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1.
Indian J Med Res ; 148(5): 496-502, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30666976

RESUMO

Vitamin A deficiency (VAD) among 1-5 yr old children is reported to be widely prevalent in Southeast Asia and some parts of Africa. It is the leading cause of preventable blindness in young children in the low-income countries in the world. Children even with milder signs of VAD have higher risk of morbidity and mortality. Inadequate dietary intakes of vitamin A with poor bioavailability associated with frequent infections are the primary contributory factors. Currently available approaches to control VAD are ensuring adequate intakes of vitamin A in daily diets, fortification of foods consumed regularly particularly among the low-income communities and periodic administration of massive dose of vitamin A supported by public health interventions and reinforced by behaviour change communication. Under the National Programme in India, six monthly administration of mega dose of vitamin A to 6-59 month old children has been implemented since 1970, to prevent particularly blindness due to VAD and control hypovitaminosis A. Despite inadequate coverage and poor implementation of the programme, blindness due to VAD in children has almost disappeared, though subclinical VAD is still widely prevalent. Based on the results of meta-analysis of eight trials, which indicated that vitamin A supplementation to children aged 6-59 months reduced child mortality rates by about 23 per cent, the World Health Organization made a strong recommendation that in areas with VAD as a public health problem, vitamin A supplementation should be given to infants and children of 6-59 months of age as a public health intervention to reduce child morbidity and improve child survival. At present, in India, there is a need for change in policy with respect to the national programme to opt for targeted instead of universal distribution. However, NITI (National Institution for Transforming India) Aayog, which formulates policies and provides technical support to the Government of India, recommends strengthening of the National Programme for control of VAD through six monthly vitamin A supplementation along with health interventions. Eventually, the goal is to implement food based and horticulture-based interventions harmonizing with public health measures, food fortification and capacity building of functionaries for elimination of VAD.


Assuntos
Cegueira , Programas Nacionais de Saúde/organização & administração , Deficiência de Vitamina A , Vitamina A/farmacologia , Cegueira/etiologia , Cegueira/prevenção & controle , Criança , Suplementos Nutricionais , Humanos , Índia/epidemiologia , Necessidades Nutricionais , Prevalência , Deficiência de Vitamina A/complicações , Deficiência de Vitamina A/epidemiologia , Deficiência de Vitamina A/terapia , Vitaminas/farmacologia
2.
Int J Phytoremediation ; 19(6): 537-544, 2017 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-27936895

RESUMO

Finding appropriate rooftop vegetation may improve the quality of runoff from green roofs. Portulaca grandiflora was examined as possible vegetation for green roofs. Green roof substrate was found to have low bulk density (360.7 kg/m3) and high water-holding capacity (49.4%), air-filled porosity (21.1%), and hydraulic conductivity (5270 mm/hour). The optimal substrate also supported the growth of P. grandiflora with biomass multiplication of 450.3% and relative growth rate of 0.038. Phytoextraction potential of P. grandiflora was evaluated using metal-spiked green roof substrate as a function of time and spiked substrate metal concentration. It was identified that P. grandiflora accumulated all metals (Al, Cd, Cr, Cu, Fe, Ni, Pb, and Zn) from metal-spiked green roof substrate. At the end of 40 days, P. grandiflora accumulated 811 ± 26.7, 87.2 ± 3.59, 416 ± 15.8, 459 ± 15.6, 746 ± 20.9, 357 ± 18.5, 565 ± 6.8, and 596 ± 24.4 mg/kg of Al, Cd, Cr, Cu, Fe, Ni, Pb and Zn, respectively. Results also indicated that spiked substrate metal concentration strongly influenced metal accumulation property of P. grandiflora with metal uptake increased and accumulation factor decreased with increase in substrate metal concentration. P. grandiflora also showed potential to translocate all the examined metals with translocation factor greater than 1 for Al, Cu, Fe, and Zn, indicating hyperaccumulation property.


