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1.
J Contam Hydrol ; 264: 104341, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38701693

RESUMO

Canada's deep geological repository (DGR) design includes an engineered barrier system where highly compacted bentonite (HCB) surrounds the copper-coated used fuel containers (UFCs). Microbial-influenced corrosion is a potential threat to long-term integrity of UFC as bisulfide (HS-) may be produced by microbial activities under anaerobic conditions and transported via diffusion through the HCB to reach the UFC surface, resulting in corrosion of copper. Therefore, understanding HS- transport mechanisms through HCB is critical for accurate prediction of copper corrosion allowance. This study investigated HS- transport behaviour through MX-80 bentonite at dry densities 1070-1615 kg m-3 by performing through-diffusion experiments. Following HS- diffusion, bromide (Br-) diffusion and Raman spectroscopy analyses were performed to explore possible physical or mineralogical alterations of bentonite caused by interacting with HS-. In addition, accessible porosity ε was estimated using extended Archie's law. Effective diffusion coefficient of HS- was found 2.5 × 10-12 m2 s-1 and 5.0× 10-12 m2 s-1 for dry densities 1330 and 1070 kg m-3, respectively. No HS- breakthrough was observed for highly compacted bentonite (1535-1615 kg m-3) over the experimental timeframe (170 days). Raman spectroscopy results revealed that HS- reacted with iron in bentonite and precipitated as mackinawite and, therefore, it was immobilized. Finally, results of this study imply that HS- transport towards UFC will be highly controlled by the available iron content and dry density of the buffer material.

2.
Gastroenterol Res Pract ; 2019: 7279163, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31781199

RESUMO

PURPOSE: The exact mechanism of action of chemoembolization with drug eluting beads loaded with irinotecan (DEBIRI) in colorectal cancer is undetermined. Posttreatment tumour contrast retention often seen on CT immediately post procedure is of indeterminate significance. This study is aimed at assessing if metabolic response on PET-CT can be related to posttreatment tumour contrast retention. MATERIALS AND METHODS: In this retrospective study, a total of 17 patients with a total of 55 marker lesions were recruited. RESULTS: The area of tumour contrast retention can be matched to a hypometabolic area on subsequent PET-CT in over 36 lesions (65.5%). Out of the 55 lesions, a total of 38 marker lesions in 11 patients who also had pre-DEBIRI PET-CT were analyzed for disease response. 10 out of 10 lesions that had a complete response on PET-CT were found to demonstrate contrast retention throughout the tumour. 12 out of 13 (92.3%) tumours that had a partial metabolic response on PET-CT were found to demonstrate contrast uptake in the hypometabolic area only. In the 15 lesions that had progression/no response, 13 (86.6%) demonstrated no relationship between tumour contrast retention and tumour response. There was a significant correlation between contrast retention and disease response (P < 0.001). CONCLUSION: Our study showed that PET-CT response can be associated with post embolization contrast retention. The data suggests blood stasis, for which tumour contrast retention is a surrogate marker, is important for the PET-CT metabolic response. The authors propose that tumour contrast retention is an important embolization endpoint in DEBIRI.

3.
Diabetes Metab Syndr ; 13(2): 1335-1339, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31336488

RESUMO

AIMS: Cardiovascular diseases are one of the leading causes of mortality and morbidity among human beings. The presence of endemic Cardiovascular diseases and their risk factors differ from population to population. The Cardiovascular diseases associated risk factors are sub-categorised into two forms, one is traditional and the other is non-traditional risk factors. The present study shows the prevalence of both risk factors and its association with Cardiovascular diseases, especially with reference to general obesity. MATERIALS AND METHODS: The present study includes a total of 506 Gaur Brahmins residing in Delhi and National Capital Region India. Household survey was conducted and data were collected by using pre-tested interview schedule. Somatometric measurements were taken following the international standard techniques. Approx 5 ml blood was collected from each individual unrelated up to the first cousion. The serum was used to analyse the lipid profiles and fasting glucose level. All necessary statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) and MS Excel. The ethical clearance was obtained from the Ethical Committee of the Department of Anthropology, University of Delhi, Delhi. RESULTS AND CONCLUSION: The mean value of Somatometric variables such as Body Mass Index, Waist circumference and Waist-hip ratio and physiological variables DBP and SBP (diastolic blood pressure and systolic blood pressure) were found to be higher than their respective ranges in the studied population. General obesity, though found to be less common in this population as compared to abdominal obesity, but it is found to be contributing to dyslipidemia.


