G. Annadurai

Adsorption of Reactive Dye on Chitin

The adsorption of reactive dye on chitin has been investigated with a view to obtain the design data for batch processing of effluents for dye adsorption. The effect of several factors governing the dye adsorption such as the adsorbent concentration, adsorbent size, temperature and pH have been elicited. Desorption of the dye at different temperatures and pH have also been investigated.

Box-Behnken design in the development of optimized complex medium for phenol degradation using Pseudomonas putida (NICM 2174)

Abstract The biodegradation of phenol by Pseudomonas putida (NICM 2174), a potential biodegradent of phenol has been investigated for its degrading potential under different operating conditions. Box-Behnken design has been employed to study the effect of different experimental variables. Four variables of maltose (0.25, 0.5, 0.75u2009g/l), phosphate (3, 12.5, 22u2009g/l), pH (7, 8, 9) and temperature (30u200a°C, 32u200a°C, 34u200a°C) were used to identify the significant effects and interactions in the batch studies. A second order polynomial regression model, has been developed using the experimental data. It was found that the degrading potential of Pseudomonas putida (NICM 2174) was strongly affected by the variations in maltose, phosphate, pH and temperature. The experimental values were in good agreement with the predicted values, the correlation coefficient was found to be 0.9980. Optimum conditions of the variables for the growth of Pseudomonas putida (NICM2174) and for maximum biodegradation of phenol are maltose (0.052u2009g/l), phosphate (8.97u2009g/l), pH (7.9) and temperature (31.5u200a°C).

Design of experiments in the biodegradation of phenol using immobilized Pseudomonas pictorum (NICM-2077) on activated carbon

Pseudomonas pictorum (NICM-2077) immobilized on various matrices are used to protect the microbes from confronting shock loads of concentrated phenol. The cells were immobilized in activated carbon and were used in biodegradation of phenol. Biodegradation of phenol using immobilized Activated Carbon matrix played an important role in reducing the toxicity of phenol. The degradation was carried and using the Box-Behnken model and analysis of variance have been applied to the experimental degradation studies. Response surface method with three levels of phenol concentration (0.200, 0.400, 0.600u2009g/l), activated carbon (0.5, 1.0, 1.5u2009g/l) and pH (7, 8, 9) were used in the identification of significant effects and interactions in the biodegradation studies. Phenol removal rate increases especially when the degradation medium was supplemented with utilizable carbon sources. A first-order polynomial regression model, which was used at first for analysis of the experiment had a significant lack of fit. Therefore, linear and quadratic terms were incorporated into the regression model through variable selection procedures. Effect of incubation phenol concentration, activated carbon and pH were significant. The predicted values using Box-Behnken model was found to be in close agreement with the experimental values, as indicated by the correlation coefficient values of 0.9463.

Influence of nutrients on cell growth and xanthan production by Xanthomonas campestris

Xanthan production by Xanthomonas campestris was performed in a batch fermentation study with a view to achieving maximum yields. The factors influencing the production — mainly the nutrients, were investigated. Trace elements such as phosphate and magnesium at 6.0 g/l and 0.2 g/l enhanced the yields.

Biodegradation of reactive dye (Verofix Red) by the white-rot fungus Phanerochaete chrysosporium using Box-Behnken experimental design

Abstract Biodegradation of reactive dye using the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance of the colour of reactive dye. An increase in dye concentration showed decreased dye degradation, and maximum dye degradation and increased biomass was observed in medium amended with limited source of nitrogen. Increasing days showed increased biomass production as well as dye degradation. Box- Behnken design with three variables like dye concentration (200, 700 and 1200u2009mg/l), days (2, 6 and 10) and nitrogen concentration at three different levels (0.054, 0.081 and 0.108u2009g/l) were studied to identify a significant correlation between the effect of these variables on the amount of biodegradation of reactive dye. The methodology identifies the principal experimental variables, which have the greatest effect in the biodegradation process. The experimental values are in good agreement with predicted values, the correlation coefficient being 0.9988.

Photocatalytic decolorization of congo red over ZnO powder using Box-Behnken design of experiments

Abstractu2002Photocatalytic decolorization of congo red under sunlight illumination has been examined using ZnO catalyst. Batch experiments were conducted and Box–Behnken design has been employed to study the effect of different variables on the photodecolorization. Four variables such as dye concentration (0.05, 0.075, 0.10u2009g/l), weight of catalyst ZnO (0.025, 0.14, 0.25u2009g/l), pH (4, 7, 10) and time (1, 2, 3 (h)) were used to identify the significant effects and interactions in the batch studies. A second order polynomial regression model has been developed using the experimental data. It was found that the photodecolorization potential of ZnO was strongly affected by the variations in dye concentration, weight of catalyst ZnO, pH and time. The experimental values were in good agreement with the predicted values and the correlation coefficient was found to be 0.9982. Optimum conditions of the variables for the maximum photodecolorization are dye concentration (0.05u2009g/l) ZnO (0.16u2009g/l), pH (7.0) and time (2.0) (h). The maximum percentage of photodecolorization was observed to be 97%.

Xanthan production — effect of agitation

Glucose fermentation by Xanthomonas campestris to xanthan was investigated in a stirred tank fermenter for the effect of agitation on cell growth and product synthesis. In the range investigated for speed between 300 to 500 rpm, these factors registered a rise with increasing degrees of turbulence, the experiments being carried out over a span of two days.