Assuntos
Alumínio/metabolismo , Metais Pesados/metabolismo , Portulaca/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Índia , Portulaca/crescimento & desenvolvimento , Chuva/química
3.
Ecotoxicol Environ Saf ; 118: 177-182, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25938698

RESUMO

The discarded materials from different sources can be utilized as effective materials in wastewater remediation. This proposed study was aimed mainly to investigate the possibility of Effective Microorganisms based compost (EMKC), which is derived from the kitchen solid waste, as a non-conventional low cost adsorbent for the removal of malachite green from aqueous solution. Batch experiments were carried out to evaluate the optimum operating parameters like pH (2-9), initial dye concentration (50-1000mg/L), adsorbent particle size (0.6-2.36mm) and adsorbent dosage (2-12g/L). EMKC recorded maximum uptake of 136.6mg/g of MG at pH 8, initial dye concentration 1000mg/L, adsorbent particle size 1.18mm and adsorbent dosage 4g/L. Two and three parameter adsorption models were employed to describe experimental biosorption isotherm data. The results revealed that the Sips model resulted in better fit than other models. The pseudo-first and -second order models were applied to describe kinetic data, of which the pseudo-second order described experimental data better with high correlation coefficient. This investigation suggested that EMKC could be an effective and low cost material for the removal of malachite green dye from aqueous solution.


Assuntos
Bactérias/metabolismo , Eliminação de Resíduos/métodos , Corantes de Rosanilina/metabolismo , Resíduos Sólidos/análise , Adsorção , Tamanho da Partícula , Eliminação de Resíduos/instrumentação , Solo/química
4.
J Environ Manage ; 160: 283-96, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26143501

RESUMO

For the past few decades, biosorption has been widely investigated for the removal of different contaminants in aqueous media. A number of biomasses of different genre have been identified to possess good biosorption capacity. Insights into biosorption mechanisms have been provided by various researchers in order to develop a fundamental scientific understanding of the biosorption process. However, biosorption has not been employed widely for its large-scale commercial applications. The key factors that affect the growth and evolution of biosorption as a practical technology for decontamination of wastewaters include, (1) lack of investigations on multi-component solutions and wastewaters with complex matrix effects, (2) incomplete understanding of physico-chemical characteristics of biomasses of different types, (3) lack of studies to improve the performance of biosorbents through surface functionalization, and (4) non-integration of biosorption in wastewater/water treatment plants. This critical review aims to identify and discuss the practical limitations of biosorption and provide future research directions to make biosorption a technologically viable process with emphasis on selection and modification of biomasses to suit desired treatment applications, identify appropriate operation modes for large-scale applications of biosorption, and perform techno-economic evaluation of overall biosorption processes.


Assuntos
Metais Pesados/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Biodegradação Ambiental , Biomassa , Descontaminação , Humanos
5.
Artigo em Inglês | MEDLINE | ID: mdl-24844899

RESUMO

In this study, in situ hybrid sand filters were designed to remove dissolved and suspended contaminants from eutrophic pond. Currently, there are no attempts made to eradicate dissolved as well as suspended contaminants from eutrophic water system in a single step. Monitoring studies revealed that examined pond contain high chlorophyll-a content (101.8 µg L(-1)), turbidity (39.5 NTU) and total dissolved solids concentration (0.04 g L(-1)). Samples were further exposed to extensive water quality analysis, which include examining physicochemical parameters (pH, conductivity, total dissolved solids, salinity, turbidity and chlorophyll-a), metals (Na, K, Ca, Mg, Al, Fe, Cu, Cd, Pb, Zn, Cr, and Ni) and anions (NO3, NO2, PO4, SO4, Cl, F and Br). To tackle pollutants, filtration system was designed to comprise of several components including fine sand, coarse sand/sorbent mix and gravel from top to bottom loaded in fiberglass tanks. All the filters (activated carbon, Sargassum and zeolite) completely removed algal biomass and showed potential to decrease pH during entire operational period of 20 h at 120 L h(-1). To examine the efficiency of filters in adverse conditions, the pond water was spiked with heavy metals (Cu, Cd, Pb, Zn, Cr, and Ni). Of the different filter systems, Sargassum-loaded filter performed exceedingly well with concentrations of heavy metals never exceeded the Environmental protection agency regulations for freshwater limits during total operational period. The total uptake capacities at the end of the fifth event were 24.9, 20.5, 0.58, 5.2, 0.091 and 2.8 mg/kg for Cr, Ni, Cu, Zn, Cd and Pb, respectively.