Assuntos
Índice de Massa Corporal , Doenças Cardiovasculares/epidemiologia , Dislipidemias/complicações , Obesidade/complicações , Circunferência da Cintura , Doenças Cardiovasculares/etiologia , Estudos Transversais , Feminino , Seguimentos , Humanos , Índia/epidemiologia , Masculino , Prevalência , Prognóstico
4.
Vet Res Commun ; 42(4): 289-295, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30219981

RESUMO

Bovine mastitis causes severe economic losses to dairy farmers. Staphylococcus aureus, is one of the most important pathogen implicated in etiology of clinical and subclinical mastitis in bovines. In view of increasing antimicrobial resistance alternatives to antibiotic therapy are much needed. The present decade has witnessed a renewed interest in phage based therapeutics and diagnostics. The present study, describes isolation and characterization of two lytic phages SAJK-IND and MSP against Staphylococcus aureus having a potential to be used in therapy against mastitis. SAJK-IND and MSP phages belonged to Myoviridae and Podoviridae families, respectively. TEM imaging of the two phages revealed an iscosahedral head. MSP phage has a short non contractile tail. SAJK-IND and MSP have a burst size of 44 ± 3 and 25 ± 5 PFU/ infected cell, respectively. SAJK-IND and MSP phages revealed Ì´ 12 and Ì´16 proteins, respectively on SDS-PAGE analysis. The lytic activity of the phages was specific for Staphylococcus aureus. SAJK-IND revealed 100% lytic activity against several strains of Staphylococcus aureus isolated from mastitis milk samples whereas, MSP had only 40% lytic activity. SAJK-IND phage genome was sequenced, assembled and deposited in Genbank under accession no MG010123.


Assuntos
Bacteriófagos , Mastite Bovina/terapia , Terapia por Fagos/veterinária , Infecções Estafilocócicas/veterinária , Animais , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Bovinos , Eletroforese em Gel de Poliacrilamida/veterinária , Feminino , Genoma Viral/genética , Índia , Microscopia Eletrônica de Transmissão/veterinária , Myoviridae/genética , Myoviridae/isolamento & purificação , Terapia por Fagos/métodos , Podoviridae/genética , Podoviridae/isolamento & purificação , Proteoma/genética , Infecções Estafilocócicas/terapia , Proteínas Virais/genética , Proteínas Virais/isolamento & purificação , Sequenciamento Completo do Genoma/veterinária
5.
Environ Technol ; 39(5): 669-681, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28327057

RESUMO

The major concerns of the modern society such as increasing population, climate change and economic development are imposing continuous stress on water and energy resources. The present work deals with the cultivation of green algae Desmodesmus abundans for optimum biomass productivity and lipid content as well as simultaneous removal of nitrate and phosphate from synthetic wastewater. The algal biomass is characterized by ultimate analysis, scanning electron microscopic analysis and thermogravimetric analysis. The effect of time, inoculum concentration and nitrate concentration on four responses (biomass productivity, lipid content, removal of nitrate and removal of phosphate) are studied by response surface methodology using central composite design. The quadratic models are found to be suitable for each response. At optimized experimental conditions, the algae showed biomass productivity of 46.96 mg L-1 day-1, lipid content of 16.23%, nitrate removal of 86.64% and phosphate removal of 87.52% after 27 days, when the initial inoculum concentration was 6% and nitrate concentration was 1.25 g L-1.


