Pemanfaatan Film Kitosan Kationik Termodifikasi EPTAC sebagai Adsorben untuk Penghilangan Zat Warna Anionik Remazol Brilliant Violet 5R dalam Larutan

Audi Rahma Aradea Aziz, Prof. Drs. Dwi Siswanta, M.Eng., Ph.D.

2026 | Skripsi | KIMIA

Limbah cair industri tekstil yang mengandung zat warna sintetis anionik seperti Remazol Brilliant Violet 5R (RBV5R) menjadi permasalahan lingkungan yang serius karena bersifat stabil, sulit terdegradasi, dan dapat menurunkan kualitas perairan serta mengganggu ekosistem akuatik. Pada penelitian ini, dilakukan pemanfaatan film kitosan kationik termodifikasi EPTAC sebagai adsorben untuk penghilangan zat warna anionik RBV5R dalam larutan. Tujuan dari penelitian ini adalah melakukan modifikasi kitosan menggunakan EPTAC untuk meningkatkan kapasitas adsorpsi terhadap RBV5R, serta menentukan kondisi optimum adsorpsi berdasarkan variasi pH, massa adsorben, waktu kontak, dan konsentrasi awal zat warna. Selain itu, penelitian ini juga bertujuan untuk memberikan wawasan mengenai model kinetika dan isoterm adsorpsi zat warna anionik RBV5R terhadap film kitosan termodifikasi EPTAC.

Modifikasi kitosan dilakukan melalui reaksi kationisasi menggunakan 2,3-epoxypropyltrimethylammonium chloride (EPTAC). Hasil modifikasi dibentuk menjadi film melalui proses taut silang menggunakan glutaraldehida. Untuk mengidentifikasi perubahan gugus fungsi serta morfologi permukaan, dilakukan karakterisasi menggunakan ATR-FTIR dan SEM-EDX. Proses adsorpsi dievaluasi terhadap pengaruh pH larutan, massa adsorben, waktu kontak, dan konsentrasi awal zat warna. Data yang diperoleh kemudian dianalisis menggunakan model kinetika dan isoterm adsorpsi untuk memahami mekanisme serta pola interaksi antara adsorben dan adsorbat.

Hasil penelitian menunjukkan bahwa modifikasi film kitosan dengan EPTAC berhasil dilakukan, yang dibuktikan oleh peningkatan kemampuan adsorpsi pada zat warna anionik RBV5R dan diperkuat melalui data karakterisasi ATR–FTIR dan SEM–EDX. Kondisi optimum diperoleh pada pH 4, massa adsorben 30 mg, waktu kontak 60 menit, dan konsentrasi awal zat warna 300 mg L^-1 dengan kapasitas adsorpsi sebesar 81,16 mg g^-1. Adsorpsi zat warna RBV5R oleh film kitosan termodifikasi EPTAC mengikuti model kinetika orde kedua semu (k₂ = 0,0024 g mg^-1 menit^-1; R² = 0,9734) dan model isoterm Langmuir (q_maks = 76,34 mg g^-1; K_L = 51612,7 L mol^-1). Hasil ini menunjukkan bahwa proses adsorpsi dipengaruhi oleh interaksi antara adsorben dan adsorbat serta keterlibatan situs aktif. Selain itu, bentuk adsorben dalam bentuk film memberikan kemudahan dalam pemisahan dari larutan setelah proses adsorpsi berlangsung. 

Textile industry wastewater containing anionic synthetic dyes such as Remazol Brilliant Violet 5R became a serious environmental problem because of its high stability, resistance to degradation, and harmful effects on water quality and aquatic ecosystems. In this study, cationic chitosan films modified with EPTAC were utilized as adsorbents for the removal of the anionic dye Remazol Brilliant Violet 5R from aqueous solutions. This research aimed to modify chitosan using EPTAC to enhance its adsorption capacity for RBV5R and to determine the optimum adsorption conditions based on variations in pH, adsorbent mass, contact time, and initial dye concentration. Furthermore, this study provided insights into the kinetic models and adsorption isotherms of the RBV5R anionic dye onto the modified EPTAC-chitosan films.

The modification of chitosan was carried out through a cationization reaction using 2,3-epoxypropyltrimethylammonium chloride (EPTAC). The modified product was then formed into films through a crosslinking process using glutaraldehyde. To identify changes in functional groups and surface morphology, characterization was performed using ATR-FTIR and SEM-EDX. The adsorption process was evaluated against the influence of solution pH, adsorbent mass, contact time, and initial dye concentration. The obtained data were analyzed using kinetic and adsorption isotherm models to understand the mechanism and interaction patterns between the adsorbent and the adsorbate.

The results showed that the modification of chitosan film adsorbent using EPTAC was successfully carried out, as evidenced by the enhanced adsorption capacity toward the anionic dye RBV5R and further supported by ATR–FTIR and SEM–EDX characterization data. The optimum adsorption conditions were obtained at pH 4, adsorbent mass of 30 mg, contact time of 60 minutes, and initial dye concentration of 300 mg L^-1, with a adsorption capacity of 81.16 mg g^-1. The adsorption of RBV5R onto the EPTAC-modified chitosan film followed the pseudo-second-order kinetic model (k₂ = 0.0024 g mg^-1 min^-1; R² = 0.9734) and the Langmuir isotherm (q_max = 76.34 mg g^-1: K_L = 51612.7 L mol^-1). These results indicated that the adsorption process was influenced by interactions between the adsorbent and adsorbate as well as the involvement of active surface sites. In addition, the film form of the adsorbent facilitated easy separation from the solution after the adsorption process.

Kata Kunci : adsorpsi, film, kationik, modifikasi, kitosan