Assuntos
Recuperação e Remediação Ambiental/métodos , Eutrofização , Poluentes da Água/química , Adsorção , Carbono/química , Clorofila/análise , Clorofila A , Filtração/métodos , Água Doce/análise , Metais/análise , Metais/química , Lagoas , Sargassum/química , Dióxido de Silício/química , Poluentes da Água/análise , Zeolitas/química
6.
Health Care Women Int ; 35(10): 1148-61, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23611111

RESUMO

Due to high cervical cancer rates and limited research on human papillomavirus (HPV) vaccine acceptability in India, the research team examined parental attitudes toward HPV vaccines. Thirty-six interviews with parents were conducted to assess sexually transmitted infection (STI)-related knowledge and HPV-specific vaccine awareness and acceptability. Despite limited knowledge, parents had positive views toward HPV vaccines. Common barriers included concerns about side effects, vaccine cost, and missing work to receive the vaccine. Parents were strongly influenced by health care providers' recommendations. Our findings suggest that addressing parental concerns, health worker training and polices, and efforts to minimize cost will be central to successful HPV vaccine implementation.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Pais , Aceitação pelo Paciente de Cuidados de Saúde , Neoplasias do Colo do Útero/prevenção & controle , Adulto , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Infecções Sexualmente Transmissíveis/prevenção & controle , Fatores Socioeconômicos , Inquéritos e Questionários , Vacinação/estatística & dados numéricos , Adulto Jovem
7.
Water Sci Technol ; 68(6): 1280-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24056424

RESUMO

One of the most effective mitigative approaches to eutrophication is the reduction of nutrient loading into water bodies. Bioremediation presents an economically viable and ecologically sustainable technology to nutrient pollution control taking advantage of the remarkable ability of plants and their associated microbial community to assimilate and remove nutrients from the environment. In this study, four emergent macrophytes (Cyperus haspan, Pandanus amaryllifolius, Pontederia cordata and Thalia geniculata) and two floating plants (Hygroryza aristata and Pistia stratiotes) were deployed in bank-side treatment beds and comparatively assessed for their remediative capabilities for nutrient control. P. stratiotes exhibited the highest removal efficiency for both nitrate and phosphate among the six plant species studied. Emergent macrophytes, P. amaryllifolius, C. haspan and P. cordata, were also found to be highly effective in nutrient uptake exhibiting removal efficiencies up to 100%. With the exception of T. geniculata, depletion of nutrients as a result of plant uptake significantly impeded the natural colonization of algae invariably leading to improvements in water quality in terms of turbidity and pH. Suppression of algae proliferation by T. geniculata was not preceded by a reduction in nutrient concentrations suggesting that T. geniculata may be directly inhibiting algal growth through allelopathy.


