Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 139
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-37360554

RESUMO

To characterize the pollutant dispersal across major metropolitan cities in India, daily particulate matter (PM10 and PM2.5) data for the study areas were collected from the National Air Quality Monitoring stations database provided by the Central Pollution Control Board (CPCB) of India. The data were analysed for three temporal ranges, i.e. before the pandemic-induced lockdown, during the lockdown, and after the upliftment of lockdown restrictions. For the purpose, the time scale ranged from 1st April to 31st May for the years 2019 (pre), 2020, and 2021 (post). Statistical distributions (lognormal, Weibull, and Gamma), aerosol optical thickness, and back trajectories were assessed for all three time periods. Most cities followed the lognormal distribution for PM2.5 during the lockdown period except Mumbai and Hyderabad. For PM10, all the regions followed the lognormal distribution. Delhi and Kolkata observed a maximum decline in particulate pollution of 41% and 52% for PM2.5 and 49% and 53% for PM10, respectively. Air mass back trajectory suggests local transmission of air mass during the lockdown period, and an undeniable decline in aerosol optical thickness was observed from the MODIS sensor. It can be concluded that statistical distribution analysis coupled with pollution models can be a counterpart in studying the dispersal and developing pollution abatement policies for specific sites. Moreover, incorporating remote sensing in pollution study can enhance the knowledge about the origin and movement of air parcels and can be helpful in taking decisions beforehand.

2.
Environ Monit Assess ; 194(2): 69, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34994867

RESUMO

An investigation of water quality and heavy metal distribution in the groundwater samples collected from the vicinity of Narora Atomic Power Station (NAPS), Narora, India, was conducted for the metals including Cu, Zn, Ni, Co, Cd, Pb, and Fe. A total of 16 water quality parameters were measured for all the groundwater samples, and TDS, TH, Mg2+, Ca2+, F-, and turbidity were found to be on the higher side in comparison to the prescribed limits of Indian standards. Geometrical mean concentrations for these heavy metals were found to be 0.049, 0.213, 0.23, 0.135, 0.017, 0.061, and BDL for Cu, Fe, Zn, Pb, Cd, Co, and Ni, respectively. Pb and Cd were more than the permissible limits (0.01 mg/L for Pb and 0.003 for Cd) prescribed for safe drinking water while Cu and Fe were exceeding the permissible limits of 0.05 mg/L and 0.3 mg/L in 32% and 36% samples, respectively. Health risk assessment was done by calculating total hazard quotient (THQ), and the values for all the metals were below the threshold value of 1.0 beyond which they may pose a significant risk.


Assuntos
Água Subterrânea , Metais Pesados , Poluentes Químicos da Água , Monitoramento Ambiental , Índia , Metais Pesados/análise , Medição de Risco , Poluentes Químicos da Água/análise
3.
Int J Environ Sci Technol (Tehran) ; 18(5): 1269-1286, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33643420

RESUMO

This paper analyses air quality data from megacity Delhi, India, during different periods related to the COVID-19, including pre-lockdown, lockdown and unlocked (post-lockdown) (2018-2020) to determine what baseline levels of air pollutants might be and the level of impact that could be anticipated under the COVID-19 lockdown emission scenario. The results show that air quality improved significantly during the lockdown phases, with the most significant changes occurring in the transportation and industrially dominated areas. A pronounced decline in PM2.5 and PM10 up to 63% and 58%, respectively, was observed during the lockdown compared to the pre-lockdown period in 2020. When compared to 2018 and 2019, they were lower by up to 51% and 61%, respectively, dropping by 56% during unlock. Some pollutants (NOx and CO) dropped significantly during lockdown, while SO2 and O3 declined only slightly. Moreover, when compared between the different phases of lockdown, the maximum decline for most of the pollutants and air quality index occurred during the lockdown phase 1; thus, this period was used to report the COVID-19 baseline threshold values (CBT; threshold value is the upper limit of baseline variation). Of the various statistical methods used median + 2 median absolute deviation (mMAD) was most suitable, indicating CBT values of 143 and 75 ug/m3 for PM10 and PM2.5, respectively. This results although preliminary, but it gives a positive indication that temporary lockdown can be considered as a boon to mitigate the damage we have done to the environment. Also, this baseline levels can be helpful as a first line of information to set future target limits or to develop effiective management policies for achieving better air quality in urban centres like Delhi. Supplementary Information: The online version contains supplementary material available at 10.1007/s13762-021-03142-3.

