Sintesis Komposit Asam Humat-Kitosan Termodifikasi Magnetit sebagai Adsorben Metilen Biru
DANIA WAFIQ AZIZAH, Prof. Dr. Bambang Rusdiarso, DEA.
2024 | Skripsi | KIMIA
Penelitian mengenai sintesis komposit asam
humat-kitosan termodifikasi magnetit untuk menghasilkan adsorben metilen biru
telah dilakukan. Penelitian ini bertujuan untuk mengetahui karakteristik
komposit asam humat-kitosan termodifikasi magnetit, mempelajari pengaruh pH
terhadap adsorpsi metilen biru, dan mempelajari kinerja komposit dalam
mengadsorpsi metilen biru melalui kajian kinetika adsorpsi dan isoterm adsorpsi.
Sintesis komposit asam humat-kitosan
termodifikasi magnetit meliputi ekstraksi asam humat, preparasi matriks asam
humat terimobilisasi pada kitosan, dan diikuti penggabungan magnetit secara
kopresipitasi. Keberhasilan sintesis
adsorben hibrida dikonfirmasi menggunakan karakterisasi FTIR, XRD, dan VSM.
Penentuan pH PZC, pH optimum, kinetika, dan isoterm adsorpsi adsorben dilakukan
untuk memahami perilaku adsorben dalam berbagai pH dan interaksinya terhadap
metilen biru.
Analisis FTIR menunjukkan bahwa komposit
asam humat-kitosan termodifikasi magnetit telah berhasil disintesis. Adsorben
memiliki struktur amorf ditandai pola difraksi yang luas dan tidak teratur.
Selanjutnya, analisis VSM mengkonfirmasi bahwa adsorben bersifat paramagnetik dengan
kurva magnetisasi yang linier dan positif terhadap medan magnetik. Adsorben
memiliki permukaan negatif pada pH > 5,5, sehingga adsorben dapat berikatan
dengan metilen biru pada rentang pH yang lebih luas. Kinetika adsorpsi ini
mengikuti model kinetika order dua semu, sedangkan isoterm adsorpsi mengikuti
model isoterm Langmuir. Kapasitas adsorpsi adsorben pada metilen biru sebesar 40,65 mg/g
pada pH 11. Berdasarkan hasil karakterisasi dan kinerja adsorben dalam interaksi
dengan metilen biru komposit asam humat-kitosan termodifikasi magnetit dapat
digunakan dalam aplikasi penyerapan metilen biru.
Kata kunci: adsorben, asam humat, kitosan,
magnetit, metilen biru
Research on the synthesis of magnetite modified humic acid-chitosan composite to produce methylene blue adsorbent has been conducted. This study was aimed to determine the characteristics of magnetite-modified humic acid-chitosan composites, study the effect of pH on methylene blue adsorption, and study the performance of the composites in adsorbing methylene blue through studies of adsorption kinetics and isotherm adsorption.
The synthesis of the magnetite
modified humic acid-chitosan composite involved the extraction of humic acid
from peat soil, preparation of humic acid matrix immobilized on chitosan, and
followed by the incorporation of magnetite by coprecipitation. The successful
synthesis of the adsorbent was confirmed using FTIR, XRD, and VSM
characterization. Determination of pH PZC, optimum pH, adsorption kinetics, and
adsorption isotherms of the adsorbent were carried out to understand the behaviour
of the adsorbent under various pH and its interaction with methylene blue.
Magnetite modified humic
acid-chitosan composite was successfully synthesized based on FTIR analysis.
The adsorbent has an amorphous structure characterized by broad and irregular
diffraction patterns. Furthermore, VSM analysis confirmed that the adsorbent is
paramagnetic indicated by the magnetization curve which is linear and positive
to the magnetic field. At pH > 5.5, the adsorbent was negatively charged,
allowing the binding to methylene blue over a broader pH range. The adsorption
kinetics of this adsorbent followed by second-order pseudo model, while the
adsorption isotherm followed the Langmuir isotherm model. The adsorption
capacity of the adsorbent on methylene blue was 40.65 mg/g at pH 11. Based on
the characterization results and the performance of the adsorbent in
interaction with methylene blue, the magnetite modified humic acid-chitosan
composite can be used in methylene blue sorption applications.
Keywords: adsorbent, humic acid, chitosan, magnetite, methylene blue
Kata Kunci : adsorben, asam humat, kitosan, magnetit, metilen biru