ADSORPSI ZAT WARNA TEKSTIL DIRECT BLUE 14 MENGGUNAKAN KITOSAN TERMODIFIKASI DAN KOMPOSIT KITOSAN TERMODIFIKASI BENTONIT

Abstract

The adsorption ability of modified chitosan and bentonite for color removal in solutions containing Direct Blue 14 (DB 14)textile dyes was carried out in this study. Modified chitosan was synthesized by adding glutaraldehyde (KG), while bentonite-chitosan modified composites were synthesized by adding bentonite to modified chitosan (KKGB). The investigated aspects consist of effect of contact time, adsorbent dosage, and initial concentration of dye solution. The mechanism of the adsorption process was evaluated using isotherm and kinetic models. The resultsof this study indicated that the increase in efficiency of color removal and the decrease of adsorption capacity of KGand KKGB was found at higher adsorbent dosage and lower initial dye concentrations. The equilibrium time of DB 14 adsorption on both adsorbents was achieved at 20 minutes. The optimum adsorbent dosage for KG and KKGB were achieved at dosage of 1.0 g/L and 1.4 g/L, with dyes removal of 91,6% and 91,8% respectively. The adsorption kinetic of DB 14 onto KG and KKGB fitted well with the pseudo second order model with K 2 of 0.060 g.g -1 . min -1 and R 2 0.999 for KG and K 2 of 0.081 g.g -1 . min -1 and R 2 0.999 for KKGB. The adsorption equillibrium data of DB 14 on KG was well described by Langmuir isotherm model with K L 8.482 L/mg and K F 7.157 mg/g and R 2 0.999 whereas KKGB was well described by Freundlich isotherm model with R 2 0.999 .