Assuntos
Magnoliopsida/metabolismo , Nitratos/metabolismo , Fosfatos/metabolismo , Poluentes da Água/metabolismo , Biodegradação Ambiental , Clorofila/metabolismo , Clorofila A , Eutrofização
8.
Artigo em Inglês | MEDLINE | ID: mdl-23947707

RESUMO

Laboratory batch and column experiments were carried out to examine the efficiency of algal-based treatment technique to clean-up wastewaters emanating from inductively coupled plasma-optical emission spectrometry (ICP-OES). Chemical characterization revealed the extreme complexity of the wastewater, with the presence of 14 different metals under very low pH (pH = 1.1), high conductivity (6.98 mS/cm), total dissolved solid (4.46 g/L) and salinity (3.77). Batch experiments using Sargassum biomass indicated that it was possible to attain high removal efficiencies at optimum pH of 4.0. Efforts were also made to continuously treat ICP-OES wastewater using up-flow packed column. However, swelling of Sargassum biomass leads to stoppage of column. To address the problem, Sargassum was mixed with sand at a ratio of 40: 60 on volume basis. Remarkably, the hybrid Sargassum-sand sorbent showed very high removal efficiency towards multiple metal ions with the column able to operate for 11 h at a flow rate of 10 mL/min. Metal ions such as Cu, Cd, and Pb were only under trace levels in the treated water until 11 h. The results of the treatment process were compared with trade effluent discharge standards. Further the process evaluation and cost analysis were presented.


Assuntos
Metais Pesados/metabolismo , Sargassum/metabolismo , Espectrofotometria Atômica , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Adsorção , Biomassa , Dióxido de Silício/química , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/instrumentação
9.
Front Cardiovasc Med ; 10: 1308173, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38288054

RESUMO

Introduction: Statins remain the first-line treatment for secondary prevention of cardiovascular (CV) events, with lowering of low-density lipoprotein cholesterol (LDL-C) being their therapeutic target. Although LDL-C reduction significantly lowers CV risk, residual risk persists, even in patients with well-controlled LDL-C; thus, statin add-on agents that target pathways other than LDL-C, such as the omega-3 fatty acid eicosapentaenoic acid, may help to further reduce persistent CV risk in patients with established CV disease. Methods: This narrative review examines the contemporary literature assessing intermediate- and long-term event rates in patients with established CV disease treated with statins. Results: CV event rates among patients treated with statins who have established CV disease, including coronary artery disease, cerebrovascular disease, or peripheral arterial disease, accumulate over time, with a cumulative incidence of CV events reaching up to approximately 40% over 10 years. Recurrent stroke occurs in up to 19% of patients seven years after a first cerebrovascular event. Repeat revascularization and CV-related death occurs in up to 38% and 33% of patients with peripheral artery disease after three years, respectively. Discussion: Additional treatment strategies, such as eicosapentaenoic acid, are needed to reduce persistent CV risk in patients with established CV disease treated with statins.

10.
J Health Popul Nutr ; 29(4): 327-38, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21957671

RESUMO

The prevalence of chronic energy deficiency (CED) among one-third of the Indian population is attributed to inadequacy of consumption of nutrients. However, considering the complexity of diets among Indians, the relationship between a particular dietary pattern and the nutritional status of the population has not been established so far. A community-based cross-sectional study was undertaken to assess estimates, at district level, of diet and nutritional status in Orissa State, India. Factor analysis was used for exploring the existence of consumption pattern of food and nutrients and their relationship with the nutritional status of rural adult population. Data on 2,864 adult men and 3,525 adult women in Orissa state revealed that there exists six patterns among food-groups explaining 59% of the total variation and three patterns among nutrients that explain 73% of the total variation among both adult men and women. The discriminant function analysis revealed that, overall, 53% of the men were correctly classified as either with chronic energy deficiency (CED) or without CED. Similarly, overall, 54% of the women were correctly classified as either with CED or without CED. The sensitivity of the model was 65% for both men and women, and the specificity was 46% and 41% respectively for men and women. In the case of classification of overweight/obesity, the prediction of the model was about 75% among both men and women, along with high sensitivity. Using factor analysis, the dietary patterns were identified from the food and nutrient intake data. There exists a strong relationship between the dietary patterns and the nutritional status of rural adults. These results will help identify the community people with CED and help planners formulate nutritional interventions accordingly.


