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Biomedical subjects

K Vijayaraghavan

Publications and source records attributed to K Vijayaraghavan.

At least 19 recordsLinked to original sources
PubMed2006

Utilization of fermentation waste (Corynebacterium glutamicum) for biosorption of Reactive Black 5 from aqueous solution.

A fermentation waste, Corynebacterium glutamicum, was successfully employed as a biosorbent for Reactive Black 5 (RB5) from aqueous solution. This paper initially studied the effect of pretreatment on the biosorption capacity of C. glutamicum toward RB5, using several chemical agents, such as HCl, H(2)SO(4), HNO(3), NaOH, Na(2)CO(3), CaCl(2) and NaCl. Among these reagents, 0.1M HNO(3) gave the maximum enhancement of the RB5 uptake, exhibiting 195mg/g at pH 1 with an initial RB5 concentration of 500mg/l. The solution pH and temperature were found to affect the biosorption capacity, and the biosorption isotherms derived at different pHs and temperatures revealed that a low pH (pH 1) and high temperature (35 degrees C) favored biosorption. The biosorption isotherm was well represented using three-parameter models (Redlich-Peterson and Sips) compared to two-parameter models (Langmuir and Freundlich models). As a result, high correlation coefficients and low average percentage error values were observed for three-parameter models. A maximum RB5 uptake of 419mg/g was obtained at pH 1 and a temperature of 35 degrees C, according to the Langmuir model. The kinetics of the biosorption process with different initial concentrations (500-2000mg/l) was also monitored, and the data were analyzed using pseudo-first and pseudo-second order models, with the latter describing the data well. Various thermodynamic parameters, such as DeltaG degrees, DeltaH degrees and DeltaS degrees, were calculated, indicating that the present system was a spontaneous and endothermic process. The use of a 0.1M NaOH solution successfully desorbed almost all the dye molecules from dye-loaded C. glutamicum biomass at different solid-to-liquid ratios examined.

Adsorption↗
PubMed2006

Potential of Sargassum wightii biomass for copper(II) removal from aqueous solutions: application of different mathematical models to batch and continuous biosorption data.

This paper reports biosorption of copper(II) ions onto Sargassum wightii biomass in batch and continuous mode of operation. Batch experiments were fundamentally aimed to determine the favorable pH for copper(II) biosorption. Langmuir model was used to describe the copper(II) biosorption isotherm and maximum uptake of 115 mg/g was obtained at pH 4.5. Continuous experiments in a packed column (2 cm i.d. and 35 cm height) were performed to study the influence of bed height, flow rate and inlet solute concentration on copper(II) biosorption. The highest bed height (25 cm), lowest flow rate (5 ml/min) and highest inlet Cu(II) concentration (100 mg/l) resulted in highest copper(II) uptake of 52.6 mg/g, compared to other conditions examined. Column data obtained at different conditions were described using the Thomas, Yoon-Nelson and modified dose-response models. All three models were able to predict breakthrough curves; in particular, the breakthrough curve prediction by the Thomas and Yoon-Nelson models were found to be very satisfactory. Also, the well-established design model, the Bed depth-service time (BDST) model was used to analyze the experimental data. The BDST model plot at 5 ml/min (flow rate) and 100 mg/l (inlet solute concentration) was used to predict bed depth-service time data at different conditions. The BDST model predicted values always coincide with experimental values with high correlation coefficients.

Adsorption↗
PubMed2006

Aerobic treatment of palm oil mill effluent.