Assuntos
Microalgas/fisiologia , Nitratos/análise , Fosfatos/análise , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Microalgas/crescimento & desenvolvimento
6.
J Forensic Leg Med ; 52: 98-109, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28888186

RESUMO

Each individual regardless of sex, age and caste has a particular identification mark present on their body. This study is mainly an attempt to understand the distribution pattern of different types of acquired body marks present on the body which can be used as a marker for individual identification in Forensics. Data was collected by means of observation, interview schedule and interviews from 160 individuals of 6 multi-caste villages of Udaipur in Rajasthan, India. A wide variation was observed in the distribution patterns of various acquired body marks. Scars were the most prevalent (87.5%) followed by body piercing (66%), occupational marks (38.5%), tattoo marks (27.5%) and body deformity (5%). There is a strong association between sex of an individual and presence of tattoo and occupational marks. Type of occupation is associated with the presence of scar and occupational marks. Age also has its influence on the presence and type of - tattoo and occupational marks. This wide variation in the distribution of acquired body marks based on sex, age, educational status, occupation, religion etc. of an individual need to be considered and included as a method of identification of unknown in Forensic Science.


Assuntos
Identificação Biométrica/métodos , Piercing Corporal , Cicatriz/epidemiologia , Tatuagem , Adolescente , Adulto , Feminino , Ciências Forenses , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Traumatismos Ocupacionais/epidemiologia , Ocupações/estatística & dados numéricos , Fatores Sexuais , Adulto Jovem
7.
Parasite Immunol ; 39(7)2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28467600

RESUMO

Neurocysticercosis (NCC), one of the most common parasitic diseases of the central nervous system, is caused by Taenia solium. This parasite involves two hosts, intermediate hosts (pig and human) and a definitive host (human) and has various stages in its complex life cycle (eggs, oncosphere, cysticerci and adult tapeworm). Hence, developing an animal model for T. solium that mimics its natural course of infection is quite challenging. We have reviewed here the animal models frequently used to study immunopathogenesis of cysticercosis and also discussed their usefulness for NCC studies. We found that researchers have used mice, rats, guinea pigs, dogs, cats and pigs as models for this disease with varying degrees of success. Mice and rats models have been utilized extensively for immunopathogenesis studies due to their relative ease of handling and abundance of commercially available reagents to study these small animal models. These models have provided some very exciting results for in-depth understanding of the disease. Of late, the experimentally/naturally infected swine model is turning out to be the best animal model as the disease progression closely resembles human infection in pigs. However, handling large experimental animals has its own challenges and limitations.


Assuntos
Modelos Animais de Doenças , Neurocisticercose/imunologia , Taenia solium/imunologia , Taenia/imunologia , Teníase/imunologia , Animais , Chinchila , Cricetinae , Humanos , Estágios do Ciclo de Vida , Macaca mulatta , Neurocisticercose/parasitologia , Ratos , Suínos
8.
Cell Death Discov ; 1: 15038, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27551468

RESUMO

Refractoriness of glioblastoma multiforme (GBM) to current treatment paradigms has necessitated identification of new targets to better the existing therapeutic strategies. One such target is peroxisome proliferator-activated receptor gamma (PPARγ) - a transcription factor involved in regulation of lipid metabolism and inflammation. Expression of PPARγ, a known regulator of cell death-inducing DFFA-like effector (CIDEA), is modulated by hypoxia inducible factor (HIF-1α). While the involvement of CIDEA in lipid metabolism is known, its role in malignancies remains largely unknown. An elevated PPARγ and low CIDEA level was observed in GBM tumors as compared with surrounding non-neoplastic tissue. As reciprocal relation exists between PPAR and HIF-1α: and as HIF-1α is a key component in glioma progression, their role in regulating CIDEA expression in glioblastoma was investigated. Although HIF-1α inhibition had no effect on CIDEA expression, pharmacological inhibition of PPARγ elevated CIDEA levels. PPARγ mediated upregulation of CIDEA was accompanied by decreased recruitment of NFκB and SP1 to their predicted binding sites on CIDEA promoter. Ectopic expression of CIDEA triggered apoptosis, activated JNK, decreased HIF-1α activation and increased PPARγ levels in glioma cells. While CIDEA overexpression induced actin cytoskeletal disruption, cell cycle arrest, release of pro-inflammatory cytokine IL-6 in a JNK-dependent manner; CIDEA mediated apoptotic cell death, decreased STAT3 phosphorylation and increased p53 acetylation was JNK independent. This study highlights for the first time the existence of (i) PPARγ-CIDEA regulatory loop in glioma and (ii) novel function of CIDEA as regulator of glioma cell survival.

