ADSORPSI ION LOGAM Pb(II) PADA MEMBRAN MAKROPORI KITOSAN-PEKTIN TERTAUT SILANG GLUTARALDEHIDA DENGAN SiO2 SEBAGAI POROGEN

DITYA RISTIANTI R, Dr. Dwi Siswanta, M.Eng.; Dr. Roto, M.Eng.

2016 | Skripsi | S1 KIMIA

Penelitian tentang adsorpsi ion logam Pb(II) pada membran makropori kitosan-pektin tertaut silang glutaraldehida dengan SiO2 sebagai porogen telah dilakukan. Membran disintesis dengan melarutkan pektin dengan akuades dan kitosan dengan asam asetat, dilakukan penambahan SiO2 sebagai porogen agar tercetak pori pada membran dan dipanaskan pada suhu 70 °C. Partikel SiO2 dilepaskan dengan penambahan natrium hidroksida. Membran dikarakterisasi dengan FTIR dan SEM. Adsorpsi dikaji dengan melakukan variasi jumlah porogen, waktu kontak, pH larutan dan konsentrasi awal Pb(II). Mekanisme adsorpsi Pb(II) dikaji dengan metode desorpsi sekuensial. Konsentrasi Pb(II) sebelum dan sesudah adsorpsi ditentukan dengan spektrometer serapan atom. Hasil penelitian menunjukan bahwa membran makropori kitosan-pektin mengadsorpsi lebih banyak ion logam Pb(II) dibandingkan dengan membran kitosan-pektin non-pori. Studi adsorpsi Pb(II) pada membran makropori kitosan-pektin menghasilkan adsorpsi optimum pada membran dengan rasio SiO2:kitosan-pektin 3:2 (b/b), dan pH larutan optimum pada pH 4. Adsorpsi membran makropori mengikuti kinetika pseudo orde-2. Adsorpsi membran makropori mengikuti isoterm adsorpsi Freundlich dan Langmuir dengan kapasitas adsorpsi sebesar 250,5 mg/g. Kajian desorpsi sekuensial menunjukkan bahwa mekanisme adsorpsi Pb(II) diduga melalui mekanisme pembentukan kompleks, pembentukan ikatan hidrogen dan pemerangkapan.

Adsorption of Pb(II) ions on macroporous chitosan-pectin membrane crosslinked with glutaraldehyde using SiO2 as porogen agent was investigated for the first time in this reasearch. The membrane was made by dissolving chitosan with acetic acid and pectin with distilled water at 70 °C . The solution was mixed with SiO2 as porogen and wich was dissolved by using NaOH. Membrane was characterized by SEM and FTIR and compared with non-porous chitosan-pectin membrane. The adsorption experiment was conducted in batch method with variation of porogen agent, pH, contact time and initial concentration of Pb(II). The adsorption mechanism of Pb(II) on macroporous membrane was studied by sequential desorption method. The concentration of Pb(II) before and after adsorption was determined with atomic absorption spectrometer. The results showed that macroporous chitosan-pectin membrane adsorbed more Pb(II) metal ions than that of non-pore chitosan-pectin membrane. The study of adsorption of Pb(II) on macroporous membrane exhibited optimum adsorption on membrane with SiO2:chitosan-pectin weight ratio was 3:2 (b/b) and optimum solution at pH 4. Adsorption of Pb(II) on macroporous chitosan-pektin membrane was estimated to follow pseudo-second order. Adsorption of Pb(II) on macroporous chitosan-pectin membrane followed Freundlich and Langmuir adsorption isoterm with the adsorption capacity was 250.5 mg/g. Sequential desorption studies showed that the adsorption of Pb(II) on chitosan-pectin macroporous membrane was estimated to follow a complex formation, hydrogen bond formation and physical entrapment mechanisms.

Kata Kunci : membran makropori, kitosan, pektin, adsorpsi, logam Pb(II)