4.
Nanotechnology ; 31(42): 425703, 2020 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-32516755

RESUMO

Enhancing the rate of decomposition or removal of organic dye by designing novel nanostructures is a subject of intensive research aimed at improving waste-water treatment in the textile and pharmaceutical industries. Despite radical progress in this challenging area using iron-based nanostructures, enhancing stability and dye adsorption performance is highly desirable. In the present manuscript alkali cations are incorporated into iron oxide nanoparticles (IONPs) to tailor their structural and magnetic properties and to magnify methyl blue (MB) removal/decomposition capability. The process automatically functionalizes the IONPs without any additional steps. The plausible mechanisms proposed for IONPs incubated in alkali chloride and hydroxide solutions are based on structural investigation and correlated with the removal/adsorption capabilities. The MB adsorption kinetics of the incubated IONPs is elucidated by the pseudo second-order reaction model. Not only are the functional groups of -OH and -Cl attached to the surface of the NPs, the present investigation also reveals that the presence of alkali cations significantly influences the MB adsorption kinetics and correlates with the cation content and atomic polarizability.

5.
Environ Res ; 172: 43-54, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30769188

RESUMO

This work explored the potential of magnetic sawdust carbon nanocomposites for cationic dyes removal from aqueous medium. EDTA modified magnetic sawdust carbon nanocomposites (EDTA@Fe3O4/SC ncs) were prepared by biogenic green reduction and precipitation approach. The surface properties, structure and composition of nanocomposites were characterized by HRTEM, FESEM, XRD, EDX, BET, FTIR etc. The Fe3O4 nanoparticles were 10-20 nm in diameters and having 14 m2/g surface area. Removal of Methylene blue (MB) and Brilliant green (BG) dyes from aqueous medium was studied in batch mode experiments. The maximum removal was achieved at neutral pH 7.0 with in 30 min. Adsorption capacity of EDTA@Fe3O4/SC for MB and BG dyes was 227.3 mg/g and 285.7 mg/g, respectively. Dye adsorption behaviour is well explained by Freundlich model. The rate of cationic dye adsorption is explained by pseudo-second order model. The value of thermodynamic parameters confirmed that adsorption process was spontaneous and favourable. Desorption and reusable efficiency of nanocomposites was also evaluated.


Assuntos
Carbono , Ácido Edético , Azul de Metileno , Nanocompostos , Compostos de Amônio Quaternário , Poluentes Químicos da Água , Purificação da Água , Água , Adsorção , Carbono/química , Corantes/química , Corantes/isolamento & purificação , Ácido Edético/química , Cinética , Azul de Metileno/química , Azul de Metileno/isolamento & purificação , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/isolamento & purificação , Água/química , Purificação da Água/métodos
6.
Environ Monit Assess ; 188(2): 86, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26759032

RESUMO

Children are vulnerable to heavy metal contamination through consumption of candies and chocolates. Considering this representative samples (69) of candies and chocolates based on cocoa, milk and sugar were analyzed for selected heavy metals by means of flame atomic absorption spectrometry. The average concentration of Zn, Pb, Ni, and Cd was found to be 2.52 ± 2.49, 2.0 ± 1.20, 0.84 ± 1.35, and 0.17 ± 0.22 µg/g respectively. Results indicate that cocoa-based candies have higher metal content than milk- or sugar-based candies. The daily dietary intake of metals for children eating candies and chocolates was also calculated, and results indicated highest intake of Pb and Zn followed by Ni, Cd, and Cu. Comparison of the current study results with other studies around the globe shows that the heavy metal content in candies and chocolates is lower in India than reported elsewhere. However, to reduce the further dietary exposure of heavy metals through candies and chocolates, their content should be monitored regularly and particularly for Pb as children are highly susceptible to its toxicity.


