Papers by Prasanna Kumar Yekula
Colloids and Surfaces B: Biointerfaces, 2012
Biosorption of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solution by biomass prepared from A... more Biosorption of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solution by biomass prepared from Acacia leucocephala bark, an agricultural solid waste has been investigated in the present study. All the experiments are carried out by batch mode technique. The resulting biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The effect of experimental parameters such as contact time, effect of pH (2-10), initial concentration of adsorbate (50-200 mg L(-1)) and amount of biosorbent dosage was evaluated. The removal was found to be pH dependent, and maximum removal was found to be at pH 5.0. The equilibrium time was found to be 3h. The biosorbent dose was increased, and the percentage removal of 2,4,6-TCP was increased, while the adsorption capacity at equilibrium q(e) (mg g(-1)) (amount of 2,4,6-TCP loaded per unit weight of adsorbent) decreased. Biosorption kinetic and isotherm studies showed the pseudo-second-order kinetics with a good correlation coefficient (R(2)=0.999), and both Langmuir and Freundlich isotherms were the best choices to describe the adsorption behaviors. The maximum monolayer biosorption capacity of A. leucocephala bark for 2,4,6-TCP was found to be 256.4 mg g(-1), at 30±1°C according to Langmuir model. This study demonstrated for the first time that the A. leucocephala bark could be an alternative for more costly adsorbents used for removal of 2,4,6-TCP from aqueous media.
Journal of Hazardous Materials, 2007
The biosorption of lead ions from aqueous solution by Syzygium cumini L. was studied in a batch a... more The biosorption of lead ions from aqueous solution by Syzygium cumini L. was studied in a batch adsorption system as a function of pH, contact time, lead ion concentration, adsorbent concentration and adsorbent size. The biosorption capacities and rates of lead ions onto S. cumini L. were evaluated. The Langmuir, Freundlich, Redlich-Peterson and Temkin adsorption models were applied to describe the isotherms and isotherm constants. Biosorption isothermal data could be well interpreted by the Langmuir model followed by Temkin model with maximum adsorption capacity of 32.47 mg/g of lead ion on S. cumini L. leaves biomass. The kinetic experimental data were properly correlated with the second-order kinetic model.
Journal of Hazardous Materials, 2006
Studies on a batch sorption system using Tectona grandis l.f. as adsorbent was investigated to re... more Studies on a batch sorption system using Tectona grandis l.f. as adsorbent was investigated to remove copper(II) from aqueous solutions. The adsorption experiments were performed under various conditions such as different initial concentrations, pH, adsorbent dosage and adsorbent particle size. The data showed that 0.1 g of Tectona grandis l.f. was found to remove 71.66% of 20 mg/L copper(II) from 30 mL aqueous solution in 180 min. The experimental equilibrium data were adjusted by the adsorption isotherms from Langmuir and Freundlich models and their equilibrium parameters were determined. The best-adjusted model to the experimental equilibrium data for Tectona grandis l.f. was the Langmuir model. Using the Langmuir model equation, the monolayer sorption capacity of Tectona grandis l.f. was evaluated and found to be 95.40 mg/g. The optimum pH value was found to be 5.5. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data. The dynamic data fitted the pseudo-second-order kinetic model.
Chemical Engineering Journal, 2008
The biosorption of zinc ions from aqueous solution by Syzygium cumini L. was studied in a batch a... more The biosorption of zinc ions from aqueous solution by Syzygium cumini L. was studied in a batch adsorption system as a function of pH, contact time, zinc ion concentration, adsorbent dosage and adsorbent size. The biosorption capacities and rates of zinc ions onto S. cumini L. were evaluated. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Biosorption isothermal data could be well interpreted by the Langmuir model followed by Freundlich model with maximum adsorption capacity of 35.84 mg/g of zinc ion on S. cumini L. leaves biomass. The kinetic experimental data was properly correlated with the second-order kinetic model.
Journal of Hazardous Materials, 2006
The removal of copper and zinc from aqueous solution by adsorption on Ulva fasciata sp. was studi... more The removal of copper and zinc from aqueous solution by adsorption on Ulva fasciata sp. was studied, as a function of contact time and pH of the solution. Adsorption of copper and zinc on U. fasciata sp. was compared. It was shown that U. fasciata sp. has high metal removal efficiency. The maximum adsorption capacity of U. fasciata sp. for copper and zinc was 26.88 and 13.5 mg/g, respectively. The adsorption of copper and zinc on U. fasciata sp. was increased with increase in pH from 2 to 5 and decreased with increase in pH from 5 to 10. The Freundlich and Langmuir model can describe the adsorption equilibrium of copper and zinc on U. fasciata sp. The Freundlich and Langmuir constants for adsorption of copper and zinc on U. fasciata sp. were determined.
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Papers by Prasanna Kumar Yekula