9.
Spectrochim Acta A Mol Biomol Spectrosc ; 128: 398-402, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24682054

RESUMO

We report hyper-Rayleigh scattering (HRS) properties of gold nanoparticles (GNPs) of five different shapes, quasi-spherical (∼10 and ∼20 nm diameter), rod (aspect ratio ∼2), and branched shapes, tetrapod, flower and star with 800 nm, 150 fs laser excitation. Using ∼10 nm spherical GNPs as reference, the first hyperpolarizability (ß) values were calculated for all other shapes. Star and flower shaped GNPs have the highest hyperpolarizability (∼130 and ∼52 times higher, respectively), while rod and tetrapod shaped GNPs only have modest enhancement (∼7 times), which is similar to ∼20 nm size quasi-spherical particles. These enhancements are attributed to reduced symmetry as well as the presence of sharp tips on GNP surface. When the ß values are normalized with respect to the number of atoms per particle, the flower and star shaped GNPs still have the highest hyperpolarizability values. The polar plots of vertically polarized HRS signal as a function of the angle of polarization of the incoming incident light shows two lobes, indicating that excitation is predominantly dipolar in nature although the size of some GNPs are big enough to show a quadrupolar response. It is believed that the presence of sharp tips at the surface of these large sized GNPs is responsible for the observed dipolar response. This study shows that GNPs having sharp tips might be a better candidate when their nonlinear properties are used for sensing applications.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Tamanho da Partícula , Espalhamento de Radiação
10.
Indian J Otolaryngol Head Neck Surg ; 66(Suppl 1): 78-80, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24533363

RESUMO

To present a case of impacted artificial denture in esophagus and its removal by flexible endoscope. A 28 year old male presented with history of ingesting his denture 2 h back. It was removed by flexible endoscope and flexible fibre optic forceps. Though rigid endoscopic removal of foreign body is safe and effective, but often requires general anaesthesia. The flexible fibre optic endoscopic removal, which can be done under local anaesthesia in outpatient department is a suitable alternative.

11.
Appl Radiat Isot ; 77: 61-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23528644

RESUMO

The superheated droplet detector (SDD) is known to be gamma ray insensitive below a threshold temperature which made them excellent candidates for neutron detection in the presence of gamma rays. Above the threshold temperature, the gamma ray detection efficiency increases with increase in temperature. In this work the gamma ray threshold temperature has been studied for SDD using R404A as the active liquid and is compared to the theoretical prediction. The temperature variation of gamma ray detection efficiency and interstate transition kinetics has also been studied using a two-state model. The experiments are performed at the ambient pressure of 1 atm and in the temperature range of 17-32 °C using a 662 keV (1)(37)Cs gamma ray source.


