shows the plot of lnKc versus 1/T. DH and DS are estimated from the slope and intercept of the line. The estimated
values of the thermodynamic parameters for the three operating temperature are shown in Table 4. The negative DG values confirm feasibility of the As(III) adsorption on coconut fiber adsorbent. The DG values obtained for the system decreases with increasing temperature which shows that the reaction is easier at higher temperatures. The positive value of entropy change (DS) suggests the increase in randomness with increase of temperature. The positive value of