The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Vimal Chandra Srivastava - One of the best experts on this subject based on the ideXlab platform.
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treatment of dairy wastewater by commercial activated carbon and bagasse fly ash parametric kinetic and equilibrium modelling disposal studies
Bioresource Technology, 2010Co-Authors: Jai Prakash Kushwaha, Vimal Chandra Srivastava, Indra Deo MallAbstract:Abstract Present study reports treatment of synthetic dairy wastewater (SDW) in terms of chemical oxygen demand (COD) removal by means of adsorption onto activated carbon-commercial grade (ACC) and bagasse fly ash (BFA). Optimum conditions for SDW treatment were found to be: initial pH ≈ 4.8, adsorbent dose of 20 g/l for ACC and 10 g/l for BFA and contact time ≈8 h. Pseudo-second-order kinetic model was found to fit the kinetic data and Redlich–Peterson isotherm model was generally found to best represent the equilibrium data for SDW treatment by ACC and BFA. The Change in Entropy and enthalpy for SDW adsorption onto ACC and BFA were estimated as 125.85 kJ/mol K and 91.53 kJ/mol; and 25.71 kJ/mol K and 17.26 kJ/mol, respectively. The negative values of Change in Gibbs free energy indicate the feasibility and spontaneous nature of the adsorptive treatment.
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adsorptive desulfurization by activated alumina
Journal of Hazardous Materials, 2009Co-Authors: Ankur Srivastav, Vimal Chandra SrivastavaAbstract:Abstract This study reports usage of commercial grade activated alumina (aluminum oxide) as adsorbent for the removal of sulfur from model oil (dibenthiophene (DBT) dissolved in n-hexane). Bulk density of alumina was found to be 1177.77 kg/m 3 . The BET surface area of alumina was found to decrease from 143.6 to 66.4 m 2 /g after the loading of DBT at optimum conditions. The carbon-oxygen functional groups present on the surface of alumina were found to be effective in the adsorption of DBT onto alumina. Optimum adsorbent dose was found to be 20 g/l. The adsorption of DBT on alumina was found to be gradual process, and quasi-equilibrium reached in 24 h. Langmuir isotherm best represented the equilibrium adsorption data. The heat of adsorption and Change in Entropy for DBT adsorption onto alumina was found to be 19.5 kJ/mol and 139.2 kJ/mol K, respectively.
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rice husk ash as an effective adsorbent evaluation of adsorptive characteristics for indigo carmine dye
Journal of Environmental Management, 2009Co-Authors: Uma R Lakshmi, Vimal Chandra Srivastava, Indra Deo Mall, Dilip H LatayeAbstract:Abstract Present study explored the adsorptive characteristics of indigo Carmine (IC) dye from aqueous solution onto rice husk ash (RHA). Batch experiments were carried out to determine the influence of parameters like initial pH (pH 0 ), contact time ( t ), adsorbent dose ( m ) and initial concentration ( C 0 ) on the removal of IC. The optimum conditions were found to be: pH 0 = 5.4, t = 8 h and m = 10.0 g/l. The pseudo-second-order kinetic model represented the adsorption kinetics of IC on to RHA. Equilibrium isotherms were analyzed by Freundlich, Langmuir, Temkin and Redlich–Peterson models using a non-linear regression technique. Adsorption of IC on RHA was favorably influenced by an increase in the temperature of the operation. The positive values of the Change in Entropy (Δ S 0 ) and heat of adsorption (Δ H 0 ); and the negative value of Change in Gibbs free energy (Δ G 0 ) indicate feasible and spontaneous adsorption of IC on to RHA.