Assuntos
Clorofluorcarbonetos de Metano/química , Clorofluorcarbonetos de Metano/efeitos da radiação , Raios gama , Calefação/instrumentação , Microfluídica/instrumentação , Modelos Químicos , Radiometria/instrumentação , Radiometria/métodos , Simulação por Computador , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Doses de Radiação , Soluções
12.
J Young Pharm ; 4(1): 38-41, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22523459

RESUMO

A series of novel 1[5"-(2"'-substituted phenyl)-4",5"'-dihydro isoxazole-3"-yl]-3-[(4 substituted phenyl)imino]1-3-dihydro-2H-indole-2-one were synthesized from different substituted chalconised indole-2,3-dione was prepared from the different chalconised Isatin. The structures of the compounds were elucidated by elemental and spectral (IR, (1)H NMR, and MS) analysis. The synthesized compounds were screened for their analgesic activity by the acetic acid induced Writhing method and in vitro antimicrobial activity against the Gram-positive bacteria-Staphylococcus aureus and the Gram-negative bacteria-Pseudomonas auroginosa, Pseudomonas mirabilis, and E. coli by the cup plate agar diffusion method. Compounds 6a(1), 6a(3), 6b(3), and 6b(2) were found to be active against bacteria. The compounds 6a(1), 6b(3), and 6a(3) show a significant analgesic activity. Synthesized compounds also screened for anthelmintic activity against Pheretima posthuma. Compounds 6a(1), 6b(1), and 6b(3) show significant anthelmintic activity.

13.
Nepal J Ophthalmol ; 4(1): 162-4, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22344014

RESUMO

INTRODUCTION: Hooch blindness following consumption of adulterated alcohol has been known for centuries. OBJECTIVE: To study cases of mass alcohol intoxication followed by Hooch blindness in eastern India. MATERIALS AND METHODS: Ten patients of toxic amblyopia collected from a community mass intoxication following consumption of adulterated alcohol were studied. The parameters studied were the findings of ocular examination, applanation tonometry, automated perimetry and visual-evoked potential (VEP). As a part of the special investigations fundus photography and OCT were done. Routine blood examination, fasting lipid profile, postprandial blood sugar estimation were done . All patients were treated with injections of methyl prednisolone and Hydroxy cobalamine, antioxidants and local neuro-protective agents. RESULTS: Along with diminished vision (from NPL to 3/60), marked pallor of the disc without any other retinal change were noted. The amplitude on VEP was significantly reduced. However, visual improvement (up to 6/18) in 7 patients was observed within 6 weeks of treatment. CONCLUSION: Hooch blindness in India can be prevented by creating awareness among the target population and reducing the cost of country liquor.


Assuntos
Cegueira/etiologia , Etanol/intoxicação , Doenças do Nervo Óptico/induzido quimicamente , Adulto , Idoso , Cegueira/diagnóstico , Diagnóstico Diferencial , Potenciais Evocados Visuais/efeitos dos fármacos , Humanos , Pessoa de Meia-Idade , Doenças do Nervo Óptico/complicações , Doenças do Nervo Óptico/diagnóstico , Prognóstico , Tomografia de Coerência Óptica
14.
Talanta ; 83(5): 1482-6, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21238740

RESUMO

Polypyrrole nanoparticles of desired structure have been synthesized through simple micelle technique. It is then grafted with functionalized silica gel to develop a novel organic-inorganic hybrid material. The role of dimethyl dichloro silane (coupling agent) in grafting is demonstrated. The nanoparticles are characterized by TEM, SEM and TGA. Grafting reactions are evaluated by spectral (FTIR) analysis and chemical test. The Cr(VI) binding behavior of the composite is studied in various pH of the medium. The selectivity in binding Cr(VI) is monitored. The metal ion adsorption capacity and surface area of the material are found to be 38 mg/g and 235 m(2)/g, respectively.


Assuntos
Cromo/química , Nanopartículas/química , Polímeros/síntese química , Pirróis/síntese química , Silanos/química , Sílica Gel/química , Reagentes de Ligações Cruzadas/química , Microscopia Eletrônica de Varredura , Estrutura Molecular , Polímeros/química , Pirróis/química
15.
J Young Pharm ; 2(2): 169-72, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21264121