In this study treatment of palm oil mill effluent (POME) was investigated using aerobic oxidation based on an activated sludge process. The effects of sludge volume index, scum index and mixed liquor suspended solids during the acclimatizing phase and biomass build-up phase were investigated in order to ascertain the reactor stability. The efficiency of the activated sludge process was evaluated by treating anaerobically digested and diluted raw POME obtained from Golden Hope Plantations, Malaysia. The treatment of POME was carried out at a fixed biomass concentration of 3900+/-200mg/L, whereas the corresponding sludge volume index was found to be around 105+/-5mL/g. The initial studies on the efficiency of the activated sludge reactor were carried out using diluted raw POME for varying the hydraulic retention time, viz: 18, 24, 30 and 36h and influent COD concentration, viz: 1000, 2000, 3000, 4000 and 5000mg/L, respectively. The results showed that at the end of 36h of hydraulic retention time for the above said influent COD, the COD removal efficiencies were found to be 83%, 72%, 64%, 54% and 42% whereas at 24h hydraulic retention time they were 57%, 45%, 38%, 30% and 27%, respectively. The effectiveness of aerobic oxidation was also compared between anaerobically digested and diluted raw POME having corresponding CODs of 3908 and 3925mg/L, for varying hydraulic retention time, viz: 18, 24, 30, 36, 42, 48, 54 and 60h. The dissolved oxygen concentration and pH in the activated sludge reactor were found to be 1.8-2.2mg/L and 7-8.5, respectively. The scum index was found to rise from 0.5% to 1.9% during the acclimatizing phase and biomass build-up phase.

Anaerobiosis↗
PubMed2006

Seaweeds for the remediation of wastewaters contaminated with zinc(II) ions.

Eleven different species of marine macroalgae were screened at different pH conditions on the basis of zinc(II) biosorption potential. Among the seaweeds, a green alga, Ulva reticulata, exhibited a highest uptake of 36.1 mg/g at pH 5.5 and 100 mg/l initial zinc(II) concentration. Further experiments were conducted to evaluate the zinc(II) biosorption potential of U. reticulata. Sorption isotherm data obtained at different pH (5-6) and temperature (25-35 degrees C) conditions were fitted well with Sips model followed by Freundlich, Redlich-Peterson and Langmuir models. A maximum zinc(II) biosorption capacity of 135.5 mg/g was observed at optimum conditions of 5.5 (pH) and 30 degrees C (temperature), according to the Langmuir model. It was observed from the kinetic data that the zinc(II) biosorption process using U. reticulata follows pseudo-second-order kinetics. Various thermodynamic parameters, such as DeltaG degrees , DeltaH degrees and DeltaS degrees were calculated and they indicated that the present system was a spontaneous and an endothermic process. The influence of the co-ions (Na(+), K(+), Ca(2+) and Mg(2+)) along with zinc(II) present in the wastewater was also studied. Desorption of zinc(II) ions from the zinc(II)-loaded biomass were examined using 0.1 M CaCl(2) at different pH conditions in three sorption-desorption cycles. A fixed-bed column (2 cm i.d. and 35 cm height) was employed to evaluate the continuous biosorption performance of U. reticulata. The column experiments at different bed heights and flow rates revealed that the maximum zinc(II) uptake was obtained at the highest bed height (25 cm) and the lowest flow rate (5 ml/min). Column data were fitted well with Thomas, Yoon-Nelson and modified dose-response models. The column regeneration studies were carried out for three sorption-desorption cycles. A loss of sorption performance was observed during regeneration cycles indicated by a shortened breakthrough time and a decreased zinc(II) uptake.

Adsorption↗
PubMed2006

Effect of micronutrient supplementation on health and nutritional status of schoolchildren: growth and morbidity.

OBJECTIVE: We evaluated the effect of a micronutrient-fortified beverage on growth and morbidity in apparently healthy schoolchildren. METHODS: This was a double-blind, placebo-controlled, matched-pair, cluster, randomized study in semi-urban middle-income residential schoolchildren aged 6 to 16 y. Anthropometrics (height and weight), clinical symptoms of deficiency, and morbidity data were collected at baseline in the supplemented group (n = 446 in 10 grades) and the placebo group (n = 423 in 10 grades) and after 14 mo of supplementation (n = 355 in the supplement group and n = 340 in the placebo group from nine pairs). RESULTS: After 14 mo of supplementation, there was a significant increase in mean increments of height and weight z scores of -0.04 and 0.02, respectively, in the supplemented group compared with -0.14 and -0.09 in the placebo group. Velocity of weight (3.56 versus 3.00) was significantly (P < 0.01) higher with supplementation. Although there were no differences in the incidence of common childhood diseases such as fever, cough and cold, diarrhea, and ear infections elicited for a reference period of 1 mo at every quarterly follow-up examination, the mean duration of illness (calculated per person per year) was significantly shorter (5.0 d) in the supplemented group than in the placebo group (7.4 d). CONCLUSIONS: The micronutrient-fortified beverage was beneficial in promoting growth and decreasing duration of common illnesses among middle-class residential schoolchildren who had adequate energy and protein intakes.