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kinetic and equilibrium isotherm studies for the adsorptive removal of brilliant green dye from aqueous solution by rice husk ash
Journal of Environmental Management, 2007Co-Authors: Venkat S Mane, Indra Deo Mall, Vimal Chandra SrivastavaAbstract:Abstract The present study deals with the adsorption of Brilliant Green (BG) on rice husk ash (RHA). RHA is a solid waste obtained from the particulate collection equipment attached to the flue gas lines of rice husk fired boilers. Batch studies were performed to evaluate the influences of various experimental parameters like initial pH ( pH 0 ), contact time, adsorbent dose and initial concentration ( C 0 ) on the removal of BG. Optimum conditions for BG removal were found to be pH 0 ≈3.0, adsorbent dose ≈6 g L −1 of solution and equilibrium time ≈5 h for the C 0 range of 50–300 mg L −1 . Adsorption of BG followed pseudo-second-order kinetics. intra-particle diffusion does not seem to control the BG removal process. Equilibrium isotherms for the adsorption of BG on RHA were analyzed by Freundlich, Langmuir, Redlich–Peterson (R–P), Dubnin–Radushkevich (D–R), and Temkin isotherm models using a non-linear regression technique. Langmuir and R–P isotherms were found to best represent the data for BG adsorption onto RHA. Adsorption of BG on RHA is favourably influenced by an increase in the temperature of the operation. Values of the Change in Entropy (Δ S 0 ) and heat of adsorption (Δ H 0 ) for BG adsorption on RHA were positive. The high negative value of Change in Gibbs free energy (Δ G 0 ) indicates the feasible and spontaneous adsorption of BG on RHA.
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adsorption thermodynamics and isosteric heat of adsorption of toxic metal ions onto bagasse fly ash bfa and rice husk ash rha
Chemical Engineering Journal, 2007Co-Authors: Vimal Chandra Srivastava, Indra Deo Mall, I M MishraAbstract:Abstract The equilibrium sorption characteristics of cadmium (Cd(II)), nickel (Ni(II)) and zinc (Zn(II)) metal ions from aqueous solutions having respective metal ion concentrations in the range of 50–500 mmol/dm 3 for two low-cost adsorbents, viz. bagasse fly ash (BFA) and rice husk ash (RHA), were studied at different temperatures in the range of 293–323 K. An increase in temperature is found to induce a positive effect on the sorption process. Toth isotherm best represents the equilibrium adsorption onto BFA and RHA. The heat of adsorption (Δ H 0 ) and Change in Entropy (Δ S 0 ) for metal adsorption on BFA and RHA are found in the range of 26–44 kJ/mol and 127–194 kJ/mol K, respectively. The isosteric heat of adsorption was quantitatively correlated with the fractional loading of metal ions onto adsorbents. The results showed that the BFA and RHA possessed heterogeneous surface with sorption sites having different activities.
Ruth Nussinov - One of the best experts on this subject based on the ideXlab platform.
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allostery absence of a Change in shape does not imply that allostery is not at play
Journal of Molecular Biology, 2008Co-Authors: Chung Jung Tsai, Ruth NussinovAbstract:Allostery is essential for controlled catalysis, signal transmission, receptor trafficking, turning genes on and off, and apoptosis. It governs the organism's response to environmental and metabolic cues, dictating transient partner interactions in the cellular network. Textbooks taught us that allostery is a Change of shape at one site on the protein surface brought about by ligand binding to another. For several years, it has been broadly accepted that the Change of shape is not induced; rather, it is observed simply because a larger protein population presents it. Current data indicate that while side chains can reorient and rewire, allostery may not even involve a Change of (backbone) shape. Assuming that the enthalpy Change does not reverse the free-energy Change due to the Change in Entropy, Entropy is mainly responsible for binding.
Indra Deo Mall - One of the best experts on this subject based on the ideXlab platform.
