SIFAT ADSORPSI SELEKTIF KITOSAN TERCETAK IONIK TEMBAGA SELECTIVE ADSORPTION PROPERTIES OF COPPER IMPRINTED IONIC CHITOSAN

DEWI WULANDARI, Prof. Dr. Narsito

2011 | Tesis | S2 Ilmu Kimia

Telah dipelajari sifat adsorpsi dari adsorben kitosan tercetak ion tembaga, KTI(Cu) melalui pembentukan kompleks kitosan-tembaga, kemudian dikait silang dengan glutaraldehid serta pelepasan ion logam prekursor dengan Na2EDTA. Karakterisasi adsorben KTI(Cu) dilakukan dengan identifikasi gugus fungsional menggunakan spektroskopi inframerah (FTIR). dan análisis luas permukaan dengan instrumen analisis adsorpsi gas (gas sorption analyzer). Stabilitas adsorben dalam media asam dipelajari berdasarkan variasi pH. Proses adsorpsi ion logam Cu(II) dilakukan dengan metode batch adsorption sebagai fungsi pH dan variasi konsentrasi ion logam Cu(II). Selektivitas adsorpsi dari adsorben dipelajari dalam campuran multilogam (Cu2+, Ca2+, dan Zn2+). Analisis Cu(II), Ca(II), dan Zn(II) sebelum dan sesudah proses adsorpsi ditentukan dengan menggunakan metode spektrofotometri serapan atom (AAS). Hasil karakterisasi dengan FTIR menunjukkan bahwa modifikasi kitosan menjadi KTI(Cu) membentuk gugus amina (NH2) dan imin (C=N). Analisis adsorpsi isoterm gas menunjukan bahwa KTI(Cu) memiliki luas permukaan lebih kecil berkisar 1,38 m2/g-1,56 m2/g dibandingkan kitosan terkait silang, KTS berkisar 1,51 m2/g-1,65 m2/g. Kajian stabilitas adsorben terhadap asam menunjukkan bahwa KTS dan KTI(Cu) memiliki stabilitas lebih besar (96,6-97%) dibandingkan dengan kitosan komersial sebesar 3%. Adsorpsi ion Cu(II) mencapai optimum disetiap adsorben pada pH 5. Pada hasil kajian kapasitas adsorpsi ion logam Cu(II) berdasarkan model Langmuir isoterm menunjukkan bahwa kapasitas adsorpsi terbesar pada KTI(Cu) C (10000 mg/L Cu2+ dan 1% glutaraldehid) , yaitu 44,22 mg/g dan KTS C (1% glutaraldehid) sebesar 26,48 mg/g. Selanjutnya hasil kajian selektivitas adsorpsi multilogam menunjukkan bahwa pada perbandingan konsentrasi yang berbeda, KTI(Cu) selektif terhadap ion logam Cu(II) sedangkan KTS memiliki selektivitas yang rendah terhadap ion logam Cu(II).

The adsorption properties of copper ion imprinted chitosan have been studied through formation of chitosan-copper complex then followed by crosslinking with glutaraldehyde and release of metal ion precursor with Na2EDTA. Characterizations of KTI(Cu) were done by identification of functional group and gas sorption analyzer to determine its specific surface area. Adsorbent stabilities has been studied in acid medium with variations of pH. The adsorption of Cu(II) was conducted by using batch adsorption method as a function pH, and variety of Cu(II) ion concentrations. Adsorption selectivities of the adsorbents have studied in metal mixtures (Cu2+, Ca2+, and Zn2+). The analysis of Cu(II), Ca(II), and Zn(II) ions before and after adsorption were done by using atomic absorption spectrometry (AAS) method. The results showed that the characterization of the modification of chitosan into IIC(Cu) using FTIR gave information that the IIC(Cu) contained amine groups (NH2) and imine groups (C=N). Gas sorption analyzer confirmed that the IIC(Cu) has a smaller specific surface area, in the ranging from 1.38 m2/g to 1.56 m2 / g than cross-linked chitosan, CC which was in the range from 1.51 m2/g to 1.65 m2 / g. Adsorbent stabilities towards acid indicated that CC and IIC(Cu) were more stable (96.6 to 97%) than commercial chitosan (3%). Optimum condition for Cu(II) adsorption for each adsorbent occurred at pH 5. The adsorption capacities of Cu(II) ion based on Langmuir adsorption isoterm model showed that the largest adsorption capacity of Cu(II) with the amount of 44.22 mg/g was achieved by IIC(Cu) C (10000 mg/L Cu2+ and 1% glutaraldehyde) and CC (C) (1% glutaraldehyde) with the amount of 26.48 mg/g. The selective multimetal adsorption showed that IIC(Cu) has a high selectivity toward metal ion Cu(II) while CC has a low selectivity metal ion Cu(II) at different concentration of Cu(II)

Kata Kunci : kitosan, glutaraldehid, kitosan tercetak ionik, adsorpsi