Adolescent↗
PubMed2006

Prevalence of anemia among pregnant women and adolescent girls in 16 districts of India.

BACKGROUND: Nutritional anemia is one of India's major public health problems. The prevalence of anemia ranges from 33% to 89% among pregnant women and is more than 60% among adolescent girls. Under the anemia prevention and control program of the Government of India, iron and folic acid tablets are distributed to pregnant women, but no such program exists for adolescent girls. OBJECTIVE: To assess the status of anemia among pregnant women and adolescent girls from 16 districts of 11 states of India. METHODS: A two-stage random sampling method was used to select 30 clusters on the basis of probability proportional to size. Anemia was diagnosed by estimating the hemoglobin concentration in the blood with the use of the indirect cyanmethemoglobin method. RESULTS: The survey data showed that 84.9% of pregnant women (n = 6,923) were anemic (hemoglobin < 110 g/L); 13.1% had severe anemia (hemoglobin < 70 g/L), and 60.1% had moderate anemia (hemoglobin > or = 70 to 100 g/L). Among adolescent girls (n = 4,337)from 16 districts, the overall prevalence of anemia (defined as hemoglobin < 120 g/L) was 90.1%, with 7.1% having severe anemia (hemoglobin < 70 g/L). CONCLUSIONS: Any intervention strategy for this population must address not only the problem of iron deficiency, but also deficiencies of other micronutrients, such as B12 and folic acid and other possible causal factors.

Adolescent↗
PubMed2005

Biosorption of nickel(II) ions onto Sargassum wightii: application of two-parameter and three-parameter isotherm models.

Biosorption of nickel(II) ions from aqueous solution onto Sargassum wightii has been studied and the equilibrium isotherms were determined. The experimental data obtained at different pH conditions (pH 3.0-4.5) have been analyzed using five two-parameter models (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Flory-Huggins) and five three-parameter models (Redlich-Peterson, Sips, Khan, Radke-Prausnitz and Toth). In order to determine the best fit isotherm, three error analysis methods were used to evaluate the data: correlation coefficient, residual root mean square error and chi-square test. The error analysis demonstrated that the three-parameter models better described the nickel biosorption data compared to two-parameter models. In particular, Toth equation provided the best model for nickel biosorption data at all pH conditions examined.

Adsorption↗
PubMed2005

Batch and column studies on biosorption of acid dyes on fresh water macro alga Azolla filiculoides.

The biosorption of Acid red 88 (AR88), Acid green 3 (AG3) and Acid orange 7 (AO7) by deactivated fresh water macro alga Azolla filiculoides was investigated in batch mode. Langmuir and Freundlich adsorption models were used for the mathematical description of the batch biosorption equilibrium data and model constants were evaluated. The adsorption capacity was pH dependent with a maximum value of 109.0 mg/g at pH 7 for AR88, 133.5 mg/g at pH 3 for AG3 and 109.6 mg/g at pH 3 for AO7, respectively, was obtained. The pseudo first and second order kinetic models were also applied to the experimental kinetic data and high correlation coefficients favor pseudo second order model for the present systems. The ability of A. filiculoides to biosorb AG3 in packed column was also investigated. The column experiments were conducted to study the effect of important design parameters such as initial dye concentration (50-100 mg/L), bed height (15-25 cm) and flow rate (5-15 mL/min) to the well-adsorbed dye. At optimum bed height (25 cm), flow rate (5 mL/min) and initial dye concentration (100 mg/L), A. filiculoides exhibited 28.1mg/g for AG3. The Bed Depth Service Time model and the Thomas model were used to analyze the experimental data and the model parameters were evaluated.

Adsorption↗
PubMed2005

Biosorption of copper(II) and cobalt(II) from aqueous solutions by crab shell particles.

