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The modification of bentonite by pillarization process of Al/Fe metal oxide has been carried with metal oxide with ratios 1:2 and 2:1. The product was characterized by FT-IR, XRD and pHpzc analysis. Thus, this optimal pillarization product was used as an adsorbent of Congo red and Direct green dyestuffs. The FTIR characterization does not show optimum pillarization processes for any metal oxide ratios, while the XRD analysis shows the optimum pillarization processes at ratio 2:1 i.e. 17.1 Å. In addition, the optimum pH for absorption of Congo red took place at 2 while for Direct green at 3. At 70oC, the highest adsorption capacity (Qe) reached 57.34 and 72.06 mol/g; and the highest adsorption energy (E) was found 3.23 kJ/mol and 4.14 kJ/mol for Direct green for Congo red and Direct green, respectively. Vice versa, the enthalpy (ΔH) and entropy (ΔS) values decreased as the increase of both Congo red and Direct green concentration.

Synthesis of chitosan-SiO2 composite has been done using the precipitation method. The chitosan-SiO2 composite was applied to removal methyl red dyes from the solution. The chitosan-SiO2 composite was characterized using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM-EDS). Adsorption by batch method with variables including contact time, weight of adsorbent and initial concentration. The FT-IR spectrum of composite showed the - OH, C-H, C-N, N-H, C-O (ether), C-H asymmetric, C-H symmetric, Si-O-Si, Si-OH and Si-O group. XRD spectra of chitosan-SiO2 composites showed a widening peak at 2θ = 19.95 and amorphous. From SEM-EDS spectra show the morphology of chitosan-SiO2 composite was rough, porous and inhomogeneous with constituent elements C, N, O, Na and Si. The chitosan-SiO2 composite has a pHpzc value at pH 7.9. Adsorption data of chitosan-SiO2 composite for adsorption methyl red dyes followed Langmuir isotherm with maximum adsorption capacity 20.876 mg/g. Adsorption methyl red dye onto chitosan-SiO2 composites according to pseudo-second order.

Research about the synthesis of chitosan/alumina composite using the sol-gel method and its application to removal procion blue MX-R dye had been conducted. The synthesized chitosan/alumina composite was characterized using FTIR to determine functional group, SEM-EDS to find out the surface morphology and elements composition of chitosan/alumina composite. The pHPZC is used to determine the appropriate pH condition on the adsorption process of chitosan and chitosan/alumina composite on procion blue dye solution. The FTIR spectra of chitosan represent the functional groups O-H, N-H, C-H and C-O while the chitosan/alumina composite is the addition of functional group of Al-O. The morphology of chitosan/alumina composite analysis by SEM showed that is heterogenous and porous. The EDX analysis showed that the present Al element of 5.49 % in the composite which indicates that synthesis of composite has been successful. Chitosan and composite have different pH pzc where chitosan at pH 6.02 and composite at pH 7.26. The optimum condition adsorption of procion blue MX-R using chitosan obtained at an initial concentration of 180 mg/L and contact time of 60 minutes, while the chitosan/alumina composite obtained at an initial concentration of 160 mg/L and 50 minutes contact time. The isotherm model that is suitable for describing the adsorption process is Freundlich isotherm for both adsorbents. The composite has the effectiveness of adsorption on procion blue MX-R from wastewater songket industry greater than chitosan ie 85.696 and 60.829 %, respectively.

The study on cellulose modification with acetic acid to cellulose-acetate has been carried out. Cellulose is extracted from the kepok banana peel (Musa paradisiaca L.). Modified cellulose acetate was characterized by FTIR spectroscopy and SEM-EDS. Cellulose acetate to removal of methylene blue with adsorption parameter include initial concentration (10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 mg/L), pH solution (3, 4, 5, 6, 7, and 8) and contact time (15, 30, 45, 60, 75, and 90 minutes). The peak of FTIR cellulose acetate obtained by functional groups -OH, C-H, C=O, and C-O esters. The morphology of cellulose-acetate has a more homogeneous than cellulose. Adsorption of cellulose-acetate on methylene blue optimum at an initial concentration of 90 mg/L, pH of solution 6, and contact time of 30 minutes. The adsorption kinetics corresponds to pseudo-second order and adsorption equilibrium corresponds to Langmuir isotherms with adsorption capacity of 42.107 mg/g.