cover and environmental disparities recorded throughout the study area. Our results show that the loss of forest cover influences the biting rhythm of sand fly species and the potential number of infectious bites with Leishmania, but the greatest entomological and potential epidemiological risk continues to be associated with sylvatic areas (amplification events). Despite this, we detected that the effect of forest cover (%) on the entomological exposure seems to be also dependent on the sand fly species, and that, albeit to a lesser extent, Leishmania parasite is circulating in disturbed landscapes through generalist and competent sand fly vector species. We also found that land use change did not affect the nocturnal activity, however we detected that important vector species were active most of the time. Contrary to our expectation, temperature and humidity did not shape the biting rhythm of sand fly species. We discuss the limitations and epidemiological implications of our findings regarding the risk of contracting leishmaniasis in southern Mexico.


Assuntos
Mordeduras e Picadas , Leishmania , Leishmaniose Cutânea , Phlebotomus , Psychodidae , Animais , Feminino , Psychodidae/parasitologia , México/epidemiologia , Insetos Vetores/parasitologia , Leishmaniose Cutânea/epidemiologia
8.
Environ Pollut ; 331(Pt 1): 121936, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37263563

RESUMO

Although aluminum is widely distributed in the earth's crust, its environmental availability and wildlife assimilation rates are only partially known. Here we analyze aluminum concentrations in bone from 10 species of marine mammals inhabiting 3 geographic areas subject to different aluminum inputs: the Río de la Plata estuary (Uruguay), the coastal waters of Mauritania and the Galapagos archipelago (Ecuador). Overall, concentrations were unusually high as compared to those of terrestrial animals, with lowest concentrations in the Galapagos archipelago, then the Río de la Plata estuary and finally Mauritania. The aluminum source varied between regions, prevailing anthropogenic sources in the Río de la Plata Estuary and natural sources (wind-blown dust) in Mauritanian waters. The type of source determined contamination levels: anthropogenic sources were most significant for coastal species and showed a decline with distance of habitat from shoreline, while natural sources had a higher influence on open waters because of the dearth of biogenic silica that eliminates aluminum from the water column. Since aluminum remains in bone for several decades, marine mammal bone reflects historical levels of aluminum and therefore is a good bioindicator of the aluminum concentration of the marine environment.


Assuntos
Alumínio , Ecossistema , Animais , Uruguai , Estuários , Mamíferos , Monitoramento Ambiental
9.
Environ Res ; 231(Pt 3): 116280, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37257742

RESUMO

This work presents a one-step synthesis methodology for preparing a hydrochar (HC) doped with TiO2 (HC-TiO2) for its application on the degradation of crystal violet (CV) using UV and visible radiation. Byrsonima crassifolia stones were used as precursors along with TiO2 particles. The HC-TiO2 sample was synthesized at 210 °C for 9 h using autogenous pressure. The photocatalyst was characterized to evaluate the TiO2 dispersion, specific surface area, graphitization degree, and band-gap value. Finally, the degradation of CV was investigated by varying the operating conditions of the system, the reuse of the catalyst, and the degradation mechanism. The physicochemical characterization of the HC-TiO2 composite showed good dispersion of TiO2 in the carbonaceous particle. The presence of TiO2 on the hydrochar surface yields a bandgap value of 1.17 eV, enhancing photocatalyst activation with visible radiation. The degradation results evidenced a synergistic effect with both types of radiation due to the hybridized π electrons in the sp2-hybridized structures in the HC surface. The degradation percentages were on average 20% higher using UV radiation than visible radiation under the following conditions: [CV] = 20 mg/L, 1 g/L of photocatalyst load, and pH = 7.0. The reusability experiments demonstrated the feasibility of reusing the HC-TiO2 material up to 5 times with a similar photodegradation percentage. Finally, the results indicated that the HC-TiO2 composite could be considered an efficient material for the photocatalytic treatment of water contaminated with CV.