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treatment of dairy wastewater by commercial activated carbon and bagasse fly ash parametric kinetic and equilibrium modelling disposal studies
Bioresource Technology, 2010Co-Authors: Jai Prakash Kushwaha, Vimal Chandra Srivastava, Indra Deo MallAbstract:Abstract Present study reports treatment of synthetic dairy wastewater (SDW) in terms of chemical oxygen demand (COD) removal by means of adsorption onto activated carbon-commercial grade (ACC) and bagasse fly ash (BFA). Optimum conditions for SDW treatment were found to be: initial pH ≈ 4.8, adsorbent dose of 20 g/l for ACC and 10 g/l for BFA and contact time ≈8 h. Pseudo-second-order kinetic model was found to fit the kinetic data and Redlich–Peterson isotherm model was generally found to best represent the equilibrium data for SDW treatment by ACC and BFA. The Change in Entropy and enthalpy for SDW adsorption onto ACC and BFA were estimated as 125.85 kJ/mol K and 91.53 kJ/mol; and 25.71 kJ/mol K and 17.26 kJ/mol, respectively. The negative values of Change in Gibbs free energy indicate the feasibility and spontaneous nature of the adsorptive treatment.
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rice husk ash as an effective adsorbent evaluation of adsorptive characteristics for indigo carmine dye
Journal of Environmental Management, 2009Co-Authors: Uma R Lakshmi, Vimal Chandra Srivastava, Indra Deo Mall, Dilip H LatayeAbstract:Abstract Present study explored the adsorptive characteristics of indigo Carmine (IC) dye from aqueous solution onto rice husk ash (RHA). Batch experiments were carried out to determine the influence of parameters like initial pH (pH 0 ), contact time ( t ), adsorbent dose ( m ) and initial concentration ( C 0 ) on the removal of IC. The optimum conditions were found to be: pH 0 = 5.4, t = 8 h and m = 10.0 g/l. The pseudo-second-order kinetic model represented the adsorption kinetics of IC on to RHA. Equilibrium isotherms were analyzed by Freundlich, Langmuir, Temkin and Redlich–Peterson models using a non-linear regression technique. Adsorption of IC on RHA was favorably influenced by an increase in the temperature of the operation. The positive values of the Change in Entropy (Δ S 0 ) and heat of adsorption (Δ H 0 ); and the negative value of Change in Gibbs free energy (Δ G 0 ) indicate feasible and spontaneous adsorption of IC on to RHA.
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kinetic and equilibrium isotherm studies for the adsorptive removal of brilliant green dye from aqueous solution by rice husk ash
Journal of Environmental Management, 2007Co-Authors: Venkat S Mane, Indra Deo Mall, Vimal Chandra SrivastavaAbstract:Abstract The present study deals with the adsorption of Brilliant Green (BG) on rice husk ash (RHA). RHA is a solid waste obtained from the particulate collection equipment attached to the flue gas lines of rice husk fired boilers. Batch studies were performed to evaluate the influences of various experimental parameters like initial pH ( pH 0 ), contact time, adsorbent dose and initial concentration ( C 0 ) on the removal of BG. Optimum conditions for BG removal were found to be pH 0 ≈3.0, adsorbent dose ≈6 g L −1 of solution and equilibrium time ≈5 h for the C 0 range of 50–300 mg L −1 . Adsorption of BG followed pseudo-second-order kinetics. intra-particle diffusion does not seem to control the BG removal process. Equilibrium isotherms for the adsorption of BG on RHA were analyzed by Freundlich, Langmuir, Redlich–Peterson (R–P), Dubnin–Radushkevich (D–R), and Temkin isotherm models using a non-linear regression technique. Langmuir and R–P isotherms were found to best represent the data for BG adsorption onto RHA. Adsorption of BG on RHA is favourably influenced by an increase in the temperature of the operation. Values of the Change in Entropy (Δ S 0 ) and heat of adsorption (Δ H 0 ) for BG adsorption on RHA were positive. The high negative value of Change in Gibbs free energy (Δ G 0 ) indicates the feasible and spontaneous adsorption of BG on RHA.
