ADSORPSI DAN DESORPSI BIRU METILEN PADA MEMBRAN MAKROPORI KITOSAN-KARBOKSIMETIL SELULOSA; ADSORPTION AND DESORPTION OF METHYLENE BLUE ON CHITOSANCARBOXYMETHYL CELLULOSE MACROPOROUS MEMBRANE

Dini, Dyahayu R, Dwi Siswanta

2015 | Skripsi | FMIPA

A study on the adsorption and desorption of methylene blue on chitosancarboxymethyl cellulose macroporous membrane crosslinked by glutaraldehyde and SiO2 as porogen has been conducted. The macroporous membrane had been obtained by mixing a solution of CMC 0,1% (w/v) and chitosan 1% (w/v) which has been set to pH 5. After silica and glutaraldehyde were added, the solution was evaporated at 70 °C. The macroporous membranes were characterized using FTIR and SEM. In the adsorption study, the effect of membrane composition, contact time, pH, the amount of porogen, adsorption-desorption kinetics, adsorption isotherms pattern, adsorption capacity, and adsorption energy were examined. The release of SiO2 porogen from the membrane to produce macroporous membrane was indicated by disappearance of a sharp peak absorption area at 1095 cm-1 which is asymmetric stretching vibration of Si-O from Si-O-Si. SEM image of macroporous membrane showed a rough and porous surface in contrast to smooth surface of non porogen membrane. The optimum conditions for adsorption of methylene blue was obtained on the macroporous membrane with chitosan:CMC composition of 30:70, 30 min adsorption, at pH 8, and the amount of porogen 50%. The adsorption of methylene blue followed the pseudo second order reaction kinetics with the Langmuir isotherm pattern. The adsorption capacity was 158.7 mg g-1 and the adsorption energy was 23.0 kJ mol-1. The maximum desorption of methylene blue using NaCl 1 M followed pseudo second order reaction kinetics.

Kata Kunci : macroporous membrane; methylene blue; adsorption; desorption, reaction kinetics