Assuntos
Violeta Genciana , Raios Ultravioleta , Luz , Titânio/química , Catálise
10.
J Environ Manage ; 336: 117664, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36921470

RESUMO

The increase in energy and fertilizer consumption makes it necessary to develop sustainable alternatives for agriculture. Anaerobic digestion and digestates appeared to be suitable options. However, untreated digestates still have high water content and can increase greenhouse gas emissions during storage and land application. In this study, manure-derived digestate and solid fraction of digestate after separation were treated with a novel solar drying technology to reduce their water content, combined with acidification to reduce the gaseous emissions. The acidified digestate and acidified solid fraction of digestate recovered more nitrogen and ammonia nitrogen than their respective non-acidified products (1.5-1.3 times for TN; 14 times for TAN). Ammonia and methane emissions were reduced up to 94% and 72% respectively, compared to the non-acidified ones, while N2O increased more than 3 times. Dried digestate and dried acidified digestate can be labeled as NPK organic fertilizer regarding the European regulation, and the dried solid fraction and the improved dried acidified solid fraction can be labeled as N or P organic fertilizer. Moreover, plant tests showed that N concentrations in fresh lettuce leaves were within the EU limit with all products in all the cases. However, zinc concentration appeared to be a limitation in some of the products as their concentration exceeded the European legal limits.


Assuntos
Amônia , Esterco , Fertilizantes , Agricultura , Nitrogênio/análise , Concentração de Íons de Hidrogênio , Água , Anaerobiose
11.
Psychol Med ; 53(9): 4266-4274, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-35534479

RESUMO

BACKGROUND: Patients with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis (ANMDARE) show a wide range of behavioral abnormalities and are often mistaken for primary psychiatric presentations. We aimed to determine the behavioral hallmarks of ANMDARE with the use of systematic neuropsychiatric and cognitive assessments. METHODS: A prospective study was conducted, with 160 patients admitted to the National Institute of Neurology and Neurosurgery of Mexico, who fulfilled criteria for possible autoimmune encephalitis and/or red flags along a time window of seven years. Cerebrospinal fluid (CSF) antibodies against the NR1 subunit of the NMDAR were processed with rat brain immunohistochemistry and cell-based assays with NMDA expressing cells. Systematic cognitive, neuropsychiatric, and functional assessments were conducted before knowing NMDAR antibodies results. A multivariate analysis was used to compare patients with and without definite ANMDARE according to antibodies in CSF. RESULTS: After obtaining the CSF antibodies results in 160 consecutive cases, 100 patients were positive and classified as having definite ANMDARE. The most frequent neuropsychiatric patterns were psychosis (81%), delirium (75%), catatonia (69%), anxiety-depression (65%), and mania (27%). Cognition was significantly impaired. A total of 34% of the patients had a predominantly neuropsychiatric presentation without seizures. After multivariate analysis, the clinical hallmarks of ANMDARE consisted of a catatonia-delirium comorbidity, tonic-clonic seizures, and orolingual dyskinesia. CONCLUSIONS: Our study supports the notion of a neurobehavioral phenotype of ANMDARE characterized by a fluctuating course with psychotic and affective symptoms, catatonic signs, and global cognitive dysfunction, often accompanied by seizures and dyskinesia. The catatonia-delirium comorbidity could be a distinctive neurobehavioral phenotype of ANMDARE.


Assuntos
Encefalite Antirreceptor de N-Metil-D-Aspartato , Catatonia , Delírio , Discinesias , Humanos , Encefalite Antirreceptor de N-Metil-D-Aspartato/diagnóstico , Encefalite Antirreceptor de N-Metil-D-Aspartato/líquido cefalorraquidiano , Catatonia/etiologia , Estudos Prospectivos , N-Metilaspartato , Receptores de N-Metil-D-Aspartato , Convulsões/complicações , Delírio/complicações , Discinesias/complicações
12.
Environ Res ; 217: 114852, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36457238

RESUMO

Metformin consumption for diabetes treatment is increasing, leading to its presence in wastewater treatment plants where conventional methods cannot remove it. Therefore, this work aims to analyze the performance of advanced oxidation processes using sulfate radicals in the degradation of metformin from water. Experiments were performed in a photoreactor provided with a low-pressure Hg lamp, using K2S2O8 as oxidant and varying the initial metformin concentration (CA0), oxidant concentration (Cox), temperature (T), and pH in a response surface experimental design. The degradation percentages ranged from 26.1 to 87.3%, while the mineralization percentages varied between 15.1 and 64%. Analysis of variance (ANOVA) showed that the output variables were more significantly affected by CA0, Cox, and T. Besides, a reduction of CA0 and an increase of Cox up to 5000 µM maximizes the metformin degradation since the generation of radicals and their interaction with metformin molecules are favored. For the greatest degradation percentage, the first order apparent rate constant achieved was 0.084 min-1. Furthermore, while in acidic pH, temperature benefits metformin degradation, an opposite behavior is obtained in a basic medium because of recombination and inhibition reactions. Moreover, three degradation pathways were suggested based on the six products detected by HPLC-MS: N-cyanoguanidine m/z = 85; N,N-dimethylurea m/z = 89; N,N-dimethyl-cyanamide m/z = 71 N,N-dimethyl-formamide m/z = 74; glicolonitrilo m/z = 58; and guanidine m/z = 60. Finally, it was shown that in general the toxicity of the degradation byproducts was lower than the toxicity of metformin toward Chlamydomonas reinhardtii.


