ABSTRACT
The removal of zinc ions from aqueous solutions on the biomass of Azadirachta indica bark has been studied by using batch adsorption technique. The biosorption studies were determined as a function of contact time, pH, initial metal ion concentration, average biosorbent size and biosorbent dosage. The equilibrium metal uptake was increased and percentage biosorption was decreased with an increase in the initial concentration and particle size of biosorbent. The maximum zinc biosorption occurred at pH 6 and percentage biosorption increases with increase in the biosorbent dosage. Experimental data obtained were tested with the adsorption models like Langmuir, Freundlich and Redlich-Peterson isotherms. Biosorption isothermal data were well interpreted by Langmuir model with maximum biosorption capacity of 33.49mg/g of zinc ions on A. indica bark biomass and kinetic data were properly fitted with the pseudo-second-order kinetic model.
Subject(s)
Azadirachta/metabolism , Plant Bark/metabolism , Zinc/metabolism , Hydrogen-Ion Concentration , Kinetics , Particle Size , Solutions , WaterABSTRACT
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.
Subject(s)
Lead/isolation & purification , Syzygium/metabolism , Water Pollutants, Chemical/isolation & purification , Water/chemistry , Adsorption , Kinetics , Plant Leaves/metabolism , SolutionsABSTRACT
The biosorption of copper(II) ions from aqueous solution by Tectona grandis L.f. was studied in a batch adsorption system as a function of pH, metal ion concentration, adsorbent concentration and adsorbent size. The biosorption capacities and rates of copper(II) ions onto T. grandis L.f. 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 with maximum adsorption capacity of 15.43 mg/g of copper(II) ion on T. grandis L.f. leaves powder. The kinetic experimental data properly correlated with the second-order kinetic model. Various thermodynamic parameters such as deltaG(o), deltaH(o), and deltaS(o) were calculated indicating that this system was a spontaneous and exothermic process.
Subject(s)
Copper/pharmacokinetics , Lamiaceae , Plant Leaves , Plant Preparations/pharmacokinetics , Water , Cations, Divalent/pharmacokinetics , SolutionsABSTRACT
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 13.5mg/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.
Subject(s)
Copper/pharmacokinetics , Models, Chemical , Ulva , Zinc/pharmacokinetics , Adsorption , Solutions , Water , Water PurificationABSTRACT
Batch adsorption experiments were carried out for the removal of copper from its aqueous solution using Ulva fasciata sp. a marine green algae as adsorbent. The adsorption of Cu(II) by Ulva fasciata sp. was investigated as a function of pH, contact time, initial Cu(II) and adsorbent concentrations and adsorbent size. About 0.1 g of Ulva fasciata sp. was found to be enough to remove 95% of 20 mg/L copper from 30 mL aqueous solution in 20 min. The optimum pH value was found to be 5. The dynamic data fitted to the pseudo-second order kinetic model. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The experimental adsorption data were fitted to the Langmuir adsorption model. The maximum adsorption capacity was 26.88 mg/g. The applicability of Lagergren kinetic model was also investigated.
Subject(s)
Chlorophyta/metabolism , Ulva/metabolism , Waste Disposal, Fluid/methods , Water Purification/methods , Adsorption , Biomass , Copper/chemistry , Hydrogen-Ion Concentration , Kinetics , Metals/chemistry , Particle Size , Time Factors , WaterABSTRACT
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.
Subject(s)
Copper/chemistry , Trees/chemistry , Adsorption , Cell Wall/chemistry , Cellulose/chemistry , Hydrogen-Ion Concentration , Kinetics , Lignin/chemistry , Models, Statistical , Particle Size , Plant Leaves/chemistry , Plant Proteins/chemistry , Powders , Solutions , Tannins/chemistry , Thermodynamics , Waste Disposal, Fluid , Water , Water Pollutants/analysisABSTRACT
The effect of various parameters on the removal of metal ions (Zinc and Cadmium) by adsorption using coconut shell coke is investigated. The time of contact, initial metal ion concentration, adsorbent dosage, volume of the adsorbate solution, size of the adsorbent particle and the effect of the presence of another metal at various concentrations are the parameters studied. The adsorption isotherms so obtained in this study followed the Freundlich and Langmuir isotherms showing a marginal average deviation.
