Author: H.Joga Rao, P. King, Y. Prasanna Kumar

DOI:

Activated carbons prepared from waste rubber tires (RTAC) are used as practical adsorbents for the speedy evacuation and quick adsorption of lead ions from the wastewater effluents.Batch studies were done to evaluate the performance of RTAC for the adsorption of Pb⁺² from aqueous solutions at various process parameters of pH (2-5), metal ion concentration (100 -200 mg/L), the mass of the adsorbent (0.025 - 0.1 g), average particle size (85 - 200 Mesh) and solution temperature (308 - 323 K) at a maximum equilibrium agitation time of 60 minutes in an orbital shaker at 200 RPM.Taking into account exploratory results, Maximum evacuation of lead onto RTAC as adsorbent by 97.55 %. Optimized the adsorption efficiency usingCentral Composite Design (CCD) at pH = 4.98, Initial concentration 140.01 mg/L, the mass of the adsorbent is 0.12 grams and temperature of the metal solution is 314.46. Experimentation led above optimum conditions, the value of 3.64 % deviationis obtained with proposed value. Adsorption isothermal data were easily interpreted by Langmuir, Freundlich,Redlich-Peterson and Dubinin–Radushkevich (D–R), a Langmuir model with maximum adsorption capacity of 125 mg/g oflead ions on RTAC and kinetic data were appropriately equipped with the pseudo-second-order kinetic model. Consequences ofthermodynamic investigations, properties of ΔH^o, ΔG^o and ΔS^o are -63.976 KJ/mole, -5.787 KJ/mole and -0.196 KJ/mole.K, demonstrates the adsorption process is exothermic nature, feasible and spontaneous at lower temperature.

Keywords: Lead, Waste Rubber tire, Adsorption Isotherms, Kinetics, Central Composite Design(CCD), thermodynamic studies.