Biosorption of each of the heavy metals, copper(II) and cobalt(II) by crab shell was investigated in this study. The biosorption capacities of crab shell for copper and cobalt were studied at different particle sizes (0.456-1.117 mm), biosorbent dosages (1-10 g/l), initial metal concentrations (500-2000 mg/l) and solution pH values (3.5-6) in batch mode. At optimum particle size (0.767 mm), biosorbent dosage (5 g/l) and initial solution pH (pH 6); crab shell recorded maximum copper and cobalt uptakes of 243.9 and 322.6 mg/g, respectively, according to Langmuir model. The kinetic data obtained at different initial metal concentrations indicated that biosorption rate was fast and most of the process was completed within 2h, followed by slow attainment of equilibrium. Pseudo-second order model fitted the data well with very high correlation coefficients (>0.998). The presence of light and heavy metal ions influenced the copper and cobalt uptake potential of crab shell. Among several eluting agents, EDTA (pH 3.5, in HCl) performed well and also caused low biosorbent damage. The biosorbent was successfully regenerated and reused for five cycles.

Absorption↗
PubMed2005

Crab shell-based biosorption technology for the treatment of nickel-bearing electroplating industrial effluents.

This paper discusses the possible application of a biosorption system with acid-washed crab shells in a packed bed up-flow column for the removal of nickel from electroplating industrial effluents. Between two nickel-bearing effluents, effluent-1 is characterized by considerable amount of light metals along with trace amounts of lead and copper. Effluent-2 is characterized by relatively low conductivity, total dissolved solids and total hardness compared to effluent-1. Crab shells exhibited uptakes of 15.08 and 20.04 mg Ni/g from effluent-1 and effluent-2, respectively. The crab shell bed was regenerated using 0.01 M EDTA (pH 9.8, aq. NH3) and reused for seven sorption-desorption cycles. The EDTA elution provided elution efficiencies up to 99% in all the seven cycles. This, together with the data from regeneration efficiencies for seven cycles, provided evidence that the reusability of crab shell in the treatment of nickel-bearing electroplating industrial effluents is viable.

Adsorption↗
PubMed2005

Biosorption of copper, cobalt and nickel by marine green alga Ulva reticulata in a packed column.

Biosorption of copper, cobalt and nickel by marine green alga Ulva reticulata were investigated in a packed bed up-flow column. The experiments were conducted to study the effect of important design parameters such as bed height and flow rate. At a bed height of 25 cm, the metal-uptake capacity of U. reticulata for copper, cobalt and nickel was found to be 56.3+/-0.24, 46.1+/-0.07 and 46.5+/-0.08 mgg(-1), respectively. The Bed Depth Service Time (BDST) model was used to analyze the experimental data. The computed sorption capacity per unit bed volume (N0) was 2580, 2245 and 1911 mgl(-1) for copper, cobalt and nickel, respectively. The rate constant (K(a)) was recorded as 0.063, 0.081 and 0.275 lmg(-1)h(-1) for copper, cobalt and nickel, respectively. In flow rate experiments, the results confirmed that the metal uptake capacity and the metal removal efficiency of U. reticulata decreased with increasing flow rate. The Thomas model was used to fit the column biosorption data at different flow rates and model constants were evaluated. The column regeneration studies were carried out for three sorption-desorption cycles. The elutant used for the regeneration of the biosorbent was 0.1 M CaCl2 at pH 3 adjusted using HCl. For all the metal ions, a decreased breakthrough time and an increased exhaustion time were observed as the regeneration cycles progressed, which also resulted in a broadened mass transfer zone. The pH variations during both sorption and desorption process have been reported.

Adsorption↗
PubMed2005

Continuous sorption of copper and cobalt by crab shell particles in a packed column.