RESUMO

Schiff bases of isatin with aminothiazole, its N-mannich bases and Spiro isatin derivatives were synthesized. Their chemical structures were confirmed by Infrared, 1H-Nuclear Magnetic Resonance data and elemental analysis. Antimicrobial evaluation was performed by the agar diffusion method against four pathogenic bacteria and two pathogenic fungi. Anti-inflammatory activity was tested by carragenin-induced rat paw edema and compounds were evaluated for analgesic action by the acetic acid-induced writhing method; Compounds Aa, Ab and A5, A6 were found to be active against bacteria and fungi. The compounds A3, A6, Aa and Ab showed anti-inflammatory activity, having a percentage protection value of 34.69, 32.65, 38.77 and 36.73 as compared with that of indomethacin, with % protection of 46.93. Similarly, the compounds Aa, Ab and A6 showed analgesic activity, with % protection of 67.51, 64.78 and 49.81 as compared with the standard with % protection of 79.56.

16.
J Basic Microbiol ; 48(6): 521-5, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18792057

RESUMO

The present paper compares the arsenic removal capacities of three bacterial strains namely, Ralstonia eutropha MTCC 2487, Pseudomonas putida MTCC 1194 and Bacillus indicus MTCC 4374 form wastewater (simulated acid mine drainage) containing arsenic (As(III):As(V)::1:1), Fe, Mn, Cu and Zn in the concentration of 15 mg/l, 10 mg/l, 2 mg/l, 5 mg/l and 10 mg/l respectively, in bulk liquid phase. Growth patterns of these bacteria in presence of arsenic in solution as well as under starvation have also been investigated as the acid mine drainage normally does not contain organic carbon and also contains high arsenic. At the nutrient broth concentration of 1.25 g/l and in presence of 15 mg/l arsenic sufficient growth of these strains have been observed. However, growth of Ralstonia eutropha MTCC 2487 has been found slightly more than Pseudomonas putida MTCC 1194 and Bacillus indicus MTCC 4374. Arsenic removal capacities of Ralstonia eutropha MTCC 2487, Pseudomonas putida MTCC 1194 and Bacillus indicus MTCC 4374 from simulated acid mine drainage are approximately 67%, 60% and 61% respectively. It has also been observed that arsenic concentration of 15 mg/l prolongs the stationary phase of these strains. pH and temperature for the above studies have been maintained at 7.1 +/- 0.1 and 29 +/- 1 degrees C, respectively.


Assuntos
Arsênio/metabolismo , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Poluentes Químicos da Água/metabolismo , Mineração , Purificação da Água/métodos
18.
J Hazard Mater ; 150(3): 695-702, 2008 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-17574333

RESUMO

This paper presents the observations of the study on arsenic removal from a contaminated ground water (simulated) by adsorption onto Fe(3+) impregnated granular activated carbon (GAC-Fe). Fe(2+), Fe(3+) and Mn(2+) have also been considered along with arsenic species in the water sample. Similar study has also been done with untreated granular activated carbon (GAC) for comparison. The effects of adsorbent dose, particle size of adsorbent and initial arsenic concentration on the removal of As(T), As(III), As(V), Fe(2+), Fe(3+) and Mn(2+) have been discussed. Under the experimental conditions, the optimum adsorbent doses for GAC-Fe and GAC have been found to be 8 g/l and 24 g/l, respectively with an agitation time of 15 h. Particle size of the adsorbents (both GAC and GAC-Fe) has shown negligible effect on the removal of arsenic and Fe species. However, for Mn removal the effect of adsorbent particle size is comparatively more. Percentage removal of As(T), As(V) and As(III) increase with the decrease in initial arsenic concentration (As(0)). However, the increase in percentage removal of all the arsenic species with decrease in As(0) are less for higher value of As(0) (3000-500 ppb) than those of the lower value of As(0) (500-10 ppb). The % removal of As(T), As(III), As(V), Fe, and Mn were approximately 95%, 92.4%, 97.6%, 99% and 41.2%, respectively when 8 g/l GAC-Fe was used at the As(0) value of 200 ppb. However, for GAC these values were approximately 55.5%, 44%, 71%, 98% and 97%. The pH and temperature of the study were 7+/-0.1 and 30+/-1 degrees C, respectively.