Assuntos
Metformina , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Oxidantes , Sulfatos/química , Oxirredução , Água , Raios Ultravioleta , Cinética
13.
Environ Res ; 216(Pt 4): 114772, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36379235

RESUMO

In this work nanocomposites based on alginate (Alg) and halloysite as a nanotubular clay (Hy) were developed. Characterization techniques reveal that Hy/Alg nanocomposites are cation exchangers with predominantly negative charge density and good thermal stability. The adsorption equilibrium of Cd(II) in aqueous solution onto Hy/Alg nanocomposites revealed that by increasing the mass of halloysite in the nanocomposite, the adsorption capacity diminished significantly due to the halloysite-alginate interactions. Maximum adsorption capacities of 8, 65, 88, and 132 mg/g of Cd(II) were obtained for samples Hy, Hy/Alg 50%, Hy/Alg 95%, and Alg, respectively. In addition, the adsorption equilibrium of Cd(II) on the Hy/Alg bionanocomposites was affected by the pH and temperature of the solution, demonstrating the presence of electrostatic interactions during adsorption and that this is an exothermic process. The controlling mechanism of adsorption was cation exchange influenced by electrostatic forces. The Cd(II) adsorption rate studies were interpreted by the diffusion-permeation model and reveal that the presence of Hy in the structure of the nanocomposites enhances the permeation coefficient, that is, the adsorption rate was increased. The values of the permeation coefficient varied from 1.95 × 10-7 to 8.50 × 10-7 cm2/s for Hy/Alg 50% and from 1.70 × 10-7 to 3.55 × 10-7 cm2/s for Hy/Alg 95%.


Assuntos
Alginatos , Nanocompostos , Argila/química , Adsorção , Alginatos/química , Cádmio , Minerais , Cinética , Concentração de Íons de Hidrogênio
14.
J Dairy Sci ; 106(1): 187-201, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36357210

RESUMO

The periparturient period is a metabolically demanding time for dairy animals because of increased nutrient requirements for milk yield. The objective of this study was to investigate the effect of feeding Saccharomyces cerevisiae boulardii (CNCM I-1079), a commercial active dry yeast (ADY), in dairy cows on productive and metabolic measures during the periparturient period. Primiparous (n = 33) and multiparous (n = 35) cows were fed a close-up total mixed ration (TMR) before calving and a lactation TMR postpartum. Three weeks before expected calving time, animals were blocked by parity and body weight and then randomly assigned to either control group (control; n = 34) or treatment (ADY; n = 34). All animals were housed in a tie-stall barn with individual feed bunks; the ADY animals received supplementary Saccharomyces cerevisiae boulardii (CNCM I-1079), top dressed daily at a predicted dosage of 1.0 × 1010 cfu (12.5 g) per head. Blood samples were collected weekly along with milk yield and milk composition data; feed intake data were collected daily. Serum samples were analyzed for glucose, nonesterified fatty acid, ß-hydroxybutyrate, haptoglobin (Hp), and the cytokines tumor necrosis factor-α, IL-6, and IL-18. Colostrum samples collected within the first 6 to 10 h were analyzed for somatic cell score and IgG, IgA, and IgM concentrations. Data were analyzed using PROC GLIMMIX in SAS with time as a repeated measure; model included time, parity, treatment, and their interactions. The ADY groups had greater milk yield (39.0 ± 2.4 vs. 36.7 ± 2.3 kg/d) and tended to produce more energy-corrected milk with better feed efficiency. There was no difference in plasma glucose, serum nonesterified fatty acid, serum ß-hydroxybutyrate, Hp, IL-6, or IL-18 due to ADY treatment. The tumor necrosis factor-α increased in ADY-supplemented animals (1.17 ± 0.69 vs. 4.96 ± 7.7 ng/mL), though week, parity, and their interactions had no effect. Serum amyloid A tended to increase in ADY-supplemented animals when compared to control animals and was additionally affected by week and parity; there were no significant interactions. No difference in colostrum IgG, IgA, and IgM was observed between treatments. Supplementing transition cow TMR with ADY (CNCM I-1079) improved milk production and tended to improve efficiency in early lactation; markers of inflammation were also influenced by ADY treatment, though the immunological effect was inconsistent.