The ability of crab shell to remove copper and cobalt from aqueous solutions was examined in an up-flow packed column. The experiments were conducted to study the effect of important design parameters such as bed height and flow rate. At a bed height of 25 cm, metal uptake capacity of crab shell for copper and cobalt was 52.07 and 20.47 mg g(-1) respectively. In addition, the results obtained at different flow rates indicated that an increase in flow rate decreased the sorption performance of the crab shell. The Bed Depth Service Time model and the Thomas model were used to analyze the experimental data and the model parameters were evaluated for copper and cobalt sorption. The column regeneration studies were carried out for five sorption-desorption cycles. Loss of sorption performance was observed as the cycles progressed, indicated by a shortened breakthrough time and a broadened mass transfer zone. However, crab shell maintained a good metal sorption capacity for all the five cycles. The elutant used for the regeneration of the crab shell, 0.01 M EDTA at pH 3.5 adjusted using HCI, exhibited elution efficiencies greater than 98%.

Absorption↗
PubMed2005

Nutritional status of the tribal elderly in India.

The objective of the paper is to assess the diet and nutritional status of the tribal elderly (> or = 60 years) using data from a cross-sectional study carried out by National Nutrition Monitoring Bureau (NNMB) exclusively in Integrated Tribal Development Project (ITDP) villages of 9 provincial States in India during 1998-1999. A total of 1,239 elderly completed the diet survey (24-hour recall) and 3,932 elderly completed anthropometric measurements. In general, the mean consumption of all the foods and the median intakes of all the nutrients were below the Recommended Dietary Intakes (RDI) in both men and women. The mean heights and weights significantly decreased with increase in age in both males and females (p < 0.001). The prevalence of Chronic Energy Deficiency (CED = BMI < 18.5) was relatively higher (65.4%) in females compared with their male counterparts (61.8%). The prevalence of CED was significantly higher (p < 0.001) among the elderly living in kutchaand landless households. The tribal elderly are subsisting on inadequate diets, which are reflected in the poor intakes of all the nutrients and higher prevalence of undernutrition. Significantly higher proportion of tribal elderly are undernourished compared with their rural counterparts (p < 0.001).

Aged↗
PubMed2004

Removal of nickel(II) ions from aqueous solution using crab shell particles in a packed bed up-flow column.

This paper investigates the ability of crab shell to remove nickel(II) ions from aqueous solution in a packed bed up-flow column with an internal diameter of 2 cm. The experiments were performed with different bed heights (15-25 cm) and using different flow rates (5-20 ml/min) in order to obtain experimental breakthrough curves. The bed depth service time (BDST) model was used to analyze the experimental data and the model parameters were evaluated. The column regeneration studies were carried out for seven sorption-desorption cycles. The elutant used for the regeneration of the sorbent was 0.01 M EDTA (disodium) solution at pH 9.8 adjusted using NH4OH. Due to continuous usage of crab shell, a performance loss was observed as the breakthrough curves become more flattened also indicated by the broadened mass transfer zone. The breakthrough time decreased uniformly from 28.1 to 9.5 h as the cycles progressed from one to seven, whereas nickel uptake remained approximately constant throughout the seven cycles. The life-factors for crab shell in terms of critical bed length and breakthrough time were found to be 1.1 cm/cycle and 0.17 per cycle, respectively. The elution efficiency was greater than 99.1% in all the seven cycles. The pH profiles during both sorption and desorption process were also reported. In sorption cycles, there was a sudden raise in pH in the early part of the process and then the pH decreased as the time progressed. In desorption cycles, pH decreased in initial stages and followed by gradual increase in pH, which eventually reached the pH of the inlet elutant.

Adsorption↗
PubMed2002

Diet and nutritional status of rural adolescents in India.