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adsorption thermodynamics and isosteric heat of adsorption of toxic metal ions onto bagasse fly ash bfa and rice husk ash rha
Chemical Engineering Journal, 2007Co-Authors: Vimal Chandra Srivastava, Indra Deo Mall, I M MishraAbstract:Abstract The equilibrium sorption characteristics of cadmium (Cd(II)), nickel (Ni(II)) and zinc (Zn(II)) metal ions from aqueous solutions having respective metal ion concentrations in the range of 50–500 mmol/dm 3 for two low-cost adsorbents, viz. bagasse fly ash (BFA) and rice husk ash (RHA), were studied at different temperatures in the range of 293–323 K. An increase in temperature is found to induce a positive effect on the sorption process. Toth isotherm best represents the equilibrium adsorption onto BFA and RHA. The heat of adsorption (Δ H 0 ) and Change in Entropy (Δ S 0 ) for metal adsorption on BFA and RHA are found in the range of 26–44 kJ/mol and 127–194 kJ/mol K, respectively. The isosteric heat of adsorption was quantitatively correlated with the fractional loading of metal ions onto adsorbents. The results showed that the BFA and RHA possessed heterogeneous surface with sorption sites having different activities.
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use of bagasse fly ash as an adsorbent for the removal of brilliant green dye from aqueous solution
Dyes and Pigments, 2007Co-Authors: Venkat S Mane, Indra Deo Mall, Vimal Chandra SrivastavaAbstract:Abstract The present study deals with the adsorption of brilliant green (BG) on carbon rich bagasse fly ash (BFA). BFA is a solid waste obtained from the particulate collection equipment attached to the flue gas line of the bagasse-fired boilers of cane sugar mills. Batch studies were performed to evaluate the influences of various experimental parameters like initial pH (pH0), contact time, adsorbent dose and initial concentration (C0) on the removal of BG. Optimum conditions for BG removal were found to be pH0 ≈ 3.0, adsorbent dose ≈ 3 g/l of solution and equilibrium time ≈ 5 h. Adsorption of BG followed pseudo-second-order kinetics. intra-particle diffusion does not seem to control the BG removal process. Equilibrium isotherms for the adsorption of BG on BFA were analyzed by Freundlich, Langmuir, Redlich–Peterson, Dubnin–Radushkevich, and Temkin isotherm models using non-linear regression technique. Redlich–Peterson and Langmuir isotherms were found to best represent the data for BG adsorption onto BFA. Adsorption of BG on BFA is favourably influenced by an increase in the temperature of the operation. Values of the Change in Entropy ( Δ S 0 ) and heat of adsorption ( Δ H 0 ) for BG adsorption on BFA were positive. The high negative value of Change in Gibbs free energy ( Δ G 0 ) indicates the feasible and spontaneous adsorption of BG on BFA.
I M Mishra - One of the best experts on this subject based on the ideXlab platform.
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adsorption thermodynamics and isosteric heat of adsorption of toxic metal ions onto bagasse fly ash bfa and rice husk ash rha
Chemical Engineering Journal, 2007Co-Authors: Vimal Chandra Srivastava, Indra Deo Mall, I M MishraAbstract:Abstract The equilibrium sorption characteristics of cadmium (Cd(II)), nickel (Ni(II)) and zinc (Zn(II)) metal ions from aqueous solutions having respective metal ion concentrations in the range of 50–500 mmol/dm 3 for two low-cost adsorbents, viz. bagasse fly ash (BFA) and rice husk ash (RHA), were studied at different temperatures in the range of 293–323 K. An increase in temperature is found to induce a positive effect on the sorption process. Toth isotherm best represents the equilibrium adsorption onto BFA and RHA. The heat of adsorption (Δ H 0 ) and Change in Entropy (Δ S 0 ) for metal adsorption on BFA and RHA are found in the range of 26–44 kJ/mol and 127–194 kJ/mol K, respectively. The isosteric heat of adsorption was quantitatively correlated with the fractional loading of metal ions onto adsorbents. The results showed that the BFA and RHA possessed heterogeneous surface with sorption sites having different activities.