Assuntos
Doces/análise , Dieta/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Contaminação de Alimentos/análise , Metais Pesados/análise , Criança , Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Contaminação de Alimentos/estatística & dados numéricos , Humanos , Índia , Espectrofotometria Atômica
7.
Indian J Lepr ; 87(1): 23-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26591847

RESUMO

Lepra reactions are acute episodes occurring during the disease process of leprosy and are of 2 types: type 1 or reversal reaction and type 2 reaction or erythema odosumleprosum (ENL). In the episodes of lepra reaction several parts are affected including face and extremities like oral cavity. In the present case report we reported a rare case of lepromatous leprosy with necrotic ENL involving scalp apart from the usual sites. A 58 year old married male presented to us with complaints of spontaneous onset, recurrent eruption of multiple reddish raised painful lesions. Biopsy from the infiltrated skin over the back showed atrophic epidermis, free Grenz zone, diffuse and periadnexal macrophage granulomas with predominant mononuclear infiltrate, appandageal atrophy, fibrosis around the neural structures and leukocytoclastic vasculitis. Fites stain showed strong positivity for M. leprae. His routine blood investigations showed anemia (Hb = 7.8 gm%), neutrophil leukocytosis (TLC = 17,600, DLC = P66L28M4E2) and raised ESR (80 mm in the first hour). These bullous and necrotic lesions in leprosy may be a manifestation of severe type II reactions in patients with very high bacillary load.


Assuntos
Eritema Nodoso/etiologia , Hanseníase Virchowiana/complicações , Eritema Nodoso/imunologia , Eritema Nodoso/microbiologia , Eritema Nodoso/patologia , Humanos , Hanseníase Virchowiana/microbiologia , Masculino , Pessoa de Meia-Idade , Mycobacterium leprae/isolamento & purificação , Mycobacterium leprae/fisiologia , Necrose , Couro Cabeludo/microbiologia , Couro Cabeludo/patologia
8.
J Food Sci Technol ; 52(8): 5299-304, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26243956

RESUMO

This study reports minerals and trace elements quantification in raw caprine milk of Beetal breed, reared in Northern India and their feed, fodder & water using flame atomic absorption spectrophotometry and flame photometry. The mineral and trace elements' concentration in the milk was in the order: K > Ca > Na > Fe > Zn > Cu. The results showed that minerals concentration in caprine milk was lesser than reference values. But trace elements concentration (Fe and Zn) was higher than reference values. Multivariate statistical techniques, viz., Pearsons' correlation, Cluster analysis (CA) and Principal component analysis (PCA) were applied to analyze the interdependences within studied variables in caprine milk. Significantly positive correlations were observed between Fe - Zn, Zn - K, Ca - Na and Ca - pH. The results of correlation matrix were further supported by Cluster analysis and Principal component analysis as primary cluster pairs were found for Ca - pH, Ca - Na and Fe - Zn in the raw milk. No correlation was found between mineral & trace elements content of the milk and feed.

9.
Eur Rev Med Pharmacol Sci ; 17(1): 49-55, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23329523

RESUMO

This review was prepared with an aim to show role of serotonin in seasonal affective disorder. Seasonal affective disorder, which is also called as winter depression or winter blues, is mood disorder in which persons with normal mental health throughout most of the year will show depressive symptoms in the winter or, less commonly, in the summer. Serotonin is an important endogenous neurotransmitter which also acts as neuromodulator. The least invasive, natural, and researched treatment of seasonal affective disorder is natural or otherwise is light therapy. Negative air ionization, which acts by liberating charged particles on the sleep environment, has also become effective in treatment of seasonal affective disorder.  


Assuntos
Transtorno Afetivo Sazonal/etiologia , Serotonina/fisiologia , Humanos , Fototerapia , Receptores de Serotonina/fisiologia , Transtorno Afetivo Sazonal/terapia
10.
Indian J Lepr ; 85(1): 27-31, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24046912

RESUMO

28 yr old male presented with asymptomatic nodules and few well to ill defined papules on ears, asymmetrical nerve enlargement and evanescent tender nodules on the extremities without any infiltration of the skin and madarosis. Slit skin smear done from normal skin was BI 6+. Skin biopsy showed features of lepromatous leprosy.