Assuntos
Arsênio/química , Carbono/química , Ferro/química , Manganês/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Cloretos , Compostos Férricos/química , Tamanho da Partícula , Abastecimento de Água
19.
J Hazard Mater ; 153(1-2): 136-45, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-17890001

RESUMO

The present paper describes the observations on the treatment of arsenic contaminated synthetic industrial effluent in a bio-column reactor. Ralstonia eutropha MTCC 2487 has been immobilized on the granular activated carbon (GAC) bed in the column reactor. The synthetic water sample containing As(T) (As(III):As(V)=1:1), Fe, Mn, Cu and Zn at the initial concentrations of 25, 10, 2, 5, 10 ppm, respectively, was used. Concentrations of all the elements have been found to be reduced below their permissible limits in the treated water. The significant effect of empty bed contact time (EBCT) and bed height on the arsenic removal was observed in the initial stage. However, after some time of operation (approximately 3-4 days) no such effect was observed. Removal of As(III) and As(V) was almost similar after approximately 2 days of operation. However, at the initial stage As(V) removal was slightly more than that of As(III). In absence of washing, after approximately 4-5 days of operation, the bio-column reactor was observed to act as a GAC column reactor based on physico-chemical adsorption. Like arsenic, the percent removals of Fe, Mn, Cu and Zn also attained minimum after approximately 1 day and increased significantly to the optimum value within 3-4 days of operation. Dissolved oxygen (DO) has been found to decrease along with the increasing bed height from the bottom. The pH of the solution in the reactor has increased slightly and oxidation-reduction potential (ORP) has decreased with the time of operation.


Assuntos
Arsênio/metabolismo , Reatores Biológicos , Ralstonia/metabolismo , Poluentes Químicos da Água/metabolismo , Resíduos Industriais , Metais Pesados/metabolismo , Mineração , Eliminação de Resíduos Líquidos/métodos
20.
J Hazard Mater ; 153(1-2): 588-99, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-17980486

RESUMO

This paper presents the observations on the bio-removal of arsenic from contaminated water by using Ralstonia eutropha MTCC 2487 and activated carbon in a batch reactor. The effects of agitation time, pH, type of granular activated carbon (GAC) and initial arsenic concentration (As(o)) on the % removal of arsenic have been discussed. Under the experimental conditions, optimum removal was obtained at the pH of 6-7 with agitation time of 100 h. The % removal of As(T) increased initially with the increase in As(o) and after attaining the maximum removal (~86%) at the As(o) value of around 15 ppm, it started to decrease. Simultaneous adsorption bioaccumulation (SABA) was observed, when fresh GAC was used as supporting media for bacterial immobilization. In case of SABA, the % removal of As(III) was almost similar (only ~1% more) to the additive values of individual removal of As(III) obtained by only adsorption and only bio-adsorption. However, for As(V) the % removal was less (~8%) than the additive value of the individual % removals obtained by only adsorption and bio-adsorption. Percentage removal of Fe, Mn, Cu and Zn were 65.17%, 72.76%, 98.6% and 99.31%, respectively. Maximum regeneration (~99.4%) of the used bio-adsorbent was achieved by the treatment with 5NH(2)SO(4) followed by 1N NaOH and 30% H(2)O(2) in HNO(3). The fitness of the isotherms to predict the specific uptake for bio-adsorption/accumulation process has been found to decrease in the following order: Temkin isotherm>Langmuir isotherm>Freundlich isotherm. For the adsorption process with fresh GAC the corresponding order is Freundlich isotherm>Langmuir isotherm>Temkin isotherm for As(V) and As(T). However, for As(III) it was Langmuir>Temkin>Freundlich.


Assuntos
Arsênio/química , Carbono/química , Cupriavidus necator/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Metais Pesados/química , Espectroscopia de Infravermelho com Transformada de Fourier
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