Isotherm studies of methylene blue adsorption onto potassium salts-modified textile sludge

In the present work,the adsorption of methylene blue from aqueous solution by textile sludge activated with potassium salts and a composite-ki,kcl,k2so4 and koh+kcl-was investigated. the impregnation ratio for all activating agents was set at 1:1 and the impregnated textile sludge samples were activated at 50°c for 1h in a furnace. the specific surface area of the activated carbon (ac) was evaluated using bet analysis. the bet surface area varied from 78.8 to 321m2/g,where it decreased in the order of k2so4-ac > kcl-ac > ki-ac > koh+kcl-ac. under room temperature condition and a shaking time of 72h,the batch adsorption results show that the minimum and maximum adsorption capacities were recorded as 39.1 and 85.0mg/g for textile sludge activated with kcl and ki,respectively. langmuir isotherm model gave the best fit to adsorption equilibrium compared to freundlich isotherm model indicating a monolayer adsorption at homogeneous sites on the adsorbent. the langmuir mechanism yielded a maximum monolayer adsorption capacity of 90.9mg/g. among the four prepared activated carbons,textile sludge activated with potassium iodide (ki-ac) gave the best performance on the adsorption of methylene blue. © 2015 penerbit utm press. all rights reserved.