Assuntos
Hanseníase Virchowiana/diagnóstico , Adulto , Braço/microbiologia , Braço/patologia , Orelha Externa/microbiologia , Orelha Externa/patologia , Histiocitoma Fibroso Benigno/microbiologia , Histiocitoma Fibroso Benigno/patologia , Histocitoquímica , Humanos , Masculino , Pele/microbiologia , Pele/patologia
11.
J Nanosci Nanotechnol ; 12(6): 4757-61, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22905527

RESUMO

This work was developed with an aqueous suspension of maghemite nanoparticles and colloidal emulsions with nanoparticles of magnetite. The nanoparticles were synthesized by co-precipitation method. The first was the magnetic emulsion nanoparticles of maghemite dispersed in the aqueous extract obtained from the leaf embauba (Cecropia Obtusifolia), whose tree is native to Central and South America. Thereby achieving the magnetic fluid extract embauba stabilized with ionic buffer solution pH 7.4. A second emulsion was prepared with colloidal magnetite nanoparticles with surfaces previously coated with oleic acid as a means of dispersing and using the oil extracted from in nature seed Andiroba (Carapa Guianensis), tree of the Brazilian Amazon. These new magnetic fluids the nanoparticles were characterized by Photoacoustic spectroscopy (PAS) to determine the coating layer of molecules on the surfaces of nanoparticles. In aqueous ionic magnetic fluid Cecropia Obtusifolia (MFCO) chlorogenic acid contributes to the electron density in the presence of four groups alcohols, a ketone group and a carboxylic group. In magnetic fluid-based oil andiroba MFAD PAS spectra show that oleic acid molecules are tightly linked on the surface of the nanoparticles.


Assuntos
Materiais Biocompatíveis/química , Compostos Férricos/química , Nanopartículas de Magnetita/química , Compostos Orgânicos/química , Óleos de Plantas/síntese química , Soluções/síntese química , Campos Magnéticos , Nanopartículas de Magnetita/ultraestrutura , Teste de Materiais
12.
Chemosphere ; 296: 133966, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35202671

RESUMO

Industrial effluents generally contain several metals, so during adsorptive treatment, they may influence the removal of each other. It is essential to explore the effect of co-cations on metal removal in multi-metal solutions. The present study examined the possibility of processed rice husk and saw dust to remove Cr6+, Ni2+, Cu2+, Cd2+ and Zn2+, from the single, binary and multi-component aqueous solutions. A substantial lesser removal of metal ions was observed in the presence of co-ions. This study revealed antagonistic effect on the removal of a particular metal ion, from the industrial effluent, even at optimum process parameters if other metal ions are present in the effluent. Although, a higher concentration of one metal ion than others in effluents increased its removal due to a greater number of ions as compared to other for the biosorption, yet presence of other ions influences the uptake of individual ions. In case of industrial effluents, maximum adsorption was obtained at pH 2.0 for Cr6+, 5.0 for Ni2+ and Cd2+ and 6.0 for Zn2+ and Cu2+. The study confirms the beneficial use of the studied biosorbents in water remediation.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Biomassa , Cádmio/análise , Concentração de Íons de Hidrogênio , Íons , Cinética , Metais Pesados/análise , Águas Residuárias , Água , Poluentes Químicos da Água/análise
13.
Chemosphere ; 301: 134714, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35489459

RESUMO

A novel green nanocomposite has been prepared by immobilizing CaO nanoparticles (CaO NPs) on the surface of graphene oxide. Biogenic CaO-NPs were synthesized from Lala clamshells. Morphological and structural characterizations of the nanocomposite were studied extensively. The adsorption capacity (qmax) of the nanocomposite for removing Cr(VI) was 38.04 mg g-1. In addition to this, the adsorption data were adequately simulated with Langmuir, Freundlich, Temkin, and pseudo-second-order models, suggesting that the adsorption process was the combination of external mass transfer and chemisorption. Electrostatic interaction was the dominant mechanism for Cr(VI) removal. In addition, the synthesized nanocomposites also serve as an excellent sensor for Cr(VI) sensing, with a limit of detection (LOD) of 0.02 µM utilizing electrochemical methods. Therefore, this green nanocomposite can simultaneously serve as an adsorbent and sensor for Cr(VI)removal from aqueous solutions.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Adsorção , Cromo/análise , Grafite , Cinética , Nanocompostos/química , Águas Residuárias , Poluentes Químicos da Água/análise
14.
Eur Rev Med Pharmacol Sci ; 15(11): 1256-63, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22195357

RESUMO

Hypertension and diabetes are becoming increasingly common. Clinical trials have demonstrated the importance of tight blood pressure control among patients with diabetes. However, little is known regarding the management of hypertension in patients with coexisting diabetes. Most patients with both disorders have a markedly worsened risk for premature micro vascular and macro vascular complications. The appropriate management of the hypertension seen in almost 70% of patients with type 2 diabetes mellitus remains controversial. However, over the past few years, many randomized, controlled trials have provided guidance for more effective therapy. These trials have established the need for a lower goal blood pressure (< 130/80 mm Hg) than has previously been recommended. To achieve therapy goals, multiple antihypertensive drugs are usually needed.