Assuntos
Saccharomyces boulardii , Saccharomyces cerevisiae , Gravidez , Feminino , Bovinos , Animais , Saccharomyces cerevisiae/metabolismo , Interleucina-18/metabolismo , Ácido 3-Hidroxibutírico , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Dieta/veterinária , Metabolismo Energético , Lactação , Leite/metabolismo , Ingestão de Alimentos , Período Pós-Parto/metabolismo , Ácidos Graxos não Esterificados , Imunoglobulina A/metabolismo , Imunoglobulina G/metabolismo , Imunoglobulina M , Ração Animal/análise
16.
Acta Trop ; 235: 106628, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35952923

RESUMO

As land use intensifies in tropical forests, it is expected that species assemblages will be modified and that key functions of these ecosystems will be affected. The latter scenario is important from a public health perspective, because the land use change has been linked the outbreaks of vector-borne diseases. In this study, we evaluated the response of Phlebotominae (Diptera: Psychodidae) assemblages and their pattern of co-occurrence in four sites with different land use in an emerging cutaneous leishmaniasis focus in Yucatan, Mexico. Our hypothesis is that the conservation status (as forest cover) will positively influence the structure and composition of sand flies' assemblages. Using three different traps over a period of five months, a sampling effort of 1, 440 night-traps was performed. A total of 7, 897 sand fly specimens belonging to six genera and 10 species were collected. Our hypothesis was partially achieved since sand fly diversity increased as forest cover increased and vice versa, however random patterns of co-occurrence in assemblages were detected among sites. Even though the high abundance of sand flies in the forest fragment suggests an amplification effect, our results show that different vector species directly dominate in each site. We discuss the potential implications of the nestedness of species dominance. We suggest that in this emerging focus and under the land use gradient, Lutzomyia cruciata and Psathyromyia cratifer could play a pivotal role in maintaining the transmission cycles of Leishmania. The apparent generalist or colonialist profile of Lu. cruciata in disturbed areas deserves attention, due to the potential risk of leishmaniasis "domiciliation". This information is essential to understand the eco-epidemiology of leishmaniasis and the factors associated with its emergence in Yucatan, Mexico.


Assuntos
Leishmaniose Cutânea , Phlebotomus , Psychodidae , Animais , Ecossistema , Insetos Vetores , Leishmaniose Cutânea/epidemiologia , México/epidemiologia
17.
Data Brief ; 43: 108410, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35811652

RESUMO

This document contains additional information for the production of activated carbons (AC) and carbon foams (CF) from agroindustrial wastes, orange peel (OP) and sugarcane bagasse (SCB). In particular, a set of data is presented for the characterization of carbonaceous structures (AC and CF) and their application in the removal of metallic ions contained in polluted waters. The adsorbent materials were obtained combining chemical and physical activation processes. Data presented here included characterization of AC and CF using dynamic light scattering (DLS), BET (Brunauer, Emmet and Teller) surface area analysis, Barrett-Joyner-Halenda (BJH) method to assess pore size distribution and zeta potential (ζ) to evaluate electrokinetic potential of carbonaceous structures. In addition, energy dispersive spectroscopy (SEM/EDS) to identify heavy metals on the surface of carbonaceous materials is shown and complementary adsorption capacity data for metal ion removal are presented in the paper. The data can be used as a reference to promote reuse of agroindustrial wastes and provide added value; particularly for the synthesis of carbonaceous structures applied to the water purification.