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adsorptive removal of phenol by bagasse fly ash and activated carbon equilibrium kinetics and thermodynamics
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2006Co-Authors: Vimal Chandra Srivastava, Indra Deo Mall, Mahadeva M Swamy, B Prasad, I M MishraAbstract:Abstract Present study deals with the adsorption of phenol on carbon rich bagasse fly ash (BFA) and activated carbon-commercial grade (ACC) and laboratory grade (ACL). BFA is a solid waste obtained from the particulate collection equipment attached to the flue gas line of the bagasse-fired boilers of cane sugar mills. Batch studies were performed to evaluate the influences of various experimental parameters like initial pH (pH0), contact time, adsorbent dose and initial concentration (C0) on the removal of phenol. C0 varied from 75 to 300 mg/l for the adsorption isotherm studies and the effect of temperature on adsorption. Optimum conditions for phenol removal were found to be pH0 ≈ 6.5, adsorbent dose ≈10 g/l of solution and equilibrium time ≈5 h. Adsorption of phenol followed pseudo-second order kinetics with the initial sorption rate for adsorption on ACL being the highest followed by those on BFA and ACC. The effective diffusion coefficient of phenol is of the order of 10−10 m2/s. Equilibrium isotherms for the adsorption of phenol on BFA, ACC and ACL were analysed by Freundlich, Langmuir, Temkin, Redlich–Peterson, Radke–Prausnitz and Toth isotherm models using non-linear regression technique. Redlich–Peterson isotherm was found to best represent the data for phenol adsorption on all the adsorbents. The Change in Entropy (ΔS°) and heat of adsorption (ΔH°) for phenol adsorption on BFA were estimated as 1.8 MJ/kg K and 0.5 MJ/kg, respectively. The high negative value of Change in Gibbs free energy (ΔG°) indicates the feasible and spontaneous adsorption of phenol on BFA. The values of isosteric heat of adsorption varied with the surface loading of phenol.
R Vijayaraghavan - One of the best experts on this subject based on the ideXlab platform.
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supersensitive detection of t 2 toxin by the in situ synthesized π conjugated molecularly imprinted nanopatterns an in situ investigation by surface plasmon resonance combined with electrochemistry
Biosensors and Bioelectronics, 2011Co-Authors: Garima Gupta, A S B Bhaskar, Brajesh K Tripathi, Pratibha Pandey, Mannan Boopathi, P Lakshmana V Rao, Beer Singh, R VijayaraghavanAbstract:A π-conjugated molecularly imprinted polymer (MIP) with nanopatterns for T-2 toxin (T-2) was prepared on SPR chip by in situ electropolymerization of 3-aminophenylboronicacid (3-APBA) with T-2. The complete removal of T-2 from polymer was confirmed in situ by SPR and EIS and also ex situ by SEM, EDAX, fluorescence microscopy and Raman spectroscopy. SEM image of T-2 MIP exhibited nanopatterns due to imprinting of T-2. The MIP of T-2 showed a linear response for T-2 from 2.1 fM to 33.6 fM with a detection limit of 0.1 fM (0.05 pg/mL). in this study, thermodynamic parameters such as Change in Gibb's free energy (ΔG), Change in enthalpy (ΔH) and Change in Entropy (ΔS) were determined and the values revealed that the interaction between T-2 and T-2 MIP as spontaneous, endothermic and Entropy driven one. Moreover, interactions of very high concentration of interferents with T-2 MIP showed very less response due to the presence of nanopatterns of T-2 in the T-2 MIP. Equilibrium constant (12.7 fM) obtained in this study indicates the super binding affinity of T-2 with T-2 MIP. Moreover, the present methodology provides an outline to develop field-detection equipment capable of detecting T-2 toxin at or well below the guideline concentrations recommended by American subcommittee on military field drinking water.