Sintesis Komposit Asam Humat-Kitin/Magnetit sebagai Adsorben Metilen Biru
ANNISA KEMALA JATI, Prof. Dr. Bambang Rusdiarso, DEA.; Prof. Drs. Sri Juari Santosa, M.Eng., Ph.D.
2024 | Skripsi | KIMIA
Sintesis komposit asam humat-kitin/magnetit (AH-kitin/magnetit) sebagai adsorben metilen biru telah dilakukan. Penelitian ini bertujuan untuk mensintesis komposit AH-kitin/magnetit dan mengkaji mekanisme adsorpsi metilen biru oleh adsorben AH-kitin/magnetit dalam kondisi pH optimum. Sintesis komposit AH-kitin/magnetit meliputi ekstraksi asam humat dari tanah gambut melalui ekstraksi alkali, imobilisasi asam humat dengan kitin, dan sintesis AH-kitin/magnetit dengan metode kopresipitasi secara ex situ dalam kondisi basa. Keberhasilan sintesis komposit dibuktikan dengan karakterisasi AHkitin/magnetit menggunakan FTIR, XRD, dan VSM. Kajian adsorpsi metilen biru oleh AH-kitin/magnetit mencakup variasi pH, pHPZC, kinetika adsorpsi, isoterm adsorpsi, dan energi adsorpsi. Konsentrasi metilen biru dalam larutan dianalisis menggunakan Spektrofotometer UV-Vis pada ?max 664 nm. Hasil karakterisasi menunjukkan bahwa sintesis komposit AHkitin/magnetit telah berhasil dilakukan. Hasil kajian adsorpsi metilen biru oleh AHkitin/magnetit menunjukkan adsorpsi optimum pada pH 11 dan diperkuat dengan pHPZC 4,8. Adsorpsi metilen biru olehAH-kitin/magnetit mengikuti model kinetika orde kedua-semu oleh Ho-McKay dengan konstanta laju adsorpsi sebesar 0,314 g/mg.min. Isoterm adsorpsi mengikuti model isoterm Langmuir dengan kapasitas adsorpsi sebesar 38,314 mg/g dan nilai konstanta Langmuir 58176,63 L mol-1 serta energi adsorpsi sebesar 27,18 kJ/mol.
Synthesis of a humic acid-chitin/magnetite (HA-chitin/magnetite) composite as an adsorbent for methylene blue has been successfully conducted. The study aimed to synthesize the composite material and analyze the adsorption mechanism of methylene blue on HA-chitin/magnetite adsorbent under optimal pH conditions. Synthesis of HA-chitin/magnetite composite involved the extraction of humic acid from peat soil using an alkali extraction method, immobilization of humic acid with chitin, and ex-situ coprecipitation synthesis of HAchitin/magnetite under basic condition. The successful synthesis of the composite material was confirmed through characterization using FTIR, XRD, and VSM. The adsorption study of methylene blue onto HA-chitin/magnetite included variations of pH, pH at the point of zero charge (pHPZC), adsorption kinetics, adsorption isotherms and adsorptions energy. The concentration of methylene blue in the solution was analyzed using UV-Vis spectrophotometry at ?max 664 nm. Characterization results indicated the successful synthesis of HAchitin/magnetite composite. The adsorption study revealed optimum adsorption at pH 11, supported by a pHpzc of approximately 4.8. Methylene blue adsorption onto HA-chitin/magnetite followed a pseudo-second-order kinetic model Ho-McKay, with an adsorption rate constant of 0.314 g/mg.min-1. The adsorption isotherm conformed to the Langmuir model with an adsorption capacity of 38.314 mg/g, a Langmuir constant of 58176.63 L mol-1 and an adsorption energy of 27.18 kJ/mol.
Kata Kunci : adsorpsi, komposit AH-kitin/magnetit, metilen biru/adsorption, HA-chitin/magnetite composite, methylene blue