Assuntos
Comportamento Alimentar , Estado Nutricional , Saúde da População Rural , Adolescente , Adulto , Idoso , Estudos Transversais , Ingestão de Energia , Análise Fatorial , Feminino , Humanos , Índia/epidemiologia , Masculino , Desnutrição/epidemiologia , Pessoa de Meia-Idade , Sobrepeso/epidemiologia , Análise de Componente Principal , Adulto Jovem
11.
Environ Monit Assess ; 182(1-4): 47-60, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21229305

RESUMO

Investigation has been made to identify groundwater vulnerability to pollution by using geoelectric and hydrochemical investigations in an important industrial town Mettur located in Tamilnadu state of India. Schlumberger vertical electric soundings were carried out in 23 locations and groundwater samples collected from bore wells in the same locations. The resistivity value with <20 Ωm up to a depth of 36 m indicate contamination of groundwater in areas influenced by sewages from industries, domestic and agricultural practices in the central and southern part of the study area. The calculated specific conductance was noted higher than EC in central and southern part of the study area with low resistivity indicating the contaminated nature of groundwater. Concentrations of Ca, Na, Mg and K along with Cl, HCO(3), SO(4) and NO(3) were higher in certain locations when compared with WHO and ISI standards. The facies concept demarcated four groups based on the nature of groundwater contamination. The trace elements Fe and Pb were higher in locations confined to industrial zones and Zn and Cu were within the prescribed limit in all the samples.


Assuntos
Monitoramento Ambiental/métodos , Água Subterrânea/química , Indústrias/estatística & dados numéricos , Poluentes Químicos da Água/análise , Sedimentos Geológicos/química , Índia , Medição de Risco
12.
Cancer Epidemiol Biomarkers Prev ; 18(5): 1373-8, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19423518

RESUMO

OBJECTIVES: Our aim was to determine if (1) Hybrid Capture 2 and a PCR-based method were comparable for detection of high-risk human papillomavirus (HPV) clinician-collected and self-collected samples were equally efficient to detect HPV and cervical cancer precursor lesions, and (3) if participation rates improved with home-based versus clinic-based self collection. METHODS: Samples were selected from women participating in a cervical cancer screening study according to HPV, visual inspection with acetic acid, or Pap smear screening results. From 432 of 892 selected women, split sample aliquots were tested for HPV DNA using both the Hybrid Capture 2 assay and the Roche prototype line blot assay. Women from a subset of villages were recruited at two separate time points for clinic-based self-collection and home-based self-collection, and participation rates were compared. RESULTS: Pairwise agreement between self- and clinician-collected samples was high by both Hybrid Capture 2 (90.8% agreement, kappa = 0.7) and PCR (92.6% agreement, kappa = 0.8), with significantly increased high-risk HPV detection in clinician-collected specimens (McNemar's P < 0.01). Ability to detect precursor lesions was highest by PCR testing of clinician-collected samples and lowest by Hybrid Capture 2 testing of self-collected samples (11 of 11 and 9 of 11 cases of cervical intraepithelial neoplasia grade 2/3 and cancer detected, respectively). Participation in home-based screening was significantly higher than clinic-based screening (71.5% and 53.8%, respectively; P < 0.001) among women ages 30 to 45 years. CONCLUSION: The combination of improved screening coverage and a high single test sensitivity afforded by HPV DNA testing of home-based self-collected swabs may have a greater programmatic effect on cervical cancer mortality reduction compared with programs requiring a pelvic exam.