Assuntos
Anti-Hipertensivos/uso terapêutico , Complicações do Diabetes/tratamento farmacológico , Hipertensão/tratamento farmacológico , Complicações do Diabetes/complicações , Quimioterapia Combinada , Guias como Assunto , Humanos , Hipertensão/complicações , Estilo de Vida , Obesidade/complicações
15.
Ecotoxicol Environ Saf ; 74(1): 19-24, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20951432

RESUMO

This paper reports the optimization of cow dung (CD) spiked pre-consumer processing vegetable waste (PPVW) for vermicomposting using Eisenia fetida in a laboratory scale study. Vermicomposting process decreased carbon and organic matter concentration and increased N, P and K content in the vermicompost. The C:N ratio was decreased by 45-69% in different vermireactors indicating stabilization of the waste. The heavy metal content was within permissible limits of their application in agricultural soils. It has been concluded from the results that addition of PPVW up to 40% with CD can produce a good quality vermicompost. Whereas, growth and fecundity of E. fetida was best when reared in 20% PPVW+80% CD feed mixture. However, higher percentages of PPVW in different vermireactors significantly affected the growth and fecundity of worms.


Assuntos
Resíduos Industriais/prevenção & controle , Esterco , Oligoquetos/efeitos dos fármacos , Eliminação de Resíduos/métodos , Poluentes do Solo/toxicidade , Verduras , Animais , Biodegradação Ambiental , Carbono/metabolismo , Bovinos , Fertilidade/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Nitrogênio/metabolismo , Oligoquetos/fisiologia , Compostos Orgânicos/metabolismo , Fósforo/metabolismo , Potássio/metabolismo , Poluentes do Solo/metabolismo , Fatores de Tempo
16.
Bioresour Technol ; 326: 124742, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33508640

RESUMO

This study reports the vermicomposting of banana crop waste biomass by Eisenia fetida. Cow dung has been used as bulking agent in this study. The experiment was conducted in six vermireactors containing different ratios of banana leaf waste biomass (BL) and cow dung (CD) for 105 days. Earthworm activity significantly reduced pH, TOC, C:N and C:P ratio of the wastes. Whereas macronutrients and micronutrients content increased after vermicomposting. TOC content of wastes reduced by 40-64% and C:N ratio of the vermicomposts was in the range of 8.9-24.3. The benefit ratio for heavy metals (Cu, Fe, Zn, Cd, Pb, Mn and Cr) was in the range of 0.23-3.44. The results indicated that the growth and fecundity of the earthworms was best in the vermireactors having 20-40% BL. Finally, it was concluded that vermicomposting can be included in the overall scheme of banana crop waste management.


Assuntos
Musa , Oligoquetos , Animais , Biomassa , Bovinos , Feminino , Esterco , Solo , Tecnologia
17.
J Nanosci Nanotechnol ; 10(2): 1251-4, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20352784

RESUMO

In this study photoacoustic spectroscopy was used to investigate the effect of dilution of an oil-based magnetic fluid sample on the magnetic nanoparticle surface-coating. Changes of the photoacoustic signal intensity on the band-L region (640 to 830 nm) upon dilution of the stock magnetic fluid sample were discussed in terms of molecular surface desorption. The model proposed here assumes that the driving force taking the molecules out from the nanoparticle surface into the bulk solvent is the gradient of osmotic pressure. This gradient of osmotic pressure is established between the nanoparticle surface and the bulk suspension. It is further assumed that the photoacoustic signal intensity (area under the photoacoustic spectra) scales linearly with the number of coating molecules (surface grafting) at the nanoparticle surface. This model picture provides a non-linear analytical description for the reduction of the surface grafting coefficient upon dilution, which was successfully-used to curve-fit the photoacoustic experimental data.

