Equilibrium Studies for the Adsorption of Acid Red 14 and Direct Yellow 86 Dyes from Aqueous Solution

This article describe the adsorption of acidic and direct dyes, namely acid red 14 (ari4) and direct yellow 86 (dy86), from aqueous solution onto activated carbon from walnut shell (acw) as an eco-friendly and low cost adsorbent. laboratory prepared acw were characterized by barrett-joiner-halenda (bjh) and ,brunauer-etrunett-teller (bet) pore structural parameters. the effect of various experimental parameters such. as initial dye concentrations, ph and acw doses were investigated in a batch adsorption technique. optimum conditions for removal of dyes were found to be ph=1and 1g of adsorbent dosage in equilibrium time of 48 h. it is shown that, lower equilibrium uptake further increase in temperature, because of the exothermic dyes biosorptionprocess. the plot of the removal versus adsorbent dosage shows the effectof the,different frequency of acw dyes .equilibrium adsorption isotherms were measured and the experimental data were analyzed using iangmuir, freundlich and temkin isotherm equations. it was found that data for dy86 temkin isotherm is preferred (r2 =0.93), while for ar14, the freundlich isotherm is more applicable (r2=0.65). the acw might be successfully used for the removal of dyes from liquid industrial wastewater.