Assuntos
Teste de Papanicolaou , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Autocuidado , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal/métodos , Adulto , DNA Viral/análise , Detecção Precoce de Câncer , Feminino , Humanos , Índia , Pessoa de Meia-Idade , Papillomaviridae/isolamento & purificação , Reação em Cadeia da Polimerase , População Suburbana
13.
J Nutr Elder ; 28(3): 301-12, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21184372

RESUMO

The prevalence of chronic energy deficiency (CED = BMI < 18.5) among older adults (≥60 years) was assessed utilizing a large data set from a community-based cross-sectional study carried out in severely drought-affected rural areas of India. Anthropometric measurements (height, weight) were recorded for a total of 3,147 individuals, and a family diet survey (one day 24-hour recall) was carried out in 1,900 households (HHs) from 190 villages. As per the Body Mass Index (BMI), the prevalence of CED was 51.1% and 48.5% among older males and females, respectively. It was higher (p < 0.001) in the 70 years and older age group compared with those aged 60-69 years. In general, the prevalence of CED was higher (p < 0.001) for those belonging to the Scheduled Caste and Scheduled Tribes, for HHs of agricultural and non-agricultural labor, and for marginal or small farmers. The prevalence of CED was relatively lower (p > 0.05) among older adults during the drought period compared with the non-drought period. This could be attributed to intervention programs initiated by the government of India during the drought. These findings illustrate the value of intervention programs in drought-afflicted and drought-prone areas and underscore the importance of monitoring the nutritional status of older adults so that appropriate programs can be initiated as needed.


Assuntos
Secas , Ingestão de Energia/fisiologia , Desnutrição/epidemiologia , Estado Nutricional , Idoso , Índice de Massa Corporal , Estudos Transversais , Inquéritos sobre Dietas , Feminino , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , População Rural
14.
Indian J Public Health ; 53(1): 41-3, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19806829

RESUMO

Infant and child mortality, including deaths due to vaccine-preventable diseases, remains high in the rural areas of India. In Andhra Pradesh, the immunisation coverage of children in the 12-23 month age-group has progressively declined to 43%, indicating the immediate need for taking corrective steps. The Rural Effective Affordable Comprehensive Healthcare (REACH) project, based on the health metrics strategy was initiated to improve childhood immunisation coverage. Information on the immunisation status of children was recorded and each child was tracked with the help of a computerised database to provide timely immunisation. The health metrics strategy resulted in complete immunisation (96%) of all the 698 children in the 12-23 month age-group residing in the villages of the Medchal Mandal in the year 2007, as compared to 43% reported by the National Family Health Survey-3. Action oriented health metrics coupled with information technology can thereby improve childhood immunisation significantly.


Assuntos
Programas de Imunização/métodos , População Rural , Agentes Comunitários de Saúde , Humanos , Esquemas de Imunização , Índia , Lactente , Sistemas Computadorizados de Registros Médicos
15.
Biotechnol Adv ; 26(3): 266-91, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18353595

RESUMO

Biosorption is a technique that can be used for the removal of pollutants from waters, especially those that are not easily biodegradable such as metals and dyes. A variety of biomaterials are known to bind these pollutants, including bacteria, fungi, algae, and industrial and agricultural wastes. In this review, the biosorption abilities of bacterial biomass towards dyes and metal ions are emphasized. The properties of the cell wall constituents, such as peptidoglycan, and the role of functional groups, such as carboxyl, amine and phosphonate, are discussed on the basis of their biosorption potentials. The binding mechanisms, as well as the parameters influencing the passive uptake of pollutants, are analyzed. A detailed description of isotherm and kinetic models and the importance of mechanistic modeling are presented. A systematic comparison of literature, based on the metal/dye binding capacity of bacterial biomass under different conditions, is also provided. To enhance biosorption capacity, biomass modifications through chemical methods and genetic engineering are discussed. The problems associated with microbial biosorption are analyzed, and suitable remedies discussed. For the continuous treatment of effluents, an up-flow packed column configuration is suggested and the factors influencing its performance are discussed. The present review also highlights the necessity for the examination of biosorbents within real situations, as competition between solutes and water quality may affect the biosorption performance. Thus, this article reviews the achievements and current status of biosorption technology, and hopes to provide insights into this research frontier.


