Saw Dust Derived Activated Carbon in Different Impregnation Ratio and Its Application in De-Fluoridation of Waste Water Using Soft Computing Techniques.

The present study is highlighted on de-fluoridation efficiency in synthetic water utilizing low cost starting material converted to activated carbon (AC), activated by magnesium chloride (MgCl₂) in different impregnation ratio (IR) (0.25,0.5,1.0) upon thermal treatment. Comparative batch studies were conducted in different experimental conditions to investigate the influence of different process parameters on de-fluoridation using interval type-2 fuzzy logic controller (IT2FLC) & Response Surface Method (RSM). The phenomenon of fluoride ion uptake was realized by Langmuir and Freundlich adsorption model. Langmuir isotherm showed satisfactory fit to the experimental data. The rate of adsorption implied that the pseudo-second-order rate well fitted the adsorption kinetics better than the pseudo-first-order rate equation. The mechanism of adsorption process was illustrated by calculating Gibbs free energy, enthalpy and entropy from thermodynamic studies. This present experiment was optimized using Response Surface Methodology and confirmed by Desirability Function. In this present investigation, it was represented that regeneration % of activated carbon (IR:1.0)prepared from saw dust in 5 adsorption-desorption cycles are 90.92%, 86.46 %, 80.13%, 71.01%, and 62.53% respectively. The optimum contact time, dosage of adsorbent and pH for activated carbon with I.R (1.0) were found to be 60 min, 1g/L and 2.00 respectively. In that condition, it was performing high level of fluoride removal efficiency (92.4%). So it may be concluded that as saw dust is easily available material, so chemically synthesized activated carbon can be used for de-fluoridation in waste water.