18.
Mol Phylogenet Evol ; 173: 107515, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35577293

RESUMO

Rapid speciation is an important aspect of adaptive radiations, but can obfuscate phylogenetic relationships among taxa. For recent radiations, there are challenges to reconstructing the relationships among the species due to often shorter branch lengths. Resolution of these relationships is further confounded when studies only use a few genetic markers. Double digest restriction-site associated DNA sequencing (ddRADseq) is a method of next generation sequencing that identifies many single nucleotide polymorphisms (SNPs) throughout the genome. This increases statistical power to resolve close phylogenetic relationships like those found within an adaptive radiation. We used this approach to understand the evolutionary history of the rockfishes of the genus Sebastes, which experienced an adaptive radiation between 3 and 5 mya. Here, we reconstructed the phylogenetic relationships among six species of rockfish within the subgenus Sebastosomus using over 11,600 SNPs. This reconstruction includes the two recently diverged species, Sebastes mystinus and S. diaconus, that were first described genetically in 2008 using mtDNA control region sequence data and six microsatellite loci. We confirmed the relationship of these cryptic species as sister-taxa and found evidence that S. melanops and S. flavidus were also sister-taxa. The latter contradicts prior studies but is supported by our reconstruction using nuclear DNA and measures of genetic differentiation tests and a discriminant analysis of principal components. The relationships between the species of Sebastosomus are further supported by morphological, biological, and ecological justifications.


Assuntos
DNA Mitocondrial , Perciformes , Animais , DNA Mitocondrial/genética , Repetições de Microssatélites , Perciformes/genética , Filogenia , Análise de Sequência de DNA
19.
Sci Total Environ ; 831: 154883, 2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35358521

RESUMO

The high levels of heavy metals contained in residual water and the pollution generated by a large amount of unexploited agro-industrial waste are a serious problem for the environment and mankind. Therefore, in the present work, with the aim of treating and reducing the pollution caused by heavy metal ions (Pb, Cd, Zn and Cu), activated carbons (ACs) were synthesized from sugarcane bagasse (SCB) and orange peel (OP) by means of physical - chemical activation method in an acid medium (H3PO4, 85 wt%) followed by an activation at high temperature (500 and 700 °C). Thereafter, these materials were used to produce carbon foams (CF) by the replica method and to evaluate their adsorbent capacity for the removal of heavy metals from synthetic water. XRD, FTIR, DLS, BET, Zeta Potential (ζ), SEM-EDS and AAS were used to investigate their structures, surface area, pore size, morphology, and adsorption capacity. The results show that as-prepared CF have a second level mesoporous structure and AC present a micro-mesoporous structure with a pore diameter between 3 and 4 nm. The experimental adsorption capacities of heavy metals showed that the CF from OP present a better elimination of heavy metals compared to the AC; exhibiting a removal capacity of 95.2 ± 3.96% (Pb) and 94.7 ± 4.88% (Cu) at pH = 5. The adsorption values showed that the optimal parameters to reach a high metal removal are pH values above 5. In the best of cases, the minimum remaining concentration of lead and copper were 2.4 and 2.6 mg L-1, respectively. The experimental data for carbon adsorbents are in accordance with the Langmuir and BET isotherms, with R2 = 0.99 and the maximum homogenous biosorption capacity for lead and copper was Qmax = 968.72 and 754.14 mg g-1, respectively. This study showed that agro-industrial wastes can be effectively retrieved to produce adsorbents materials for wastewater treatment applications.


Assuntos
Citrus sinensis , Metais Pesados , Saccharum , Poluentes Químicos da Água , Adsorção , Biomassa , Celulose , Cobre , Concentração de Íons de Hidrogênio , Resíduos Industriais , Íons , Cinética , Chumbo , Metais Pesados/análise , Água/química , Poluentes Químicos da Água/análise
20.
Sci Rep ; 12(1): 1882, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35115557

RESUMO

Swine wastewater treatment is a complex challenge, due to the high organic matter (OM) and nitrogen (N) concentrations which require an efficient process. This study focused on evaluating two different support media for OM and N removal from an Upflow Anaerobic Sludge Blanket (UASB) reactor fed with swine wastewater. Maximum specific nitrification (MSNA) and denitrification (MSDA) activity test for both biofilm and suspended biomass were carried out using as supports: polyurethane foam (R1) and polyethylene rings (R2). The results showed that R2 system was more efficiently than R1, reaching OM removal of 77 ± 8% and N of 98 ± 4%, attributed to higher specific denitrifying activity recorded (5.3 ± 0.34 g NO3-N/g TVS∙h). Furthermore, 40 ± 5% of the initial N in the wastewater could have been transformed into molecular nitrogen through SND, of which only 10 ± 1% was volatilized. In this sense, MSDA tests indicated that suspended biomass was responsible for at least 70% of N removal and only 20% can be attributed to biofilm. SND could be confirmed with the analysis of microbial diversity, due to the presence of the genus Pseudomonas dominated the prokaryotic community of the system in 54.4%.

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