Assuntos
Bactérias/metabolismo , Poluentes Ambientais/metabolismo , Desintoxicação por Sorção , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/farmacocinética , Adsorção , Bactérias/genética , Biomassa , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
16.
Bioresour Technol ; 99(8): 2864-71, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17664064

RESUMO

The amino acid fermentation industry waste, Corynebacterium glutamicum, has been found to possess excellent biosorption capacity towards methylene blue (MB). Due to practical difficulties in solid-liquid separation and biomass regeneration, C. glutamicum was immobilized in a polysulfone matrix. The pH edge experiments revealed that neutral or alkaline pH values favored MB biosorption. Isotherm experiments indicated that C. glutamicum, when in immobilized state, exhibited slightly inferior dye uptake compared to free biomass. Also considering the two forms, immobilized biomass took a long time to attain equilibrium. An attempt to identify the diffusion limitations in immobilized beads was successful, with the Weber-Morris model clearly indicating intraparticle as the rate controlling step. Regeneration of the free biomass was not possible as it tended to become damaged under strong acidic conditions. On the other hand, immobilized biomass performed well with 99% desorption of MB from the biosorbent with the aid of 0.1 mol/l HCl. The immobilized biomass was also successfully regenerated and reused for three cycles without significant loss in sorption capacity. An up-flow packed column loaded with immobilized biomass was employed for the removal of MB. The column performed well in the biosorption of MB, exhibiting a delayed and favorable breakthrough curve with MB uptake and % removal of 124 mg/g biomass and 70.1%, respectively.


Assuntos
Células Imobilizadas/fisiologia , Corynebacterium glutamicum/fisiologia , Resíduos Industriais , Azul de Metileno/isolamento & purificação , Polímeros , Sulfonas , Biomassa , Fermentação , Concentração de Íons de Hidrogênio , Modelos Biológicos , Soluções , Água
17.
Bioresour Technol ; 99(13): 5778-85, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18060770

RESUMO

This work focused on the development of a practical biosorbent for the decolorization of textile effluents. The fermentation waste, Corynebacterium glutamicum biomass, when decarboxylated and immobilized in polysulfone matrix performed well in decolorization of simulated reactive dye bath effluent comprised of four different reactive dyes and other auxiliary chemicals. The regeneration of polysulfone-immobilized C. glutamicum was successful with the aid of 0.01 M NaOH as the eluant, which enabled the biosorbent to maintain consistent decolorization efficiency for up to 25 cycles. An up-flow packed column loaded with polysulfone-immobilized biomass performed well in the continuous treatment of Remazol effluent. Samples collected after 14 h of column operation revealed almost zero color and TOC. The column was also able to decrease the TDS level from 55,840 to 33,480 mg/L. Column regeneration experiments revealed that the biosorbent was able to continuously treat Remazol effluent over ten cycles, with more than 90.6% decolorization efficiency.


Assuntos
Corantes/análise , Corynebacterium glutamicum/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Antraquinonas/análise , Materiais Biocompatíveis/análise , Biodegradação Ambiental , Cor , Naftalenossulfonatos
18.
J Colloid Interface Sci ; 320(1): 22-9, 2008 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18221943

RESUMO

Banana pith was used as precursor material to prepare carbon with and without porogens. Characterization of the carbons showed higher BET surface area (1285 m2/g) for ZnCl2-treated carbon, comparatively. Adsorption experiments were conducted to study the removal of 2,4-dichlorophenol (DCP) from aqueous solutions using the carbons under varying experimental conditions. Decrease in pH increased the percentage removal. All the carbons studied showed greater percentage of DCP removal with decrease in the initial concentration of DCP. Kinetic studies showed that the adsorption of DCP on the carbons was a rapid process. Nonlinear forms of pseudo-first-order and pseudo-second-order models were used to fit the experimental data. Among these the pseudo-first-order model described the data with high correlation coefficients and low percentage error values. Four nonlinear isotherm models including the Langmuir, Freundlich, Toth, and Sips were used to analyze the experimental DCP isotherms under different pH (2-4) conditions. Adsorption capacities (Qmax) from the Langmuir model were found to be 129.4, 67.7, and 49.9 mg/g for ZnCl2-treated, KOH-treated, and porogen-free carbon, respectively, at pH 2. From desorption studies it seemed that chemisorption played a major role in the adsorption process. The results indicated that ZnCl2-treated carbon could effectively remove phenols from wastewater.


Assuntos
Carbono/química , Clorofenóis/isolamento & purificação , Musa/química , Caules de Planta/química , Adsorção , Agricultura , Resíduos Industriais , Cinética , Microscopia Eletrônica de Varredura , Modelos Teóricos , Porosidade , Difração de Raios X
19.
Ecotoxicol Environ Saf ; 71(1): 166-71, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17692914

RESUMO

In this study, the effects of several ionic liquids and traditional organic solvents on the growth of the green microalga, Selenastrum capricornutum, were investigated. The toxicities were strongly related to the incubation time and chemical structures of the ionic liquids. The toxicities of tetrabutylphosphonium and tetrabutylammonium containing bromide anion were observed to decrease when the incubation time was raised from 48 to 96 h. Conversely, the toxicities of 1-butyl-3-methylimidazolium and 1-butyl-3-methylpyridinium containing bromide anion were found to increase with increasing incubation time. Of the ionic liquids tested, 1-butyl-1-methylpyrrolidinium bromide was found to be the least toxic, which is similar in toxicity level of dimethylformamide. In general, the toxicities of the ionic liquids were estimated to be two and four orders of magnitude greater than those of the organic solvents examined, although ionic liquids are being considered as green solvents.


Assuntos
Eucariotos/efeitos dos fármacos , Líquidos Iônicos/toxicidade , Compostos Orgânicos/toxicidade , Solventes/toxicidade , Poluentes Químicos da Água/toxicidade , Relação Dose-Resposta a Droga , Líquidos Iônicos/química , Estrutura Molecular , Compostos Orgânicos/química , Solventes/química , Poluentes Químicos da Água/química
20.
J Hazard Mater ; 153(1-2): 478-86, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-17913354

RESUMO

Competition of Reactive red 4 (RR4), Reactive orange 16 (RO16) and Basic blue 3 (BB3) during biosorption of Reactive blue 4 (RB4) by polysulfone-immobilized protonated Corynebacterium glutamicum (PIPC) was investigated in batch and column mode of operations. Through potentiometric titrations, and with the aid of proton-binding model, carboxyl, phosphonate and amine were identified as functional groups of PIPC, with apparent pK(a) values of 3.47+/-0.05, 7.08+/-0.07 and 9.90+/-0.05 mmol/g, respectively. Since reactive dyes release dye anions (ROSO(3)(-)) in solutions, the positively charged amine groups were responsible for biosorption. PIPC favored biosorption at pH 3 when RB4 was studied/used as single-solute; while the presence of RR4 and RO16 severely affected the RB4 biosorption. When present as a single-solute, PIPC recorded 184.5mg RB4/g; while PIPC exhibited 126.9, 120.9 and 169.6 mg RB4/g in the presence of RR4, RO16 and BB3, respectively. In general, the accessibility of amine group depends on the molecular size, number of sulfonate groups and reactivity of each reactive dye. Single and multicomponent Freundlich equations successfully described the biosorption isotherms. With 0.1M NaOH, it is possible to reuse PIPC for RB4 biosorption in 10 repeated cycles. Column experiments in an up-flow packed column coincided with batch results, that is PIPC showed strong preference towards highly reactive and relatively small RB4 anions; however, the presence of competing dyes hinder the RB4 column biosorption performance.


Assuntos
Corantes/química , Corynebacterium glutamicum/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Compostos Azo/química , Biomassa , Concentração de Íons de Hidrogênio , Cinética , Modelos Químicos , Polímeros/química , Sulfonas/química , Triazinas/química
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