OBJECTIVE: To study the current diet and nutritional status of rural adolescents in India. DESIGN: Cross-sectional study with household as the unit of randomization. SETTING: National Nutrition Monitoring Bureau collected information in the rural areas of the nine States. METHODS: In each State, 120 villages were selected from eight districts. From each of the selected villages, 20 households (HHs) were selected from five clusters. The information on socio-demographic profile was collected in all the 20 HHs, while anthropometric data such as weight, height and clinical signs of nutritional deficiency was collected on all the available adolescents in the selected households. In every fourth sampled household, ie five HHs, dietary information on all the members was collected using 24 h dietary recall. The outcome measures for nutritional status were proportion of underweight (<median -2 s.d. of NCHS standards of weight for age), stunted (<median -2 s.d. of NCHS standards of height for age) and body mass index. The nutrient intakes were compared with recommended dietary allowances (RDA). RESULTS: Anthropometric and socio-economic information on 12 124 adolescent boys and girls and dietary information on 2579 individuals in 1996-1997 was available for the analysis. The major occupation of the heads of the households surveyed was agriculture. More than a third (37.3%) of the families with adolescents did not possess any land. The per capita income per month was about Rs 250/- at 1996-1997 prices. About 23% of the adolescent girls were married before the age of 18 y. About a quarter of the married adolescent girls had short stature and 18.6% were underweight. They considered as 'at risk'. About 39% of the adolescents were stunted (<Median -2 s.d. of NCHS height for age) irrespective of sex. The prevalence of undernutrition (<median -2 s.d. of NCHS weight for age) is higher (53.1%) in boys than in girls (39.5%). The extent of stunting was higher (42.7%) among adolescents belonging to the scheduled caste community. In the case of girls, the extent of underweight was considerably less in each age group than their male counterparts. About 70% of adolescents consumed more than 70% of RDA for energy. The intakes of micronutrients such as vitamin A and riboflavin were woefully inadequate. CONCLUSIONS: The extent of undernutrition was high among adolescents and was higher among boys than girls. Adolescent girls in the rural areas could be at greater risk of nutritional stress because of early marriage and early conception before completion of their physical growth.

Adolescent↗
PubMed2002

Time trends in the intrafamily distribution of dietary energy in rural India.

The intrafamily distribution of dietary energy in 5,458 households from seven states in India was assessed from 24-hour dietary recall data collected by the National Nutrition Monitoring Bureau during 1996-97. The energy consumption, expressed as percentage of recommended dietary intake (%RDI), of preschool children, schoolchildren, and adolescents was compared with that of adult men and women in the same households. Time trends in the intrafamily distribution of dietary energy were assessed by comparing the data with those collected in 1975-80 using the same procedures in the same villages. About one-third of the preschool children had an inadequate intake of energy, even when their adult counterparts had an adequate intake, whereas only about 7% of the preschoolers and their parents were consuming inadequate amounts of energy. The extent of energy inadequacy was much less in adolescents and school-age children than in preschool children. This was true even when the adults in the same households had an adequate energy intake. In 1996-97, there was a significant increase in the proportion of households with preschool children consuming inadequate energy, although both adult men and women were consuming energy-adequate diets as compared with the dietary data collected in the same villages in 1975-80. The results indicate the need to provide effective nutrition education for parents regarding the nutritional needs of their children.

Adolescent↗
PubMed2002

Control of micronutrient deficiencies in India: obstacles and strategies.

Micronutrient deficiencies of vitamin A, iron, and iodine continue to be of public health significance in India. The government of India initiated national programs to prevent, control and combat these deficiencies and their serious consequences. The interventions involved (1) distribution of iodized salt in the endemic areas, (2) administration of semiannual massive dose of vitamin A to young children, and (3) distribution of iron-folic acid tablets to the vulnerable groups. Evaluations revealed that the biologic impact of these interventions was unsatisfactory. Inadequate allocation of funds (10% of the actual needs) necessary to cover the enormous number of beneficiaries was one of the important obstacles. Consequently, the allocation of supplies to different provinces was far short of the requirements (10-30%). As a result of poor orientation, the functionaries were not adhering to the guidelines, leading to woefully inadequate (1-20%) and irregular coverage. There was no proper monitoring or supervision to make midcourse corrections to improve the functioning. The community was not informed of the purpose and details of each intervention. Hence, it did not utilize the resources completely and remained passive recipients. The community was not aware of the dietary approaches to prevent micronutrient disorders owing to absence of nutrition education. With the adoption of National Nutrition Policy by the government of India, a concerted and focused approach should be adopted. The future strategies should include a mix of short-term supplementation and food-based strategy encompassing food fortification and home gardening. Innovative approaches in information, education, and communication (such as social marketing strategy) for making the interventions sustainable should be adopted.

Dietary Supplements↗