18.
Environ Monit Assess ; 170(1-4): 657-60, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20020323

RESUMO

Popularity of herbal drugs is increasing all over the world because of lesser side effects as compared to synthetic drugs besides it cost effectiveness and easy availability to poor people particularly in developing countries. Keeping in view the increased market demand of herbal drugs, it is essential to ensure their chemical quality prior to use. Raw drugs and herbs are usually collected from different places, which might be contaminated with various contaminants. It is pertinent to estimate the levels of heavy metals and other micronutrients, which could be affected by their presence in the surrounding environments. Heavy metals are known to pose a potential threat to terrestrial and aquatic biota. Keeping this in view, samples of ten plants or plant parts used in drug making were collected from local markets of Punjab for heavy metal and micronutrient estimation. It was found that the samples were contaminated having cadmium, lead, chromium, iron, manganese, and zinc. The highest mean level of cadmium (23.1 µg/kg) was found in Haritaki sample. Chromium concentration of the plant samples ranged between 7.25 and 1.34 µg/kg with the highest values was in Daruharidra and lowest in Pippali. The levels of these heavy metals were within permissible limits.


Assuntos
Poluentes Ambientais/análise , Metais Pesados/análise , Preparações de Plantas/análise , Plantas Medicinais/química , Monitoramento Ambiental , Micronutrientes/análise
19.
Waste Manag Res ; 28(1): 71-5, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19748951

RESUMO

In India, millions of tons of press mud (PM) are generated by sugar mills every year. This paper reports the potential of vermitechnology to convert sugar industry waste PM mixed with cow dung (CD) into vermicompost, employing an epigeic earthworm Eisenia fetida. A total of six different reactors were established having different ratios of PM and CD including one control (CD only). The growth and fecundity of E. fetida was monitored for 13 weeks. Maximum growth was recorded in 100% CD, but earthworms grew and reproduced favourably up to 1:1 PM and CD feed composition. However, greater percentages of PM in different reactors significantly affected the growth and fecundity of worms. Vermicomposting resulted in a decrease in carbon concentration and an increase in nitrogen, phosphorus and calcium concentrations of the vermicompost. Investigations indicated that vermicomposting could be an alternative technology for the management of PM into useful fertilizing material, if mixed at maximum 50% with CD.


Assuntos
Carboidratos , Conservação dos Recursos Naturais/métodos , Fezes/química , Indústria Alimentícia , Resíduos Industriais , Oligoquetos/metabolismo , Eliminação de Resíduos/métodos , Animais , Biomassa , Reatores Biológicos , Cálcio/metabolismo , Carbono/metabolismo , Bovinos , Fezes/microbiologia , Índia , Resíduos Industriais/análise , Resíduos Industriais/prevenção & controle , Nitrogênio/metabolismo , Oligoquetos/crescimento & desenvolvimento , Fósforo/metabolismo , Fatores de Tempo
20.
Chemosphere ; 247: 125803, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31972482

RESUMO

The present study explored removal of carcinogenic cationic and anionic dyes from aqueous medium using green fabricated zinc oxide nanoparticles (ZnO-NPs). The ZnO-NPs were synthesized employing biogenic green reduction and precipitation approach. The characterization of ZnO NPs was done using various techniques such as FESEM, XRD, BET, TGA, HRTEM, EDX, and FTIR. All experiments were conducted in batch mode. Maximum removal was achieved at pH 6.0 and pH 8.0 for Congo Red (CR) and Malachite Green (MG) dyes respectively. Dye adsorption process showed better fit with Langmuir and Temkin isotherm models for CR dye and MG dye respectively. Maximum adsorption capacity of ZnO NPs was 48.3 mg/g for CR dye and 169.5 mg/g for MG dye. The dye adsorption followed pseudo-second order model and values of thermodynamic parameters confirmed that the adsorption process was spontaneous and favourable. Reusability efficiency of the nanoparticle was explored using ethanol and water and based on results it was inferred that ZnO-NPs can be reused for dye removal. Effect of salinity on the removal of CR and MG dyes was also explored and found that presence of salinity in aqueous medium have adverse impact on the dye removal efficiency of ZnO-NPs.


Assuntos
Corantes/química , Eucalyptus/química , Nanopartículas Metálicas/química , Folhas de Planta/química , Águas Residuárias/química , Purificação da Água/métodos , Óxido de Zinco/química , Adsorção , Vermelho Congo/química , Concentração de Íons de Hidrogênio , Cinética , Corantes de Rosanilina/química , Termodinâmica , Poluentes Químicos da Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA